Nature , IF:49.962 , 2022 Dec doi: 10.1038/s41586-022-05529-9
NLR surveillance of pathogen interference with hormone receptors induces immunity.
Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China.; Howard Hughes Medical Institute, Department of Biology, Duke University, Durham, NC, USA.; Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, CA, USA.; Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China. taoxiaorong@njau.edu.cn.
Phytohormone signalling pathways have an important role in defence against pathogens mediated by cell-surface pattern recognition receptors and intracellular nucleotide-binding leucine-rich repeat class immune receptors(1,2) (NLR). Pathogens have evolved counter-defence strategies to manipulate phytohormone signalling pathways to dampen immunity and promote virulence(3). However, little is known about the surveillance of pathogen interference of phytohormone signalling by the plant innate immune system. The pepper (Capsicum chinense) NLR Tsw, which recognizes the effector nonstructural protein NSs encoded by tomato spotted wilt orthotospovirus (TSWV), contains an unusually large leucine-rich repeat (LRR) domain. Structural modelling predicts similarity between the LRR domain of Tsw and those of the jasmonic acid receptor COI1, the auxin receptor TIR1 and the strigolactone receptor partner MAX2. This suggested that NSs could directly target hormone receptor signalling to promote infection, and that Tsw has evolved a LRR resembling those of phytohormone receptors LRR to induce immunity. Here we show that NSs associates with COI1, TIR1 and MAX2 through a common repressor-TCP21-which interacts directly with these phytohormone receptors. NSs enhances the interaction of COI1, TIR1 or MAX2 with TCP21 and blocks the degradation of corresponding transcriptional repressors to disable phytohormone-mediated host immunity to the virus. Tsw also interacts directly with TCP21 and this interaction is enhanced by viral NSs. Downregulation of TCP21 compromised Tsw-mediated defence against TSWV. Together, our findings reveal that a pathogen effector targets TCP21 to inhibit phytohormone receptor function, promoting virulence, and a plant NLR protein has evolved to recognize this interference as a counter-virulence strategy, thereby activating immunity.
PMID: 36517600
Nature , IF:49.962 , 2022 Nov , V611 (7934) : P133-138 doi: 10.1038/s41586-022-05369-7
Adenylate cyclase activity of TIR1/AFB auxin receptors in plants.
Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.; Department of Plant Physiology and Biotechnology, Nicolaus Copernicus University in Torun, Torun, Poland.; Readiness and Response Directorate, Biosecurity New Zealand, Wellington, New Zealand.; Centre for Fluid and Complex Systems, Coventry University, Coventry, UK.; School of Life Sciences, University of Warwick, Coventry, UK.; Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria. jiri.friml@ist.ac.at.
The phytohormone auxin is the major coordinative signal in plant development(1), mediating transcriptional reprogramming by a well-established canonical signalling pathway. TRANSPORT INHIBITOR RESPONSE 1 (TIR1)/AUXIN-SIGNALING F-BOX (AFB) auxin receptors are F-box subunits of ubiquitin ligase complexes. In response to auxin, they associate with Aux/IAA transcriptional repressors and target them for degradation via ubiquitination(2,3). Here we identify adenylate cyclase (AC) activity as an additional function of TIR1/AFB receptors across land plants. Auxin, together with Aux/IAAs, stimulates cAMP production. Three separate mutations in the AC motif of the TIR1 C-terminal region, all of which abolish the AC activity, each render TIR1 ineffective in mediating gravitropism and sustained auxin-induced root growth inhibition, and also affect auxin-induced transcriptional regulation. These results highlight the importance of TIR1/AFB AC activity in canonical auxin signalling. They also identify a unique phytohormone receptor cassette combining F-box and AC motifs, and the role of cAMP as a second messenger in plants.
PMID: 36289340
Science , IF:47.728 , 2022 Nov , V378 (6621) : P762-768 doi: 10.1126/science.add3771
Hydraulic flux-responsive hormone redistribution determines root branching.
Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.; Earth and Life Institute, Universite catholique de Louvain, 1348 Louvain-la-Neuve, Belgium.; Sainsbury Laboratory, University of Cambridge, Cambridge, UK.; School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB-UGent, 9052 Ghent, Belgium.; Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 87 Umea, Sweden.; Lancaster Environment Centre, Lancaster University, Lancaster, UK.; Division of Plant Science and Technology, University of Missouri, Columbia, MO, USA.; Department of Biosciences, University of Durham, Durham, UK.
Plant roots exhibit plasticity in their branching patterns to forage efficiently for heterogeneously distributed resources, such as soil water. The xerobranching response represses lateral root formation when roots lose contact with water. Here, we show that xerobranching is regulated by radial movement of the phloem-derived hormone abscisic acid, which disrupts intercellular communication between inner and outer cell layers through plasmodesmata. Closure of these intercellular pores disrupts the inward movement of the hormone signal auxin, blocking lateral root branching. Once root tips regain contact with moisture, the abscisic acid response rapidly attenuates. Our study reveals how roots adapt their branching pattern to heterogeneous soil water conditions by linking changes in hydraulic flux with dynamic hormone redistribution.
PMID: 36395221
Trends Plant Sci , IF:18.313 , 2022 Nov doi: 10.1016/j.tplants.2022.10.007
Growth or stress responses: TMK-FER balancing act.
State Key Laboratory of Crop Biology, Engineering Center of Saline-Alkali Soil Plant - Microbial Joint Restoration, Shandong Agricultural University, Tai'an 271018, China.; State Key Laboratory of Crop Biology, Engineering Center of Saline-Alkali Soil Plant - Microbial Joint Restoration, Shandong Agricultural University, Tai'an 271018, China. Electronic address: shizhong@sdau.edu.cn.; State Key Laboratory of Crop Biology, Engineering Center of Saline-Alkali Soil Plant - Microbial Joint Restoration, Shandong Agricultural University, Tai'an 271018, China. Electronic address: cczheng@sdau.edu.cn.
Transmembrane kinases (TMKs) and Feronia (FER) belong to the leucine-rich repeat receptor-like kinase family. Recent studies reveal that they coordinate plant growth and stress responses by regulating the balance between acidification and alkalization and crosstalk between auxin and abscisic acid, revealing a dynamic equilibrium in the regulation of the TMK-FER module in plants.
PMID: 36371397
Trends Plant Sci , IF:18.313 , 2023 Jan , V28 (1) : P54-73 doi: 10.1016/j.tplants.2022.08.019
Is auxin enough? Cytokinins and margin patterning in simple leaves.
Instituto de Bioingenieria, Universidad Miguel Hernandez, Campus de Elche, 03202 Elche, Alicante, Spain.; Instituto de Bioingenieria, Universidad Miguel Hernandez, Campus de Elche, 03202 Elche, Alicante, Spain. Electronic address: jlmicol@umh.es.
The interplay between auxin and cytokinins affects facets of plant development as different as ovule formation and lateral root initiation. Moreover, cytokinins favor complexity in the development of Solanum lycopersicum and Cardamine hirsuta compound leaves. Nevertheless, no role has been proposed for cytokinins in patterning the margins of the simple leaves of Arabidopsis thaliana, a process that is assumed to be sufficiently explained by auxin localization. Here, we discuss evidence supporting the hypothesis that cytokinins play a role in simple leaf margin morphogenesis via crosstalk with auxin, as occurs in other plant developmental events. Indeed, mutant or transgenic arabidopsis plants defective in cytokinin biosynthesis or signaling, or with increased cytokinin degradation have leaf margins less serrated than the wild type.
PMID: 36180378
Trends Plant Sci , IF:18.313 , 2022 Dec , V27 (12) : P1196-1198 doi: 10.1016/j.tplants.2022.08.011
Spatiotemporal imaging clarifies leaf primordium patterning.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China. Electronic address: yuling.jiao@pku.edu.cn.
The first step in organ morphogenesis is the subdivision of a primordium into discrete regions by patterning genes. Recently, Burian et al. used live imaging and cell-lineage tracing to illuminate early patterning events during the establishment of leaf primordium adaxial-abaxial (dorsoventral) polarity, which clarifies controversies in the field.
PMID: 36055917
Trends Plant Sci , IF:18.313 , 2022 Dec , V27 (12) : P1209-1217 doi: 10.1016/j.tplants.2022.06.002
Towards a hierarchical gene regulatory network underlying somatic embryogenesis.
National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, PR China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China; ShanghaiTech University, Shanghai 200031, PR China. Electronic address: jwwang@sippe.ac.cn.
Genome-editing technologies have advanced in recent years but designing future crops remains limited by current methods of improving somatic embryogenesis (SE) capacity. In this Opinion, we provide an update on the molecular event by which the phytohormone auxin promotes the acquisition of plant cell totipotency through evoking massive changes in transcriptome and chromatin accessibility. We propose that the chromatin states and individual totipotency-related transcription factors (TFs) from disparate gene families organize into a hierarchical gene regulatory network underlying SE. We conclude with a discussion of the practical paths to probe the cellular origin of the somatic embryo and the epigenetic landscape of the totipotent cell state in the era of single-cell genomics.
PMID: 35810071
Nat Microbiol , IF:17.745 , 2022 Nov , V7 (11) : P1817-1833 doi: 10.1038/s41564-022-01244-3
Diverse MarR bacterial regulators of auxin catabolism in the plant microbiome.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.; Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Division of Oral and Craniofacial Health Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Plant and Environmental Sciences, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.; Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. redinbo@unc.edu.; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. redinbo@unc.edu.; Department of Biochemistry and Biophysics, and the Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. redinbo@unc.edu.; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. redinbo@unc.edu.; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.
Chemical signalling in the plant microbiome can have drastic effects on microbial community structure, and on host growth and development. Previously, we demonstrated that the auxin metabolic signal interference performed by the bacterial genus Variovorax via an auxin degradation locus was essential for maintaining stereotypic root development in an ecologically relevant bacterial synthetic community. Here, we dissect the Variovorax auxin degradation locus to define the genes iadDE as necessary and sufficient for indole-3-acetic acid (IAA) degradation and signal interference. We determine the crystal structures and binding properties of the operon's MarR-family repressor with IAA and other auxins. Auxin degradation operons were identified across the bacterial tree of life and we define two distinct types on the basis of gene content and metabolic products: iac-like and iad-like. The structures of MarRs from representatives of each auxin degradation operon type establish that each has distinct IAA-binding pockets. Comparison of representative IAA-degrading strains from diverse bacterial genera colonizing Arabidopsis plants show that while all degrade IAA, only strains containing iad-like auxin-degrading operons interfere with auxin signalling in a complex synthetic community context. This suggests that iad-like operon-containing bacterial strains, including Variovorax species, play a key ecological role in modulating auxins in the plant microbiome.
PMID: 36266335
Nat Plants , IF:15.793 , 2022 Dec , V8 (12) : P1408-1422 doi: 10.1038/s41477-022-01274-z
Genome-wide dissection of changes in maize root system architecture during modern breeding.
College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China.; Cereal Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou, China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China.; Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, China.; Cereal Crops Research Institute, Pirsabak, Nowshera, Pakistan.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China. caucfj@cau.edu.cn.; Sanya Institute of China Agricultural University, Sanya, China. caucfj@cau.edu.cn.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China. yuanlixing@cau.edu.cn.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China. yuanlixing@cau.edu.cn.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China. panqingchun@cau.edu.cn.; Sanya Institute of China Agricultural University, Sanya, China. panqingchun@cau.edu.cn.
Appropriate root system architecture (RSA) can improve maize yields in densely planted fields, but little is known about its genetic basis in maize. Here we performed root phenotyping of 14,301 field-grown plants from an association mapping panel to study the genetic architecture of maize RSA. A genome-wide association study identified 81 high-confidence RSA-associated candidate genes and revealed that 28 (24.3%) of known root-related genes were selected during maize domestication and improvement. We found that modern maize breeding has selected for a steeply angled root system. Favourable alleles related to steep root system angle have continuously accumulated over the course of modern breeding, and our data pinpoint the root-related genes that have been selected in different breeding eras. We confirm that two auxin-related genes, ZmRSA3.1 and ZmRSA3.2, contribute to the regulation of root angle and depth in maize. Our genome-wide identification of RSA-associated genes provides new strategies and genetic resources for breeding maize suitable for high-density planting.
PMID: 36396706
Nat Commun , IF:14.919 , 2022 Nov , V13 (1) : P6960 doi: 10.1038/s41467-022-34723-6
Specification of female germline by microRNA orchestrated auxin signaling in Arabidopsis.
Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA.; T3 Bioscience LLC, Mequon, WI, 53092, USA.; Beijing Genesee Biotech, Inc, 101400, Beijing, China.; Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.; Institute of Plant Sciences, ARO, Volcani Center, HaMaccabbim Road 68, 7505101, Rishon LeZion, Israel.; Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria.; Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA. dzhao@uwm.edu.
Germline determination is essential for species survival and evolution in multicellular organisms. In most flowering plants, formation of the female germline is initiated with specification of one megaspore mother cell (MMC) in each ovule; however, the molecular mechanism underlying this key event remains unclear. Here we report that spatially restricted auxin signaling promotes MMC fate in Arabidopsis. Our results show that the microRNA160 (miR160) targeted gene ARF17 (AUXIN RESPONSE FACTOR17) is required for promoting MMC specification by genetically interacting with the SPL/NZZ (SPOROCYTELESS/NOZZLE) gene. Alterations of auxin signaling cause formation of supernumerary MMCs in an ARF17- and SPL/NZZ-dependent manner. Furthermore, miR160 and ARF17 are indispensable for attaining a normal auxin maximum at the ovule apex via modulating the expression domain of PIN1 (PIN-FORMED1) auxin transporter. Our findings elucidate the mechanism by which auxin signaling promotes the acquisition of female germline cell fate in plants.
PMID: 36379956
Nat Commun , IF:14.919 , 2022 Nov , V13 (1) : P6897 doi: 10.1038/s41467-022-34637-3
Lipid-mediated activation of plasma membrane-localized deubiquitylating enzymes modulate endosomal trafficking.
Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, Universitatsstrasse 10, 78464, Konstanz, Germany.; Computational and Theoretical Chemistry, Department of Chemistry, University of Konstanz, Universitatsstrasse 10, 78464, Konstanz, Germany.; Biophysical Chemistry, Department of Chemistry, University of Konstanz, Universitatsstrasse 10, D-78464, Konstanz, Germany.; School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.; NMR, Department of Chemistry, University of Konstanz, Universitatsstrasse 10, 78464, Konstanz, Germany.; Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, Universitatsstrasse 10, 78464, Konstanz, Germany. erika.isono@uni-konstanz.de.
The abundance of plasma membrane-resident receptors and transporters has to be tightly regulated by ubiquitin-mediated endosomal degradation for the proper coordination of environmental stimuli and intracellular signaling. Arabidopsis OVARIAN TUMOR PROTEASE (OTU) 11 and OTU12 are plasma membrane-localized deubiquitylating enzymes (DUBs) that bind to phospholipids through a polybasic motif in the OTU domain. Here we show that the DUB activity of OTU11 and OTU12 towards K63-linked ubiquitin is stimulated by binding to lipid membranes containing anionic lipids. In addition, we show that the DUB activity of OTU11 against K6- and K11-linkages is also stimulated by anionic lipids, and that OTU11 and OTU12 can modulate the endosomal degradation of a model cargo and the auxin efflux transporter PIN2-GFP in vivo. Our results suggest that the catalytic activity of OTU11 and OTU12 is tightly connected to their ability to bind membranes and that OTU11 and OTU12 are involved in the fine-tuning of plasma membrane proteins in Arabidopsis.
PMID: 36371501
Sci Adv , IF:14.136 , 2022 Dec , V8 (49) : Peabq2047 doi: 10.1126/sciadv.abq2047
Endoreplication mediates cell size control via mechanochemical signaling from cell wall.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90187 Umea, Sweden.; IRBV, Department of Biological Sciences, University of Montreal, 4101 Sherbrooke Est, Montreal H1X 2B2, QC, Canada.; Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium.; VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium.; Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, 69364 Lyon, France.
Endoreplication is an evolutionarily conserved mechanism for increasing nuclear DNA content (ploidy). Ploidy frequently scales with final cell and organ size, suggesting a key role for endoreplication in these processes. However, exceptions exist, and, consequently, the endoreplication-size nexus remains enigmatic. Here, we show that prolonged tissue folding at the apical hook in Arabidopsis requires endoreplication asymmetry under the control of an auxin gradient. We identify a molecular pathway linking endoreplication levels to cell size through cell wall remodeling and stiffness modulation. We find that endoreplication is not only permissive for growth: Endoreplication reduction enhances wall stiffening, actively reducing cell size. The cell wall integrity kinase THESEUS plays a key role in this feedback loop. Our data thus explain the nonlinearity between ploidy levels and size while also providing a molecular mechanism linking mechanochemical signaling with endoreplication-mediated dynamic control of cell growth.
PMID: 36490331
Mol Plant , IF:13.164 , 2022 Dec doi: 10.1016/j.molp.2022.12.013
Natural variations of OsAUX5, a target gene of OsWRKY78, control the contents of neutral essential amino acids in rice grains.
Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China; College of Tropical Crops, Hainan University, Haikou 570228, China.; Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany.; National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.; Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China; College of Tropical Crops, Hainan University, Haikou 570228, China. Electronic address: Jincheng@hainanu.edu.cn.
Grain essential amino acid (EAA) levels contribute to rice nutritional quality. However, the molecular mechanisms underlying EAA accumulation and natural variation in rice grain remain unclear. Here, we report the identification of a previously unrecognized auxin influx carrier subfamily gene, OsAUX5, which encodes an amino acid transporter that functions in the uptake of multiple amino acids. We identified an elite haplotype of Pro::OsAUX5(Hap2) that enhances grain EAA accumulation without an apparent negative impact on agronomic traits. OsAUX5 differs in promoter cis-elements with natural variation, which are differentially activated due to the different binding affinity between OsWRKY78 and the W-box, contributing to grain EAA variation among rice varieties. The two distinct haplotypes were shown to have originated from different O. rufipogon progenitors, which contributed to the divergence between japonica and indica. Furthermore, introduction of the indica-type Pro::OsAUX5(Hap2) genotype into japonica could significantly increase EAA levels, thereby revealing that indica-type Pro::OsAUX5(Hap2) can be utilized to increase grain EAAs of japonica. Taken together, our study uncovers a WRKY78-OsAUX5-based regulatory mechanism controlling grain EAAs accumulation and provides a potential target for designing EAAs-rich rice.
PMID: 36540024
Mol Plant , IF:13.164 , 2022 Dec , V15 (12) : P1838-1840 doi: 10.1016/j.molp.2022.11.012
Adenylate cyclase activity of TIR1/AFB links cAMP to auxin-dependent responses.
Department of Biology, College of Science and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou 325060, Zhejiang Province, China; Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Ouhai, Wenzhou 325060, Zhejiang Province, China; Zhejiang Bioinformatics International Science and Technology Cooperation Center, Ouhai, Wenzhou 325060, Zhejiang Province, China.; Department of Chemistry, Biology & Biotechnology, University of Perugia, Perugia 06121, Italy. Electronic address: christophandreas.gehring@UniPG.it.
PMID: 36419358
Mol Plant , IF:13.164 , 2022 Dec , V15 (12) : P1947-1961 doi: 10.1016/j.molp.2022.11.001
Submergence promotes auxin-induced callus formation through ethylene-mediated post-transcriptional control of auxin receptors.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, Korea.; Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon 34113, Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, Korea; Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea. Electronic address: hyojunlee@kribb.re.kr.
Plant cells in damaged tissue can be reprogrammed to acquire pluripotency and induce callus formation. However, in the aboveground organs of many species, somatic cells that are distal to the wound site become less sensitive to auxin-induced callus formation, suggesting the existence of repressive regulatory mechanisms that are largely unknown. Here we reveal that submergence-induced ethylene signals promote callus formation by releasing post-transcriptional silencing of auxin receptor transcripts in non-wounded regions. We determined that short-term submergence of intact seedlings induces auxin-mediated cell dedifferentiation across the entirety of Arabidopsis thaliana explants. The constitutive triple response 1-1 (ctr1-1) mutation induced callus formation in explants without submergence, suggesting that ethylene facilitates cell dedifferentiation. We show that ETHYLENE-INSENSITIVE 2 (EIN2) post-transcriptionally regulates the abundance of transcripts for auxin receptor genes by facilitating microRNA393 degradation. Submergence-induced calli in non-wounded regions were suitable for shoot regeneration, similar to those near the wound site. We also observed submergence-promoted callus formation in Chinese cabbage (Brassica rapa), indicating that this may be a conserved mechanism in other species. Our study identifies previously unknown regulatory mechanisms by which ethylene promotes cell dedifferentiation and provides a new approach for boosting callus induction efficiency in shoot explants.
PMID: 36333910
Mol Plant , IF:13.164 , 2022 Nov , V15 (11) : P1744-1758 doi: 10.1016/j.molp.2022.09.021
Pepper variome reveals the history and key loci associated with fruit domestication and diversification.
Key Laboratory of Vegetables, Genetics, and Physiology of China Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture and Rural Affairs, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, CAAS (Chinese Academy of Agricultural Sciences), 12 Zhongguancun South Street, Beijing 100081, P. R. China.; INRAE, GAFL, Unite de Genetique et Amelioration des Fruits et Legumes, 84140 Montfavet, France.; Institute of Vegetables, Academy of Agricultural Sciences of Guangxi, 174 Daxue East Road, Nanning 53007, P. R. China.; Department of Plant and Environmental Sciences, NMSU, Las Cruces, NM 88003, USA.; Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel.; Biotechnology and Agroindustry Division, ENEA, Italian National Agency for New Technologies, Energy and Sustainable Development, Via Anguillarese, 301-00123 Roma, Italy. Electronic address: giovanni.giuliano@enea.it.; Key Laboratory of Vegetables, Genetics, and Physiology of China Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture and Rural Affairs, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, CAAS (Chinese Academy of Agricultural Sciences), 12 Zhongguancun South Street, Beijing 100081, P. R. China. Electronic address: wanglihao@caas.cn.; Key Laboratory of Vegetables, Genetics, and Physiology of China Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture and Rural Affairs, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, CAAS (Chinese Academy of Agricultural Sciences), 12 Zhongguancun South Street, Beijing 100081, P. R. China. Electronic address: chengfeng@caas.cn.
Pepper (Capsicum spp.) is an important vegetable crop that provides a unique pungent sensation when eaten. Through construction of a pepper variome map, we examined the main groups that emerged during domestication and breeding of C. annuum, their relationships and temporal succession, and the molecular events underlying the main transitions. The results showed that the initial differentiation in fruit shape and pungency, increase in fruit weight, and transition from erect to pendent fruits, as well as the recent appearance of large, blocky, sweet fruits (bell peppers), were accompanied by strong selection/fixation of key alleles and introgressions in two large genomic regions. Furthermore, we identified Up, which encodes a BIG GRAIN protein involved in auxin transport, as a key domestication gene that controls erect vs pendent fruit orientation. The up mutation gained increased expression especially in the fruit pedicel through a 579-bp sequence deletion in its 5' upstream region, resulting in the phenotype of pendent fruit. The function of Up was confirmed by virus-induced gene silencing. Taken together, these findings constitute a cornerstone for understanding the domestication and differentiation of a key horticultural crop.
PMID: 36176193
Plant Cell , IF:11.277 , 2022 Dec doi: 10.1093/plcell/koac369
Cytokinin-responsive MdTCP17 interacts with MdWOX11 to repress adventitious root primordium formation in apple rootstocks.
College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling, 712100, Shaanxi, P. R. China.
Adventitious root (AR) formation plays an important role in vegetatively propagated plants. Cytokinin (CK) inhibits AR formation, but the molecular mechanisms driving this process remain unknown. In this study, we confirmed that CK content is related to AR formation and further revealed that a high auxin/CK ratio was beneficial to AR formation in apple (Malus domestica). A correlation between expression of CK-responsive TEOSINTE BRANCHED1, CYCLOIDEA, and PCF17 (MdTCP17) and AR formation in response to CK was identified, and overexpression of MdTCP17 in transgenic apple inhibited AR formation. Yeast two-hybrid, bimolecular fluorescence complementation, and co-immunoprecipitation assays revealed an interaction between MdTCP17 and WUSCHEL-RELATED HOMEOBOX11 (MdWOX11), and a significant correlation between the expression of MdWOX11 and AR ability. Overexpression of MdWOX11 promoted AR primordium formation in apple, while interference of MdWOX11 inhibited AR primordium production. Moreover, a positive correlation was found between MdWOX11 and LATERAL ORGAN BOUNDARIES DOMAIN29 (MdLBD29) expression, and yeast one-hybrid, dual luciferase reporter, and ChIP-qPCR assays verified the binding of MdWOX11 to the MdLBD29 promoter with a WOX-box element in the binding sequence. Furthermore, MdTCP17 reduced the binding of MdWOX11 and MdLBD29 promoters, and co-expression of MdTCP17 and MdWOX11 reduced MdLBD29 expression. Together, these results explain the function and molecular mechanism of MdTCP17-mediated CK inhibition of AR primordium formation, which could be used to improve apple rootstocks genetically.
PMID: 36544357
Plant Cell , IF:11.277 , 2022 Dec doi: 10.1093/plcell/koac367
Auxin signaling is essential for organogenesis but not for cell survival in the liverwort Marchantia polymorpha.
Graduate School of Biostudies, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.; Graduate School of Life Sciences, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577, Japan.; Graduate School of Science, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan.; Graduate School of Science and Engineering, Ehime University, 2-5, Bunkyo-cho, Matsuyama, 790-8577, Japan.; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan.
Auxin plays pleiotropic roles in plant development via gene regulation upon its perception by the receptors TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFBs). This auxin-regulated transcriptional control mechanism originated in the common ancestor of land plants. Although the complete loss of TIR1/AFBs causes embryonic lethality in Arabidopsis thaliana, it is unclear whether the requirement for TIR1-mediated auxin perception in cell viability can be generalized. The model liverwort Marchantia polymorpha has a minimal auxin signaling system with only a single TIR1/AFB, MpTIR1. Here we show by genetic, biochemical, and transcriptomic analyses that MpTIR1 functions as an evolutionarily conserved auxin receptor. Null mutants and conditionally knocked-out mutants of MpTIR1 were viable but incapable of forming any organs and grew as cell masses. Principal component analysis performed using transcriptomes at various developmental stages indicated that MpTIR1 is involved in the developmental transition from spores to organized thalli, during which apical notches containing stem cells are established. In Mptir1 cells, stem-cell- and differentiation-related genes were up- and down-regulated, respectively. Our findings suggest that, in M. polymorpha, auxin signaling is dispensable for cell division but is essential for three-dimensional patterning of the plant body by establishing pluripotent stem cells for organogenesis, a derived trait of land plants.
PMID: 36529527
Plant Cell , IF:11.277 , 2022 Dec doi: 10.1093/plcell/koac362
Auxin contributes to jasmonate-mediated regulation of abscisic acid signaling during seed germination in Arabidopsis.
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.; College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou 550025, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
Abscisic acid (ABA) represses seed germination and post-germinative growth in Arabidopsis thaliana. Auxin and jasmonic acid (JA) stimulate ABA function; however, the possible synergistic effects of auxin and JA on ABA signaling and the underlying molecular mechanisms remain elusive. Here, we show that exogenous auxin works synergistically with JA to enhance the ABA-induced delay of seed germination. Auxin biosynthesis, perception, and signaling are crucial for JA-promoted ABA responses. The auxin-dependent transcription factors AUXIN RESPONSE FACTOR10 (ARF10) and ARF16 interact with JASMONATE ZIM-DOMAIN (JAZ) repressors of JA signaling. ARF10 and ARF16 positively mediate JA-increased ABA responses, and overaccumulation of ARF16 partially restores the hyposensitive phenotype of JAZ-accumulating plants defective in JA signaling in response to combined ABA and JA treatment. Furthermore, ARF10 and ARF16 physically associate with ABSCISIC ACID INSENSITIVE5 (ABI5), a critical regulator of ABA signaling, and the ability of ARF16 to stimulate JA-mediated ABA responses is mainly dependent on ABI5. ARF10 and ARF16 activate the transcriptional function of ABI5, whereas JAZ repressors antagonize their effects. Collectively, our results demonstrate that auxin contributes to the synergetic modulation of JA on ABA signaling, and explain the mechanism by which ARF10/16 coordinate with JAZ and ABI5 to integrate the auxin, JA, and ABA signaling pathways.
PMID: 36516412
Plant Cell , IF:11.277 , 2022 Nov doi: 10.1093/plcell/koac335
Natural variation in CRABS CLAW contributes to fruit length divergence in cucumber.
State Key Laboratories of Agrobiotechnology, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, MOE Joint Laboratory for International Cooperation in Crop Molecular Breeding, China Agricultural University, Beijing, 100193, China.; School of Life Science, Key Laboratory of Herbage ＆ Endemic Crop Biology, Ministry of Education, Inner Mongolia University, Hohhot 010070, China.; Horticulture Department, University of Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706, USA.; College of Horticulture, Hunan Agricultural University, Changsha, China.; USDA-ARS, Vegetable Crops Research Unit, 1575 Linden Drive, Madison, WI 53706, USA.
Fruit length is a key domestication trait that affects crop yield and appearance. Cucumber (Cucumis sativus) fruits vary from 5 approximately 60 cm in length. Despite the identification of several regulators and multiple quantitative trait loci (QTLs) underlying fruit length, the natural variation and molecular mechanisms underlying differences in fruit length are poorly understood. Through map-based cloning, we identified a nonsynonymous polymorphism (G to A) in CRABS CLAW (CsCRC) as underlying the major-effect fruit size/shape QTL FS5.2 in cucumber. The short fruit allele CsCRCA is a rare allele that has only been found in round-fruited semi-wild Xishuangbanna cucumbers. A near-isogenic line (NIL) homozygous for CsCRCA exhibited a 34 approximately 39% reduction in fruit length. Introducing CsCRCG into this NIL rescued the short-fruit phenotype, and knockdown of CsCRCG resulted in shorter fruit and smaller cells. In natural cucumber populations, CsCRCG expression was positively correlated with fruit length. Further, CsCRCG, but not CsCRCA, targets the downstream auxin-responsive protein gene CsARP1 to regulate its expression. Knockout of CsARP1 produced shorter fruit with smaller cells. Hence, our work suggests that CsCRCG positively regulates fruit elongation through transcriptional activation of CsARP1 and thus enhances cell expansion. Using different CsCRC alleles provides a strategy to manipulate fruit length in cucumber breeding.
PMID: 36427253
Plant Cell , IF:11.277 , 2022 Nov doi: 10.1093/plcell/koac316
Brassinosteroids promote etiolated apical structures in darkness by amplifying the ethylene response via the EBF-EIN3/PIF3 circuit.
School of Life Sciences, Southwest University, Chongqing 400715, China.; State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, School of Life Sciences, and Academy for Advanced Interdisciplinary Studies, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.; Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life Sciences, Westlake Univ., 18 Shilongshan Road, Hangzhou 310024, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
Germinated plants grow in darkness until they emerge above the soil. To help the seedling penetrate the soil, most dicot seedlings develop an etiolated apical structure consisting of an apical hook and folded, unexpanded cotyledons atop a rapidly elongating hypocotyl. Brassinosteroids (BRs) are necessary for etiolated apical development, but their precise role and mechanisms remain unclear. Arabidopsis thaliana SMALL AUXIN UP RNA17 (SAUR17) is an apical-organ-specific regulator that promotes production of an apical hook and closed cotyledons. In darkness, ethylene and BRs stimulate SAUR17 expression by transcription factor complexes containing PHYTOCHROME-INTERACTING FACTORs (PIFs), ETHYLENE INSENSITIVE 3 (EIN3) and its homolog EIN3-LIKE 1 (EIL1), and BRASSINAZOLE RESISTANT1 (BZR1). BZR1 requires EIN3 and PIFs for enhanced DNA-binding and transcriptional activation of the SAUR17 promoter; while EIN3, PIF3 and PIF4 stability depends on BR signaling. BZR1 transcriptionally downregulates EIN3-BINDING F-BOX 1 and 2 (EBF1 and EBF2, which encode ubiquitin ligases mediating EIN3 and PIF3 protein degradation. By modulating the EBF-EIN3/PIF protein-stability circuit, BRs induce EIN3 and PIF3 accumulation, which underlies BR-responsive expression of SAUR17 and HOOKLESS1 and ultimately apical hook development. We suggest that in the etiolated development of apical structures, BRs primarily modulate plant sensitivity to darkness and ethylene.
PMID: 36321994
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Dec , V119 (50) : Pe2210338119 doi: 10.1073/pnas.2210338119
Transcriptional repressor RST1 controls salt tolerance and grain yield in rice by regulating gene expression of asparagine synthetase.
College of Life Sciences, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; Jiangsu Coastal Area Institute of Agricultural Science, Yancheng 224002, China.; State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Department of Integrative Biological Sciences and Industry, Sejong University, Seoul 05006, Korea.
Salt stress impairs nutrient metabolism in plant cells, leading to growth and yield penalties. However, the mechanism by which plants alter their nutrient metabolism processes in response to salt stress remains elusive. In this study, we identified and characterized the rice (Oryza sativa) rice salt tolerant 1 (rst1) mutant, which displayed improved salt tolerance and grain yield. Map-based cloning revealed that the gene RST1 encoded an auxin response factor (OsARF18). Molecular analyses showed that RST1 directly repressed the expression of the gene encoding asparagine synthetase 1 (OsAS1). Loss of RST1 function increased the expression of OsAS1 and improved nitrogen (N) utilization by promoting asparagine production and avoiding excess ammonium (NH(4)(+)) accumulation. RST1 was undergoing directional selection during domestication. The superior haplotype RST1(Hap III) decreased its transcriptional repression activity and contributed to salt tolerance and grain weight. Together, our findings unravel a synergistic regulator of growth and salt tolerance associated with N metabolism and provide a new strategy for the development of tolerant cultivars.
PMID: 36472959
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Dec , V119 (50) : Pe2215569119 doi: 10.1073/pnas.2215569119
Polar auxin transport modulates early leaf flattening.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; Centro de Biotecnologia y Genomica de Plantas (CBGP), Universidad Politecnica de Madrid (UPM), Centro Nacional Instituto de Investigacion y Tecnologia Agraria y Alimentaria (INIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcon, 28223, Madrid, Spain.; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China.; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China.
The flattened leaf form is an important adaptation for efficient photosynthesis, and the developmental process of flattened leaves has been intensively studied. Classic microsurgery studies in potato and tomato suggest that the shoot apical meristem (SAM) communicates with the leaf primordia to promote leaf blade formation. More recently, it was found that polar auxin transport (PAT) could mediate this communication. However, it is unclear how the expression of leaf patterning genes is tailored by PAT routes originating from SAM. By combining experimental observations and computer model simulations, we show that microsurgical incisions and local inhibition of PAT in tomato interfere with auxin transport toward the leaf margins, reducing auxin response levels and altering the leaf blade shape. Importantly, oval auxin responses result in the bipolar expression of SlLAM1 that determines leaf blade formation. Furthermore, wounding caused by incisions promotes degradation of SlREV, a known regulator of leaf polarity. Additionally, computer simulations suggest that local auxin biosynthesis in early leaf primordia could remove necessity for external auxin supply originating from SAM, potentially explaining differences between species. Together, our findings establish how PAT near emerging leaf primordia determines spatial auxin patterning and refines SlLAM1 expression in the leaf margins to guide leaf flattening.
PMID: 36469773
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Dec , V119 (49) : Pe2212881119 doi: 10.1073/pnas.2212881119
Mitochondrial GPAT-derived LPA controls auxin-dependent embryonic and postembryonic development.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China.; Ministry of Agriculture (MOA) Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
Membrane properties are emerging as important cues for the spatiotemporal regulation of hormone signaling. Lysophosphatidic acid (LPA) evokes multiple biological responses by activating G protein-coupled receptors in mammals. In this study, we demonstrated that LPA derived from the mitochondrial glycerol-3-phosphate acyltransferases GPAT1 and GPAT2 is a critical lipid-based cue for auxin-controlled embryogenesis and plant growth in Arabidopsis thaliana. LPA levels decreased, and the polarity of the auxin efflux carrier PIN-FORMED1 (PIN1) at the plasma membrane (PM) was defective in the gpat1 gpat2 mutant. As a consequence of distribution defects, instructive auxin gradients and embryonic and postembryonic development are severely compromised. Further cellular and genetic analyses revealed that LPA binds directly to PIN1, facilitating the vesicular trafficking of PIN1 and polar auxin transport. Our data support a model in which LPA provides a lipid landmark that specifies membrane identity and cell polarity, revealing an unrecognized aspect of phospholipid patterns connecting hormone signaling with development.
PMID: 36454754
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Dec , V119 (49) : Pe2209256119 doi: 10.1073/pnas.2209256119
Chemical genetic screening identifies nalacin as an inhibitor of GH3 amido synthetase for auxin conjugation.
Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.; Institute for Advanced Studies, Wuhan University, Wuhan 430072, P.R. China.; Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 1138657, Japan.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093.; Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
Auxin inactivation is critical for plant growth and development. To develop plant growth regulators functioning in auxin inactivation pathway, we performed a phenotype-based chemical screen in Arabidopsis and identified a chemical, nalacin, that partially mimicked the effects of auxin. Genetic, pharmacological, and biochemical approaches demonstrated that nalacin exerts its auxin-like activities by inhibiting indole-3-acetic acid (IAA) conjugation that is mediated by Gretchen Hagen 3 (GH3) acyl acid amido synthetases. The crystal structure of Arabidopsis GH3.6 in complex with D4 (a derivative of nalacin) together with docking simulation analysis revealed the molecular basis of the inhibition of group II GH3 by nalacin. Sequence alignment analysis indicated broad bioactivities of nalacin and D4 as inhibitors of GH3s in vascular plants, which were confirmed, at least, in tomato and rice. In summary, our work identifies nalacin as a potent inhibitor of IAA conjugation mediated by group II GH3 that plays versatile roles in hormone-regulated plant development and has potential applications in both basic research and agriculture.
PMID: 36454752
Curr Biol , IF:10.834 , 2022 Dec doi: 10.1016/j.cub.2022.11.045
Local light signaling at the leaf tip drives remote differential petiole growth through auxin-gibberellin dynamics.
Plant-Environment Signaling, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.; Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.; Plant-Environment Signaling, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands.; Laboratory for Molecular Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.; Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands.; Plant-Environment Signaling, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands. Electronic address: r.pierik@uu.nl.
Although plants are immobile, many of their organs are flexible to move in response to environmental cues. In dense vegetation, plants detect neighbors through far-red light perception with their leaf tip. They respond remotely, with asymmetrical growth between the abaxial and adaxial sides of the leafstalk, the petiole. This results in upward movement that brings the leaf blades into better lit zones of the canopy. The plant hormone auxin is required for this response, but it is not understood how non-differential leaf tip-derived auxin can remotely regulate movement. Here, we show that remote signaling of far-red light promotes auxin accumulation in the abaxial petiole. This local auxin accumulation is facilitated by reinforcing an intrinsic directionality of the auxin transport protein PIN3 on the petiole endodermis, as visualized with a PIN3-GFP line. Using an auxin biosensor, we show that auxin accumulates in all cell layers from endodermis to epidermis in the abaxial petiole, upon far-red light signaling in the remote leaf tip. In the petiole, auxin elicits a response to both auxin itself as well as a second growth promoter; gibberellin. We show that this dual regulation is necessary for hyponastic leaf movement in response to light. Our data indicate that gibberellin is required to permit cell growth, whereas differential auxin accumulation determines which cells can grow. Our results reveal how plants can spatially relay information about neighbor proximity from their sensory leaf tips to the petiole base, thus driving adaptive growth.
PMID: 36538931
Curr Biol , IF:10.834 , 2022 Nov , V32 (22) : P4854-4868.e5 doi: 10.1016/j.cub.2022.09.055
Differential growth dynamics control aerial organ geometry.
College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; Centro de Biotecnologia y Genomica de Plantas (CBGP), Universidad Politecnica de Madrid (UPM), Centro Nacional Instituto de Investigacion y Tecnologia Agraria y Alimentaria (INIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcon, 28223 Madrid, Spain.; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; Key Laboratory of Microgravity (National Microgravity Laboratory), Center of Biomechanics and Bioengineering, and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yingwang@ucas.ac.cn.; Centro de Biotecnologia y Genomica de Plantas (CBGP), Universidad Politecnica de Madrid (UPM), Centro Nacional Instituto de Investigacion y Tecnologia Agraria y Alimentaria (INIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcon, 28223 Madrid, Spain. Electronic address: k.wabnik@upm.es.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Center for Quantitative Biology, Peking University, Beijing 100871, China; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, China. Electronic address: yuling.jiao@pku.edu.cn.
How gene activities and biomechanics together direct organ shapes is poorly understood. Plant leaf and floral organs develop from highly similar initial structures and share similar gene expression patterns, yet they gain drastically different shapes later-flat and bilateral leaf primordia and radially symmetric floral primordia, respectively. We analyzed cellular growth patterns and gene expression in young leaves and flowers of Arabidopsis thaliana and found significant differences in cell growth rates, which correlate with convergence sites of phytohormone auxin that require polar auxin transport. In leaf primordia, the PRESSED-FLOWER-expressing middle domain grows faster than adjacent adaxial domain and coincides with auxin convergence. In contrast, in floral primordia, the LEAFY-expressing domain shows accelerated growth rates and pronounced auxin convergence. This distinct cell growth dynamics between leaf and flower requires changes in levels of cell-wall pectin de-methyl-esterification and mechanical properties of the cell wall. Data-driven computer model simulations at organ and cellular levels demonstrate that growth differences are central to obtaining distinct organ shape, corroborating in planta observations. Together, our study provides a mechanistic basis for the establishment of early aerial organ symmetries through local modulation of differential growth patterns with auxin and biomechanics.
PMID: 36272403
J Hazard Mater , IF:10.588 , 2022 Nov , V445 : P130530 doi: 10.1016/j.jhazmat.2022.130530
Pre treatment of melatonin rescues cotton seedlings from cadmium toxicity by regulating key physio-biochemical and molecular pathways.
State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China; School of Life Science and Technology, Henan Institute of Science and Technology, Hualan St. 90, Xinxiang 453003, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang 450000, China; Hainan Yazhou Bay Seed Laboratory, Sanya 572024, China; National Nanfan Research Institute (Sanya), Chinese Academy of Agriculture Sciences, Sanya 572024, China.; School of Life Science and Technology, Henan Institute of Science and Technology, Hualan St. 90, Xinxiang 453003, China.; Faculty of Science, University Brunei Darussalam, Jalan Tungku Link, Gadong BE1410, Brunei Darussalam.; Institute of Ecology and Evolution, 5289 University of Oregon, Eugene, OR 97403, USA.; Sinopharm Wuhan Plasma-derived Biotherapies Co., Ltd, Wuhan, China.; School of Life Science and Technology, Henan Institute of Science and Technology, Hualan St. 90, Xinxiang 453003, China. Electronic address: ruiyangzh@gmail.com.; State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China. Electronic address: xiongyc@lzu.edu.cn.
Melatonin, a plant/animal origin hormone, regulates plant response to abiotic stresses by protecting them from oxidative damage. This study identified physiochemical and molecular mechanism of melatonin-induced cadmium (Cd) stress tolerance and detoxification in cotton seedlings. Cotton seedlings, with or without melatonin (15 microM) pretreatment, were subjected to Cd (100 microM) stress in a hydroponic medium for eight days. We found that higher cellular Cd accumulation in leaf tissues significantly inhibited the growth and physiology of cotton seedlings. In contrast, melatonin-treated seedlings maintained leaf photosynthetic capacity, producing relatively higher fresh (17.4%) and dry (19.3%) weights than non-melatonin-treated plants under Cd-contaminated environments. The improved growth and leaf functioning were strongly linked with the melatonin-induced repression of Cd transporter genes (LOC107894197, LOC107955631, LOC107899273) in roots. Thus, melatonin induced downregulation of the Cd transporter genes further inhibited Cd ion transport towards leaf tissues. This suggests that the differentially expressed transporter genes (DEG) are key drivers of the melatonin-mediated regulation of Cd transportation and sequestration in cotton. Melatonin also protected cotton seedlings from Cd-induced oxidative injury by reducing tissues malondialdehyde (MDA) and hydrogen peroxide (H(2)O(2)) levels and increasing the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) enzymes. Transcriptomic analysis revealed that melatonin activated mitogen-activated protein kinase (MAPK) signaling pathways to simulate stomatal adjustment and photosynthesis in Cd-stressed leaves. Further, melatonin protects intercellular organs, particularly ribosomes, from Cd-induced oxidative damage by promoting ribosomal biosynthesis and improving translational efficiency. The findings elucidated the molecular basis of melatonin-mediated Cd stress tolerance in plants and provided a key for the effective strategy of Cd accumulation in cotton.
PMID: 36463746
J Hazard Mater , IF:10.588 , 2023 Feb , V444 (Pt A) : P130427 doi: 10.1016/j.jhazmat.2022.130427
Transcriptome reveals the exposure effects of CeO(2) nanoparticles on pakchoi (Brassica chinensis L.) photosynthesis.
College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China. Electronic address: jhong@zjut.edu.cn.; College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.; College of Life Sciences, Shanxi Agricultural University, Taigu, Shanxi 030801, China.; Department of Chemistry and Biochemistry, The University of Texas, El Paso, TX 79968, United States.
In this study, soil-grown pakchoi after 2 weeks seedling cultivation were exposed to CeO(2) nanoparticles (CeO(2) NPs) at 0.7, 7, 70, and 350 mg kg(-1) for 30 days. Results showed that chlorophyll content and photosynthetic assimilation rate were decreased significantly under all treatments with the largest decrease of 34.16% (0.7 mg kg(-1) CeO(2) NPs), however, sub-stomatal CO(2) was increased dramatically under low dose of CeO(2) NPs (0.7 mg kg(-1)). There were 4576, 3548, 2787, and 2514 genes up/down regulated significantly by 0.7, 7, 70, and 350 mg kg(-1) CeO(2) NPs, respectively, and 767 genes affected under all treatments. In addition, 0.7 mg kg(-1) CeO(2) NPs up-regulated 10 chlorophyll synthesis genes, 20 photosynthesis genes, and 10 carbon fixation enzyme genes; while 350 mg kg(-1) CeO(2) NPs down-regulated 5 photosynthesis genes and 28 auxin-activated genes. Among the key genes of photosynthesis, Ferredoxin-NADP reductase (PetH) was upregulated in 0.7, 7 and 70 mg kg(-1) treatments, while Photosystem II lipoprotein (Psb27) was downregulated under 7, 70 and 350 mg kg(-1) treatments. Top 20 metabolic pathways affected by CeO(2) NPs including plant hormone, amino acids, and glutathione, and carbon metabolism These results provide information about utilizing CeO(2) NPs more safely and effectively in the future.
PMID: 36410248
J Hazard Mater , IF:10.588 , 2023 Jan , V441 : P129843 doi: 10.1016/j.jhazmat.2022.129843
Changes in the m6A RNA methylome accompany the promotion of soybean root growth by rhizobia under cadmium stress.
College of Agriculture, Northeast Agricultural University, Harbin 150030, Heilongjiang, People's Republic of China.; Daqing Branch, Heilongjiang Academy of Agricultural Sciences, Daqing 163316, Heilongjiang, People's Republic of China.; College of Agriculture, Northeast Agricultural University, Harbin 150030, Heilongjiang, People's Republic of China. Electronic address: qshchen@126.com.; College of Agriculture, Northeast Agricultural University, Harbin 150030, Heilongjiang, People's Republic of China. Electronic address: qizhaoming1860@126.com.
Cadmium (Cd) is the most widely distributed heavy metal pollutant in soil and has significant negative effects on crop yields and human health. Rhizobia can enhance soybean growth in the presence of heavy metals, and the legume-rhizobia symbiosis has been used to promote heavy-metal phytoremediation, but much remains to be learned about the molecular networks that underlie these effects. Here, we demonstrated that soybean root growth was strongly suppressed after seven days of Cd exposure but that the presence of rhizobia largely eliminated this effect, even prior to nodule development. Moreover, rhizobia did not appear to promote root growth by limiting plant Cd uptake: seedlings with and without rhizobia had similar root Cd concentrations. Previous studies have demonstrated a role for m6A RNA methylation in the response of rice and barley to Cd stress. We therefore performed transcriptome-wide m6A methylation profiling to investigate changes in the soybean RNA methylome in response to Cd with and without rhizobia. Here, we provide some of the first data on transcriptome-wide m6a RNA methylation patterns in soybean; m6A modifications were concentrated at the 3' UTR of transcripts and showed a positive relationship with transcript abundance. Transcriptome-wide m6A RNA methylation peaks increased in the presence of Cd, and the integration of m6A methylome and transcriptome results enabled us to identify 154 genes whose transcripts were both differentially methylated and differentially expressed in response to Cd stress. Annotation results suggested that these genes were associated with Ca(2+) homeostasis, ROS pathways, polyamine metabolism, MAPK signaling, hormones, and biotic stress responses. There were 176 differentially methylated and expressed transcripts under Cd stress in the presence of rhizobia. In contrast to the Cd-only gene set, they were also enriched in genes related to auxin, jasmonic acid, and brassinosteroids, as well as abiotic stress tolerance. They contained fewer genes related to Ca(2+) homeostasis and also included candidates with known functions in the legume-rhizobia symbiosis. These findings offer new insights into how rhizobia promote soybean root growth under Cd stress; they provide candidate genes for research on plant heavy metal responses and for the use of legumes in phytoremediation.
PMID: 36113351
New Phytol , IF:10.151 , 2022 Nov doi: 10.1111/nph.18625
Hormonal control of medial-lateral growth and vein formation in the maize leaf.
Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, Columbia, MO, 65211, USA.; Department of Biology, School of Science and Engineering, Ateneo de Manila University, Loyola Heights, Quezon City, Metro Manila, 1108, Philippines.
Parallel veins are characteristic of monocots, including grasses (Poaceae). Therefore, how parallel veins develop as the leaf grows in the medial-lateral (ML) dimension is a key question in grass leaf development. Using fluorescent protein reporters, we mapped auxin, cytokinin (CK), and gibberellic acid (GA) response patterns in maize (Zea mays) leaf primordia. We further defined the roles of these hormones in ML growth and vein formation through combinatorial genetic analyses and measurement of hormone concentrations. We discovered a novel pattern of auxin response in the adaxial protoderm that we hypothesize has important implications for the orderly formation of 3 degrees veins early in leaf development. In addition, we found an auxin transport and response pattern in the margins that correlates with the transition from ML to PD growth. We present evidence that auxin efflux precedes CK response in procambial strand development. We also determined that GA plays an early role in the shoot apical meristem as well as a later role in the primordium to restrict ML growth. We propose an integrative model whereby auxin regulates ML growth and vein formation in the maize leaf through control of GA and CK.
PMID: 36404129
New Phytol , IF:10.151 , 2022 Nov doi: 10.1111/nph.18602
Extranuclear auxin signaling: a new insight into auxin's versatility.
Department of Botany and Plant Sciences, Institute of Integrated Genome Biology, University of California, Riverside, CA, 92521, USA.; FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
Auxin phytohormone has a role in most aspects of the life of a land plant and is found even in ancient plants such as single-cell green algae. Auxin's ubiquitous but specific effects have been mainly explained by the extraordinary ability of plants to interpret spatiotemporal patterns of auxin concentrations via the regulation of gene transcription. This is thought to be achieved through the combinatorial effects of two families of nuclear coreceptor proteins, that is the TRANSPORT INHIBITOR RESPONSE1 and AUXIN-SIGNALING F-BOX (TIR1/AFB) and AUXIN/INDOLE ACETIC ACID. Recent evidence has suggested transcription-independent roles of TIR1/AFBs localized outside the nucleus and TRANSMEMBRANE KINASE (TMK)-based auxin signaling occurring in the plasma membrane. Furthermore, emerging evidence supports a coordinated action of the intra- and extranuclear auxin signaling pathways to regulate specific auxin responses. Here, we highlight how auxin signaling acts inside and outside the nucleus for the regulation of growth and morphogenesis and propose that the future direction of auxin biology lies in the elucidation of a new collaborative paradigm of intra- and extranuclear auxin signaling.
PMID: 36336825
New Phytol , IF:10.151 , 2022 Nov doi: 10.1111/nph.18600
Soilborne bacterium Klebsiella pneumoniae promotes cluster root formation in white lupin through ethylene mediation.
Joint International Research Laboratory of Water and Nutrient in Crop, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Department of Biology, Hong Kong Baptist University and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, 999077, China.
Cluster roots of white lupin are induced by low phosphorus (LP) to efficiently access unavailable P, but how soilborne microbes are associated with cluster root formation (CRF) is unclear. We investigated the roles of soilborne bacteria in CRF response to LP by high-throughput sequencing and root-bacteria interactions. Cluster root number was significantly decreased in plants grown in sterilized soil compared with nonsterilized soil. Proteobacteria was enriched in CR, as shown by microbiome analysis of soil (bulk, rhizosphere, and rhizosheath) and roots (main, lateral, and CR). Large-scale gene expression level implicated ethylene mediation in CRF. Klebsiella pneumoniae (P7), a soilborne bacterium belonging to Proteobacteria, was isolated from CR. Among 11 isolated strains, P7 exhibited the highest 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity; this enzyme inhibits the biosynthesis of ethylene in plants by the cleavage of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid and promotes CRF under LP. We constructed an ACCD-deficit mutant accd in the P7 genetic background. The loss-of-function mutation failed to promote CRF under LP conditions. Also, auxin responses may be involved in K. pneumoniae-ethylene-mediated CRF. Overall, we propose that the soilborne bacterium K. pneumoniae promotes CRF of white lupin in response to LP by ethylene mediation.
PMID: 36336781
New Phytol , IF:10.151 , 2022 Nov doi: 10.1111/nph.18589
A GT-1 and PKc domain-containing transcription regulator SIMPLE LEAF1 controls compound leaf development in woodland strawberry.
Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA.
Leaves are strikingly diverse in terms of shapes and complexity. The wild and cultivated strawberry plants mostly develop trifoliate compound leaves, yet the underlying genetic basis remains unclear in this important fruit crop in Rosaceae. Here, we identified two EMS mutants designated simple leaf1 (sl1-1 and sl1-2) and one natural simple-leafed mutant monophylla in Fragaria vesca. Their causative mutations all reside in SL1 (FvH4_7g28640) causing premature stop codon at different positions in sl1-1 and sl1-2 and an eight-nucleotide insertion (GTTCATCA) in monophylla. SL1 encodes a transcription regulator with the conserved DNA-binding domain GT-1 and the catalytic domain of protein kinases PKc. Expression of SL1pro::SL1 in sl1-1 completely restored compound leaf formation. The 35S::SL1 lines developed palmate-like leaves with four or five leaflets at a low penetrance. However, overexpressing the truncated SL1(DeltaPK) caused no phenotypes, probably due to the disruption of homodimerization. SL1 is preferentially expressed at the tips of leaflets and serrations. Moreover, SL1 is closely associated with the auxin pathway and works synergistically with FveLFYa in leaf morphogenesis. Overall, our work uncovered a new type of transcription regulator that promotes compound leaf formation in the woodland strawberry and shed new lights on the diversity of leaf complexity control.
PMID: 36319612
New Phytol , IF:10.151 , 2023 Jan , V237 (2) : P563-575 doi: 10.1111/nph.18552
Root placement patterns in allelopathic plant-plant interactions.
College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.; Department of Biological Sciences, Eastern Illinois University, Charleston, IL, 61920, USA.
Plants actively respond to their neighbors by altering root placement patterns. Neighbor-modulated root responses involve root detection and interactions mediated by root-secreted functional metabolites. However, chemically mediated root placement patterns and their underlying mechanisms remain elusive. We used an allelopathic wheat model system challenged with 60 target species to identify root placement responses in window rhizobox experiments. We then tested root responses and their biochemical mechanisms in incubation experiments involving the addition of activated carbon and functional metabolites with amyloplast staining and auxin localization in roots. Wheat and each target species demonstrated intrusive, avoidant or unresponsive root placement, resulting in a total of nine combined patterns. Root placement patterns were mediated by wheat allelochemicals and (-)-loliolide signaling of neighbor species. In particular, (-)-loliolide triggered wheat allelochemical production that altered root growth and placement, degraded starch grains in the root cap and induced uneven distribution of auxin in target species roots. Root placement patterns in wheat-neighbor interactions were perception dependent and species dependent. Signaling (-)-loliolide induced the production and release of wheat allelochemicals that modulated root placement patterns. Therefore, root placement patterns are generated by both signaling chemicals and allelochemicals in allelopathic plant-plant interactions.
PMID: 36263726
New Phytol , IF:10.151 , 2023 Jan , V237 (2) : P483-496 doi: 10.1111/nph.18556
The RhLOL1-RhILR3 module mediates cytokinin-induced petal abscission in rose.
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing, 100193, China.; Crops Pathology and Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA, 95616, USA.; Department of Plant Sciences, University of California at Davis, Davis, CA, 95616, USA.
In many plant species, petal abscission can be considered the final step of petal senescence. Cytokinins (CKs) are powerful suppressors of petal senescence; however, their role in petal abscission is ambiguous. Here, we observed that, in rose (Rosa hybrida), biologically active CK is accumulated during petal abscission and acts as an accelerator of the abscission process. Using a combination of reverse genetics, and molecular and biochemical techniques, we explored the roles of a LESION SIMULATING DISEASE1 (LSD1) family member RhLOL1 interacting with a bHLH transcription factor RhILR3 in CK-induced petal abscission. Silencing RhLOL1 delays rose petal abscission, while the overexpression of its ortholog SlLOL1 in tomato (Solanum lycopersicum) promotes pedicel abscission, indicating the conserved function of LOL1 in activating plant floral organ abscission. In addition, we identify a bHLH transcription factor, RhILR3, that interacts with RhLOL1. We show that RhILR3 binds to the promoters of the auxin signaling repressor auxin/indole-3-acetic acid (Aux/IAA) genes to inhibit their expression; however, the interaction of RhLOL1 with RhILR3 activates the expression of the Aux/IAA genes including RhIAA4-1. Silencing RhIAA4-1 delays rose petal abscission. Our results thus reveal a RhLOL1-RhILR3 regulatory module involved in CK-induced petal abscission via the regulation of the expression of the Aux/IAA genes.
PMID: 36263705
New Phytol , IF:10.151 , 2023 Jan , V237 (1) : P78-87 doi: 10.1111/nph.18536
SUE4, a novel PIN1-interacting membrane protein, regulates acropetal auxin transport in response to sulfur deficiency.
Division of Life Sciences and Medicine, Hefei National Science Center for Physical Sciences at the Microscale, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province, 230027, China.; Division of Molecular & Cell Biophysics, Hefei National Science Center for Physical Sciences at the Microscale, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province, 230027, China.; College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, China.; State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; College of Environmental and Resources Sciences, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.; Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China.
Sulfur (S) is an essential macronutrient for plants and a signaling molecule in abiotic stress responses. It is known that S availability modulates root system architecture; however, the underlying molecular mechanisms are largely unknown. We previously reported an Arabidopsis gain-of-function mutant sulfate utilization efficiency4 (sue4) that could tolerate S deficiency during germination and early seedling growth with faster primary root elongation. Here, we report that SUE4, a novel plasma membrane-localized protein, interacts with the polar auxin transporter PIN1, resulting in reduced PIN1 protein levels and thus decreasing auxin transport to the root tips, which promotes primary root elongation. Moreover, SUE4 is induced by sulfate deficiency, consistent with its role in root elongation. Further analyses showed that the SUE4-PIN1 interaction decreased PIN1 levels, possibly through 26 S proteasome-mediated degradation. Taken together, our finding of SUE4-mediated root elongation is consistent with root adaptation to highly mobile sulfate in soil, thus revealing a novel component in the adaptive response of roots to S deficiency.
PMID: 36226797
New Phytol , IF:10.151 , 2022 Dec , V236 (6) : P2216-2232 doi: 10.1111/nph.18491
Osa-miR160a confers broad-spectrum resistance to fungal and bacterial pathogens in rice.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China.
Rice production is threatened by multiple pathogens. Breeding cultivars with broad-spectrum disease resistance is necessary to maintain and improve crop production. Previously we found that overexpression of miR160a enhanced rice blast disease resistance. However, it is unclear whether miR160a also regulates resistance against other pathogens, and what the downstream signaling pathways are. Here, we demonstrate that miR160a positively regulates broad-spectrum resistance against the causative agents of blast, leaf blight and sheath blight in rice. Mutations of miR160a-targeted Auxin Response Factors result in different alteration of resistance conferred by miR160a. miR160a enhances disease resistance partially by suppressing ARF8, as mutation of ARF8 in MIM160 background partially restores the compromised resistance resulting from MIM160. ARF8 protein binds directly to the promoter and suppresses the expression of WRKY45, which acts as a positive regulator of rice immunity. Mutation of WRKY45 compromises the enhanced blast resistance and bacterial leaf blight resistance conferred by arf8 mutant. Overall, our results reveal that a microRNA coordinates rice broad-spectrum disease resistance by suppressing multiple target genes that play different roles in disease resistance, and uncover a new regulatory pathway mediated by the miR160a-ARF8 module. These findings provide new resources to potentially improve disease resistance for breeding in rice.
PMID: 36101507
New Phytol , IF:10.151 , 2023 Jan , V237 (2) : P408-413 doi: 10.1111/nph.18487
Systemic control of plant regeneration and wound repair.
The Institute of Plant Sciences, Faculty of Agriculture, The Hebrew University, Rehovot, 761000, Israel.
Plants have a broad capacity to regenerate damaged organs. The study of wounding in multiple developmental systems has uncovered many of the molecular properties underlying plants' competence for regeneration at the local cellular level. However, in nature, wounding is rarely localized to one place, and plants need to coordinate regeneration responses at multiple tissues with environmental conditions and their physiological state. Here, we review the evidence for systemic signals that regulate regeneration on a plant-wide level. We focus on the role of auxin and sugars as short- and long-range signals in natural wounding contexts and discuss the varied origin of these signals in different regeneration scenarios. Together, this evidence calls for a broader, system-wide view of plant regeneration competence.
PMID: 36101501
New Phytol , IF:10.151 , 2022 Dec , V236 (6) : P2265-2281 doi: 10.1111/nph.18483
Nodule INception-independent epidermal events lead to bacterial entry during nodule development in peanut (Arachis hypogaea).
National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India.; Amity University Haryana, Amity Education Valley, Panchgaon, Manesar, Haryana, 122412, India.
Legumes can host nitrogen-fixing rhizobia inside root nodules. In model legumes, rhizobia enter via infection threads (ITs) and develop nodules in which the infection zone contains a mixture of infected and uninfected cells. Peanut (Arachis hypogaea) diversified from model legumes c. 50-55 million years ago. Rhizobia enter through 'cracks' to form nodules in peanut roots where cells of the infection zone are uniformly infected. Phylogenomic studies have indicated symbiosis as a labile trait in peanut. These atypical features prompted us to investigate the molecular mechanism of peanut nodule development. Combining cell biology, genetics and genomic tools, we visualized the status of hormonal signaling in peanut nodule primordia. Moreover, we dissected the signaling modules of Nodule INception (NIN), a master regulator of both epidermal infection and cortical organogenesis. Cytokinin signaling operates in a broad zone, from the epidermis to the pericycle inside nodule primordia, while auxin signaling is narrower and focused. Nodule INception is involved in nodule organogenesis, but not in crack entry. Nodulation Pectate Lyase, which remodels cell walls during IT formation, is not required. By contrast, Nodule enhanced Glycosyl Hydrolases (AhNGHs) are recruited for cell wall modification during crack entry. While hormonal regulation is conserved, the function of the NIN signaling modules is diversified in peanut.
PMID: 36098671
New Phytol , IF:10.151 , 2022 Dec , V236 (5) : P1637-1654 doi: 10.1111/nph.18474
Gravity sensing and responses in the coordination of the shoot gravitropic setpoint angle.
Division of Plant Environmental Responses, National Institute for Basic Biology, Myodaiji, Okazaki, 444-8556, Japan.
Gravity is one of the fundamental environmental cues that affect plant development. Indeed, the plant architecture in the shoots and roots is modulated by gravity. Stems grow vertically upward, whereas lateral organs, such as the lateral branches in shoots, tend to grow at a specific angle according to a gravity vector known as the gravitropic setpoint angle (GSA). During this process, gravity is sensed in specialised gravity-sensing cells named statocytes, which convert gravity information into biochemical signals, leading to asymmetric auxin distribution and driving asymmetric cell division/expansion in the organs to achieve gravitropism. As a hypothetical offset mechanism against gravitropism to determine the GSA, the anti-gravitropic offset (AGO) has been proposed. According to this concept, the GSA is a balance of two antagonistic growth components, that is gravitropism and the AGO. Although the nature of the AGO has not been clarified, studies have suggested that gravitropism and the AGO share a common gravity-sensing mechanism in statocytes. This review discusses the molecular mechanisms underlying gravitropism as well as the hypothetical AGO in the control of the GSA.
PMID: 36089891
New Phytol , IF:10.151 , 2022 Dec , V236 (5) : P1762-1778 doi: 10.1111/nph.18467
Phosphorylation status of Bbeta subunit acts as a switch to regulate the function of phosphatase PP2A in ethylene-mediated root growth inhibition.
Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, 78712, USA.; Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA.; Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Center, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
The various combinations and regulations of different subunits of phosphatase PP2A holoenzymes underlie their functional complexity and importance. However, molecular mechanisms governing the assembly of PP2A complex in response to external or internal signals remain largely unknown, especially in Arabidopsis thaliana. We found that the phosphorylation status of Bbeta of PP2A acts as a switch to regulate the activity of PP2A. In the absence of ethylene, phosphorylated Bbeta leads to an inactivation of PP2A; the substrate EIR1 remains to be phosphorylated, preventing the EIR1-mediated auxin transport in epidermis, leading to normal root growth. Upon ethylene treatment, the dephosphorylated Bbeta mediates the formation of the A2-C4-Bbeta protein complex to activate PP2A, resulting in the dephosphorylation of EIR1 to promote auxin transport in epidermis of elongation zone, leading to root growth inhibition. Altogether, our research revealed a novel molecular mechanism by which the dephosphorylation of Bbeta subunit switches on PP2A activity to dephosphorylate EIR1 to establish EIR1-mediated auxin transport in the epidermis in elongation zone for root growth inhibition in response to ethylene.
PMID: 36073540
New Phytol , IF:10.151 , 2022 Dec , V236 (5) : P1748-1761 doi: 10.1111/nph.18459
Karrikin signaling regulates hypocotyl shade avoidance response by modulating auxin homeostasis in Arabidopsis.
Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.; University of Chinese Academy of Sciences, Beijing, 100039, China.
Shade affects all aspects of plant growth and development, including seed germination, hypocotyl elongation, petiole growth, leaf hyponasty, and flowering time. Here, we found that mutations in the key Arabidopsis karrikins signal perception-associated KARRIKIN INSENSITIVE 2 (KAI2) gene, encoding an alpha/beta-fold hydrolase, and the MORE AXILLARY GROWTH 2 (MAX2) gene, encoding an F-box protein, led to greater hypocotyl elongation under shade avoidance conditions. We further verified that these phenotypes were caused by perception of the endogenous KAI2-ligands (KLs), and that this phenotype is independent of strigolactone biosynthetic or signaling pathways. Upon perception of a KL, it is probable that the target protein forms a complex with the KAI2/MAX2 proteins, which are degraded through the action of the 26S proteasome. We demonstrated that SUPPRESSOR OF MAX2-1 (SMAX1) is the degradation target for the KAI2/MAX2 complex in the context of shade avoidance. KAI2 and MAX2 require SMAX1 to limit the hypocotyl growth associated with shade avoidance. Treatment with l-kynurenine, an inhibitor of auxin accumulation, partially restored elongation of kai2 mutant hypocotyls under simulated shade. Furthermore, KAI2 is involved in regulating auxin accumulation and polar auxin transport, which may contribute to the hypocotyl shade response. In addition, SMAX1 gene overexpression promoted the hypocotyl shade response. RNA-sequencing analysis revealed that SMAX1-overexpression affected the expression of many auxin homeostasis genes, especially under simulated shade. Altogether, our data support the conclusion that KL signaling regulates shade avoidance by modulating auxin homeostasis in the hypocotyl.
PMID: 36068957
New Phytol , IF:10.151 , 2022 Dec , V236 (5) : P1734-1747 doi: 10.1111/nph.18448
Bipartite phosphoinositide-dependent modulation of auxin signaling during xylem differentiation in Arabidopsis thaliana roots.
Department of Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092, Zurich, Switzerland.
Efficient root-to-shoot delivery of water and nutrients in plants relies on the correct differentiation of xylem cells into hollow elements. While auxin is integral to the formation of xylem cells, it remains poorly characterized how each subcellular pool of this hormone regulates this process. Combining genetic and cell biological approaches, we investigated the bipartite activity of nucleoplasmic vs plasma membrane-associated phosphatidylinositol 4-phosphate kinases PIP5K1 and its homolog PIP5K2 in Arabidopsis thaliana roots and uncovered a novel mechanism by which phosphoinositides integrate distinct aspects of the auxin signaling cascade and, in turn, regulate the onset of xylem differentiation. The appearance of undifferentiated cells in protoxylem strands of pip5k1 pip5k2 is phenomimicked in auxin transport and perception mutants and can be partially restored by the nuclear residence of PIP5K1. By contrast, exclusion of PIP5K1 from the nucleus hinders the auxin-mediated induction of the xylem master regulator VASCULAR RELATED NAC DOMAIN (VND) 7. A xylem-specific increase of auxin levels abolishes pip5k1 pip5k2 vascular defects, indicating that the establishment of auxin maxima is required to activate VND7-mediated xylem differentiation. Our results describe a new mechanism by which distinct subcellular pools of phosphoinositides integrate auxin transport and perception to initiate xylem differentiation in a spatiotemporal manner.
PMID: 36039703
New Phytol , IF:10.151 , 2022 Dec , V236 (5) : P1721-1733 doi: 10.1111/nph.18440
Feedback regulation of auxin signaling through the transcription of H2A.Z and deposition of H2A.Z to SMALL AUXIN UP RNAs in Arabidopsis.
Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200032, China.
Auxin is a critical phytohormone that is involved in the regulation of most plant growth and developmental responses. In particular, epigenetic mechanisms, like histone modifications and DNA methylation, were reported to affect auxin biosynthesis and transport. However, the involvement of other epigenetic factors, such as histone variant H2A.Z, in the auxin-related developmental regulation remains unclear. We report that the histone variant H2A.Z knockdown mutant in Arabidopsis Col-0 ecotype, h2a.z-kd, has more lateral roots and weak gravitational responses related to auxin-regulated growth performances. Further study revealed that auxin promotes the eviction of H2A.Z from the auxin-responsive genes SMALL AUXIN-UP RNAs (SAURs) to activate their transcriptions. We found that IAA promotes the transcription of H2A.Z genes through HOMEOBOX PROTEIN 22/25 (AtHB22/25) transcription factors which work as downstream targets of ARF7/19 in auxin signaling. Double mutant of hb22 hb25 showed similar lateral root and gravitropism phenotypes to h2a.z-kd. Our results shed light on a reciprocal regulation hub through INOSITOL AUXOTROPHY 80-mediated H2A.Z eviction and ARF7/19-HB22/25-mediated H2A.Z transcription to modulate the activation of SAURs and plant growth in Arabidopsis.
PMID: 36017638
New Phytol , IF:10.151 , 2022 Nov , V236 (4) : P1455-1470 doi: 10.1111/nph.18315
Many ways to TOPLESS - manipulation of plant auxin signalling by a cluster of fungal effectors.
Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Vienna Bio Center (VBC), Dr. Bohr-Gasse 3, 1030, Vienna, Austria.; Department of Plant Pathology, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Nussallee 9, 53115, Bonn, Germany.; CEPLAS, Institute for Plant Sciences, University of Cologne, 50674, Cologne, Germany.; Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany.
Plant biotrophic pathogens employ secreted molecules, called effectors, to suppress the host immune system and redirect the host's metabolism and development in their favour. Putative effectors of the gall-inducing maize pathogenic fungus Ustilago maydis were analysed for their ability to induce auxin signalling in plants. Using genetic, biochemical, cell-biological, and bioinformatic approaches we functionally elucidate a set of five, genetically linked effectors, called Topless (TPL) interacting protein (Tips) effectors that induce auxin signalling. We show that Tips induce auxin signalling by interfering with central corepressors of the TPL family. CRISPR-Cas9 mutants and deletion strain analysis indicate that the auxin signalling inducing subcluster effectors plays a redundant role in virulence. Although none of the Tips seem to have a conserved interaction motif, four of them bind solely to the N-terminal TPL domain and, for Tip1 and Tip4, we demonstrate direct competition with auxin/indole-3-acetic acid transcriptional repressors for their binding to TPL class of corepressors. Our findings reveal that TPL proteins, key regulators of growth-defence antagonism, are a major target of the U. maydis effectome.
PMID: 35944559
New Phytol , IF:10.151 , 2022 Nov , V236 (3) : P929-942 doi: 10.1111/nph.18381
The Arabidopsis IDD14 transcription factor interacts with bZIP-type ABFs/AREBs and cooperatively regulates ABA-mediated drought tolerance.
School of Life Sciences, Qilu Normal University, Jinan, 250200, China.; School of Life Sciences, Shandong Normal University, Jinan, 250014, China.; State Key Laboratory of Genetic Engineering and Fudan Center for Genetic Diversity and Designing Agriculture, School of Life Sciences, Fudan University, Shanghai, 200438, China.; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
The INDETERMINATE DOMAIN (IDD) transcription factors mediate various aspects of plant growth and development. We previously reported that an Arabidopsis IDD subfamily regulates spatial auxin accumulation, and thus organ morphogenesis and gravitropic responses. However, its functions in stress responses are not well defined. Here, we use a combination of physiological, biochemical, molecular, and genetic approaches to provide evidence that the IDD14 cooperates with basic leucine zipper-type binding factors/ABA-responsive element (ABRE)-binding proteins (ABRE-binding factors (ABFs)/AREBs) in ABA-mediated drought tolerance. idd14-1D, a gain-of-function mutant of IDD14, exhibits decreased leaf water loss and improved drought tolerance, whereas inactivation of IDD14 in idd14-1 results in increased transpiration and reduced drought tolerance. Altered IDD14 expression affects ABA sensitivity and ABA-mediated stomatal closure. IDD14 can physically interact with ABF1-4 and subsequently promote their transcriptional activities. Moreover, ectopic expression and mutation of ABFs could, respectively, suppress and enhance plant sensitivity to drought stress in the idd14-1 mutant. Our results demonstrate that IDD14 forms a functional complex with ABFs and positively regulates drought-stress responses, thus revealing a previously unidentified role of IDD14 in ABA signaling and drought responses.
PMID: 35842794
Plant Biotechnol J , IF:9.803 , 2022 Dec doi: 10.1111/pbi.13974
Profiling of phytohormone-specific microRNAs and characterization of the miR160-ARF1 module involved in glandular trichome development and artemisinin biosynthesis in Artemisia annua.
Medical School of Nantong University, Nantong, China.; School of Food and Bioengineering, Fujian Polytechnic Normal University, Fuqing, China.; Department of Pharmaceutical Botany, School of Pharmacy, Naval Medical University, Shanghai, China.; Research and Development Center of Chinese Medicine Resources and Biotechnology, Shanghai University of Traditional Chinese Medicine, Shanghai, China.; Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Shanghai, China.; Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Shanghai, China.; Innovative Drug R&D Center, College of Life Sciences, Huaibei Normal University, Huaibei, China.
MicroRNAs (miRNAs) play crucial roles in plant development and secondary metabolism through different modes of sequence-specific interaction with their targets. Artemisinin biosynthesis is extensively regulated by phytohormones. However, the function of phytohormone-responsive miRNAs in artemisinin biosynthesis remains enigmatic. Thus, we combined the analysis of transcriptomics, small RNAs, and the degradome to generate a comprehensive resource for identifying key miRNA-target circuits involved in the phytohormone-induced process of artemisinin biosynthesis in Artemisia annua. In total, 151 conserved and 52 novel miRNAs and their 4132 targets were determined. Based on the differential expression analysis, miR160 was selected as a potential miRNA involved in artemisinin synthesis. Overexpressing MIR160 significantly impaired glandular trichome formation and suppressed artemisinin biosynthesis in A. annua, while repressing its expression resulted in the opposite effect, indicating that miR160 negatively regulates glandular trichome development and artemisinin biosynthesis. RNA ligase-mediated 5' RACE and transient transformation assays showed that miR160 mediates the RNA cleavage of Auxin Response Factor 1 (ARF1) in A. annua. Furthermore, ARF1 was shown to increase artemisinin synthesis by activating AaDBR2 expression. Taken together, our results reveal the intrinsic link between the miR160-ARF1 module and artemisinin biosynthesis, and may expedite the innovation of metabolic engineering approaches for high and stable production of artemisinin in the future.
PMID: 36478140
Plant Physiol , IF:8.34 , 2022 Dec doi: 10.1093/plphys/kiac581
The Mediator complex subunit MED25 interacts with HDA9 and PIF4 to regulate thermomorphogenesis.
Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.; Temasek Life Science Laboratory, 1 Research Link, National University of Singapore, Singapore.; Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.; Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Trisaia Research Centre, S.S. Ionica, km 419.5, 75026 Rotondella (Matera), Italy.
Thermomorphogenesis is, among other traits, characterised by enhanced hypocotyl elongation due to induction of auxin biosynthesis genes like YUCCA8 by transcription factors, most notably PHYTOCHROME INTERACTING FACTOR 4 (PIF4). Efficient binding of PIF4 to the YUCCA8 locus under warmth depends on HISTONE DEACETYLASE 9 (HDA9) activity, which mediates histone H2A.Z depletion at the YUCCA8 locus. However, HDA9 lacks intrinsic DNA binding capacity, and how HDA9 is recruited to YUCCA8, and possibly other PIF4-target sites, is currently not well-understood. The Mediator complex functions as a bridge between transcription factors bound to specific promoter sequences and the basal transcription machinery containing RNA polymerase II. Mutants of Mediator component Mediator25 (MED25) exhibit reduced hypocotyl elongation and reduced expression of YUCCA8 at 27 degrees C. In line with a proposed role for MED25 in thermomorphogenesis in Arabidopsis (Arabidopsis thaliana), we demonstrated enhanced association of MED25 to the YUCCA8 locus under warmth and interaction of MED25 with both PIF4 and HDA9. Genetic analysis confirmed that MED25 and HDA9 operate in the same pathway. Intriguingly, we also showed that MED25 destabilises HDA9 protein. Based on our findings, we propose that MED25 recruits HDA9 to the YUCCA8 locus by binding to both PIF4 and HDA9.
PMID: 36537119
Plant Physiol , IF:8.34 , 2022 Dec doi: 10.1093/plphys/kiac586
Abscisic acid promotes auxin biosynthesis to inhibit primary root elongation in rice.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing 100081, China.
Soil compaction is a global problem causing inadequate rooting and poor yield in crops. Accumulating evidence indicates that phytohormones coordinately regulate root growth via regulating specific growth processes in distinct tissues. However, how abscisic acid (ABA) signaling translates into auxin production to control root growth during adaptation to different soil environments is unclear. In this study, we report that ABA has biphasic effects on primary root growth in rice (Oryza sativa) through an auxin biosynthesis-mediated process, causing suppression of root elongation and promotion of root swelling in response to soil compaction. We found that ABA treatment induced the expression of auxin biosynthesis genes and auxin accumulation in roots. Conversely, blocking auxin biosynthesis reduced ABA sensitivity in roots, showing longer and thinner primary roots with larger root meristem size and smaller root diameter. Further investigation revealed that the transcription factor basic region and leucine zipper 46 (OsbZIP46), involved in ABA signaling, can directly bind to the YUCCA8/rice ethylene-insensitive 7 (OsYUC8/REIN7) promoter to activate its expression, and genetic analysis revealed that OsYUC8/REIN7 is located downstream of OsbZIP46. Moreover, roots of mutants defective in ABA or auxin biosynthesis displayed the enhanced ability to penetrate compacted soil. Thus, our results disclose the mechanism in which ABA employs auxin as a downstream signal to modify root elongation and radial expansion, resulting in short and swollen roots impaired in their ability to penetrate compacted soil. These findings provide avenues for breeders to select crops resilient to soil compaction.
PMID: 36535001
Plant Physiol , IF:8.34 , 2022 Dec doi: 10.1093/plphys/kiac553
SUMO E3 ligase AtMMS21-dependent SUMOylation of AUXIN/INDOLE-3-ACETIC ACID 17 regulates auxin signaling.
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, PR China.
Changes in plant auxin levels can be perceived and converted into cellular responses by auxin signal transduction. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins are auxin transcriptional inhibitors that play important roles in regulating auxin signal transduction. The stability of Aux/IAA proteins is important for transcription initiation and downstream auxin-related gene expression. Here, we report that the Aux/IAA protein IAA17 interacts with the small ubiquitin-related modifier (SUMO) E3 ligase METHYL METHANESULFONATE-SENSITIVE 21 (AtMMS21) in Arabidopsis (Arabidopsis thaliana). AtMMS21 regulated the SUMOylation of IAA17 at the K41 site. Notably, root length was suppressed in plants overexpressing IAA17, whereas the roots of K41-mutated IAA17 transgenic plants were not significantly different from wild-type roots. Biochemical data indicated that K41-mutated IAA17 or IAA17 in the AtMMS21 knock-out mutant was more likely to be degraded compared to non-mutated IAA17 in wild-type plants. In conclusion, our data revealed a role for SUMOylation in the maintenance of IAA17 protein stability, which contributes to improving our understanding of the mechanisms of auxin signaling.
PMID: 36464768
Plant Physiol , IF:8.34 , 2022 Dec doi: 10.1093/plphys/kiac535
Wheat AUXIN RESPONSE FACTOR 15 delays senescence through competitive interaction at the TaNAM1 locus.
Department of Plant Biology and Genome Center, University of California, Davis, California 95616.
PMID: 36454670
Plant Physiol , IF:8.34 , 2022 Nov doi: 10.1093/plphys/kiac530
SYNTAXIN OF PLANTS81 regulates root meristem activity and stem cell niche maintenance via ROS signaling.
Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong, 261000, China.; Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China.; Institute of Advanced Biotechnology and School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.; Center for Advanced Bioindustry Technologies, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Root growth and development depend on continuous cell division and differentiation in root tips. In these processes, reactive oxygen species (ROS) play a critical role as signaling molecules. However, few ROS signaling regulators have been identified. In this study, we found knockdown of a syntaxin gene, SYNTAXIN OF PLANTS81 in Arabidopsis thaliana (AtSYP81) resulted in severe reduction in root meristem activity and disruption of root stem cell niche (SCN) identity. Subsequently, we found AtSYP81 was highly expressed in roots and localized on the endoplasmic reticulum (ER). Interestingly, the reduced expression of AtSYP81 conferred decreased number of peroxisomes in root meristem cells, raising a possibility that AtSYP81 regulates root development through peroxisome-mediated ROS production. Further transcriptome analysis revealed that class III peroxidases, which are responsible for intracellular ROS homeostasis, showed significantly changed expression in the atsyp81 mutants and AtSYP81 overexpression lines, adding evidence of the regulatory role of AtSYP81 in ROS signaling. Accordingly, rescuing the decreased ROS level via applying ROS donors effectively restored the defects in root meristem activity and SCN identity in the atsyp81 mutants. APETALA2 (AP2) transcription factors PLETHORA1 and 2 (PLT1 and PLT2) were then established as the downstream effectors in this pathway, while potential crosstalk between ROS signaling and auxin signaling was also indicated. Taken together, our findings suggest that AtSYP81 regulates root meristem activity and maintains root SCN identity by controlling peroxisome- and peroxidase-mediated ROS homeostasis, thus both broadening and deepening our understanding of biological roles of SNARE proteins and ROS signaling.
PMID: 36427205
Plant Physiol , IF:8.34 , 2022 Nov doi: 10.1093/plphys/kiac516
The B-box transcription factor IbBBX29 regulates leaf development and flavonoid biosynthesis in sweet potato.
Key Laboratory of Sweet Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis & Utilization and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China.; Sanya Institute of China Agricultural University, Hainan 572025, China.; Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210000, Jiangsu, China.; Institute of Grain and Oil Crops, Yantai Academy of Agricultural Sciences, Yantai 265500, China.; College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
Plant flavonoids are valuable natural antioxidants. Sweet potato (Ipomoea batatas) leaves are rich in flavonoids, regenerate rapidly, and can adapt to harsh environments, making them an ideal material for flavonoid biofortification. Here, we demonstrate that the B-box (BBX) family transcription factor IbBBX29 regulates the flavonoid contents and development of sweet potato leaves. IbBBX29 was highly expressed in sweet potato leaves and significantly induced by auxin (IAA). Overexpression of IbBBX29 contributed to a 21.37-70.94% increase in leaf biomass, a 12.08-21.85% increase in IAA levels, and a 31.33-63.03% increase in flavonoid accumulation in sweet potato, whereas silencing this gene produced opposite effects. Heterologous expression of IbBBX29 in Arabidopsis (Arabidopsis thaliana) led to a dwarfed phenotype, along with enhanced IAA and flavonoid accumulation. RNA-seq analysis revealed that IbBBX29 modulates the expression of genes involved in the auxin signaling and flavonoid biosynthesis pathways. ChIP-qPCR and EMSA indicated that IbBBX29 targets key genes of auxin signaling and flavonoid biosynthesis to activate their expression by binding to specific T/G-boxes in their promoters, especially those adjacent to the transcription start site. Moreover, IbBBX29 physically interacted with developmental and phenylpropanoid biosynthesis-related proteins, such as MADS-box protein IbAGL21 and MYB308-like protein IbMYB308L. Finally, overexpressing IbBBX29 also increased flavonoid contents in sweet potato storage roots. These findings indicate that IbBBX29 plays a pivotal role in regulating IAA-mediated leaf development and flavonoid biosynthesis in sweet potato and Arabidopsis, providing a candidate gene for flavonoid biofortification in plants.
PMID: 36377782
Plant Physiol , IF:8.34 , 2022 Nov doi: 10.1093/plphys/kiac513
Transcription factors KNAT3 and KNAT4 are essential for integument and ovule formation in Arabidopsis.
The State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umea 90183, Sweden.; Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China.; Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan.; Guangdong Laboratory of Lingnan Modern Agriculture, Guangzhou 510642, China.
Integuments form important protective cell layers surrounding the developing ovules in gymno- and angiosperms. Although several genes have been shown to influence the development of integuments, the transcriptional regulatory mechanism is still poorly understood. In this work, we report that the Class II KNOTTED1-LIKE HOMEOBOX (KNOX II) transcription factors KNOTTED1-LIKE HOMEBOX GENE 3 (KNAT3) and KNAT4 regulate integument development in Arabidopsis (Arabidopsis thaliana). KNAT3 and KNAT4 were co-expressed in inflorescences and especially in young developing ovules. The loss-of-function double mutant knat3 knat4 showed an infertility phenotype, in which both inner and outer integuments of the ovule are arrested at an early stage and form an amorphous structure as in the bell1 (bel1) mutant. The expression of chimeric KNAT3- and KNAT4-EAR motif repression domain (SRDX repressors) resulted in severe seed abortion. Protein-protein interaction assays demonstrated that KNAT3 and KNAT4 interact with each other and also with INNER NO OUTER (INO), a key transcription factor required for outer integument formation. Transcriptome analysis showed that expression of genes related with integument development is influenced in the knat3 knat4 mutant. The knat3 knat4 mutant also had a lower IAA content, and some auxin signalling pathway genes were down-regulated. Moreover, transactivation analysis indicated that KNAT3/4 and INO activate the auxin signaling gene INDOLE-3-ACETIC ACID INDUCIBLE 14 (IAA14). Taken together, our study identified KNAT3 and KNAT4 as key factors in integument development in Arabidopsis.
PMID: 36342216
Plant Physiol , IF:8.34 , 2022 Nov doi: 10.1093/plphys/kiac511
HEAT RESPONSIVE PROTEIN regulates heat stress via fine-tuning ethylene/auxin signaling pathways in cotton.
Institute of Crop Science, Plant Precision Breeding Academy, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.; Institute of Plant Breeding and Biotechnology, MNS University of Agriculture Multan.; National Center for Gene Research, State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Plants sense and respond to fluctuating temperature and light conditions during the circadian cycle; however, the molecular mechanism underlying plant adaptability during daytime warm conditions remains poorly understood. In this study, we reveal that ectopic regulation of a HEAT RESPONSIVE PROTEIN (GhHRP) controls the adaptation and survival of cotton (Gossypium hirsutum) plants in response to warm conditions via modulating phytohormone signaling. Increased ambient temperature promptly enhanced binding of the phytochrome interacting factor 4 (GhPIF4)/ethylene-insensitive 3 (GhEIN3) complex to the GhHRP promoter to increase its mRNA level. Ectopic expression of GhHRP promoted temperature-dependent accumulation of GhPIF4 transcripts and hypocotyl elongation by triggering thermoresponsive growth-related genes. Notably, upregulation of the GhHRP/GhPIF4 complex improved plant growth via modulating the abundance of Arabidopsis thaliana auxin biosynthetic gene YUCCA8 (AtYUC8)/1-aminocyclopropane-1-carboxylate synthase 8 (AtACS8) for fine-tuning the auxin/ethylene interplay, ultimately resulting in decreased ethylene biosynthesis. GhHRP thus protects chloroplasts from photo-oxidative bursts via repressing AtACS8 and AtACS7 and suppressing AtYUC8 and the heat shock transcription factors (HSFA2), heat shock proteins (HSP70 and HSP20). Strikingly, the Deltahrp disruption mutant exhibited compromised production of HSP/YUC8 that resulted in an opposite phenotype with loss of the ability to respond to warm conditions. Our results show that GhHRP is a heat-responsive signaling component that assists plants in confronting the dark phase and modulates auxin signaling to rescue growth under temperature fluctuations.
PMID: 36342207
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2739-2756 doi: 10.1093/plphys/kiac426
Early defoliation induces auxin redistribution, promoting paradormancy release in pear buds.
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China.; Zhejiang Provincial Key Laboratory of Integrative Biology of Horticultural Plants, Hangzhou, 310058 Zhejiang, China.; The Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture of China, Hangzhou, 310058, Zhejiang, China.; Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University, Haidian, Beijing 100083, China.; Yantai Institute, China Agricultural University, Yantai, Shandong 264670, China.; Hainan Institute of Zhejiang University, Sanya, Hainan 572000, China.
Paradormancy of fruit trees occurs in summer and autumn when signals from adjacent organs stimulate buds to develop slowly. This stage has received less attention that the other stages of dormancy, and the underlying mechanism remains uncharacterized. Early defoliation in late summer and early autumn is usually followed by out-of-season blooming in pear (Pyrus spp.), which substantially decreases the number of buds the following spring and negatively affects fruit production. This early bud flush is an example of paradormancy release. Here, we determined that flower bud auxin content is stable after defoliation; however, polar distribution of the pear (Pyrus pyrifolia) PIN-FORMED auxin efflux carrier 1b (PpyPIN1b) implied that auxin tends to be exported from buds. Transcriptome analysis of floral buds after artificial defoliation revealed changes in auxin metabolism, transport, and signal transduction pathways. Exogenous application of a high concentration of the auxin analog 1-naphthaleneacetic acid (300 mg/L) suppressed PpyPIN1b expression and its protein accumulation in the cell membrane, likely leading to decreased auxin efflux from buds, which hindered flower bud sprouting. Furthermore, carbohydrates and additional hormones also influenced out-of-season flowering. Our results indicate that defoliation-induced auxin efflux from buds accelerates bud paradormancy release. This differs from release of apical-dominance-related lateral bud paradormancy after the apex is removed. Our findings and proposed model further elucidate the mechanism underlying paradormancy and will help researchers to develop methods for inhibiting early defoliation-induced out-of-season bud sprouting.
PMID: 36200868
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2501-2518 doi: 10.1093/plphys/kiac440
Abscisic acid-responsive transcription factors PavDof2/6/15 mediate fruit softening in sweet cherry.
Department of Pomology, College of Horticulture, China Agricultural University, Beijing 100193, China.
Softening is a key step during fruit ripening that is modulated by the interplay between multiple phytohormones. The antagonistic action of abscisic acid (ABA) and auxin determines the rate of fruit ripening and softening. However, the transcription factors that integrate ABA and auxin signals to regulate fruit softening remain to be determined. In this study, we identified several DNA-binding with One Finger (Dof) transcription factors essential for ABA-promoted fruit softening, based on transcriptome analysis of two sweet cherry (Prunus avium L.) varieties with different fruit firmness. We show that PavDof6 directly binds to the promoters of genes encoding cell wall-modifying enzymes to activate their transcription, while PavDof2/15 directly repress their transcription. Transient overexpression of PavDof6 and PavDof2/15 in sweet cherry fruits resulted in precocious and delayed softening, respectively. In addition, we show that the auxin response factor PavARF8, the expression of whose encoding gene is repressed by ABA, activates PavDof2/15 transcription. Furthermore, PavDof2/6/15 and PavARF8 directly bind to the 9-cis-epoxycarotenoid dioxygenase 1 (PavNCED1) promoter and regulate its expression, forming a feedback mechanism for ABA-mediated fruit softening. These findings unveil the physiological framework of fruit softening and establish a direct functional link between the ABA-PavARF8-PavDofs module and cell-wall-modifying genes in mediating fruit softening.
PMID: 36130298
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2775-2796 doi: 10.1093/plphys/kiac441
Ethylene response factor ERF.D7 activates auxin response factor 2 paralogs to regulate tomato fruit ripening.
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India.; Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
Despite the obligatory role of ethylene in climacteric fruit ripening and the identification of 77 ethylene response factors (ERFs) in the tomato (Solanum lycopersicum) genome, the role of few ERFs has been validated in the ripening process. Here, using a comprehensive morpho-physiological, molecular, and biochemical approach, we demonstrate the regulatory role of ERF D7 (SlERF.D7) in tomato fruit ripening. SlERF.D7 expression positively responded to exogenous ethylene and auxin treatments, most likely in a ripening inhibitor-independent manner. SlERF.D7 overexpression (OE) promoted ripening, and its silencing had the opposite effect. Alterations in its expression modulated ethylene production, pigment accumulation, and fruit firmness. Consistently, genes involved in ethylene biosynthesis and signaling, lycopene biosynthesis, and cell wall loosening were upregulated in the OE lines and downregulated in RNAi lines. These transgenic lines also accumulated altered levels of indole-3-acetic acid at late-breaker stages. A positive association between auxin response factor 2 (ARF2) paralog's transcripts and SlERF.D7 mRNA levels and that SlARF2A and SlARF2B are direct targets of SlERF.D7 underpinned the perturbed auxin-ethylene crosstalk for the altered ripening program observed in the transgenic fruits. Overall, this study uncovers that SlERF.D7 positively regulates SlARF2A/B abundance to amalgamate auxin and ethylene signaling pathways for controlling tomato fruit ripening.
PMID: 36130295
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2722-2738 doi: 10.1093/plphys/kiac425
INOSITOL (1,3,4) TRIPHOSPHATE 5/6 KINASE1-dependent inositol polyphosphates regulate auxin responses in Arabidopsis.
Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-Universitat Bonn, Bonn 53115, Germany.; Department of Physiology & Cell Biology, Leibniz-Institute of Plant Genetics and Crop Plant Research, Gatersleben 06466, Germany.; Department of Chemistry and Pharmacy & CIBSS-The Center for Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany.; Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, Karnataka, India.; Laboratory of Signal Transduction and Plant Resistance, Regional Centre for Biotechnology, NCR-Biotech Science Cluster, Faridabad 121001, Haryana, India.; Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA.; Medical Research Council Laboratory for Molecular Cell Biology (MRC-LMCB), University College London, London WC1E 6BT, UK.
The combinatorial phosphorylation of myo-inositol results in the generation of different inositol phosphates (InsPs), of which phytic acid (InsP6) is the most abundant species in eukaryotes. InsP6 is also an important precursor of the higher phosphorylated inositol pyrophosphates (PP-InsPs), such as InsP7 and InsP8, which are characterized by a diphosphate moiety and are also ubiquitously found in eukaryotic cells. While PP-InsPs regulate various cellular processes in animals and yeast, their biosynthesis and functions in plants has remained largely elusive because plant genomes do not encode canonical InsP6 kinases. Recent work has shown that Arabidopsis (Arabidopsis thaliana) INOSITOL (1,3,4) TRIPHOSPHATE 5/6 KINASE1 (ITPK1) and ITPK2 display in vitro InsP6 kinase activity and that, in planta, ITPK1 stimulates 5-InsP7 and InsP8 synthesis and regulates phosphate starvation responses. Here we report a critical role of ITPK1 in auxin-related processes that is independent of the ITPK1-controlled regulation of phosphate starvation responses. Those processes include primary root elongation, root hair development, leaf venation, thermomorphogenic and gravitropic responses, and sensitivity to exogenously applied auxin. We found that the recombinant auxin receptor complex, consisting of the F-Box protein TRANSPORT INHIBITOR RESPONSE1 (TIR1), ARABIDOPSIS SKP1 HOMOLOG 1 (ASK1), and the transcriptional repressor INDOLE-3-ACETIC ACID INDUCIBLE 7 (IAA7), binds to anionic inositol polyphosphates with high affinity. We further identified a physical interaction between ITPK1 and TIR1, suggesting a localized production of 5-InsP7, or another ITPK1-dependent InsP/PP-InsP isomer, to activate the auxin receptor complex. Finally, we demonstrate that ITPK1 and ITPK2 function redundantly to control auxin responses, as deduced from the auxin-insensitive phenotypes of itpk1 itpk2 double mutant plants. Our findings expand the mechanistic understanding of auxin perception and suggest that distinct inositol polyphosphates generated near auxin receptors help to fine-tune auxin sensitivity in plants.
PMID: 36124979
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2449-2465 doi: 10.1093/plphys/kiac418
Root acid phosphatases and rhizobacteria synergistically enhance white lupin and rice phosphorus acquisition.
Joint International Research Laboratory of Water and Nutrient in Crops, Haixia Institute of Ecology and Environmental Engineering, College of Resource and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; College of Agriculture, Yangzhou University, Yangzhou 225009, China.; Department of Biology, Hong Kong Baptist University, Hong Kong.; State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong.; Institute of Agricultural Sciences, ICA-CSIC, Madrid 28006, Spain.; School of Agriculture and Environment, UWA Institute of Agriculture, University of Western Australia, Perth, Western Australia 6009, Australia.; College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
The rhizosheath is a belowground area that acts as a communication hub at the root-soil interface to promote water and nutrient acquisition. Certain crops, such as white lupin (Lupinus albus), acquire large amounts of phosphorus (P), owing partially to exudation of acid phosphatases (APases). Plant growth-promoting rhizobacteria also increase soil P availability. However, potential synergistic effects of root APases and rhizosheath-associated microbiota on P acquisition require further research. In this study, we investigated the roles of root purple APases (PAPs) and plant growth-promoting rhizobacteria in rhizosheath formation and P acquisition under conditions of soil drying (SD) and P treatment (+P: soil with P fertilizer; -P: soil without fertilizer). We expressed purple acid phosphatase12 (LaPAP12) in white lupin and rice (Oryza sativa) plants and analyzed the rhizosheath-associated microbiome. Increased or heterologous LaPAP12 expression promoted APase activity and rhizosheath formation, resulting in increased P acquisition mainly under SD-P conditions. It also increased the abundance of members of the genus Bacillus in the rhizosheath-associated microbial communities of white lupin and rice. We isolated a phosphate-solubilizing, auxin-producing Bacillus megaterium strain from the rhizosheath of white lupin and used this to inoculate white lupin and rice plants. Inoculation promoted rhizosheath formation and P acquisition, especially in plants with increased LaPAP12 expression and under SD-P conditions, suggesting a functional role of the bacteria in alleviating P deficit stress via rhizosheath formation. Together, our results suggest a synergistic enhancing effect of LaPAP12 and plant growth-promoting rhizobacteria on rhizosheath formation and P acquisition under SD-P conditions.
PMID: 36066452
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2706-2721 doi: 10.1093/plphys/kiac412
PHYTOCHROME-INTERACTING FACTOR 4/HEMERA-mediated thermosensory growth requires the Mediator subunit MED14.
Department of Biology, University of Mississippi, Oxford, Mississippi 38677, USA.; Natural Products Utilization Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Oxford, Mississippi, USA.; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, Mississippi, USA.; Division of Pharmacology, Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, Mississippi, USA.
While moderately elevated ambient temperatures do not trigger stress responses in plants, they do substantially stimulate the growth of specific organs through a process known as thermomorphogenesis. The basic helix-loop-helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) plays a central role in regulating thermomorphogenetic hypocotyl elongation in various plant species, including Arabidopsis (Arabidopsis thaliana). Although it is well known that PIF4 and its co-activator HEMERA (HMR) promote plant thermosensory growth by activating genes involved in the biosynthesis and signaling of the phytohormone auxin, the detailed molecular mechanism of such transcriptional activation is not clear. In this report, we investigated the role of the Mediator complex in the PIF4/HMR-mediated thermoresponsive gene expression. Through the characterization of various mutants of the Mediator complex, a tail subunit named MED14 was identified as an essential factor for thermomorphogenetic hypocotyl growth. MED14 was required for the thermal induction of PIF4 target genes but had a marginal effect on the levels of PIF4 and HMR. Further transcriptomic analyses confirmed that the expression of numerous PIF4/HMR-dependent, auxin-related genes required MED14 at warm temperatures. Moreover, PIF4 and HMR physically interacted with MED14 and both were indispensable for the association of MED14 with the promoters of these thermoresponsive genes. While PIF4 did not regulate MED14 levels, HMR was required for the transcript abundance of MED14. Taken together, these results unveil an important thermomorphogenetic mechanism, in which PIF4 and HMR recruit the Mediator complex to activate auxin-related growth-promoting genes when plants sense moderate increases in ambient temperature.
PMID: 36063057
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2350-2365 doi: 10.1093/plphys/kiac374
Identification of growth regulators using cross-species network analysis in plants.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; Institute of Biosciences and Bioresources, National Research Council (CNR), Via Amendola 165/A, 70126 Bari, Italy.; Department of Plant Physiology, Umea Plant Science Centre (UPSC), Umea University, 90187 Umea, Sweden.; SweTree Technologies AB, Skogsmarksgrand 7, SE-907 36 Umea, Sweden.; Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432 As, Norway.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences, 90183 Umea, Sweden.; Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.
With the need to increase plant productivity, one of the challenges plant scientists are facing is to identify genes that play a role in beneficial plant traits. Moreover, even when such genes are found, it is generally not trivial to transfer this knowledge about gene function across species to identify functional orthologs. Here, we focused on the leaf to study plant growth. First, we built leaf growth transcriptional networks in Arabidopsis (Arabidopsis thaliana), maize (Zea mays), and aspen (Populus tremula). Next, known growth regulators, here defined as genes that when mutated or ectopically expressed alter plant growth, together with cross-species conserved networks, were used as guides to predict novel Arabidopsis growth regulators. Using an in-depth literature screening, 34 out of 100 top predicted growth regulators were confirmed to affect leaf phenotype when mutated or overexpressed and thus represent novel potential growth regulators. Globally, these growth regulators were involved in cell cycle, plant defense responses, gibberellin, auxin, and brassinosteroid signaling. Phenotypic characterization of loss-of-function lines confirmed two predicted growth regulators to be involved in leaf growth (NPF6.4 and LATE MERISTEM IDENTITY2). In conclusion, the presented network approach offers an integrative cross-species strategy to identify genes involved in plant growth and development.
PMID: 35984294
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2335-2349 doi: 10.1093/plphys/kiac370
Cell- and noncell-autonomous AUXIN RESPONSE FACTOR3 controls meristem proliferation and phyllotactic patterns.
State Key Laboratory of North China Crop Improvement and Regulation; Key Laboratory of Crop Growth Regulation of Hebei Province, College of Agronomy, Hebei Agricultural University, Baoding, Hebei, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University; Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, China.; State Key Laboratory of North China Crop Improvement and Regulation; Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, College of Life Sciences, Hebei Agricultural University, Baoding, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Shijiazhuang, China.
In cell-cell communication, noncell-autonomous transcription factors play vital roles in controlling plant stem cell fate. We previously reported that AUXIN RESPONSE FACTOR3 (ARF3), a member of the ARF family with critical roles in floral meristem maintenance and determinacy, has a distinct accumulation pattern that differs from the expression domain of its encoding gene in the shoot apical meristem (SAM). However, the biological meaning of this difference is obscure. Here, we demonstrate that ARF3 expression in Arabidopsis (Arabidopsis thaliana) is mainly activated at the periphery of the SAM by auxin where ARF3 cell autonomously regulates the expression of meristem-organ boundary-specific genes, such as CUP-SHAPED COTYLEDON1-3 (CUC1-3), BLADE ON PETIOLE1-2 (BOP1-2), and TARGETS UNDER ETTIN CONTROL3 (TEC3) to regulate the arrangement of organs in regular pattern, a phenomenon referred to as phyllotaxis. We also show that ARF3 is translocated into the organizing center where it represses cytokinin activity and WUSCHEL expression to regulate meristem activity noncell-autonomously. Therefore, ARF3 acts as a molecular link that mediates the interaction of auxin and cytokinin signaling in the SAM while coordinating the balance between meristem maintenance and organogenesis. Our findings reveal an ARF3-mediated coordination mechanism through cell-cell communication in dynamic SAM maintenance.
PMID: 35972411
Environ Pollut , IF:8.071 , 2022 Nov , V312 : P120084 doi: 10.1016/j.envpol.2022.120084
Chromium in plant growth and development: Toxicity, tolerance and hormesis.
CONACYT-Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C.P. 58030, Morelia, Michoacan, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C.P. 58030, Morelia, Michoacan, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C.P. 58030, Morelia, Michoacan, Mexico. Electronic address: jbucio@umich.mx.
Research over the last three decades showed that chromium, particularly the oxyanion chromate Cr(VI) behaves as a toxic environmental pollutant that strongly damages plants due to oxidative stress, disruption of nutrient uptake, photosynthesis and metabolism, and ultimately, represses growth and development. However, mild Cr(VI) concentrations promote growth, induce adventitious root formation, reinforce the root cap, and produce twin roots from single root meristems under conditions that compromise cell viability, indicating its important role as a driver for root organogenesis. In recent years, considerable advance has been made towards deciphering the molecular mechanisms for root sensing of chromate, including the identification of regulatory proteins such as SOLITARY ROOT and MEDIATOR 18 that orchestrate the multilevel dynamics of the oxyanion. Cr(VI) decreases the expression of several glutamate receptors, whereas amino acids such as glutamate, cysteine and proline confer protection to plants from hexavalent chromium stress. The crosstalk between plant hormones, including auxin, ethylene, and jasmonic acid enables tissues to balance growth and defense under Cr(VI)-induced oxidative damage, which may be useful to better adapt crops to biotic and abiotic challenges. The highly contrasting responses of plants manifested at the transcriptional and translational levels depend on the concentration of chromate in the media, and fit well with the concept of hormesis, an adaptive mechanism that primes plants for resistance to environmental challenges, toxins or pollutants. Here, we review the contrasting facets of Cr(VI) in plants including the cellular, hormonal and molecular aspects that mechanistically separate its toxic effects from biostimulant outputs.
PMID: 36057328
Sci Total Environ , IF:7.963 , 2023 Jan , V855 : P158888 doi: 10.1016/j.scitotenv.2022.158888
Regulation of rhizospheric microbial network to enhance plant growth and resist pollutants: Unignorable weak electric field.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China.; College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.; MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China. Electronic address: tianli1@nankai.edu.cn.
The union of Plant Growth-Promoting Bacteria (PGPB) and rhizosphere confers a series of functions beneficial to plant. However, the lack of an opearable in situ method limits the further understanding on the mechanism. In this study, a weak electric field was designed to regulate rhizospheric microflora in a constructed root-splitting reactor. Compared with the control, the aboveground and underground biomass of rice seedling increased by 17 % and 18 % (p < 0.05) respectively under the exist of weak electric field of 0.14 V/cm. The joint action of rhizosphere and PGPB displayed the detoxification ability in the condition of soluble petroleum hydrocarbons, where the height, stem diameter, biomass and root vigor of the plant was increased by 58 %, 32 %, 43 % and 48 % respectively than the control. The selective reproduction of endophytes and ectophytes (denitrifying, auxin-producing, hydrocarbon-degrading and electroactive bacteria) was observed under applied weak electric field, which enhanced the nitrogen utilization, cellular metabolic activity and resistance to toxic organics of plant. This was further confirmed by the up-regulated OTUs related to the hydrocarbon degradation function, tryptophan metabolism and metabolism of nicotinate and nicotinamide. Moreover, the weak electric field also enhanced the transfer ability of partial endophytes grown in the root to improve plant stress resistance. The results in this work inspired an exercisable method for in situ enrichment of PGPB in the rhizosphere to cope with food crisis and provided a new way to deal with sudden environmental events.
PMID: 36165908
Sci Total Environ , IF:7.963 , 2022 Dec , V851 (Pt 2) : P158287 doi: 10.1016/j.scitotenv.2022.158287
Perfluorooctanoic acid and perfluorooctane sulfonic acid inhibit plant growth through the modulation of phytohormone signalling pathways: Evidence from molecular and genetic analysis in Arabidopsis.
College of Horticulture, Shanxi Agricultural University, Taigu 030801, China.; College of Horticulture, Shanxi Agricultural University, Taigu 030801, China. Electronic address: xujin@sxau.edu.cn.
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most representative perfluoroalkyl substances that accumulate in the food chain and are harmful to the environment. The uptake, translocation and physiological effects of PFOA and PFOS in plants have been reported in recent years; however, the regulatory mechanisms underlying PFOA- and PFOS-mediated plant growth and development remain largely unclear. Here, using Arabidopsis thaliana as the study material, we showed that both PFOA and PFOS inhibited plant growth; PFOS showed a stronger inhibitory effect on primary root (PR) growth, whereas PFOA exerted a stronger inhibitory effect on photosynthesis. Transcriptome analysis revealed that PFOA- and PFOS-modulated plant growth and development were correlated with the phytohormones auxin and abscisic acid (ABA). Further genetic analyses using mutants related to auxin biosynthesis, receptors and transport and mutants related to ABA biosynthesis and signalling transduction revealed that both PFOA and PFOS inhibited PR growth by modulating auxin biosynthesis and signalling pathways, and the ABA signalling pathway was also involved in PFOS-mediated PR growth inhibition. Collectively, these results shed new light on the molecular mechanisms of PFOA- and PFOS-mediated root system growth and their effects on phytohormone signalling pathways in plants.
PMID: 36030856
Sci Total Environ , IF:7.963 , 2022 Nov , V845 : P157157 doi: 10.1016/j.scitotenv.2022.157157
The molecular characteristics of DOMs derived from bio-stabilized wastewater activated sludge and its effect on alleviating Cd-stress in rice seedlings (Oryza sativa L.).
Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China.; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China.; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China. Electronic address: zhwj_1986@126.com.
To recycle fertilizing contents in wastewater activated sludge (WAS) is attracting increasing interest. Dissolved organic matters (DOMs) in WAS with high content are biologically active. In this work, the molecular composition of DOMs derived from two typical bio-stabilized WAS (DOM(BWS)), aerobic composting (DOM(ACS)) and anaerobic digestion (DOM(ADS)), were analyzed. The mitigative effect and molecular mechanisms of DOM(BWS) on rice seedlings (Oryza sativa L.) under Cd-stress were investigated. Our study indicated that DOM(BWS) significantly alleviated Cd-stress and facilitated growth recovery of rice seedlings with distinct absorption mechanisms. DOM(ACS), primarily composed of CHO class with low molecular weight rich in carboxyl groups, forming labile Cd-DOM complexes, which promoted Cd-absorption of rice seedlings. While DOM(ADS) comprised large molecular weight of CHON class interacted with Cd to produce stable macromolecular complexes in the form of microaggregates, consequently reducing Cd-absorption. At transcriptional level, DOM(BWS) restored auxin signal transduction and phenylpropanoid biosynthesis pathways in root cells, and got the expression of glutathione S-transferase well. Besides, DOM(ACS) significantly promoted the metabolism of amino acids to alleviate phytotoxicity, while DOM(ADS) improved the DNA repair function of rice seedlings. These findings provided novel insights into land-use of bio-stabilized WAS for remediation of heavy metals contaminated soils and food security.
PMID: 35803417
Food Chem , IF:7.514 , 2022 Dec , V408 : P135215 doi: 10.1016/j.foodchem.2022.135215
A multiomics integrative analysis of color de-synchronization with softening of 'Hass' avocado fruit: A first insight into a complex physiological disorder.
Escuela de Agronomia, Facultad de Ciencias Agronomicas y de los Alimentos, Pontificia Universidad Catolica de Valparaiso, Quillota, Chile.; KU Leuven, Facility for Systems Biology based Mass Spectrometry SYBIOMA, Leuven, Belgium; Biodiversity International, Biodiversity for Food and Agriculture, Leuven, Belgium.; Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.; Universidad Nacional Agraria La Molina, Instituto de Biotecnologia, Lima, Peru.; Centro de Estudios Postcosecha, Facultad de Ciencias Agronomicas, Universidad de Chile, Santiago, Chile.; Departamento de Fruticultura y Enologia, Facultad de Agronomia e Ingenieria Forestal, Pontificia Universidad Catolica de Chile, Santiago, Chile; Departamento de Genetica Molecular y Microbiologia, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago, Chile; ANID-Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile; Millennium Institute Center for Genome Regulation (CRG), Santiago, Chile. Electronic address: claudio.meneses@uc.cl.; Escuela de Agronomia, Facultad de Ciencias Agronomicas y de los Alimentos, Pontificia Universidad Catolica de Valparaiso, Quillota, Chile; Millennium Institute Center for Genome Regulation (CRG), Santiago, Chile. Electronic address: romina.pedreschi@pucv.cl.
Exocarp color de-synchronization with softening of 'Hass' avocado is a relevant recurrent problem for the avocado supply chain. This study aimed to unravel the mechanisms driving this de-synchronization integrating omics datasets from avocado exocarp of different storage conditions and color phenotypes. In addition, we propose potential biomarkers to predict color synchronized/de-synchronized fruit. Integration of transcriptomics, proteomics and metabolomics and network analysis revealed eight transcription factors associated with differentially regulated genes between regular air (RA) and controlled atmosphere (CA) and twelve transcription factors related to avocado fruit color de-synchronization control in ready-to-eat stage. CA was positively correlated to auxins, ethylene, cytokinins and brassinosteroids-related genes, while RA was characterized by enrichment of cell wall remodeling and abscisic acid content associated genes. At ready-to-eat higher contents of flavonoids, abscisic acid and brassinosteroids were associated with color-softening synchronized avocados. In contrast, de-synchronized fruit revealed increases of jasmonic acid, salicylic acid and auxin levels.
PMID: 36528992
BMC Biol , IF:7.431 , 2022 Nov , V20 (1) : P252 doi: 10.1186/s12915-022-01450-9
Temporal change in chromatin accessibility predicts regulators of nodulation in Medicago truncatula.
Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA.; School of Forest Resources and Conservation, University of Florida, Gainesville, FL, 32611, USA.; Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA.; Department of Agronomy, University of Wisconsin, Madison, WI, 53706, USA.; School of Forest Resources and Conservation, University of Florida, Gainesville, FL, 32611, USA. mkirst@ufl.edu.; Genetics Institute, University of Florida, Gainesville, FL, 32611, USA. mkirst@ufl.edu.; Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA. sroy@biostat.wisc.edu.; Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, 53792, USA. sroy@biostat.wisc.edu.; Department of Computer Sciences, University of Wisconsin, Madison, WI, 53792, USA. sroy@biostat.wisc.edu.
BACKGROUND: Symbiotic associations between bacteria and leguminous plants lead to the formation of root nodules that fix nitrogen needed for sustainable agricultural systems. Symbiosis triggers extensive genome and transcriptome remodeling in the plant, yet an integrated understanding of the extent of chromatin changes and transcriptional networks that functionally regulate gene expression associated with symbiosis remains poorly understood. In particular, analyses of early temporal events driving this symbiosis have only captured correlative relationships between regulators and targets at mRNA level. Here, we characterize changes in transcriptome and chromatin accessibility in the model legume Medicago truncatula, in response to rhizobial signals that trigger the formation of root nodules. RESULTS: We profiled the temporal chromatin accessibility (ATAC-seq) and transcriptome (RNA-seq) dynamics of M. truncatula roots treated with bacterial small molecules called lipo-chitooligosaccharides that trigger host symbiotic pathways of nodule development. Using a novel approach, dynamic regulatory module networks, we integrated ATAC-seq and RNA-seq time courses to predict cis-regulatory elements and transcription factors that most significantly contribute to transcriptomic changes associated with symbiosis. Regulators involved in auxin (IAA4-5, SHY2), ethylene (EIN3, ERF1), and abscisic acid (ABI5) hormone response, as well as histone and DNA methylation (IBM1), emerged among those most predictive of transcriptome dynamics. RNAi-based knockdown of EIN3 and ERF1 reduced nodule number in M. truncatula validating the role of these predicted regulators in symbiosis between legumes and rhizobia. CONCLUSIONS: Our transcriptomic and chromatin accessibility datasets provide a valuable resource to understand the gene regulatory programs controlling the early stages of the dynamic process of symbiosis. The regulators identified provide potential targets for future experimental validation, and the engineering of nodulation in species is unable to establish that symbiosis naturally.
PMID: 36352404
Plant Cell Environ , IF:7.228 , 2022 Dec doi: 10.1111/pce.14517
ZmBET5L1 inhibits primary root growth and decreases osmotic stress tolerance by mediating vesicle aggregation and tethering in maize.
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China.; State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Shandong, Tai-An, China.; Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China.
Improving osmotic stress tolerance is critical to help crops to thrive and maintain high yields in adverse environments. Here, we characterized a core subunit of the transport protein particle (TRAPP) complex, ZmBET5L1, in maize using knowledge-driven data mining and genome editing. We found that ZmBET5L1 can interact with TRAPP I complex subunits and act as a tethering factor to mediate vesicle aggregation and targeting from the endoplasmic reticulum to the Golgi apparatus. ZmBET5L1 knock-out increased the primary root elongation rate under 20% polyethylene glycol-simulated osmotic stress and the survival rate under drought stress compared to wild-type seedlings. In addition, we found that ZmBET5L1 moderates PIN1 polar localization and auxin flow to maintain normal root growth. ZmBET5L1 knock-out optimized auxin flow to the lateral side of the root and promoted its growth to generate a robust root, which may be related to improved osmotic stress tolerance. Together, these findings demonstrate that ZmBET5L1 inhibits primary root growth and decreases osmotic stress tolerance by regulating vesicle transport and auxin distribution. This study has improved our understanding of the role of tethering factors in response to abiotic stresses and identified desirable variants for breeding osmotic stress tolerance in maize.
PMID: 36515184
Plant Cell Environ , IF:7.228 , 2022 Dec doi: 10.1111/pce.14508
Wheat genome architecture influences interactions with phytobeneficial microbial functional groups in the rhizosphere.
Univ Lyon, Universite Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR5557 Ecologie Microbienne, Villeurbanne, France.; Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.
Wheat has undergone a complex evolutionary history, which led to allopolyploidization and the hexaploid bread wheat Triticum aestivum. However, the significance of wheat genomic architecture for beneficial plant-microbe interactions is poorly understood, especially from a functional standpoint. In this study, we tested the hypothesis that wheat genomic architecture was an overriding factor determining root recruitment of microorganisms with particular plant-beneficial traits. We chose five wheat species representing genomic profiles AA (Triticum urartu), BB SS (Aegilops speltoides), DD (Aegilops tauschii), AABB (Triticum dicoccon) and AABBDD (Triticum aestivum) and assessed by quantitative polymerase chain reaction their ability to interact with free-nitrogen fixers, 1-aminocyclopropane-1-carboxylate deaminase producers, 2,4-diacetylphloroglucinol producers and auxin producers via the phenylpyruvate decarboxylase pathway, in combination with Illumina MiSeq metabarcoding analysis of N fixers (and of the total bacterial community). We found that the abundance of the microbial functional groups could fluctuate according to wheat genomic profile, as did the total bacterial abundance. N fixer diversity and total bacterial diversity were also influenced significantly by wheat genomic profile. Often, rather similar results were obtained for genomes DD (Ae. tauschii) and AABBDD (T. aestivum), pointing for the first time that the D genome could be particularly important for wheat-bacteria interactions.
PMID: 36494920
Plant Cell Environ , IF:7.228 , 2022 Nov doi: 10.1111/pce.14494
Roles of auxin response factors in rice development and stress responses.
Joint International Research Laboratory of Metabolic & Developmental Sciences, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
Auxin signalling plays a key role in various developmental processes ranging from embryogenesis to senescence in plants. Auxin response factor (ARF), a key component of auxin signalling, functions by binding to auxin response element within promoter of auxin response genes, activating or repressing the target genes. Increasing evidences show that ARFs are crucial for plant response to stresses. This review summarises the recent advance on the functions and their regulatory pathways of rice ARFs in development and responding to stresses. The importance of OsARFs is demonstrated by their roles in triggering various physiological, biochemical and molecular reactions to resist adverse environmental conditions. We also describe the transcriptional and post-transcriptional regulation of OsARFs, and discuss the major challenges in this area.
PMID: 36397176
Plant Cell Environ , IF:7.228 , 2022 Nov doi: 10.1111/pce.14491
ABA-responsive AREB1/ABI3-1/ABI5 cascade regulates IAA oxidase gene SlDAO2 to inhibit hypocotyl elongation in tomato.
Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing, People's Republic of China.; Crop Breeding and Cultivation Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China.
Hypocotyl elongation is dramatically influenced by environmental factors and phytohormones. Indole-3-acetic acid (IAA) plays a prominent role in hypocotyl elongation, whereas abscisic acid (ABA) is regarded as an inhibitor through repressing IAA synthesis and signalling. However, the regulatory role of ABA in local IAA deactivation remains largely uncharacterized. In this study, we confirmed the antagonistic interplay of ABA and IAA during the hypocotyl elongation of tomato (Solanum lycopersicum) seedlings. We identified an IAA oxidase enzyme DIOXYGENASE FOR AUXIN OXIDATION2 (SlDAO2), and its expression was induced by both external and internal ABA signals in tomato hypocotyls. Moreover, the overexpression of SlDAO2 led to a reduced sensitivity to IAA, and the knockout of SlDAO2 alleviated the inhibitory effect of ABA on hypocotyl elongation. Furthermore, an ABA-responsive regulatory SlAREB1/SlABI3-1/SlABI5 cascade was identified to act upstream of SlDAO2 and to precisely control its expression. SlAREB1 directly bound to the ABRE present in the SlDAO2 promoter to activate SlDAO2 expression, and SlABI3-1 enhanced while SlABI5 inhibited the activation ability of SlAREB1 by directly interacting with SlAREB1. Our findings revealed that ABA might induce local IAA oxidation and deactivation via SlDAO2 to modulate IAA homoeostasis and thereby repress hypocotyl elongation in tomato.
PMID: 36369997
Plant Cell Environ , IF:7.228 , 2022 Nov doi: 10.1111/pce.14486
Low iron ameliorates the salinity-induced growth cessation of seminal roots in wheat seedlings.
School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.; School of Life Sciences, Zhengzhou University, Zhengzhou, China.
Wheat plants are ubiquitously simultaneously exposed to salinity and limited iron availability caused by soil saline-alkalisation. Through this study, we found that both low Fe and NaCl severely inhibited the growth of seminal roots in wheat seedlings; however, sufficient Fe caused greater growth cessation of seminal roots than low Fe under salt stress. Low Fe improved the root meristematic division activity, not altering the mature cell sizes compared with sufficient Fe under salt stress. Foliar Fe spray and split-root experiments showed that low Fe-alleviating the salinity-induced growth cessation of seminal roots was dependent on local low Fe signals in the roots. Ionomics combined with TEM/X-ray few differences in the root Na(+) uptake and vacuolar Na(+) sequestration between two Fe levels under salt stress. Phytohormone profiling and metabolomics revealed salinity-induced overaccumulation of ACC/ethylene and tryptophan/auxin in the roots under sufficient Fe than under low Fe. Differential gene expression, pharmacological inhibitor addition and the root growth performance of transgenic wheat plants revealed that the rootward auxin efflux and was responsible for the low Fe-mediated amelioration of the salinity-induced growth cessation of seminal roots. Our findings will provide novel insights into the modulation of crop root growth under salt stress.
PMID: 36358019
Plant Cell Environ , IF:7.228 , 2023 Jan , V46 (1) : P306-321 doi: 10.1111/pce.14460
Integrated transcriptomic and metabolomic profiles reveal adaptive responses of three poplar varieties against the bacterial pathogen Lonsdalea populi.
National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China.; The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China.
Different poplar varieties vary in their tolerance to certain pathogens. However, knowledge about molecular regulation and critical responses of resistant poplars during pathogen infection remains scarce. To investigate adaptive responses to canker disease caused by the bacterium Lonsdalea populi, we screened three poplar varieties with contrasting tolerance, including Populus deltoides. 'Zhonglin 2025' (2025), Populus x Euramericana. '74/76' (107) and Populus tomentosa cv 'henan' (P. tomentosa). Transcriptomic analysis revealed significant changes in the expression levels of defence-related genes in different poplar varieties in response to infection, which reshaped the PTI and ETI processes. Intriguingly, photosynthesis-related genes were found to be highly expressed in the resistant variety, whereas the opposite was observed in the susceptible variety. Susceptible poplars maintained the activation of defence-related genes during early period of onset, which restricted the expression of photosynthesis-related and auxin signal-related genes. Furthermore, combined with metabolomic analysis, differences in the content of antibacterial substances and key differentially expressed genes in phenylpropane and flavonoid biosynthesis pathways were identified. Delayed induction of catechin in the susceptible variety and it's in vitro antibacterial activity were considered to be one of the important reasons for the differences in resistance to L. populi compared with the resistant variety, which is of practical interest for tree breeding. Moreover, the trade-off between growth and defence observed among the three poplar varieties during infection provides new insights into the multilevel regulatory circuits in tree-pathogen interactions.
PMID: 36217265
Plant Cell Environ , IF:7.228 , 2023 Jan , V46 (1) : P215-238 doi: 10.1111/pce.14451
Impacts of iron on phosphate starvation-induced root hair growth in Arabidopsis.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China and University of Chinese Academy of Sceinces, Beijing, China.; Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China.
In Arabidopsis, phosphate starvation (-Pi)-induced responses of primary root and lateral root growth are documented to be correlated with ambient iron (Fe) status. However, whether and how Fe participates in -Pi-induced root hair growth (RHG) remains unclear. Here, responses of RHG to different Fe concentrations under Pi sufficiency/deficiency were verified. Generally, distinct dosage effects of Fe on RHG appeared at both Pi levels, due to the generation of reactive oxygen species. Following analyses using auxin mutants and the phr1 mutant revealed that auxin and the central regulator PHR1 are required for Fe-triggered RHG under -Pi. A further proteomic study indicated that processes of vesicle trafficking and auxin synthesis and transport were affected by Fe under -Pi, which were subsequently validated by using a vesicle trafficking inhibitor, brefeldin A, and an auxin reporter, R2D2. Moreover, vesicle trafficking-mediated recycling of PIN2, an auxin efflux transporter, was notably affected by Fe under -Pi. Correspondingly, root hairs of pin2 mutant displayed attenuated responses to Fe under -Pi. Together, we propose that Fe affects auxin signalling probably by modulating vesicle trafficking, chiefly the PIN2 recycling, which might work jointly with PHR1 on modulating -Pi-induced RHG.
PMID: 36174546
Chemosphere , IF:7.086 , 2022 Dec : P137571 doi: 10.1016/j.chemosphere.2022.137571
Toxicity effects of nanoplastics on soybean (Glycine max L.): Mechanisms and transcriptomic analysis.
Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.; Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.; Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China. Electronic address: hanxuerong@jlau.edu.cn.; Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address: yuhw@iga.ac.cn.
Microplastic (MP) pollution has become a major concern in recent years. In agricultural production, MPs can not only affect the growth of crops but also affect yield. Compared with micron-sized MPs, nanoplastics (NPs) may be more harmful to plants. However, the effects of NPs on plant growth and development have attracted relatively little attention. As such, research has currently plateaued at the level of morphology and physiology, and the molecular mechanisms are still unclear. In this study, soybeans (Glycine max L.) were treated with polystyrene nanoplastics (PS-NPs) to observe phenotypic changes and measure the effects of PS-NPs on diverse aspects of soybeans. Compared to the control group, the soybean stem and root lengths were inhibited by 11.78% and 12.58%, respectively. The reactive oxygen species content and the antioxidant enzyme activities changed significantly (p < 0.05). The accumulation of manganese (Mn) and magnesium (Mg) in the roots revealed that root transmembrane transport was affected by PS-NPs stress. The content of salicylic acid 2-O-beta-glucoside was inhibited whereas the accumulation of l-tryptophan, the precursor of auxin synthesis, was significantly increased (p < 0.05) in leaves. Transcriptomic analysis showed that PS-NPs could affect soybean DNA repair, membrane protein transport, and hormone synthesis and response. This study revealed the toxicity of NPs to soybeans and that NPs affected a variety of biological processes through transcriptome and hormone metabolome analysis, which provides a theoretical basis to further study the molecular mechanism of the effects on plants.
PMID: 36535503
J Integr Plant Biol , IF:7.061 , 2022 Dec doi: 10.1111/jipb.13441
To curve for survival: Apical hook development.
Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong, 518055, China.
Apical hook is a simple curved structure formed at the upper part of hypocotyls when dicot seeds germinate in darkness. The hook structure is transient but essential for seedlings' survival during soil emergence due to its efficient protection of the delicate shoot apex from mechanical injury. As a superb model system for studying plant differential growth, apical hook has fascinated botanists as early as the Darwin age, and significant advances have been achieved at both the morphological and molecular levels to understand how apical hook development is regulated. Here, we will mainly summarize the research progresses at these two regards. We will also briefly compare the growth dynamics between apical hook and hypocotyl gravitropic bending at early seed germination phase, with the aim to deduce certain consensus on their connections. Finally, we will outline the remaining questions and future research perspectives for apical hook development. This article is protected by copyright. All rights reserved.
PMID: 36562414
J Integr Plant Biol , IF:7.061 , 2022 Dec , V64 (12) : P2425-2437 doi: 10.1111/jipb.13387
High auxin stimulates callus through SDG8-mediated histone H3K36 methylation in Arabidopsis.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Plant Synthetic Biology Center, FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China.; Basic Forestry and Proteomics Research Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300072, China.
Callus induction, which results in fate transition in plant cells, is considered as the first and key step for plant regeneration. This process can be stimulated in different tissues by a callus-inducing medium (CIM), which contains a high concentration of phytohormone auxin. Although a few key regulators for callus induction have been identified, the multiple aspects of the regulatory mechanism driven by high levels of auxin still need further investigation. Here, we find that high auxin induces callus through a H3K36 histone methylation-dependent mechanism, which requires the methyltransferase SET DOMAIN GROUP 8 (SDG8). During callus induction, the increased auxin accumulates SDG8 expression through a TIR1/AFBs-based transcriptional regulation. SDG8 then deposits H3K36me3 modifications on the loci of callus-related genes, including a master regulator WOX5 and the cell proliferation-related genes, such as CYCB1.1. This epigenetic regulation in turn is required for the transcriptional activation of these genes during callus formation. These findings suggest that the massive transcriptional reprogramming for cell fate transition by auxin during callus formation requires epigenetic modifications including SDG8-mediated histone H3K36 methylation. Our results provide insight into the coordination between auxin signaling and epigenetic regulation during fundamental processes in plant development.
PMID: 36250442
J Integr Plant Biol , IF:7.061 , 2022 Nov , V64 (11) : P2150-2167 doi: 10.1111/jipb.13347
The SlTPL3-SlWUS module regulates multi-locule formation in tomato by modulating auxin and gibberellin levels in the shoot apical meristem.
Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.; Laboratory of Genomics and Biotechnology of Fruits, INRA, Toulouse INP, University of Toulouse, Castanet Tolosan, F-31326, France.
Malformed fruits depreciate a plant's market value. In tomato (Solanum lycopersicum), fruit malformation is associated with the multi-locule trait, which involves genes regulating shoot apical meristem (SAM) development. The expression pattern of TOPLESS3 (SlTPL3) throughout SAM development prompted us to investigate its functional significance via RNA interference (RNAi) and clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (Cas9)-mediated gene editing. Lower SlTPL3 transcript levels resulted in larger fruits with more locules and larger SAMs at the 5 d after germination (DAG5) stage. Differentially expressed genes in the SAM of wild-type (WT) and SlTPL3-RNAi plants, identified by transcriptome deep sequencing (RNA-seq), were enriched in the gibberellin (GA) biosynthesis and plant hormone signaling pathways. Moreover, exogenous auxin and paclobutrazol treatments rescued the multi-locule phenotype, indicating that SlTPL3 affects SAM size by mediating auxin and GA levels in the SAM. Furthermore, SlTPL3 interacted with WUSCHEL (SlWUS), which plays an important role in SAM size maintenance. We conducted RNA-seq and DNA affinity purification followed by sequencing (DAP-seq) analyses to identify the genes regulated by SlTPL3 and SlWUS in the SAM and to determine how they regulate SAM size. We detected 24 overlapping genes regulated by SlTPL3 and SlWUS and harboring an SlWUS-binding motif in their promoters. Furthermore, functional annotation revealed a notable enrichment for functions in auxin transport, auxin signal transduction, and GA biosynthesis. Dual-luciferase assays also revealed that SlTPL3 enhances SlWUS-mediated regulation (repression and activation) of SlPIN3 and SlGA2ox4 transcription, indicating that the SlTPL3-SlWUS module regulates SAM size by mediating auxin distribution and GA levels, and perturbations of this module result in enlarged SAM. These results provide novel insights into the molecular mechanism of SAM maintenance and locule formation in tomato and highlight the SlTPL3-SlWUS module as a key regulator.
PMID: 35980297
J Exp Bot , IF:6.992 , 2022 Dec doi: 10.1093/jxb/erac508
Fine-Tuned Nitric Oxide And Hormone Interface In Plant Root Development And Regeneration.
Dpto. de Botanica y Fisiologia Vegetal. Instituto de Investigacion en Agrobiotecnologia (CIALE). Facultad de Biologia. Universidad de Salamanca. C/ Rio Duero 12, 37185 Salamanca, Spain.; Universidad Politecnica de Madrid, Madrid, Spain.
Plant root growth and developmental capacities reside in a few stem cells of the root apical meristem (RAM). Maintenance of these stem cells requires regenerative divisions of the initial stem cell niche (SCN) cells, self-maintenance, and proliferative divisions of the daughter cells. This ensures sufficient cell diversity to guarantee the development of complex root tissues in the plant. Damage in the root during growth involves the formation of a new post-embryonic root, a process known as regeneration. Post-embryonic root development and organogenesis processes include primary root (PR) development and SCN maintenance, plant regeneration and the development of adventitious and lateral roots. These developmental processes require a fine-tuned balance between cell proliferation and maintenance. An important regulator during root development and regeneration is the gasotransmitter nitric oxide (NO). In this review we have sought to compile how NO regulates cell rate proliferation, cell differentiation, and quiescence of SCNs, usually through interaction with phytohormones, or other molecular mechanisms involved in cellular redox homeostasis. NO exerts a role on molecular components of the auxin (Aux) and cytokinin (CK) signaling pathways in PR that affects cell proliferation and maintenance of the RAM. During root regeneration, a peak of Aux and CKs triggers specific molecular programs. Moreover, NO participates in adventitious root formation through its interaction with players of the brassinosteroids (BRs) and CKs signaling cascade. Lately, NO has been implicated in root regeneration under hypoxia conditions by regulating stem cell specification through phytoglobins.
PMID: 36548145
J Exp Bot , IF:6.992 , 2022 Nov doi: 10.1093/jxb/erac443
Phytohormones in plant responses to boron deficiency and toxicity.
International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China.; Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7001, Australia.; Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia.; School of Biological Science, University of Western Australia, Crawley, WA6009, Australia.
Boron (B) is an essential element for plant growth. Many agricultural soils around the globe have either insufficient or excessive amounts of available B, with major implications for crop production. Understanding major limitations imposed by B nutritional disorders may allow breeding crops for improved B use efficiency as well as make them more resilient to excessive B, thus reducing yield penalties. It has become apparent that B-related physiological disorders are mediated in large part by their impact on plant hormonal production and signaling. The aim of this review is to summarize the current knowledge of the roles of hormones in plant responses to B and their impact on plant growth and development. The most significant effect of B deficiency is the inhibition of root elongation. B deficiency promotes the redistribution of auxin in the root elongation zone. Together with cytokinin signals and ethylene, this redistribution and modulation of auxin content triggers inhibition of the root cell elongation. Under B deficiency, root development is also regulated by brassinosteroids and jasmonic acid. Excess B can induce the production of reactive oxygen species (ROS). Abscisic acid and salicylic acid are both produced in response to B toxicity, and both can induce the antioxidant defense system to detoxify ROS. Another adaptation to B toxicity involves changes in the expression levels and activity of aquaporins in roots, thus reducing the uptake of water and delivery of B into the transpiration stream. In addition, abscisic acid mediates stomatal closure to further limit transpiration and the consequent accumulation of B in leaves.
PMID: 36398724
J Exp Bot , IF:6.992 , 2022 Nov doi: 10.1093/jxb/erac441
Jasmonate-regulated Root Growth Inhibition and Root Hair Elongation.
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming 650091, China.
The phytohormone jasmonate is an essential endogenous signal to regulate multiple plant processes for environmental adaptations, such as primary root growth inhibition and root hair elongation. Perception of environmental stresses promotes the accumulation of jasmonate which is sensed by the CORONATINE INSENSITIVE1 (COI1)-JASMONATE ZIM-DOMAIN (JAZ) co-receptor, triggering the degradation of JAZ repressors and induction of transcriptional reprogramming. The basic helix-loop-helix (bHLH) subgroup IIIe transcription factors MYC2, MYC3, and MYC4 are the most extensively characterized JAZ-binding factors and together stimulate jasmonate-signaled primary root growth inhibition. Conversely, the bHLH subgroup IIId transcription factors (i.e. bHLH3 and bHLH17) physically associate with JAZ proteins and suppress jasmonate-induced root growth inhibition. For root hair development, JAZ proteins interact with and inhibit ROOT HAIR DEFECTIVE 6 (RHD6) and RHD6 LIKE1 (RSL1) transcription factors to modulate jasmonate-enhanced root hair elongation. Moreover, jasmonate also interacts with other signaling pathways (such as ethylene and auxin) to regulate primary root growth and/or root hair elongation. Here, we review the recent progresses that have provided insights into jasmonate-mediated primary root growth and root hair development.
PMID: 36346644
J Exp Bot , IF:6.992 , 2023 Jan , V74 (1) : P364-376 doi: 10.1093/jxb/erac421
Metabolic link between auxin production and specialized metabolites in Sorghum bicolor.
Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611, USA.; Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA.; Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.; Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL 32608, USA.; Department of Microbiology & Cell Science, Gainesville, FL 32611, USA.; UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA.; Florida Center for Renewable Chemicals and Fuels, University of Florida, Gainesville, FL 32611, USA.
Aldoximes are amino acid derivatives that serve as intermediates for numerous specialized metabolites including cyanogenic glycosides, glucosinolates, and auxins. Aldoxime formation is mainly catalyzed by cytochrome P450 monooxygenases of the 79 family (CYP79s) that can have broad or narrow substrate specificity. Except for SbCYP79A1, aldoxime biosynthetic enzymes in the cereal sorghum (Sorghum bicolor) have not been characterized. This study identified nine CYP79-encoding genes in the genome of sorghum. A phylogenetic analysis of CYP79 showed that SbCYP79A61 formed a subclade with maize ZmCYP79A61, previously characterized to be involved in aldoxime biosynthesis. Functional characterization of this sorghum enzyme using transient expression in Nicotiana benthamiana and stable overexpression in Arabidopsis thaliana revealed that SbCYP79A61 catalyzes the production of phenylacetaldoxime (PAOx) from phenylalanine but, unlike the maize enzyme, displays no detectable activity against tryptophan. Additionally, targeted metabolite analysis after stable isotope feeding assays revealed that PAOx can serve as a precursor of phenylacetic acid (PAA) in sorghum and identified benzyl cyanide as an intermediate of PAOx-derived PAA biosynthesis in both sorghum and maize. Taken together, our results demonstrate that SbCYP79A61 produces PAOx in sorghum and may serve in the biosynthesis of other nitrogen-containing phenylalanine-derived metabolites involved in mediating biotic and abiotic stresses.
PMID: 36300527
J Exp Bot , IF:6.992 , 2023 Jan , V74 (1) : P265-282 doi: 10.1093/jxb/erac416
GhROP6 GTPase modulates auxin accumulation in cotton fibers by regulating cell-specific GhPIN3a localization.
Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400715, PR China.; Academy of Agricultural Sciences, Southwest University, Chongqing, PR China.; Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Southwest University, Chongqing, PR China.
PIN-FORMED- (PIN) mediated polar auxin transport plays a predominant role in most auxin-triggered organogenesis in plants. Global control of PIN polarity at the plasma membrane contributes to the essential establishment of auxin maxima in most multicellular tissues. However, establishment of auxin maxima in single cells is poorly understood. Cotton fibers, derived from ovule epidermal cells by auxin-triggered cell protrusion, provide an ideal model to explore the underlying mechanism. Here, we report that cell-specific degradation of GhPIN3a, which guides the establishment of the auxin gradient in cotton ovule epidermal cells, is associated with the preferential expression of GhROP6 GTPase in fiber cells. In turn, GhROP6 reduces GhPIN3a abundance at the plasma membrane and facilitates intracellular proteolysis of GhPIN3a. Overexpression and activation of GhROP6 promote cell elongation, resulting in a substantial improvement in cotton fiber length.
PMID: 36255218
J Exp Bot , IF:6.992 , 2023 Jan , V74 (1) : P233-250 doi: 10.1093/jxb/erac406
RsCLE22a regulates taproot growth through an auxin signaling-related pathway in radish (Raphanus sativus L.).
National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.; College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225009, China.
CLAVATA3/EMBRYO SURROUNDING REGION-related (CLE) peptides are a class of small molecules involved in plant growth and development. Although radish (Raphanus sativus) is an important root vegetable crop worldwide, the functions of CLE peptides in its taproot formation remain elusive. Here, a total of 48 RsCLE genes were identified from the radish genome. RNA in situ hybridization showed that RsCLE22a gene was highly expressed in the vascular cambium. Overexpression of RsCLE22a inhibited root growth by impairing stem cell proliferation in Arabidopsis, and radish plants with exogenous supplementation of RsCLE22 peptide (CLE22p) showed a similar phenotype. The vascular cambial activity was increased in RsCLE22a-silenced plants. Transcriptome analysis revealed that CLE22p altered the expression of several genes involved in meristem development and hormone signal transduction in radish. Immunolocalization results showed that CLE22p increased auxin accumulation in vascular cambium. Yeast one-hybrid and dual-luciferase assays showed that the WUSCHEL-RELATED HOMEOBOX 4 (RsWOX4) binds to RsCLE22a promoter and activates its transcription. The expression level of RsWOX4 was related to vascular cambial activity and was regulated by auxin. Furthermore, a RsCLE22a-RsWOX4 module is proposed to regulate taproot vascular cambium activity through an auxin signaling-related pathway in radish. These findings provide novel insights into the regulation of root growth in a horticultural crop.
PMID: 36239471
J Exp Bot , IF:6.992 , 2022 Nov , V73 (19) : P6838-6852 doi: 10.1093/jxb/erac337
Regulation of primary seed dormancy by MAJOR LATEX PROTEIN-LIKE PROTEIN329 in Arabidopsis is dependent on DNA-BINDING ONE ZINC FINGER6.
Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117558, Singapore.
Seeds exhibit primary dormancy to prevent germination under unfavourable conditions. Previous studies have shown that the gibberellin signalling intermediate RGA-LIKE2 (RGL2) forms a transcription factor complex with DNA-BINDING ONE ZINC FINGER6 (DOF6) in regulating seed dormancy in Arabidopsis. Using an RNA-sequencing approach, we identified MAJOR LATEX PROTEIN-LIKE PROTEIN329 (MLP329) as a downstream target of DOF6. MLP329 was found to be a positive regulator of primary seed dormancy, because freshly harvested unstratified mlp329 mutant seeds showed early germination, while unstratified transgenic seeds overexpressing MLP329 showed poor germination. MLP329 expression level was reduced in wild-type seeds upon dry storage and cold stratification. MLP329 expression level was enhanced by DOF6; however, DOF6-dependent MLP329 expression was suppressed in the presence of RGL2. MLP329 expression was enhanced in seeds treated with ABA and auxin IAA. Moreover, the mlp329 mutant seeds exhibited enhanced expression of the GA biosynthetic gene GA1 and suppression of the ABA biosynthetic gene ZEP compared to the overexpression lines. The observed suppression of DOF6-dependent MLP329 expression by RGL2 reveals a possible negative feedback mechanism to modulate seed dormancy. MLP329 also probably enhances the endogenous ABA/GA ratio to positively regulate primary seed dormancy.
PMID: 35969447
J Exp Bot , IF:6.992 , 2022 Nov , V73 (19) : P6711-6726 doi: 10.1093/jxb/erac336
Genetic modification of PIN genes induces causal mechanisms of stay-green drought adaptation phenotype.
University of Queensland, Queensland Alliance for Agriculture and Food Innovation (QAAFI), Warwick, QLD 4370, Australia.; University of Queensland, QAAFI, Brisbane, QLD 4072, Australia.; Agri-Science Queensland, Department of Agriculture & Fisheries, Warwick, QLD 4370, Australia.; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.; Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA.
The stay-green trait is recognized as a key drought adaptation mechanism in cereals worldwide. Stay-green sorghum plants exhibit delayed senescence of leaves and stems, leading to prolonged growth, a reduced risk of lodging, and higher grain yield under end-of-season drought stress. More than 45 quantitative trait loci (QTL) associated with stay-green have been identified, including two major QTL (Stg1 and Stg2). However, the contributing genes that regulate functional stay-green are not known. Here we show that the PIN FORMED family of auxin efflux carrier genes induce some of the causal mechanisms driving the stay-green phenotype in sorghum, with SbPIN4 and SbPIN2 located in Stg1 and Stg2, respectively. We found that nine of 11 sorghum PIN genes aligned with known stay-green QTL. In transgenic studies, we demonstrated that PIN genes located within the Stg1 (SbPIN4), Stg2 (SbPIN2), and Stg3b (SbPIN1) QTL regions acted pleiotropically to modulate canopy development, root architecture, and panicle growth in sorghum, with SbPIN1, SbPIN2, and SbPIN4 differentially expressed in various organs relative to the non-stay-green control. The emergent consequence of such modifications in canopy and root architecture is a stay-green phenotype. Crop simulation modelling shows that the SbPIN2 phenotype can increase grain yield under drought.
PMID: 35961690
J Exp Bot , IF:6.992 , 2022 Nov , V73 (19) : P6646-6662 doi: 10.1093/jxb/erac318
Soybean GmHY2a encodes a phytochromobilin synthase that regulates internode length and flowering time.
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Changchun 130102, China.; University of Chinese Academy of Sciences, Beijing 100049, China.
Plant height and flowering time are important agronomic traits that directly affect soybean [Glycine max (L.) Merr.] adaptability and yield. Here, the Glycine max long internode 1 (Gmlin1) mutant was selected from an ethyl methyl sulfonate (EMS)-mutated Williams 82 population due to its long internodes and early flowering. Using bulked segregant analysis (BSA), the Gmlin1 locus was mapped to Glyma.02G304700, a homologue of the Arabidopsis HY2 gene, which encodes a phytochromobilin (PPhiB) synthase involved in phytochrome chromophore synthesis. Mutation of GmHY2a results in failure of the de-etiolation response under both red and far-red light. The Gmlin1 mutant exhibits a constitutive shade avoidance response under normal light, and the mutations influence the auxin and gibberellin pathways to promote internode elongation. The Gmlin1 mutant also exhibits decreased photoperiod sensitivity. In addition, the soybean photoperiod repressor gene E1 is down-regulated in the Gmlin1 mutant, resulting in accelerated flowering. The nuclear import of phytochrome A (GmphyA) and GmphyB following light treatment is decreased in Gmlin1 protoplasts, indicating that the weak light response of the Gmlin1 mutant is caused by a decrease in functional phytochrome. Together, these results indicate that GmHY2a plays an important role in soybean phytochrome biosynthesis and provide insights into the adaptability of the soybean plant.
PMID: 35946571
J Exp Bot , IF:6.992 , 2022 Nov , V73 (19) : P6784-6799 doi: 10.1093/jxb/erac326
The protein phosphatase 2A catalytic subunit StPP2Ac2b is involved in the control of potato tuber sprouting and source-sink balance in tubers and sprouts.
Instituto de Investigaciones en Ingenieria Genetica y Biologia Molecular 'Dr. Hector Torres', Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET). Vuelta de Obligado, Buenos Aires, Argentina.
Sprouting negatively affects the quality of stored potato tubers. Understanding the molecular mechanisms that control this process is important for the development of potato varieties with desired sprouting characteristics. Serine/threonine protein phosphatase type 2A (PP2A) has been implicated in several developmental programs and stress responses in plants. PP2A comprises a catalytic (PP2Ac), a scaffolding (A), and a regulatory (B) subunit. In cultivated potato, six PP2Ac isoforms were identified, named StPP2Ac1, 2a, 2b, 3, 4, and 5. In this study we evaluated the sprouting behavior of potato tubers overexpressing the catalytic subunit 2b (StPP2Ac2b-OE). The onset of sprouting and initial sprout elongation is significantly delayed in StPP2Ac2b-OE tubers; however, sprout growth is accelerated during the late stages of development, due to a high degree of branching. StPP2Ac2b-OE tubers also exhibit a pronounced loss of apical dominance. These developmental characteristics are accompanied by changes in carbohydrate metabolism and response to gibberellic acid, and a differential balance between abscisic acid, gibberellic acid, cytokinins, and auxin. Overexpression of StPP2Ac2b alters the source-sink balance, increasing the source capacity of the tuber, and the sink strength of the sprout to support its accelerated growth.
PMID: 35925650
J Exp Bot , IF:6.992 , 2022 Nov , V73 (19) : P6916-6930 doi: 10.1093/jxb/erac319
Up-regulation of bZIP88 transcription factor is involved in resistance to three different herbicides in both Echinochloa crus-galli and E. glabrescens.
College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China.
The resistance of weeds to herbicides poses a major threat to agricultural production, and non-target-site resistance (NTSR) is often a serious problem as its mechanisms can in some cases confer resistance to herbicides with different modes of action. In this study, we hypothesized that bZIP transcription factors (TFs), which regulate abiotic stress responses in many plants, play a regulatory role in NTSR. Whole-plant assays indicated that the wild grasses Echinochloa crus-galli and E. glabrescens are resistant to the herbicides penoxsulam, cyhalofop-butyl, and quintrione. Transcriptome sequencing then identified 101 and 49 bZIP TFs with differential expression following penoxsulam treatment in E. crus-galli and E. glabrescens, respectively. Twelve of these genes had >60% homology with rice genes. The expression of bZIP88 was considerably up-regulated 6 h after treatment with the three different herbicides, and it was similar between resistant and susceptible populations; however, the relative expression levels before herbicide treatment and 24 h after were the same. We used rice (Oryza sativa ssp. japonica cv Nipponbare) as a model system for functional validation and found that CRISPR-Cas9-knockout of the rice bZIP88 ortholog increased the sensitivity to herbicide, whereas overexpression reduced it. The OsbZIP88 protein was localized to the nucleus. Using ChIP coupled with high-throughput sequencing, OsbZIP88 was found to form a network regulatory center with other TFs such as bZIP20/52/59 to regulate OsKS1, OsCOE1, and OsIM1, which are related to auxin, abscisic acid, brassinosteroids, and gibberellic acid. Based on these results, we have established a database of bZIP TFs corresponding to herbicide stress, and resolved the mechanisms of the positive regulation of herbicide resistance by bZIP88, thereby providing new insights for NTSR.
PMID: 35867472
J Exp Bot , IF:6.992 , 2022 Nov , V73 (20) : P7041-7054 doi: 10.1093/jxb/erac282
TOR kinase, a GPS in the complex nutrient and hormonal signaling networks to guide plant growth and development.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.; Haixia Institute of Science and Technology, Plant Synthetic Biology Center, Fujian Agriculture and Forestry University, Fuzhou, China.; Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA.
To survive and sustain growth, sessile plants have developed sophisticated internal signalling networks that respond to various external and internal cues. Despite the central roles of nutrient and hormone signaling in plant growth and development, how hormone-driven processes coordinate with metabolic status remains largely enigmatic. Target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates energy, nutrients, growth factors, hormones, and stress signals to promote growth in all eukaryotes. Inspired by recent comprehensive systems, chemical, genetic, and genomic studies on TOR in plants, this review discusses a potential role of TOR as a 'global positioning system' that directs plant growth and developmental programs both temporally and spatially by integrating dynamic information in the complex nutrient and hormonal signaling networks. We further evaluate and depict the possible functional and mechanistic models for how a single protein kinase, TOR, is able to recognize, integrate, and even distinguish a plethora of positive and negative input signals to execute appropriate and distinct downstream biological processes via multiple partners and effectors.
PMID: 35781569
Int J Biol Macromol , IF:6.953 , 2022 Dec doi: 10.1016/j.ijbiomac.2022.12.230
Genome-wide identification and characterization of PIN-FORMED (PIN) and PIN-LIKES (PILS) gene family reveals their role in adventitious root development in tea nodal cutting (Camellia Sinensis).
International Institute of Tea Industry Innovation for "the Belt and Road", Nanjing Agricultural University, Nanjing 210095, Jiangsu, PR China.; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, PR China.; Department of Biotechnology, Karpagam Academy of Higher Education, Coimbatore 21, Tamilnadu, India.; International Institute of Tea Industry Innovation for "the Belt and Road", Nanjing Agricultural University, Nanjing 210095, Jiangsu, PR China. Electronic address: lxh@njau.edu.cn.
Auxin affects all aspects of plant growth and development, including morphogenesis and adaptive responses. Auxin transmembrane transport is promoted by PIN formation (PIN) and a structurally similar PIN-like (PILS) gene family, which jointly controls the directional transport of the auxin between plant cells, and the accumulation of intracellular auxin. At present, there is no study investigating the roles of CslPIN and CslPILS gene family in root development in the tea plant (Camellia sinensis). In this study, 8 CslPIN and 10 CslPILS genes were identified in the tea plant, and their evolutionary relationships, physical and chemical properties, conserved motifs, cis-acting elements, chromosome location, collinearity, and expression characteristics were analyzed. The mechanism of CslPIN and CslPILS in the formation of tea adventitious roots (ARs) was studied by the AR induction system. Through functional verification, the regulation of CslPIN3 gene on root growth and development of tea plant was studied by over-expression of CslPIN3 in Arabidopsis thaliana and in situ hybridization in Camellia sinensis. The results confirmed CslPIN3 was involved in the regulation of root growth and development as well as auxin accumulation. This study provides a better insight into the regulatory mechanism of CslPIN and CslPILS gene family on the formation of AR in tea plant.
PMID: 36572081
Int J Biol Macromol , IF:6.953 , 2022 Dec , V227 : P285-296 doi: 10.1016/j.ijbiomac.2022.12.175
Genome-wide evolutionary analysis of AUX/IAA gene family in wheat identifies a novel gene TaIAA15-1A regulating flowering time by interacting with ARF.
College of Agronomy, Liaocheng University, Liaocheng 252059, PR China. Electronic address: pssu2014@163.com.; College of Agronomy, Liaocheng University, Liaocheng 252059, PR China.; Lianyungang Academy of Agricultural Sciences, Lianyungang 222000, PR China.; Key Laboratory of Huang-Huai-Hai Smart Agricultural Technology of the Ministry of Agriculture and Rural Affairs, College of Information Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China. Electronic address: xinsinian2006@163.com.; College of Agronomy, Liaocheng University, Liaocheng 252059, PR China. Electronic address: guoshangjing@lcu.edu.cn.
Flowering time is a critical agronomic trait that has strong effects on crop yields. Auxin signaling pathway plays an important role in various development processes, such as flowering, grain development. However, no Aux/IAA gene had been reported to have functions involving in wheat flowering time. Here, we systematically performed genome-wide identification, classification, domain distribution, exon-intron structure, chromosome locations and global expression pattern of Aux/IAA gene family in 14 plant genomes (including Triticum aestivum). A phylogenetic model was proposed to infer the Aux/IAA evolutionary history involving in a central exon-intron structure "2121" during evolution. Overexpression of TaIAA15-1A caused an early flowering time in Brachypodium. RNA-seq analysis showed that TaIAA15-1A overexpression alters various pathways including phytohormone signaling pathway, flowering-related pathway, and polyamine biosynthesis pathway. Screening of auxin response factor (ARF) genes identified BdARF16 that interacted with TaIAA15-1A. Exogenous polyamine (spermidine and spermine) treatments promoted early flowering and (putrescine and DCHA) delayed flowering time of WT plants. Our finding will provide insights on mechanisms of Aux/IAAs gene family and TaIAA15-1A, illustrating the potential during crop improvement programs.
PMID: 36549029
Int J Biol Macromol , IF:6.953 , 2022 Nov , V220 : P67-78 doi: 10.1016/j.ijbiomac.2022.08.065
PIN and PILS family genes analyses in Chrysanthemum seticuspe reveal their potential functions in flower bud development and drought stress.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Flower Biology and Germplasm Innovation, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, Nanjing Agricultural University, Nanjing 210095, China; College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Flower Biology and Germplasm Innovation, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, Nanjing Agricultural University, Nanjing 210095, China; College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: chensm@njau.edu.cn.
Auxin affects almost all plant growth and developmental processes. The PIN-FORMED (PIN) and PIN-LIKES (PILS) family genes determine the direction and distribution gradient of auxin flow by polar localization on the cell membrane. However, there are no systematic studies on PIN and PILS family genes in chrysanthemum. Here, 18 PIN and 13 PILS genes were identified in Chrysanthemum seticuspe. The evolutionary relationships, physicochemical properties, conserved motifs, cis-acting elements, chromosome localization, collinearity, and expression characteristics of these genes were analyzed. CsPIN10a, CsPIN10b, and CsPIN10c are unique PIN genes in C. seticuspe. Expression pattern analysis showed that these genes had different tissue specificities, and the expression levels of CsPIN8, CsPINS1, CsPILS6, and CsPILS10 were linearly related to the developmental period of the flower buds. In situ hybridization assay showed that CsPIN1a, CsPIN1b, and CsPILS8 were expressed in floret primordia and petal tips, and CsPIN1a was specifically expressed in the middle of the bract primordia, which might regulate lateral expansion of the bracts. CsPIN and CsPILS family genes are also involved in drought stress responses. This study provides theoretical support for the cultivation of new varieties with attractive flower forms and high drought tolerance.
PMID: 35970365
Development , IF:6.868 , 2022 Dec , V149 (24) doi: 10.1242/dev.200370
Surface-localized glycoproteins act through class C ARFs to fine-tune gametophore initiation in Physcomitrium patens.
Institute of Plant and Microbial Biology, Academia Sinica, 128 Sec.2, Academia Rd., Nankang, Taipei 11529, Taiwan.; Department of Biological Sciences, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan.; Graduate School of Life Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan.; Division of Life Science, Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan.
Arabinogalactan proteins are functionally diverse cell wall structural glycoproteins that have been implicated in cell wall remodeling, although the mechanistic actions remain elusive. Here, we identify and characterize two AGP glycoproteins, SLEEPING BEAUTY (SB) and SB-like (SBL), that negatively regulate the gametophore bud initiation in Physcomitrium patens by dampening cell wall loosening/softening. Disruption of SB and SBL led to accelerated gametophore formation and altered cell wall compositions. The function of SB is glycosylation dependent and genetically connected with the class C auxin response factor (ARF) transcription factors PpARFC1B and PpARFC2. Transcriptomics profiling showed that SB upregulates PpARFC2, which in turn suppresses a range of cell wall-modifying genes that are required for cell wall loosening/softening. We further show that PpARFC2 binds directly to multiple AuxRE motifs on the cis-regulatory sequences of PECTIN METHYLESTERASE to suppress its expression. Hence, our results demonstrate a mechanism by which the SB modulates the strength of intracellular auxin signaling output, which is necessary to fine-tune the timing of gametophore initials formation.
PMID: 36520083
Development , IF:6.868 , 2022 Dec , V149 (23) doi: 10.1242/dev.199773
Position of meristems and the angles of the cell division plane regulate the uniqueness of lateral organ shape.
Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.; Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan.; Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
Leaf meristem is a cell proliferative zone present in the lateral organ primordia. In this study, we examined how cell proliferative zones in primordia of planar floral organs and polar auxin transport inhibitor (PATI)-treated leaf organs differ from those of non-treated foliage leaves of Arabidopsis thaliana, with a focus on the accumulation pattern of ANGUSTIFOLIA3 (AN3) protein, a key element for leaf meristem positioning. We found that PATI-induced leaf shape changes were correlated with cell division angle but not with meristem positioning/size or AN3 localisation. In contrast, different shapes between sepals and petals compared with foliage leaves were associated with both altered meristem position, due to altered AN3 expression patterns, and different distributions of cell division angles. A numerical simulation showed that meristem position majorly affected the final shape but biased cell division angles had a minor effect. Taken together, these results suggest that the unique shapes of different lateral organs depend on the position of the meristem in the case of floral organs and cell division angles in the case of leaf organs with different auxin flow.
PMID: 36373561
Development , IF:6.868 , 2022 Nov , V149 (22) doi: 10.1242/dev.200927
Complementary roles for auxin and auxin signalling revealed by reverse engineering lateral root stable prebranch site formation.
Computational Developmental Biology Group, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands.
Priming is the process through which periodic elevations in auxin signalling prepattern future sites for lateral root formation, called prebranch sites. Thus far, the extent to which elevations in auxin concentration and/or auxin signalling are required for priming and prebranch site formation has remained a matter of debate. Recently, we discovered a reflux-and-growth mechanism for priming generating periodic elevations in auxin concentration that subsequently dissipate. Here, we reverse engineer a mechanism for prebranch site formation that translates these transient elevations into a persistent increase in auxin signalling, resolving the prior debate into a two-step process of auxin concentration-mediated initial signal and auxin signalling capacity-mediated memorization. A crucial aspect of the prebranch site formation mechanism is its activation in response to time-integrated rather than instantaneous auxin signalling. The proposed mechanism is demonstrated to be consistent with prebranch site auxin signalling dynamics, lateral inhibition, and symmetry-breaking mechanisms and perturbations in auxin homeostasis.
PMID: 36314783
Development , IF:6.868 , 2022 Nov , V149 (21) doi: 10.1242/dev.200899
A mutation in THREONINE SYNTHASE 1 uncouples proliferation and transition domains of the root apical meristem: experimental evidence and in silico proposed mechanism.
Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico (UNAM), Av. Universidad, 2001, Cuernavaca 62250, Mexico.; Facultad de Ciencias de la Salud, Universidad Tecnologica de Mexico - UNITEC MEXICO - Campus Atizapan, Av. Calacoaya 7, Atizapan de Zaragoza, Estado de Mexico, 52970, Mexico.
A continuum from stem to transit-amplifying to a differentiated cell state is a common theme in multicellular organisms. In the plant root apical meristem (RAM), transit-amplifying cells are organized into two domains: cells from the proliferation domain (PD) are displaced to the transition domain (TD), suggesting that both domains are necessarily coupled. Here, we show that in the Arabidopsis thaliana mto2-2 mutant, in which threonine (Thr) synthesis is affected, the RAM lacks the PD. Through a combination of cell length profile analysis, mathematical modeling and molecular markers, we establish that the PD and TD can be uncoupled. Remarkably, although the RAM of mto2-2 is represented solely by the TD, the known factors of RAM maintenance and auxin signaling are expressed in the mutant. Mathematical modeling predicts that the stem cell niche depends on Thr metabolism and that, when disturbed, the normal continuum of cell states becomes aborted.
PMID: 36278862
Plant J , IF:6.417 , 2022 Nov doi: 10.1111/tpj.16042
A genome-wide association study identifies novel players in Na and Fe homeostasis in Arabidopsis thaliana under alkaline-salinity stress.
Plant Physiology Laboratory, Bioscience Faculty, Universitat Autonoma de Barcelona, C/de la Vall Moronta s/n, E-08193, Bellaterra, Spain.; Department of Botany and Plant Biology, University of Geneva, 1211, Geneva, Switzerland.; Laboratory of Genetics, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
In nature, multiple stress factors occur simultaneously. The screening of natural diversity panels and subsequent Genome-Wide Association Studies (GWAS) is a powerful approach to identify genetic components of various stress responses. Here, the nutritional status variation of a set of 270 natural accessions of Arabidopsis thaliana grown on a natural saline-carbonated soil is evaluated. We report significant natural variation on leaf Na (LNa) and Fe (LFe) concentrations in the studied accessions. Allelic variation in the NINJA and YUC8 genes is associated with LNa diversity, and variation in the ALA3 is associated with LFe diversity. The allelic variation detected in these three genes leads to changes in their mRNA expression and correlates with plant differential growth performance when plants are exposed to alkaline salinity treatment under hydroponic conditions. We propose that YUC8 and NINJA expression patters regulate auxin and jasmonic signaling pathways affecting plant tolerance to alkaline salinity. Finally, we describe an impairment in growth and leaf Fe acquisition associated with differences in root expression of ALA3, encoding a phospholipid translocase active in plasma membrane and the trans Golgi network which directly interacts with proteins essential for the trafficking of PIN auxin transporters, reinforcing the role of phytohormonal processes in regulating ion homeostasis under alkaline salinity.
PMID: 36433704
Plant J , IF:6.417 , 2022 Nov doi: 10.1111/tpj.16039
RAV1 mediates cytokinin signaling for regulating primary root growth in Arabidopsis.
Department of Biotechnology, St Xavier's College, 30, Mother Teresa Sarani, Kolkata, 700016, India.; Department of Mechanical Engineering, Indian Institute of Technology, Surjyamukhi Road, Amingaon, Guwahati, Assam, 781039, India.
Root growth dynamics is an outcome of complex hormonal crosstalk. The primary root meristem size, for example, is determined by antagonizing actions of cytokinin and auxin. Here we show that RAV1, a member of the AP2/ERF family of transcription factors, mediates cytokinin signaling in roots to regulate meristem size. The rav1 mutants have prominently longer primary roots, with a meristem that is significantly enlarged and contains higher cell numbers, compared with wild-type. The mutant phenotype could be restored on exogenous cytokinin application or by inhibiting auxin transport. At the transcript level, primary cytokinin-responsive genes like ARR1, ARR12 were significantly downregulated in the mutant root, indicating impaired cytokinin signaling. In concurrence, cytokinin induced regulation of SHY2, an Aux/IAA gene, and auxin efflux carrier PIN1 was hindered in rav1, leading to altered auxin transport and distribution. This effectively altered root meristem size in the mutant. Notably, CRF1, another member of the AP2/ERF family implicated in cytokinin signaling, is transcriptionally repressed by RAV1 to promote cytokinin response in roots. Further associating RAV1 with cytokinin signaling, our results demonstrate that cytokinin upregulates RAV1 expression through ARR1, during post-embryonic root development. Regulation of RAV1 expression is a part of secondary cytokinin response that eventually represses CRF1 to augment cytokinin signaling. To conclude, RAV1 functions in a branch pathway downstream to ARR1 that regulates CRF1 expression to enhance cytokinin action during primary root development in Arabidopsis.
PMID: 36423224
Plant J , IF:6.417 , 2022 Nov doi: 10.1111/tpj.16036
CRISPR/Cas9 genome-editing applied to MdPGT1 in apple results in reduced foliar phloridzin without impacting plant growth.
Research and Innovation Centre, Edmund Mach Foundation, Via Edmund Mach 1, San Michele all'Adige, 38098, Italy.; C3A Center Agriculture Food Environment, University of Trento, Via Edmund Mach 1, San Michele all'Adige, 38098, Italy.; The New Zealand Institute for Plant and Food Research Limited, 120 Mt Albert Road, Auckland, 1025, New Zealand.; Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Hans-Knoll-Strasse 8, Jena, 07745, Germany.; Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences and Palacky University, Slechtitelu 19, Olomouc, CZ-783 71, Czech Republic.
Phloridzin is the most abundant polyphenolic compound in apple (Malus x domestica Borkh.), which results from the action of a key phloretin-specific UDP-2'-O-glucosyltransferase (MdPGT1). Here, we simultaneously assessed the effects of targeting MdPGT1 by conventional transgenesis and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome editing. To this end, we conducted transcriptomic and metabolic analyses of MdPGT1 RNA interference knockdown and genome-edited lines. Knockdown lines exhibited characteristic impairment of plant growth and leaf morphology, whereas genome-edited lines exhibited normal growth despite reduced foliar phloridzin. RNA-sequencing analysis identified a common core of regulated genes, involved in phenylpropanoid and flavonoid pathways. However, we identified genes and processes differentially modulated in stunted and genome-edited lines, including key transcription factors and genes involved in phytohormone signalling. Therefore, we conducted a phytohormone profiling to obtain insight into their role in the phenotypes observed. We found that salicylic and jasmonic acid were increased in dwarf lines, whereas auxin and ABA showed no correlation with the growth phenotype. Furthermore, bioactive brassinosteroids were commonly up-regulated, whereas gibberellin GA(4) was distinctively altered, showing a sharp decrease in RNA interference knockdown lines. Expression analysis by reverse transcriptase-quantitative polymerase chain reaction expression analysis further confirmed transcriptional regulation of key factors involved in brassinosteroid and gibberellin interaction. These findings suggest that a differential modulation of phytohormones may be involved in the contrasting effects on growth following phloridzin reduction. The present study also illustrates how CRISPR/Cas9 genome editing can be applied to dissect the contribution of genes involved in phloridzin biosynthesis in apple.
PMID: 36401738
Plant J , IF:6.417 , 2022 Dec , V112 (6) : P1462-1472 doi: 10.1111/tpj.16027
Arabidopsis cyclin-dependent kinase C2 interacts with HDA15 and is involved in far-red light-mediated hypocotyl cell elongation.
Institute of Plant Biology, National Taiwan University, Taipei, 10617, Taiwan.
Histone deacetylases (HDAs) regulate many aspects of plant development and responses to environmental changes. Previous studies have demonstrated that the Arabidopsis histone deacetylase HDA15 is a positive regulator in far-red (FR) light-mediated inhibition of hypocotyl elongation. Furthermore, HDA15 can be phosphorylated and its enzymatic activity is negatively regulated by phosphorylation. However, the kinases that can phosphorylate HDA15 are still unknown. Cyclin-dependent kinases (CDKs) are a large family of serine/threonine protein kinases and have been identified as major regulators of the cell cycle and transcription. In this study, we show that the cyclin-dependent kinase CDKC2 interacts with HDA15 both in vitro and in vivo. In vitro kinase assays show that CDKC2 phosphorylates HDA15. Genetic evidence suggests that HDA15 acts downstream of CDKC2 in hypocotyl elongation under FR light. Furthermore, HDA15 and CDKC2 function synergistically in the regulation of FR-mediated cell elongation. The expression of cell wall organization- and auxin signaling-related genes under FR light is increased in hda15 and cdkc2/hda15 mutants. Taken together, our study indicates that CDKC2 can phosphorylate HDA15 and plays an important role in FR light-regulated hypocotyl elongation.
PMID: 36367383
Plant J , IF:6.417 , 2022 Nov doi: 10.1111/tpj.16024
Endogenous auxin maintains embryonic cell identity and promotes somatic embryo development in Arabidopsis.
Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.; Bioscience, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
Somatic embryogenesis (SE), or embryo development from in vitro cultured vegetative explants, can be induced in Arabidopsis by the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) or by overexpression of specific transcription factors, such as AT-HOOK MOTIF NUCLEAR LOCALIZED 15 (AHL15). Here, we explored the role of endogenous auxin [indole-3-acetic acid (IAA)] during 2,4-D and AHL15-induced SE. Using the pWOX2:NLS-YFP reporter, we identified three distinct developmental stages for 2,4-D and AHL15-induced SE in Arabidopsis, with these being (i) acquisition of embryo identity; (ii) formation of pro-embryos; and (iii) somatic embryo patterning and development. The acquisition of embryo identity coincided with enhanced expression of the indole-3-pyruvic acid auxin biosynthesis YUCCA genes, resulting in an enhanced pDR5:GFP-reported auxin response in the embryo-forming tissues. Chemical inhibition of the indole-3-pyruvic acid pathway did not affect the acquisition of embryo identity, but significantly reduced or completely inhibited the formation of pro-embryos. Co-application of IAA with auxin biosynthesis inhibitors in the AHL15-induced SE system rescued differentiated somatic embryo formation, confirming that increased IAA levels are important during the last two stages of SE. Our analyses also showed that polar auxin transport, with AUXIN/LIKE-AUX influx and PIN-FORMED1 efflux carriers as important drivers, is required for the transition of embryonic cells to proembryos and, later, for correct cell fate specification and differentiation. Taken together, our results indicate that endogenous IAA biosynthesis and its polar transport are not required for the acquisition of embryo identity, but rather to maintain embryonic cell identity and for the formation of multicellular proembryos and their development into histodifferentiated embryos.
PMID: 36345646
Plant J , IF:6.417 , 2022 Dec , V112 (5) : P1127-1140 doi: 10.1111/tpj.15993
Auxin triggers pectin modification during rootlet emergence in white lupin.
IPSiM, Univ Montpellier, CNRS, INRAE, Supagro, 34060, Montpellier, France.; Umea Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83, Umea, Sweden.; UMR INRAE 1158 BioEcoAgro, BIOPI Biologie des Plantes et Innovation, SFR Condorcet FR CNRS 3417, Universite de Picardie, 80039, Amiens, France.
Emergence of secondary roots through parental tissue is a highly controlled developmental process. Although the model plant Arabidopsis has been useful to uncover the predominant role of auxin in this process, its simple root structure is not representative of how emergence takes place in most plants, which display more complex root anatomy. White lupin is a legume crop producing structures called cluster roots, where closely spaced rootlets emerge synchronously. Rootlet primordia push their way through several cortical cell layers while maintaining the parent root integrity, reflecting more generally the lateral root emergence process in most multilayered species. In this study, we showed that lupin rootlet emergence is associated with an upregulation of cell wall pectin modifying and degrading genes under the active control of auxin. Among them, we identified LaPG3, a polygalacturonase gene typically expressed in cells surrounding the rootlet primordium and we showed that its downregulation delays emergence. Immunolabeling of pectin epitopes and their quantification uncovered a gradual pectin demethylesterification in the emergence zone, which was further enhanced by auxin treatment, revealing a direct hormonal control of cell wall properties. We also report rhamnogalacturonan-I modifications affecting cortical cells that undergo separation as a consequence of primordium outgrowth. In conclusion, we describe a model of how external tissues in front of rootlet primordia display cell wall modifications to allow for the passage of newly formed rootlets.
PMID: 36178138
Plant J , IF:6.417 , 2022 Nov , V112 (3) : P860-874 doi: 10.1111/tpj.15987
The Germin-like protein OsGER4 is involved in promoting crown root development under exogenous jasmonic acid treatment in rice.
University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, 100000, Vietnam.; School of Applied Mathematics and Informatics, University of Science and Technology of Hanoi, 1 Dai Co Viet, Hai Ba Trung, Hanoi, Vietnam.; Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, 100000, Vietnam.; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, 100000, Vietnam.
In rice (Oryza sativa L.), crown roots (CRs) have many important roles in processes such as root system expansion, water and mineral uptake, and adaptation to environmental stresses. Phytohormones such as auxin, cytokinin, and ethylene are known to control CR initiation and development in rice. However, the role of jasmonic acid (JA) in CR development remained elusive. Here, we report that JA promotes CR development by regulating OsGER4, a rice Germin-like protein. Root phenotyping analysis revealed that exogenous JA treatment induced an increase in CR number in a concentration-dependent manner. A subsequent genome-wide association study and gene expression analyses pinpointed a strong association between the Germin-like protein OsGER4 and the increase in CR number under exogenous JA treatment. The ProGER4::GUS reporter line showed that OsGER4 is a hormone-responsive gene involved in various stress responses, mainly confined to epidermal and vascular tissues during CR primordia development and to vascular bundles of mature crown and lateral roots. Notable changes in OsGER4 expression patterns caused by the polar auxin transport inhibitor NPA support its connection to auxin signaling. Phenotyping experiments with OsGER4 knockout mutants confirmed that this gene is required for CR development under exogenous JA treatment. Overall, our results provide important insights into JA-mediated regulation of CR development in rice.
PMID: 36134434
Plant J , IF:6.417 , 2022 Nov , V112 (3) : P812-829 doi: 10.1111/tpj.15983
Multi-omics provides new insights into the domestication and improvement of dark jute (Corchorus olitorius).
Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205, China.; Novogene Bioinformatics Institute, Beijing, 100015, China.; Department of Ecology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, 430072, China.; Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 637616, Singapore.; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
Jute (Corchorus sp.) is the most important bast fiber crop worldwide; however, the mechanisms underlying domestication and improvement remain largely unknown. We performed multi-omics analysis by integrating de novo sequencing, resequencing, and transcriptomic and epigenetic sequencing to clarify the domestication and improvement of dark jute Corchorus olitorius. We demonstrated that dark jute underwent early domestication and a relatively moderate genetic bottleneck during improvement breeding. A genome-wide association study of 11 important agronomic traits identified abundant candidate loci. We characterized the selective sweeps in the two breeding stages of jute, prominently, soil salinity differences played an important role in environmental adaptation during domestication, and the strongly selected genes for improvement had an increased frequency of favorable haplotypes. Furthermore, we speculated that an encoding auxin/indole-3-acetic acid protein COS07g_00652 could enhance the flexibility and strength of the stem to improve fiber yield. Our study not only provides valuable genetic resources for future fiber breeding in jute, but also is of great significance for reviewing the genetic basis of early crop breeding.
PMID: 36129373
Plant J , IF:6.417 , 2022 Nov , V112 (3) : P772-785 doi: 10.1111/tpj.15979
N-terminal domain of ARF-GEF GNOM prevents heterodimerization with functionally divergent GNL1 in Arabidopsis.
Center for Plant Molecular Biology (ZMBP), Developmental Genetics, University of Tubingen, Auf der Morgenstelle 32, 72076, Tubingen, Germany.
Evolutionary change following gene duplication can lead to functionally divergent paralogous proteins. If comprising identical subunits their random assortment would also form potentially detrimental heteromeric proteins. In Arabidopsis, the ARF GTPase guanine-nucleotide exchange factor GNOM is essential for polar recycling of auxin-efflux transporter PIN1 from endosomes to the basal plasma membrane whereas its paralog GNL1 mediates retrograde Golgi-endoplasmic reticulum traffic. Here we show that both GNOM and GNL1 form homodimers but no heterodimers. To assess the biological significance of this, we generated transgenic plants expressing engineered heterodimer-compatible GNOM variants. Those plants showed developmental defects such as the failure to produce lateral roots. To identify mechanisms underlying heterodimer prevention, we analyzed interactions of the N-terminal dimerization and cyclophilin-binding (DCB) domain. Each DCB domain interacted with the complementary fragment (DeltaDCB) both of their own and of the paralogous protein. However, only DCB(GNOM) interacted with itself whereas DCB(GNL1) failed to interact with itself and with DCB(GNOM) . GNOM variants in which the DCB domain was removed or replaced by DCB(GNL1) revealed a role for DCB-DCB interaction in the prevention of GNOM-GNL1 heterodimers whereas DCB-DeltaDCB interaction was essential for dimer formation and GNOM function. Our data suggest a model of early DCB-DCB interaction that facilitates GNOM homodimer formation, indirectly precluding formation of detrimental heterodimers.
PMID: 36106415
Commun Biol , IF:6.268 , 2022 Dec , V5 (1) : P1410 doi: 10.1038/s42003-022-04313-9
Significance of NatB-mediated N-terminal acetylation of auxin biosynthetic enzymes in maintaining auxin homeostasis in Arabidopsis thaliana.
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.; Gansu Province Key Laboratory of Gene Editing for Breeding, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.; Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.; Basic Forestry and Proteomics Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China. leiwu@lzu.edu.cn.; Gansu Province Key Laboratory of Gene Editing for Breeding, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China. leiwu@lzu.edu.cn.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China. gqguo@lzu.edu.cn.; Gansu Province Key Laboratory of Gene Editing for Breeding, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China. gqguo@lzu.edu.cn.
The auxin IAA (Indole-3-acetic acid) plays key roles in regulating plant growth and development, which depends on an intricate homeostasis that is determined by the balance between its biosynthesis, metabolism and transport. YUC flavin monooxygenases catalyze the rate-limiting step of auxin biosynthesis via IPyA (indole pyruvic acid) and are critical targets in regulating auxin homeostasis. Despite of numerous reports on the transcriptional regulation of YUC genes, little is known about those at the post-translational protein level. Here, we show that loss of function of CKRC3/TCU2, the auxiliary subunit (Naa25) of Arabidopsis NatB, and/or of its catalytic subunit (Naa20), NBC, led to auxin-deficiency in plants. Experimental evidences show that CKRC3/TCU2 can interact with NBC to form a NatB complex, catalyzing the N-terminal acetylation (NTA) of YUC proteins for their intracellular stability to maintain normal auxin homeostasis in plants. Hence, our findings provide significantly new insight into the link between protein NTA and auxin biosynthesis in plants.
PMID: 36550195
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232416146
Comparative Analysis of Physiological, Hormonal and Transcriptomic Responses Reveal Mechanisms of Saline-Alkali Tolerance in Autotetraploid Rice (Oryza sativa L.).
Faculty of Agronomy, Jilin Agricultural University, Changchun 130118, China.
Saline-alkali soil has posed challenges to the growth of agricultural crops, while polyploidy often show greater adaptability in diverse and extreme environments including saline-alkali stress, but its defense mechanisms in rice remain elusive. Herein, we explored the mechanisms of enhanced saline-alkali tolerance of autotetraploid rice 93-11T relative to diploid rice 93-11D, based on physiological, hormonal and transcriptomic profilings. Physiologically, the enhanced saline-alkali tolerance in 93-11T was manifested in higher soluble sugar accumulation and stronger superoxide dismutase (SOD) and peroxidase (POD) activities in leaves during 24 h after saline-alkali shock. Furthermore, various hormone levels in leaves of 93-11T altered greatly, such as the negative correlation between salicylic acid (SA) and the other four hormones changed to positive correlation due to polyploidy. Global transcriptome profiling revealed that the upregulated differentially expressed genes (DEGs) in leaves and roots of 93-11T were more abundant than that in 93-11D, and there were more DEGs in roots than in leaves under saline-alkali stress. Genes related to phytohormone signal transduction of auxin (AUX) and SA in roots, lignin biosynthesis in leaves or roots, and wax biosynthesis in leaves were obviously upregulated in 93-11T compared with 93-11D under saline-alkali condition. Collectively, 93-11T subjected to saline-alkali stress possibly possesses higher osmotic regulation ability due to cuticular wax synthesis, stronger negative regulation of reactive oxygen species (ROS) production by increasing the SA levels and maintaining relative lower levels of IAA, and higher antioxidant capacity by increasing activities of SOD and POD, as well as lignin biosynthesis. Our research provides new insights for exploring the mechanisms of saline-alkali tolerance in polyploid rice and discovering new gene targets for rice genetic improvement.
PMID: 36555786
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232416112
Identification of Transcriptional Networks Involved in De Novo Organ Formation in Tomato Hypocotyl Explants.
Instituto de Bioingenieria, Universidad Miguel Hernandez, 03202 Elche, Spain.
Some of the hormone crosstalk and transcription factors (TFs) involved in wound-induced organ regeneration have been extensively studied in the model plant Arabidopsis thaliana. In previous work, we established Solanum lycopersicum "Micro-Tom" explants without the addition of exogenous hormones as a model to investigate wound-induced de novo organ formation. The current working model indicates that cell reprogramming and founder cell activation requires spatial and temporal regulation of auxin-to-cytokinin (CK) gradients in the apical and basal regions of the hypocotyl combined with extensive metabolic reprogramming of some cells in the apical region. In this work, we extended our transcriptomic analysis to identify some of the gene regulatory networks involved in wound-induced organ regeneration in tomato. Our results highlight a functional conservation of key TF modules whose function is conserved during de novo organ formation in plants, which will serve as a valuable resource for future studies.
PMID: 36555756
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232415950
Induction of Somatic Embryogenesis in Plants: Different Players and Focus on WUSCHEL and WUS-RELATED HOMEOBOX (WOX) Transcription Factors.
Department of Agriculture Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
In plants, other cells can express totipotency in addition to the zygote, thus resulting in embryo differentiation; this appears evident in apomictic and epiphyllous plants. According to Haberlandt's theory, all plant cells can regenerate a complete plant if the nucleus and the membrane system are intact. In fact, under in vitro conditions, ectopic embryos and adventitious shoots can develop from many organs of the mature plant body. We are beginning to understand how determination processes are regulated and how cell specialization occurs. However, we still need to unravel the mechanisms whereby a cell interprets its position, decides its fate, and communicates it to others. The induction of somatic embryogenesis might be based on a plant growth regulator signal (auxin) to determine an appropriate cellular environment and other factors, including stress and ectopic expression of embryo or meristem identity transcription factors (TFs). Still, we are far from having a complete view of the regulatory genes, their target genes, and their action hierarchy. As in animals, epigenetic reprogramming also plays an essential role in re-establishing the competence of differentiated cells to undergo somatic embryogenesis. Herein, we describe the functions of WUSCHEL-RELATED HOMEOBOX (WOX) transcription factors in regulating the differentiation-dedifferentiation cell process and in the developmental phase of in vitro regenerated adventitious structures.
PMID: 36555594
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232415918
Genome-Wide Identification of Wheat KNOX Gene Family and Functional Characterization of TaKNOX14-D in Plants.
College of Agronomy, Northwest A&F University, Xianyang 712100, China.
The KNOX genes play important roles in maintaining SAM and regulating the development of plant leaves. However, the TaKNOX genes in wheat are still not well understood, especially their role in abiotic stress. In this study, a total of 36 KNOX genes were identified, and we demonstrated the function of the TaKNOX14-D gene under mechanical injury and cold stress. Thirty-six TaKNOX genes were divided into two groups, and thirty-four TaKNOX genes were predicted to be located in the nucleus by Cell-PLoc. These genes contained five tandem duplications. Fifteen collinear gene pairs were exhibited in wheat and rice, one collinear gene pair was exhibited in wheat and Arabidopsis. The phylogenetic tree and motif analysis suggested that the TaKNOX gene appeared before C3 and C4 diverged. Gene structure showed that the numbers of exons and introns in TaKNOX gene are different. Wheat TaKNOX genes showed different expression patterns during the wheat growth phase, with seven TaKNOX genes being highly expressed in the whole growth period. These seven genes were also highly expressed in most tissues, and also responded to most abiotic stress. Eleven TaKNOX genes were up-regulated in the tillering node during the leaf regeneration period after mechanical damage. When treating the wheat with different hormones, the expression patterns of TaKNOX were changed, and results showed that ABA promoted TaKNOX expression and seven TaKNOX genes were up-regulated under cytokinin and auxin treatment. Overexpression of the TaKNOX14-D gene in Arabidopsis could increase the leaf size, plant height and seed size. This gene overexpression in Arabidopsis also increased the compensatory growth capacity after mechanical damage. Overexpression lines also showed high resistance to cold stress. This study provides a better understanding of the TaKNOX genes.
PMID: 36555558
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232415729
Genome-Wide Identification and Expression Analysis of the Aux/IAA Gene Family of the Drumstick Tree (Moringa oleifera Lam.) Reveals Regulatory Effects on Shoot Regeneration.
College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, Guangzhou 510642, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources South China Agricultural University, Guangzhou 510642, China.; Guangdong Province Research Center of Woody Forage Engineering Technology, Guangzhou 510642, China.
Auxin plays a critical role in organogenesis in plants. The classical auxin signaling pathway holds that auxin initiates downstream signal transduction by degrading Aux/IAA transcription repressors that interact with ARF transcription factors. In this study, 23 MoIAA genes were identified in the drumstick tree genome. All MoIAA genes were located within five subfamilies based on phylogenetic evolution analysis; the gene characteristics and promoter cis-elements were also analyzed. The protein interaction network between the MoIAAs with MoARFs was complex. The MoIAA gene family responded positively to NAA treatment, exhibiting different patterns and degrees, notably for MoIAA1, MoIAA7 and MoIAA13. The three genes expressed and functioned in the nucleus; only the intact encoding protein of MoIAA13 exhibited transcriptional activation activity. The shoot regeneration capacity in the 35S::MoIAA13-OE transgenic line was considerably lower than in the wild type. These results establish a foundation for further research on MoIAA gene function and provide useful information for improved tissue culture efficiency and molecular breeding of M. oleifera.
PMID: 36555370
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232415718
Transcriptional Regulation of zma-MIR528a by Action of Nitrate and Auxin in Maize.
Departamento de Bioquimica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad de Mexcio 04510, Mexico.; Department of Plant Biology, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.; Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Av. Universidad 2001, Cuernavaca 62210, Mexico.; Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Ciudad de Mexico 04510, Mexico.
In recent years, miR528, a monocot-specific miRNA, has been assigned multifaceted roles during development and stress response in several plant species. However, the transcription regulation and the molecular mechanisms controlling MIR528 expression in maize are still poorly explored. Here we analyzed the zma-MIR528a promoter region and found conserved transcription factor binding sites related to diverse signaling pathways, including the nitrate (TGA1/4) and auxin (AuxRE) response networks. Accumulation of both pre-miR528a and mature miR528 was up-regulated by exogenous nitrate and auxin treatments during imbibition, germination, and maize seedling establishment. Functional promoter analyses demonstrated that TGA1/4 and AuxRE sites are required for transcriptional induction by both stimuli. Overall, our findings of the nitrogen- and auxin-induced zma-MIR528a expression through cis-regulatory elements in its promoter contribute to the knowledge of miR528 regulome.
PMID: 36555358
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (24) doi: 10.3390/ijms232415600
Auxin Biosynthesis Genes in Allotetraploid Oilseed Rape Are Essential for Plant Development and Response to Drought Stress.
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China.
Crucial studies have verified that IAA is mainly generated via the two-step pathway in Arabidopsis, in which tryptophan aminotransferase (TAA) and YUCCA (YUC) are the two crucial enzymes. However, the role of the TAA (or TAR) and YUC genes in allotetraploid oilseed rape underlying auxin biosynthesis and development regulation remains elusive. In the present study, all putative TAR and YUC genes were identified in B. napus genome. Most TAR and YUC genes were tissue that were specifically expressed. Most YUC and TAR proteins contained trans-membrane regions and were confirmed to be endoplasmic reticulum localizations. Enzymatic activity revealed that YUC and TAR protein members were involved in the conversion of IPA to IAA and Trp to IPA, respectively. Transgenic plants overexpressing BnaYUC6a in both Arabidopsis and B. napus displayed high auxin production and reduced plant branch angle, together with increased drought resistance. Moreover, mutation in auxin biosynthesis BnaTARs genes by CRISPR/Cas9 caused development defects. All these results suggest the convergent role of BnaYUC and BnaTAR genes in auxin biosynthesis. Different homoeologs of BnaYUC and BnaTAR may be divergent according to sequence and expression variation. Auxin biosynthesis genes in allotetraploid oilseed rape play a pivotal role in coordinating plant development processes and stress resistance.
PMID: 36555242
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (23) doi: 10.3390/ijms232315436
Arabidopsis Cys2/His2 Zinc Finger Transcription Factor ZAT18 Modulates the Plant Growth-Defense Tradeoff.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.
Plant defense responses under unfavorable conditions are often associated with reduced growth. However, the mechanisms underlying the growth-defense tradeoff remain to be fully elucidated, especially at the transcriptional level. Here, we revealed a Cys2/His2-type zinc finger transcription factor, namely, ZAT18, which played dual roles in plant immunity and growth by oppositely regulating the signaling of defense- and growth-related hormones. ZAT18 was first identified as a salicylic acid (SA)-inducible gene and was required for plant responses to SA in this study. In addition, we observed that ZAT18 enhanced the plant immunity with growth penalties that may have been achieved by activating SA signaling and repressing auxin signaling. Further transcriptome analysis of the zat18 mutant showed that the biological pathways of defense-related hormones, including SA, ethylene and abscisic acid, were repressed and that the biological pathways of auxin and cytokinin, which are growth-related hormones, were activated by abolishing the function of ZAT18. The ZAT18-mediated regulation of hormone signaling was further confirmed using qRT-PCR. Our results explored a mechanism by which plants handle defense and growth at the transcriptional level under stress conditions.
PMID: 36499767
Int J Mol Sci , IF:5.923 , 2022 Dec , V23 (23) doi: 10.3390/ijms232315246
Transcriptome Analysis Reveals the Molecular Regularity Mechanism Underlying Stem Bulblet Formation in Oriental Lily 'Siberia'; Functional Characterization of the LoLOB18 Gene.
Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.; College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
The formation of underground stem bulblets in lilies is a complex biological process which is key in their micropropagation. Generally, it involves a stem-to-bulblet transition; however, the underlying mechanism remains elusive. It is important to understand the regulatory mechanism of bulblet formation for the reproductive efficiency of Lilium. In this study, we investigated the regulatory mechanism of underground stem bulblet formation under different conditions regarding the gravity point angle of the stem, i.e., vertical (control), horizontal, and slanting. The horizontal and slanting group displayed better formation of bulblets in terms of quality and quantity compared with the control group. A transcriptome analysis revealed that sucrose and starch were key energy sources for bulblet formation, auxin and cytokinin likely promoted bulblet formation, and gibberellin inhibited bulblet formation. Based on transcriptome analysis, we identified the LoLOB18 gene, a homolog to AtLOB18, which has been proven to be related to embryogenic development. We established the stem bud growth tissue culture system of Lilium and silenced the LoLOb18 gene using the VIGS system. The results showed that the bulblet induction was reduced with down-regulation of LoLOb18, indicating the involvement of LoLOb18 in stem bulblet formation in lilies. Our research lays a solid foundation for further molecular studies on stem bulblet formation of lilies.
PMID: 36499579
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (23) doi: 10.3390/ijms232314817
IAA Plays an Important Role in Alkaline Stress Tolerance by Modulating Root Development and ROS Detoxifying Systems in Rice Plants.
State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, China.; College of Horticulture, Northwest A & F University, Xianyang 712100, China.; Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Auxin regulates plant growth and development, as well as helps plants to survive abiotic stresses, but the effects of auxin on the growth of alkaline-stressed rice and the underlying molecular and physiological mechanisms remain unknown. Through exogenous application of IAA/TIBA, this study explored the physiological and molecular mechanisms of alkaline stress tolerance enhancement using two rice genotypes. Alkaline stress was observed to damage the plant growth, while exogenous application of IAA mitigates the alkaline-stress-induce inhibition of plant growth. After application of exogenous IAA to alkaline-stressed rice, dry shoot biomass, foliar chlorophyll content, photosynthetic rate in the two rice genotypes increased by 12.6-15.6%, 11.7-40.3%, 51.4-106.6%, respectively. The adventitious root number, root surface area, total root length and dry root biomass in the two rice genotypes increased by 29.3-33.3%, 26.4-27.2%, 42.5-35.5% and 12.8-33.1%, respectively. The accumulation of H(2)O(2), MAD were significantly decreased with the application of IAA. The activities of CAT, POD, and SOD in rice plants were significantly increased by exogenous application of IAA. The expression levels of genes controlling IAA biosynthesis and transport were significantly increased, while there were no significant effects on the gene expression that controlled IAA catabolism. These results showed that exogenous application of IAA could mitigate the alkaline-stress-induced inhibition of plant growth by regulating the reactive oxygen species scavenging system, root development and expression of gene involved in IAA biosynthesis, transport and catabolism. These results provide a new direction and empirical basis for improving crop alkaline tolerance with exogenous application of IAA.
PMID: 36499144
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214288
Hormone Regulation of CCCH Zinc Finger Proteins in Plants.
College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, China.; College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.; Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.; Institute of Efficient Agricultural Carbon Neutrality in Middle-Lower Yellow River Regions, Qingdao 266109, China.
CCCH zinc finger proteins contain one to six tandem CCCH motifs composed of three cysteine and one histidine residues and have been widely found in eukaryotes. Plant CCCH proteins control a wide range of developmental and adaptive processes through DNA-protein, RNA-protein and/or protein-protein interactions. The complex networks underlying these processes regulated by plant CCCH proteins are often involved in phytohormones as signal molecules. In this review, we described the evolution of CCCH proteins from green algae to vascular plants and summarized the functions of plant CCCH proteins that are influenced by six major hormones, including abscisic acid, gibberellic acid, brassinosteroid, jasmonate, ethylene and auxin. We further compared the regulatory mechanisms of plant and animal CCCH proteins via hormone signaling. Among them, Arabidopsis AtC3H14, 15 and human hTTP, three typical CCCH proteins, are able to integrate multiple hormones to participate in various biological processes.
PMID: 36430765
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214208
Low Temperature Inhibits the Defoliation Efficiency of Thidiazuron in Cotton by Regulating Plant Hormone Synthesis and the Signaling Pathway.
Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Key Laboratory of Cotton and Rapeseed, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China.; College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
Thidiazuron (TDZ) is the main defoliant used in production to promote leaf abscission for machine-picked cotton. Under low temperatures, the defoliation rate of cotton treated with TDZ decreases and the time of defoliation is delayed, but there is little information about this mechanism. In this study, RNA-seq and physiological analysis are performed to reveal the transcriptome profiling and change in endogenous phytohormones upon TDZ treatment in abscission zones (AZs) under different temperatures (daily mean temperatures: 25 degrees C and 15 degrees C). Genes differentially expressed in AZs between TDZ treatment and control under different temperatures were subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to compare the enriched GO terms and KEGG pathways between the two temperature conditions. The results show that, compared with the corresponding control group, TDZ induces many differentially expressed genes (DEGs) in AZs, and the results of the GO and KEGG analyses show that the plant hormone signaling transduction pathway is significantly regulated by TDZ. However, under low temperature, TDZ induced less DEGs, and the enriched GO terms and KEGG pathways were different with those under normal temperature condition. Many genes in the plant hormone signal transduction pathway could not be induced by TDZ under low temperature conditions. In particular, the upregulated ethylene-signaling genes and downregulated auxin-signaling genes in AZs treated with TDZ were significantly affected by low temperatures. Furthermore, the expression of ethylene and auxin synthesis genes and their content in AZs treated with TDZ were also regulated by low temperature conditions. The upregulated cell wall hydrolase genes induced by TDZ were inhibited by low temperatures. However, the inhibition of low temperature on genes in AZs treated with TDZ was relieved with the extension of the treatment time. Together, these results indicate that the responses of ethylene and auxin synthesis and the signaling pathway to TDZ are inhibited by low temperatures, which could not induce the expression of cell wall hydrolase genes, and then inhibit the separation of AZ cells and the abscission of cotton leaves. This result provides new insights into the mechanism of defoliation induced by TDZ under low temperature conditions.
PMID: 36430686
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214103
Identification of the Karyopherin Superfamily in Maize and Its Functional Cues in Plant Development.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.; College of Agronomy, Shandong Agricultural University, Taian 271018, China.
Appropriate nucleo-cytoplasmic partitioning of proteins is a vital regulatory mechanism in phytohormone signaling and plant development. However, how this is achieved remains incompletely understood. The Karyopherin (KAP) superfamily is critical for separating the biological processes in the nucleus from those in the cytoplasm. The KAP superfamily is divided into Importin alpha (IMPalpha) and Importin beta (IMPbeta) families and includes the core components in mediating nucleocytoplasmic transport. Recent reports suggest the KAPs play crucial regulatory roles in Arabidopsis development and stress response by regulating the nucleo-cytoplasmic transport of members in hormone signaling. However, the KAP members and their associated molecular mechanisms are still poorly understood in maize. Therefore, we first identified seven IMPalpha and twenty-seven IMPbeta genes in the maize genome and described their evolution traits and the recognition rules for substrates with nuclear localization signals (NLSs) or nuclear export signals (NESs) in plants. Next, we searched for the protein interaction partners of the ZmKAPs and selected the ones with Arabidopsis orthologs functioning in auxin biosynthesis, transport, and signaling to predict their potential function. Finally, we found that several ZmKAPs share similar expression patterns with their interacting proteins, implying their function in root development. Overall, this article focuses on the Karyopherin superfamily in maize and starts with this entry point by systematically comprehending the KAP-mediated nucleo-cytoplasmic transport process in plants, and then predicts the function of the ZmKAPs during maize development, with a perspective on a closely associated regulatory mechanism between the nucleo-cytoplasmic transport and the phytohormone network.
PMID: 36430578
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214036
Identification of Differentially Expressed Genes Related to Floral Bud Differentiation and Flowering Time in Three Populations of Lycoris radiata.
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, China.; Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing 210014, China.
The transition from vegetative to reproductive growth is important for controlling the flowering of Lycoris radiata. However, the genetic control of this complex developmental process remains unclear. In this study, 18 shoot apical meristem (SAM) samples were collected from early-, mid- and late-flowering populations during floral bud differentiation. The histological analysis of paraffin sections showed that the floral bud differentiation could be divided into six stages; the differentiation time of the early group was earlier than that of the middle and late groups, and the late group was the latest. In different populations, some important differential genes affecting the flowering time were identified by transcriptome profiles of floral bud differentiation samples. Weighted gene co-expression network analysis (WGCNA) was performed to enrich the gene co-expression modules of diverse flowering time populations (FT) and floral bud differentiation stages (ST). In the MEyellow module, five core hub genes were identified, including CO14, GI, SPL8, SPL9, and SPL15. The correlation network of hub genes showed that they interact with SPLs, AP2, hormone response factors (auxin, gibberellin, ethylene, and abscisic acid), and several transcription factors (MADS-box transcription factor, bHLH, MYB, and NAC3). It suggests the important role of these genes and the complex molecular mechanism of floral bud differentiation and flowering time in L. radiata. These results can preliminarily explain the molecular mechanism of floral bud differentiation and provide new candidate genes for the flowering regulation of Lycoris.
PMID: 36430515
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214029
Transcription Factor IAA27 Positively Regulates P Uptake through Promoted Adventitious Root Development in Apple Plants.
College of Horticulture, China Agricultural University, Beijing 100193, China.; Key Laboratory of Stress Physiology and Molecular Biology for Fruit Trees in Beijing Municipality, China Agricultural University, Beijing 100193, China.
Phosphate (P) deficiency severely limits the growth and production of plants. Adventitious root development plays an essential role in responding to low phosphorus stress for apple plants. However, the molecular mechanisms regulating adventitious root growth and development in response to low phosphorus stress have remained elusive. In this study, a mutation (C-T) in the coding region of the apple AUXIN/INDOLE-3-ACETIC ACID 27 (IAA27) gene was identified. MdIAA27T-overexpressing transgenic apple improved the tolerance to phosphorus deficiency, which grew longer and denser adventitious roots and presented higher phosphorous content than the control plants under low phosphorus conditions, while the overexpression of MdIAA27C displayed the opposite trend. Moreover, the heterologous overexpression of MdIAA27 in tobacco yielded the same results, supporting the aforementioned findings. In vitro and in vivo assays showed that MdIAA27 directly interacted with AUXIN RESPONSE FACTOR (ARF8), ARF26 and ARF27, which regulated Small Auxin-Up RNA 76 (MdSAUR76) and lateral organ boundaries domain 16 (MdLBD16) transcription. The mutation in IAA27 resulted in altered interaction modes, which in turn promoted the release of positive ARFs to upregulate SAUR76 and LBD16 expression in low phosphorus conditions. Altogether, our studies provide insights into how the allelic variation of IAA27 affects adventitious root development in response to low phosphorus stress.
PMID: 36430505
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214021
Genome-Wide Identification of the SAUR Gene Family in Wax Gourd (Benincasa hispida) and Functional Characterization of BhSAUR60 during Fruit Development.
Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.; Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, China.
The wax gourd (Benincasa hispida) is an important vegetable crop whose fruits contain nutrients and metabolites. Small auxin upregulated RNA (SAUR) genes constitute the largest early auxin-responsive gene family and regulate various biological processes in plants, although this gene family has not been studied in the wax gourd. Here, we performed genome-wide identification of the SAUR gene family in wax gourds and analyzed their syntenic and phylogenetic relationships, gene structures, conserved motifs, cis-acting elements, and expression patterns. A total of 68 SAUR (BhSAUR) genes were identified, which were distributed on nine chromosomes with 41 genes in two clusters. More than half of the BhSAUR genes were derived from tandem duplication events. The BhSAUR proteins were classified into seven subfamilies. BhSAUR gene promoters contained cis-acting elements involved in plant hormone and environmental signal responses. Further expression profiles showed that BhSAUR genes displayed different expression patterns. BhSAUR60 was highly expressed in fruits, and overexpression led to longer fruits in Arabidopsis. In addition, the plants with overexpression displayed longer floral organs and wavy stems. In conclusion, our results provide a systematic analysis of the wax gourd SAUR gene family and facilitate the functional study of BhSAUR60 during wax gourd fruit development.
PMID: 36430500
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232214019
Encapsulation Reduces the Deleterious Effects of Salicylic Acid Treatments on Root Growth and Gravitropic Response.
Departamento de Biologia, Bioquimica y Ciencias Naturales, Universitat Jaume I, 12071 Castellon de la Plana, Spain.; Departamento de Ingenieria Quimica, Instituto Universitario de Tecnologia Ceramica, Universitat Jaume I, 12071 Castellon de la Plana, Spain.
The role of salicylic acid (SA) on plant responses to biotic and abiotic stresses is well documented. However, the mechanism by which exogenous SA protects plants and its interactions with other phytohormones remains elusive. SA effect, both free and encapsulated (using silica and chitosan capsules), on Arabidopsis thaliana development was studied. The effect of SA on roots and rosettes was analysed, determining plant morphological characteristics and hormone endogenous levels. Free SA treatment affected length, growth rate, gravitropic response of roots and rosette size in a dose-dependent manner. This damage was due to the increase of root endogenous SA concentration that led to a reduction in auxin levels. The encapsulation process reduced the deleterious effects of free SA on root and rosette growth and in the gravitropic response. Encapsulation allowed for a controlled release of the SA, reducing the amount of hormone available and the uptake by the plant, mitigating the deleterious effects of the free SA treatment. Although both capsules are suitable as SA carrier matrices, slightly better results were found with chitosan. Encapsulation appears as an attractive technology to deliver phytohormones when crops are cultivated under adverse conditions. Moreover, it can be a good tool to perform basic experiments on phytohormone interactions.
PMID: 36430498
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232213958
Enhanced Resistance to Sclerotinia sclerotiorum in Brassica rapa by Activating Host Immunity through Exogenous Verticillium dahliae Aspf2-like Protein (VDAL) Treatment.
Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas of Zhejiang Province, College of Horticulture Science, Zhejiang A&F University, Hangzhou 311300, China.; Department of Biotechnology, University of Houston Clear Lake, Houston, TX 77058-1098, USA.; College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China.
Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most destructive diseases in Brassica rapa. Verticillium dahliae Aspf2-like protein (VDAL) is a secretory protein of V. dahliae which has been shown to enhance the resistance against fungal infections in several plants. Nonetheless, the molecular mechanisms of VDAL-primed disease resistance are still poorly understood. In this study, we performed physiological, biochemical, and transcriptomic analyses of Brassica rapa in order to understand how VDAL confers resistance to S. sclerotiorumn infections in plants. The results showed that foliar application of VDAL significantly reduced the plaque area on leaves inoculated with S. sclerotiorum. It also enhanced antioxidant capacity by increasing activities of superoxide dismutase (SOD), peroxidase (POD), peroxidase (APX), glutathione reductase (GR), protoporphyrinogen oxidase (PPO), and defense-related enzymes beta-1,3-glucanase and chitinase during the infection periods. This occurred in parallel with significantly reduced relative conductivity at different periods and lower malondialdehyde (MDA) content as compared to sole S. sclerotiorum inoculation. Transcriptomic analysis showed a total of 146 (81 up-regulated and 65 down-regulated) differentially expressed genes (DEGs) in VDAL-treated leaves compared to the control. The most enriched three Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were the mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signal transduction, and plant-pathogen interaction, all of which were associated with plant immunity. DEGs associated with MAPK and hormone signal transduction pathways were ethylene response sensor ERS2, EIN3 (Ethylene Insensitive3)-binding F-box protein 2 (EBF2), ethylene-responsive transcription factor ERF94, MAPK 9 (MKK9), protein phosphatase 2C (PP2C37), auxin-responsive proteins (AUX/IAA1 and 19), serine/threonine-protein kinase CTR1, and abscisic acid receptors (PLY 4 and 5). Among the DEGs linked with the plant-pathogen interaction pathway were calmodulin-like proteins (CML5, 24, 27), PTI1-like tyrosine protein kinase 3 (Pti13) and transcription factor MYB30, all of which are known to play key roles in pathogen-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI) for hypersensitive response (HR), cell wall reinforcement, and stomatal closure in plants. Overall, VDLA treatment triggered repression of the auxin and ABA signaling pathways and de-repression of the ethylene signaling pathways in young B. rapa seedlings to increase plant innate immunity. Our results showed that VDAL holds great potential to enhance fungal disease resistance in B. rapa crop.
PMID: 36430439
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (22) doi: 10.3390/ijms232213721
Genome-Wide Comparison of Structural Variations and Transposon Alterations in Soybean Cultivars Induced by Spaceflight.
Hangzhou Sub-Center of National Soybean Improvement, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.; Zhejiang Key Laboratory of Digital Dry Land Crops, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Space mutation causes genetic and phenotypic changes in biological materials. Transposon activation is an adaptive mechanism for organisms to cope with changes in the external environment, such as space mutation. Although transposon alterations have been widely reported in diverse plant species, few studies have assessed the global transposon alterations in plants exposed to the space environment. In this study, for the first time, the effects of transposon alterations in soybean caused by space mutation were considered. A new vegetable soybean variety, 'Zhexian 9' (Z9), derived from space mutation treatment of 'Taiwan 75' (T75), was genetically analyzed. Comparative analyses of these two soybean genomes uncovered surprising structural differences, especially with respect to translocation breakends, deletions, and inversions. In total, 12,028 structural variations (SVs) and 29,063 transposable elements (TEs) between T75 and Z9 were detected. In addition, 1336 potential genes were variable between T75 and Z9 in terms of SVs and TEs. These differential genes were enriched in functions such as defense response, cell wall-related processes, epigenetics, auxin metabolism and transport, signal transduction, and especially methylation, which implied that regulation of epigenetic mechanisms and TE activity are important in the space environment. These results are helpful for understanding the role of TEs in response to the space environment and provide a theoretical basis for the selection of wild plant materials suitable for space breeding.
PMID: 36430198
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (21) doi: 10.3390/ijms232113576
Transcriptome Analysis Reveals a Comprehensive Virus Resistance Response Mechanism in Pecan Infected by a Novel Badnavirus Pecan Virus.
Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
Pecan leaf-variegated plant, which was infected with a novel badnavirus named pecan mosaic virus (PMV) detected by small RNA deep sequencing, is a vital model plant for studying the molecular mechanism of retaining green or chlorosis of virus-infected leaves. In this report, PMV infection in pecan leaves induced PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). PMV infection suppressed the expressions of key genes of fatty acid, oleic acid (C18:1), and very-long-chain fatty acids (VLCFA) biosynthesis, indicating that fatty acids-derived signaling was one of the important defense pathways in response to PMV infection in pecan. PMV infection in pecans enhanced the expressions of pathogenesis-related protein 1 (PR1). However, the transcripts of phenylalanine ammonia-lyase (PAL) and isochorismate synthase (ICS) were downregulated, indicating that salicylic acid (SA) biosynthesis was blocked in pecan infected with PMV. Meanwhile, disruption of auxin signaling affected the activation of the jasmonic acid (JA) pathway. Thus, C18:1 and JA signals are involved in response to PMV infection in pecan. In PMV-infected yellow leaves, damaged chloroplast structure and activation of mitogen-activated protein kinase 3 (MPK3) inhibited photosynthesis. Cytokinin and SA biosynthesis was blocked, leading to plants losing immune responses and systemic acquired resistance (SAR). The repression of photosynthesis and the induction of sink metabolism in the infected tissue led to dramatic changes in carbohydrate partitioning. On the contrary, the green leaves of PMV infection in pecan plants had whole cell tissue structure and chloroplast clustering, establishing a strong antiviral immunity system. Cytokinin biosynthesis and signaling transductions were remarkably strengthened, activating plant immune responses. Meanwhile, cytokinin accumulation in green leaves induced partial SA biosynthesis and gained comparatively higher SAR compared to that of yellow leaves. Disturbance of the ribosome biogenesis might enhance the resistance to PMV infection in pecan and lead to leaves staying green.
PMID: 36362365
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (21) doi: 10.3390/ijms232113549
Transcription Factor SmSPL2 Inhibits the Accumulation of Salvianolic Acid B and Influences Root Architecture.
Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University, Xi'an 710062, China.
The SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL) transcription factor play vital roles in plant growth and development. Although 15 SPL family genes have been recognized in the model medical plant Salvia miltiorrhiza Bunge, most of them have not been functionally characterized to date. Here, we performed a careful characterization of SmSPL2, which was expressed in almost all tissues of S. miltiorrhiza and had the highest transcriptional level in the calyx. Meanwhile, SmSPL2 has strong transcriptional activation activity and resides in the nucleus. We obtained overexpression lines of SmSPL2 and rSmSPL2 (miR156-resistant SmSPL2). Morphological changes in roots, including longer length, fewer adventitious roots, decreased lateral root density, and increased fresh weight, were observed in all of these transgenic lines. Two rSmSPL2-overexpressed lines were subjected to transcriptome analysis. Overexpression of rSmSPL2 changed root architectures by inhibiting biosynthesis and signal transduction of auxin, while triggering that of cytokinin. The salvianolic acid B (SalB) concentration was significantly decreased in rSmSPL2-overexpressed lines. Further analysis revealed that SmSPL2 binds directly to the promoters of Sm4CL9, SmTAT1, and SmPAL1 and inhibits their expression. In conclusion, SmSPL2 is a potential gene that efficiently manipulate both root architecture and SalB concentration in S. miltiorrhiza.
PMID: 36362335
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (21) doi: 10.3390/ijms232113509
Genome-Wide Analysis of Auxin Response Factors in Lettuce (Lactuca sativa L.) Reveals the Positive Roles of LsARF8a in Thermally Induced Bolting.
National Engineering Research Center for Vegetables, Key Laboratory of Urban Agriculture (North China), Institute of Vegetable Sciences, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.; Beijing Key Laboratory of New Technology in Agricultural Application, National Demonstration Center for Experimental Plant Production Education, Plant Science and Technology College, Beijing University of Agriculture, Beijing 102206, China.
Warm temperatures induce plant bolting accompanied by flower initiation, where endogenous auxin is dynamically associated with accelerated growth. Auxin signaling is primarily regulated by a family of plant-specific transcription factors, AUXIN RESPONSE FACTORS (ARFs), which either activate or repress the expression of downstream genes in response to developmental and environmental cues. However, the relationship between ARFs and bolting has not been completely understood in lettuce yet. Here, we identified 24 LsARFs (Lactuca sativa ARFs) in the lettuce genome. The phylogenetic tree indicated that LsARFs could be classified into three clusters, which was well supported by the analysis of exon-intron structure, consensus motifs, and domain compositions. RNA-Seq analysis revealed that more than half of the LsARFs were ubiquitously expressed in all tissues examined, whereas a small number of LsARFs responded to UV or cadmium stresses. qRT-PCR analysis indicated that the expression of most LsARFs could be activated by more than one phytohormone, underling their key roles as integrative hubs of different phytohormone signaling pathways. Importantly, the majority of LsARFs displayed altered expression profiles under warm temperatures, implying that their functions were tightly associated with thermally accelerated bolting in lettuce. Importantly, we demonstrated that silencing of LsARF8a, expression of which was significantly increased by elevated temperatures, resulted in delayed bolting under warm temperatures, suggesting that LsARF8a might conduce to the thermally induced bolting. Together, our results provide molecular insights into the LsARF gene family in lettuce, which will facilitate the genetic improvement of the lettuce in an era of global warming.
PMID: 36362292
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (21) doi: 10.3390/ijms232113386
Aux/IAA11 Is Required for UV-AB Tolerance and Auxin Sensing in Arabidopsis thaliana.
Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, 02-787 Warsaw, Poland.
In order to survive, plants have, over the course of their evolution, developed sophisticated acclimation and defense strategies governed by complex molecular and physiological, and cellular and extracellular, signaling pathways. They are also able to respond to various stimuli in the form of tropisms; for example, phototropism or gravitropism. All of these retrograde and anterograde signaling pathways are controlled and regulated by waves of reactive oxygen species (ROS), electrical signals, calcium, and hormones, e.g., auxins. Auxins are key phytohormones involved in the regulation of plant growth and development. Acclimation responses, which include programmed cell death induction, require precise auxin perception. However, our knowledge of these pathways is limited. The Aux/IAA family of transcriptional corepressors inhibits the growth of the plant under stress conditions, in order to maintain the balance between development and acclimation responses. In this work, we demonstrate the Aux/IAA11 involvement in auxin sensing, survival, and acclimation to UV-AB, and in carrying out photosynthesis under inhibitory conditions. The tested iaa11 mutants were more susceptible to UV-AB, photosynthetic electron transport (PET) inhibitor, and synthetic endogenous auxin. Among the tested conditions, Aux/IAA11 was not repressed by excess light stress, exclusively among its phylogenetic clade. Repression of transcription by Aux/IAA11 could be important for the inhibition of ROS formation or efficiency of ROS scavenging. We also hypothesize that the demonstrated differences in the subcellular localization of the two Aux/IAA11 protein variants might indicate their regulation by alternative splicing. Our results suggest that Aux/IAA11 plays a specific role in chloroplast retrograde signaling, since it is not repressed by high (excess) light stress, exclusively among its phylogenetic clade.
PMID: 36362171
Int J Mol Sci , IF:5.923 , 2022 Nov , V23 (21) doi: 10.3390/ijms232113301
Transcriptomic and Metabolomic Analysis of Korean Pine Cell Lines with Different Somatic Embryogenic Potential.
State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 150040, China.; State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin 150040, China.; Laboratory of Forest Genetics and Breeding, V.N. Sukachev Institute of Forest, Siberian Branch of RAS, Krasnoyarsk 660036, Russia.; Department of Cell Biology, Institute of Plant Physiology K.A. Timiryazev, Russian Academy of Sciences, Moscow 127276, Russia.; Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow 119991, Russia.
The embryogenesis capacity of conifer callus is not only highly genotype-dependent, but also gradually lost after long-term proliferation. These problems have seriously limited the commercialization of conifer somatic embryogenesis (SE) technology. In this study, the responsive SE cell line (R-EC), the blocked SE cell line (B-EC), and the loss of SE cell line (L-EC) were studied. The morphological, physiological, transcriptomic, and metabolomic profiles of these three types of cells were analyzed. We found that R-EC had higher water content, total sugar content, and putrescine (Put) content, as well as lower superoxide dismutase (SOD) activity and H(2)O(2) content compared to B-EC and L-EC. A total of 2566, 13,768, and 13,900 differentially expressed genes (DEGs) and 219, 253, and 341 differentially expressed metabolites (DEMs) were found in the comparisons of R-EC versus B-EC, R-EC versus B-EC, and B-EC versus L-EC, respectively. These DEGs and DEMs were mainly found to be involved in plant signal transduction, starch and sugar metabolism, phenylpropane metabolism, and flavonoid metabolism. We found that the AUX1 and AUX/IAA families of genes were significantly up-regulated after the long-term proliferation of callus, resulting in higher auxin content. Most phenylpropane and flavonoid metabolites, which act as antioxidants to protect cells from damage, were found to be significantly up-regulated in R-EC.
PMID: 36362088
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232113271
Genome-Wide Analysis of SAUR Gene Family Identifies a Candidate Associated with Fruit Size in Loquat (Eriobotrya japonica Lindl.).
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.; Key Laboratory of Innovation and Utilization of Horticultural Crop Resources in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.; Department of Environmental Horticulture, Gulf Coast Research and Education Center, IFAS, University of Florida, Wimauma, FL 33598, USA.; Fruit Research Institute, Fujian Academy of Agricultural Science, Fuzhou 350013, China.; College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
Fruit size is an important fruit quality trait that influences the production and commodity values of loquats (Eriobotrya japonica Lindl.). The Small Auxin Upregulated RNA (SAUR) gene family has proven to play a vital role in the fruit development of many plant species. However, it has not been comprehensively studied in a genome-wide manner in loquats, and its role in regulating fruit size remains unknown. In this study, we identified 95 EjSAUR genes in the loquat genome. Tandem duplication and segmental duplication contributed to the expansion of this gene family in loquats. Phylogenetic analysis grouped the SAURs from Arabidopsis, rice, and loquat into nine clusters. By analyzing the transcriptome profiles in different tissues and at different fruit developmental stages and comparing two sister lines with contrasting fruit sizes, as well as by functional predictions, a candidate gene (EjSAUR22) highly expressed in expanding fruits was selected for further functional investigation. A combination of Indoleacetic acid (IAA) treatment and virus-induced gene silencing revealed that EjSAUR22 was not only responsive to auxin, but also played a role in regulating cell size and fruit expansion. The findings from our study provide a solid foundation for understanding the molecular mechanisms controlling fruit size in loquats, and also provide potential targets for manipulation of fruit size to accelerate loquat breeding.
PMID: 36362065
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232113248
Investigating Grapevine Red Blotch Virus Infection in Vitis vinifera L. cv. Cabernet Sauvignon Grapes: A Multi-Omics Approach.
United States Department of Agriculture, Department of Viticulture and Enology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.; Genome Center, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.; Department of Food Science and Technology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.; Department of Viticulture & Enology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.; United States Department of Agriculture, Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
Grapevine red blotch virus (GRBV) is a recently identified virus. Previous research indicates primarily a substantial impact on berry ripening in all varieties studied. The current study analyzed grapes' primary and secondary metabolism across grapevine genotypes and seasons to reveal both conserved and variable impacts to GRBV infection. Vitis vinifera cv. Cabernet Sauvignon (CS) grapevines grafted on two different rootstocks (110R and 420A) were analyzed in 2016 and 2017. Metabolite profiling revealed a considerable impact on amino acid and malate acid levels, volatile aroma compounds derived from the lipoxygenase pathway, and anthocyanins synthesized in the phenylpropanoid pathway. Conserved transcriptional responses to GRBV showed induction of auxin-mediated pathways and photosynthesis with inhibition of transcription and translation processes mainly at harvest. There was an induction of plant-pathogen interactions at pre-veraison, for all genotypes and seasons, except for CS 110R in 2017. Lastly, differential co-expression analysis revealed a transcriptional shift from metabolic synthesis and energy metabolism to transcription and translation processes associated with a virus-induced gene silencing transcript. This plant-derived defense response transcript was only significantly upregulated at veraison for all genotypes and seasons, suggesting a phenological association with disease expression and plant immune responses.
PMID: 36362035
J Fungi (Basel) , IF:5.816 , 2022 Nov , V8 (11) doi: 10.3390/jof8111166
Clonostachys rosea Promotes Root Growth in Tomato by Secreting Auxin Produced through the Tryptamine Pathway.
College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin 150038, China.; School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand.; College of Arts and Sciences, Northeast Agricultural University, Harbin 150038, China.; College of Life Sciences, Northeast Agricultural University, Harbin 150038, China.
Clonostachys rosea (Link) Schroers is a filamentous fungus that has been widely used for biological control, biological fermentation, biodegradation and bioenergy. In this research, we investigated the impact of this fungus on root growth in tomato and the underlying mechanisms. The results showed that C. rosea can promote root growth in tomato, and tryptophan enhances its growth-promoting impacts. The results also showed that tryptophan increases the abundance of metabolites in C. rosea, with auxin (IAA) and auxin-related metabolites representing a majority of the highly abundant metabolites in the presence of tryptophan. It was noted that C. rosea could metabolize tryptophan into tryptamine (TRA) and indole-3-acetaldehyde (IAAId), and these two compounds are used by C. rosea to produce IAA through the tryptamine (TAM) pathway, which is one of the major pathways in tryptophan-dependent IAA biosynthesis. The IAA produced is used by C. rosea to promote root growth in tomato. To the best of our knowledge, this is the first report on IAA biosynthesis by C. rosea through the TAM pathway. More research is needed to understand the molecular mechanisms underlying IAA biosynthesis in C. rosea, as well as to examine the ability of this fungus to boost plant development in the field.
PMID: 36354933
Front Plant Sci , IF:5.753 , 2022 , V13 : P1049144 doi: 10.3389/fpls.2022.1049144
Alkaline stress reduces root waving by regulating PIN7 vacuolar transport.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.; Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China.; Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China.; Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schanzlestr. 1, Freiburg, Germany.
Root development and plasticity are assessed via diverse endogenous and environmental cues, including phytohormones, nutrition, and stress. In this study, we observed that roots in model plant Arabidopsis thaliana exhibited waving and oscillating phenotypes under normal conditions but lost this pattern when subjected to alkaline stress. We later showed that alkaline treatment disturbed the auxin gradient in roots and increased auxin signal in columella cells. We further demonstrated that the auxin efflux transporter PIN-FORMED 7 (PIN7) but not PIN3 was translocated to vacuole lumen under alkaline stress. This process is essential for root response to alkaline stress because the pin7 knockout mutants retained the root waving phenotype. Moreover, we provided evidence that the PIN7 vacuolar transport might not depend on the ARF-GEFs but required the proper function of an ESCRT subunit known as FYVE domain protein required for endosomal sorting 1 (FREE1). Induced silencing of FREE1 disrupted the vacuolar transport of PIN7 and reduced sensitivity to alkaline stress, further highlighting the importance of this cellular process. In conclusion, our work reveals a new role of PIN7 in regulating root morphology under alkaline stress.
PMID: 36582637
Front Plant Sci , IF:5.753 , 2022 , V13 : P1090072 doi: 10.3389/fpls.2022.1090072
Identification of genomic regions associated with soybean responses to off-target dicamba exposure.
Fisher Delta Research, Extension, and Education Center, Division of Plant Science and Technology, University of Missouri, Portageville, MO, United States.; Agronomy Department, University of Florida, Gainesville, FL, United States.; Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, United States.; Division of Plant Science and Technology, University of Missouri, Columbia, MO, United States.; Department of Crop Sciences, University of Illinois, Urbana, IL, United States.; Department of Electrical Engineering and Computer Science, Bond Life Sciences Center, University of Missouri, Columbia, MO, United States.
The widespread adoption of genetically modified (GM) dicamba-tolerant (DT) soybean was followed by numerous reports of off-target dicamba damage and yield losses across most soybean-producing states. In this study, a subset of the USDA Soybean Germplasm Collection consisting of 382 genetically diverse soybean accessions originating from 15 countries was used to identify genomic regions associated with soybean response to off-target dicamba exposure. Accessions were genotyped with the SoySNP50K BeadChip and visually screened for damage in environments with prolonged exposure to off-target dicamba. Two models were implemented to detect significant marker-trait associations: the Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK) and a model that allows the inclusion of population structure in interaction with the environment (GxE) to account for variable patterns of genotype responses in different environments. Most accessions (84%) showed a moderate response, either moderately tolerant or moderately susceptible, with approximately 8% showing tolerance and susceptibility. No differences in off-target dicamba damage were observed across maturity groups and centers of origin. Both models identified significant associations in regions of chromosomes 10 and 19. The BLINK model identified additional significant marker-trait associations on chromosomes 11, 14, and 18, while the GxE model identified another significant marker-trait association on chromosome 15. The significant SNPs identified by both models are located within candidate genes possessing annotated functions involving different phases of herbicide detoxification in plants. These results entertain the possibility of developing non-GM soybean cultivars with improved tolerance to off-target dicamba exposure and potentially other synthetic auxin herbicides. Identification of genetic sources of tolerance and genomic regions conferring higher tolerance to off-target dicamba may sustain and improve the production of other non-DT herbicide soybean production systems, including the growing niche markets of organic and conventional soybean.
PMID: 36570921
Front Plant Sci , IF:5.753 , 2022 , V13 : P1025422 doi: 10.3389/fpls.2022.1025422
Transcriptional profiling of defense responses to Botrytis cinerea infection in leaves of Fragaria vesca plants soil-drenched with beta-aminobutyric acid.
Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, As, Norway.; Department of Plant Sciences, Norwegian University of Life Sciences (NMBU), As, Norway.; Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.; Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.; Department of Genetics, Genomics and Breeding, National Institute of Agricultural Botany- East Malling Research Station, East Malling, United Kingdom.
Grey mold caused by the necrotrophic fungal pathogen Botrytis cinerea can affect leaves, flowers, and berries of strawberry, causing severe pre- and postharvest damage. The defense elicitor beta-aminobutyric acid (BABA) is reported to induce resistance against B. cinerea and many other pathogens in several crop plants. Surprisingly, BABA soil drench of woodland strawberry (Fragaria vesca) plants two days before B. cinerea inoculation caused increased infection in leaf tissues, suggesting that BABA induce systemic susceptibility in F. vesca. To understand the molecular mechanisms involved in B. cinerea susceptibility in leaves of F. vesca plants soil drenched with BABA, we used RNA sequencing to characterize the transcriptional reprogramming 24 h post-inoculation. The number of differentially expressed genes (DEGs) in infected vs. uninfected leaf tissue in BABA-treated plants was 5205 (2237 upregulated and 2968 downregulated). Upregulated genes were involved in pathogen recognition, defense response signaling, and biosynthesis of secondary metabolites (terpenoid and phenylpropanoid pathways), while downregulated genes were involved in photosynthesis and response to auxin. In control plants not treated with BABA, we found a total of 5300 DEGs (2461 upregulated and 2839 downregulated) after infection. Most of these corresponded to those in infected leaves of BABA-treated plants but a small subset of DEGs, including genes involved in 'response to biologic stimulus', 'photosynthesis' and 'chlorophyll biosynthesis and metabolism', differed significantly between treatments and could play a role in the induced susceptibility of BABA-treated plants.
PMID: 36570914
Front Plant Sci , IF:5.753 , 2022 , V13 : P1049681 doi: 10.3389/fpls.2022.1049681
Proteome-wide analysis of hydrogen peroxide-induced protein carbonylation in Arabidopsis thaliana.
Groupe de Recherche et Biologie Vegetale (GRBV), Department of Chemistry, Biochemistry and Physics, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, Canada.
INTRODUCTION: Protein carbonylation is a non-enzymatic and irreversible post-translational modification that occurs naturally in living organisms under the direct or indirect effect of reactive oxygen species (ROS). In animals, signaling pathways involving numerous carbonylated proteins have been identified, highlighting the dual role of these molecules in ROS signal transduction. In plants, studies on phytohormone signaling (auxin, methyl jasmonate, abscisic acid) have shown that reactive carbonyl species (RCS: acrolein, malondialdehyde, 4-hydroxynonenal, etc.), derived from the action of ROS on lipids, play important roles in secondary root formation and stomatal closure. However, the carbonylated proteins involved in these signaling pathways remain to be identified. METHODS: In this study, we analyzed proteins responsive to carbonylation by exogenous hydrogen peroxide (H2O2) by profiling the carbonyl proteome extracted from Arabidopsis thaliana leaves after H2O2 treatment. Carbonylated proteins were enriched at the peptide level and analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). RESULTS AND DISCUSSION: We identified 35 and 39 uniquely carbonylated proteins in the untreated and the H2O2-treated plant samples, respectively. In comparison to the control treatment, gene ontology enrichment analysis revealed that most of the carbonylated proteins identified in the H2O2-treated plant samples are related to sulfate adenylyl transferases and amidophosphoribosyl transferases involved in the immune system response, defense response, and external stimulus-response. These results indicated that exogenous H2O2 caused a change in the pattern of protein carbonylation in A. thaliana leaves. Protein carbonylation may thus influence the plant transcriptome and metabolism in response to H2O2 and ROS-triggering external stimuli.
PMID: 36544875
Front Plant Sci , IF:5.753 , 2022 , V13 : P1059559 doi: 10.3389/fpls.2022.1059559
Characterization and expression profiling of PIN auxin efflux transporters reveal their role in developmental and abiotic stress conditions in rice.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India.; Department of Botany, Christ Church College, Kanpur, India.
The auxin efflux transporter proteins called PINs ferry auxin from its source to sinks in particular directions depending on their polar localizations in the plasma membrane, thus facilitating the development of the entire plant architecture. The rice genome has 12 PIN genes distributed over eight chromosomes. To study their roles in plant development, abiotic stress responsiveness, and shaping an auxin-dependent root architecture, a genome-wide analysis was carried out. Based on phylogeny, cellular localization, and hydrophilic loop domain size, the PINs were categorized into canonical and noncanonical PINs. PINs were found expressed in all of the organs of plants that emphasized their indispensable role throughout the plant's life cycle. We discovered that PIN5C and PIN9 were upregulated during salt and drought stress. We also found that regardless of its cellular level, auxin functioned as a molecular switch to turn on auxin biosynthesis genes. On the contrary, although PIN expression was upregulated upon initial treatment with auxin, prolonged auxin treatment not only led to their downregulation but also led to the development of auxin-dependent altered root formation in rice. Our study paves the way for developing stress-tolerant rice and plants with a desirable root architecture by genetic engineering.
PMID: 36531415
Front Plant Sci , IF:5.753 , 2022 , V13 : P1035022 doi: 10.3389/fpls.2022.1035022
Improving berry quality and antioxidant ability in 'Ruidu Hongyu' grapevine through preharvest exogenous 2,4-epibrassinolide, jasmonic acid and their signaling inhibitors by regulating endogenous phytohormones.
Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.; College of Chemistry and Chemical Engineering, Zhongkai University of Agricultural Engineering, Guangzhou, China.; Grape and Wine Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China.
Grape berries contain a variety of metabolites, such as anthocyanins, sugars, fatty acids, and antioxidants. Endogenous phytohormones strongly influence these metabolites, which regulate berry quality improvement. In this study, we evaluated the effects of 2,4-epibrassinolide (EBR, brassinolide (BR)-like growth regulator), jasmonic acid (JA), and their signaling inhibitors brassinazole (Brz), and sodium diethyldithiocarbamate (DIECA) on berry quality and antioxidant ability. Overall, the pre-harvest application of 0.5 mg L(-1) EBR and 100 mumol L(-1) JA significantly influences the quality of the grape berry. Results showed that EBR was superior to other treatments at enhancing the content of different metabolites, including anthocyanins, fructose, glucose, and a variety of fatty acids, in grapes. EBR and JA also enhanced the synthesis of gibberellin(3) (GA(3)), cytokinin (CTK), salicylic acid (SA), JA, methyl jasmonate (MeJA), BR, and abscisic acid (ABA), while inhibiting the synthesis of auxin (IAA). Most genes related to BR/JA and anthocyanins/sugars/fatty acids biosynthesis were up-regulated. The effects of Brz and DIECA on the grape berry quality were totally reversed throughout the study, as shown by EBR and JA. According to correlation analysis, EBR and JA have a beneficial positive interaction that promotes the formation of strong coherences in grape berries between ABA/IAA/ZT-fruit expansion, BR/JA/MeJA/GA(3)/ZR-biochemical characteristics development, JA/MeJA/ABA/GA(3)/SA/ZR-antioxidant capacity enhancement, and JA/MeJA/IAA/GA(3)/ZT/ZR-fatty acids accumulation. In this regard, we concluded that preharvest exogenous 0.5 mg L(-1) EBR and 100 mumol L(-1) JA is a successful way to improve grape berry quality.
PMID: 36531411
Front Plant Sci , IF:5.753 , 2022 , V13 : P1065253 doi: 10.3389/fpls.2022.1065253
Knockout of a papain-like cysteine protease gene OCP enhances blast resistance in rice.
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; University of Chinese Academy of Sciences, Beijing, China.; College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China.
Papain-like cysteine proteases (PLCPs) play an important role in the immune response of plants. In Arabidopsis, several homologous genes are known to be involved in defending against pathogens. However, the effects of PLCPs on diseases that afflict rice are largely unknown. In this study, we show that a PLCP, an oryzain alpha chain precursor (OCP), the ortholog of the Arabidopsis protease RD21 (responsive to dehydration 21), participates in regulating resistance to blast disease with a shorter lesion length characterizing the knockout lines (ocp-ko), generated via CRISPR/Cas9 technology. OCP was expressed in all rice tissues and mainly located in the cytoplasm. We prove that OCP, featuring cysteine protease activity, interacts with OsRACK1A (receptor for activated C kinase 1) and OsSNAP32 (synaptosome-associated protein of 32 kD) physically in vitro and in vivo, and they co-locate in the rice cytoplasm but cannot form a ternary complex. Many genes related to plant immunity were enriched in the ocp-ko1 line whose expression levels changed significantly. The expression of jasmonic acid (JA) and ethylene (ET) biosynthesis and regulatory genes were up-regulated, while that of auxin efflux transporters was down-regulated in ocp-ko1. Therefore, OCP negatively regulates blast resistance in rice by interacting with OsRACK1A or OsSNAP32 and influencing the expression profiles of many resistance-related genes. Moreover, OCP might be the cornerstone of blast resistance by suppressing the activation of JA and ET signaling pathways as well as promoting auxin signaling pathways. Our research provides a comprehensive resource of PLCPs for rice plants in defense against pathogens that is also of potential breeding value.
PMID: 36531367
Front Plant Sci , IF:5.753 , 2022 , V13 : P1060228 doi: 10.3389/fpls.2022.1060228
Molecular mechanism of leaf adaxial upward curling caused by BpPIN3 suppression in Betula pendula.
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.; Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States.
Leaves are one of the vegetative organs of plants that are essential for plant growth and development. PIN-FORMED (PINs) gene is an indoleacetic acid (IAA) transporter that plays a critical role in leaf development. To determine the function of BpPIN3 in leaf polarity formation in Betula pendula, the transgenic lines with BpPIN3 overexpression (OE) and BpPIN3-reduced expression (RE) were analyzed using the Agrobacterium-mediated method. The RE lines displayed the characteristics of leaf margin adaxial upward curling, with lower expression of BpPIN3 resulting in greater rolling. Tissue localization of IAA in the auxin GUS reporter system proved that auxin in the RE was mainly distributed in the secondary veins, palisade tissues, and epidermal cells in the leaf margin area. The auxin content in the leaf margin area was significantly greater than that in the main vein tissue. The cell density of the palisade tissue and the ratio of palisade tissue to spongy tissue in the curled leaf margin of the RE lines were found to be significantly decreased. RNA-seq analysis revealed that the RE hormone-signaling pathway genes were significantly enriched compared with those of the OE and WT lines; in particular, the auxin response-related genes SAURs (i.e., SAUR23, SAUR24, SAUR28, and SAUR50) and GH3.10 were found to be significantly upregulated. qRT-PCR analysis indicated that BpPIN3 expression at the leaf margin was significantly lower than that near the main vein in the RE lines. In contrast, the expression levels of SAURs and GH3.10 were significantly higher than those near the midrib. In conclusion, BpPIN3 regulates the expression of auxin response-related genes and the polar transport of auxin to change the polar form of the proximal and distal axes of birch leaves.
PMID: 36531359
Front Plant Sci , IF:5.753 , 2022 , V13 : P1083409 doi: 10.3389/fpls.2022.1083409
TIR1/AFB proteins: Active players in abiotic and biotic stress signaling.
Key Laboratory for Vegetable Germplasm Enhancement and Utilization of Hebei, Collaborative Innovation Center of Vegetable Industry in Hebei, College of Horticulture, Hebei Agricultural University, Baoding, China.; Hebei University Characteristic sericulture Application Technology Research and Development Center, Institute of Sericulture, Chengde Medical University, Chengde, China.
The TIR1/AFB family of proteins is a group of functionally diverse auxin receptors that are only found in plants. TIR1/AFB family members are characterized by a conserved N-terminal F-box domain followed by 18 leucine-rich repeats. In the past few decades, extensive research has been conducted on the role of these proteins in regulating plant development, metabolism, and responses to abiotic and biotic stress. In this review, we focus on TIR1/AFB proteins that play crucial roles in plant responses to diverse abiotic and biotic stress. We highlight studies that have shed light on the mechanisms by which TIR1/AFB proteins are regulated at the transcriptional and post-transcriptional as well as the downstream in abiotic or biotic stress pathways regulated by the TIR1/AFB family.
PMID: 36523629
Front Plant Sci , IF:5.753 , 2022 , V13 : P1059482 doi: 10.3389/fpls.2022.1059482
Transcriptome and hormone Analyses reveal that melatonin promotes adventitious rooting in shaded cucumber hypocotyls.
College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, China.; Experimental Teaching Center, Shanxi Agricultural University, Taigu, Shanxi, China.; College of Horticulture, Northwest A&F University, Yangling, China.
Melatonin, a multi-regulatory molecule, stimulates root generation and regulates many aspects of plant growth and developmental processes. To gain insight into the effects of melatonin on adventitious root (AR) formation, we use cucumber seedings subjected to one of three treatments: EW (hypocotyl exposed and irrigated with water), SW (hypocotyl shaded and irrigated with water) and SM (hypocotyl shaded and irrigated with 100 microM melatonin). Under shaded conditions, melatonin induced significant AR formation in the hypocotyl. To explore the mechanism of this melatonin-induced AR formation, we used transcriptome analysis to identify 1296 significant differentially expressed genes (DEGs). Comparing SM with SW, a total of 774 genes were upregulated and 522 genes were downregulated. The DEGs were classified among different metabolic pathways, especially those connected with the synthesis of secondary metabolites, with hormone signal transduction and with plant-pathogen interactions. Analyses indicate exogenous melatonin increased contents of endogenous auxin, jasmonic acid, salicylic acid, cytokinin and abscisic acid levels during AR formation. This study indicates melatonin promotes AR formation in cucumber seedings by regulating the expressions of genes related to hormone synthesis, signaling and cell wall formation, as well as by increasing the contents of auxin, cytokinin, jasmonic acid, salicylic acid and abscisic acid. This research elucidates the molecular mechanisms of melatonin's role in promoting AR formation in the hypocotyl of cucumber seedings under shaded conditions.
PMID: 36518515
Front Plant Sci , IF:5.753 , 2022 , V13 : P1011360 doi: 10.3389/fpls.2022.1011360
Tryptophan synthase ss subunit 1 affects stomatal phenotypes in Arabidopsis thaliana.
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya, Japan.; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, Japan.
Stomata open in response to several environmental stimuli, such as light and low CO(2). Plasma membrane (PM) H(+)-ATPase in guard cells plays a pivotal role for light-induced stomatal opening. In contrast, stomata close in response to the dark or plant hormone abscisic acid (ABA). However, molecular mechanisms of stomatal movements remain unclear. To elucidate the molecular mechanism of stomatal movements, we performed a genetic screen based on stomatal aperture-dependent weight decrease of detached leaves from EMS-treated Arabidopsis thaliana and isolated a rapid transpiration in detached leaves 2 (rtl2). The rtl2 mutant showed constitutive open-stomata phenotype with lower leaf temperature. ABA had no effect on stomatal aperture in rtl2. The rtl2 mutant also showed increased stomatal density, severe dwarf phenotype with pale green leaves and dark veins. Map-based analysis of the RTL2 locus revealed that the rtl2 mutant possesses a single nucleotide substitution, which induces amino acid substitution Gly162 to Glu in the tryptophan synthase ss subunit 1 (TSB1). The TSB1 encodes an enzyme in tryptophan (Trp) biosynthetic pathway. Amount of TSB1 protein was drastically reduced in rtl2 mutant. A different allele of tsb1 mutant (tsb1-1) also showed constitutive open-stomata phenotype with reduced TSB1 protein as in rtl2. Analyses of test-crossed plants of rtl2 and tsb1-1 showed open-stomata and dwarf phenotypes. These results indicate that a responsible gene for rtl2 is TSB1. We further investigated stomatal phenotype in mutants from Trp biosynthetic pathway, such as wei2-1 wei7-1, trp3-1, and tsb2-1. The trp3-1 mutant showed significant wider stomatal aperture as well as tsb1-1. Trp biosynthetic pathway closely relates to auxin biosynthesis. Then, we investigated auxin responsible genes and found that an expression of AUR3 was up in rtl2. In contrast, auxin had no effect on stomatal aperture in Arabidopsis and the phosphorylation status of PM H(+)-ATPase in guard cell protoplasts from Vicia faba. In addition, auxin antagonist had no effect on stomatal aperture. Interestingly, tsb1-1 grown under hydroponic culture system showed normal stomatal aperture by exogenously application of Trp. These results suggest that open stomata phenotype in tsb1-1 is due to Trp deficiency but not auxin.
PMID: 36518509
Front Plant Sci , IF:5.753 , 2022 , V13 : P1037109 doi: 10.3389/fpls.2022.1037109
Auxin biosynthesis by Microbacterium testaceum Y411 associated with orchid aerial roots and their efficacy in micropropagation.
Microbial Biotechnology Laboratory, Biological Sciences and Technology Division, Council of Scientific & Industrial Research (CSIR)-North East Institute of Science and Technology, Jorhat, Assam, India.; Department of Applied Biology, University of Science and Technology, Meghalaya, India.
Root-associated bacteria strongly affect plant growth and development by synthesizing growth regulators and stress-relieving metabolites. The present study is mainly focused on assessing aerial root-associated bacteria of Rhynchostylis retusa (L.) Blume is an endemic epiphytic orchid responsible for auxin production and influencing plant growth. A bacterial isolate, Microbacterium testaceum Y411, was found to be the most active producer of indole-3-acetic acid (IAA). The maximum IAA production (170microg/mL) was recorded with the bacterium at optimum process parameters such as pH 7, temperature 30 degrees C, and tryptophan 1000 microg/mL in a culture medium for 48 h. The extracted auxin was purified and analyzed by FT-IR, HPLC, and HR-MS, indicating bacterial auxin has a similar mass value to 4-chloroindole-3-acetic acid auxin. Furthermore, the bacterial auxin was tested on in vitro propagation of orchid, Cymbidium aloifolium, and 90% seed germination was recorded in Murashige and Skoog's medium supplemented with bacterial auxin. The novel results obtained in this study are used for agricultural applications and the Microbacterium testaceum Y411 is a valuable biotechnological resource for a natural auxin.
PMID: 36518501
Front Plant Sci , IF:5.753 , 2022 , V13 : P939395 doi: 10.3389/fpls.2022.939395
Understanding plant-microbe interaction of rice and soybean with two contrasting diazotrophic bacteria through comparative transcriptome analysis.
Indian Council of Agricultural Research (ICAR) National Institute for Plant Biotechnology, New Delhi, India.; Kalinga Institute of Industrial Technology (KIIT) School of Biotechnology, KIIT University, Bhubaneswar, India.; ICAR-Indian Institute of Rice Research, Hyderabad, India.; Division of Nematology, ICAR- Indian Agriculture Research Institute, New Delhi, India.
Understanding the beneficial plant-microbe interactions is becoming extremely critical for deploying microbes imparting plant fitness and achieving sustainability in agriculture. Diazotrophic bacteria have the unique ability to survive without external sources of nitrogen and simultaneously promote host plant growth, but the mechanisms of endophytic interaction in cereals and legumes have not been studied extensively. We have studied the early interaction of two diazotrophic bacteria, Gluconacetobacter diazotrophicus (GAB) and Bradyrhizobium japonicum (BRH), in 15-day-old seedlings of rice and soybean up to 120 h after inoculation (hai) under low-nitrogen medium. Root colonization of GAB in rice was higher than that of BRH, and BRH colonization was higher in soybean roots as observed from the scanning electron microscopy at 120 hai. Peroxidase enzyme was significantly higher at 24 hai but thereafter was reduced sharply in soybean and gradually in rice. The roots of rice and soybean inoculated with GAB and BRH harvested from five time points were pooled, and transcriptome analysis was executed along with control. Two pathways, "Plant pathogen interaction" and "MAPK signaling," were specific to Rice-Gluconacetobacter (RG), whereas the pathways related to nitrogen metabolism and plant hormone signaling were specific to Rice-Bradyrhizobium (RB) in rice. Comparative transcriptome analysis of the root tissues revealed that several plant-diazotroph-specific differentially expressed genes (DEGs) and metabolic pathways of plant-diazotroph-specific transcripts, viz., chitinase, brassinosteroid, auxin, Myeloblastosis (MYB), nodulin, and nitrate transporter (NRT), were common in all plant-diazotroph combinations; three transcripts, viz., nitrate transport accessory protein (NAR), thaumatin, and thionin, were exclusive in rice and another three transcripts, viz., NAC (NAM: no apical meristem, ATAF: Arabidopsis thaliana activating factor, and CUC: cup-shaped cotyledon), ABA (abscisic acid), and ammonium transporter, were exclusive in soybean. Differential expression of these transcripts and reduction in pathogenesis-related (PR) protein expression show the early interaction. Based on the interaction, it can be inferred that the compatibility of rice and soybean is more with GAB and BRH, respectively. We propose that rice is unable to identify the diazotroph as a beneficial microorganism or a pathogen from an early response. So, it expressed the hypersensitivity-related transcripts along with PR proteins. The molecular mechanism of diazotrophic associations of GAB and BRH with rice vis-a-vis soybean will shed light on the basic understanding of host responses to beneficial microorganisms.
PMID: 36483966
Front Plant Sci , IF:5.753 , 2022 , V13 : P1079087 doi: 10.3389/fpls.2022.1079087
UV-B induces the expression of flavonoid biosynthetic pathways in blueberry (Vaccinium corymbosum) calli.
Department of Horticulture, College of Plant Science, Jilin University, Changchun, China.
Ultraviolet-B (UV-B) radiation is an environmental signal that affects the accumulation of secondary metabolites in plants. In particular, UV-B promotes flavonoid biosynthesis, leading to improved fruit quality. To explore the underlying molecular mechanism, we exposed blueberry (Vaccinium corymbosum) calli to UV-B radiation and performed a transcriptome deep sequencing (RNA-seq) analysis to identify differentially expressed genes (DEGs). We detected 16,899 DEGs among different treatments, with the largest number seen after 24 h of UV-B exposure relative to controls. Functional annotation and enrichment analysis showed a significant enrichment for DEGs in pathways related to plant hormone signal transduction and phenylpropanoid and flavonoid biosynthesis. In agreement with the transcriptome data, flavonol, anthocyanin and proanthocyanidin accumulated upon UV-B radiation, and most DEGs mapping to the phenylpropanoid and flavonoid biosynthetic pathways using the KEGG mapper tool were upregulated under UV-B radiation. We also performed a weighted gene co-expression network analysis (WGCNA) to explore the relationship among genes involved in plant hormone signal transduction, encoding transcription factors or participating in flavonoid biosynthesis. The transcription factors VcMYBPA1, MYBPA2.1, MYB114, MYBA2, MYBF, and MYB102 are likely activators, whereas MYB20, VcMYB14, MYB44, and VcMYB4a are inhibitors of the flavonoid biosynthetic pathway, as evidenced by the direction of correlation between the expression of these MYBs and flavonoid biosynthesis-related genes. The transcription factors bHLH74 and bHLH25 might interact with MYB repressors or directly inhibited the expression of flavonoid biosynthetic genes to control flavonoid accumulation. We also observed the downregulation of several genes belonging to the auxin, gibberellin and brassinosteroid biosynthetic pathways, suggesting that MYB inhibitors or activators are directly or indirectly regulated to promote flavonoid biosynthesis under UV-B radiation.
PMID: 36483950
Front Plant Sci , IF:5.753 , 2022 , V13 : P1017672 doi: 10.3389/fpls.2022.1017672
Genetic dissection of the soybean dwarf mutant dm with integrated genomic, transcriptomic and methylomic analyses.
College of Life Science, Yangtze University, Jingzhou, China.; National Key Facility for Gene Resources and Genetic Improvement (NFCRI)/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.; Department of Genetics, University of Georgia, Athens, AB, United States.; Department of Computer Science, Yangtze University, Jingzhou, China.; Soybean Research Institute, Heilongjiang Academy of Agricultural Sciences, Harbin, China.; College of Agriculture, Yangtze University, Jingzhou, China.
Plant height affects crop production and breeding practices, while genetic control of dwarfism draws a broad interest of researchers. Dwarfism in soybean (Glycine max) is mainly unexplored. Here, we characterized a dwarf mutant dm screened from ethyl methanesulfonate (EMS) mutated seeds of the soybean cultivar Zhongpin 661(ZP). Phenotypically, dm showed shorter and thinner stems, smaller leaves, and more nodes than ZP under greenhouse conditions. Genetically, whole-genome sequencing and comparison revealed that 210K variants of SNPs and InDel in ZP relative to the soybean reference genome Williams82, and EMS mutagenesis affected 636 genes with variants predicted to have a large impact on protein function in dm. Whole-genome methylation sequencing found 704 differentially methylated regions in dm. Further whole-genome RNA-Seq based transcriptomic comparison between ZP and dm leaves revealed 687 differentially expressed genes (DEGs), including 263 up-regulated and 424 down-regulated genes. Integrated omics analyses revealed 11 genes with both differential expressions and DNA variants, one gene with differential expression and differential methylation, and three genes with differential methylation and sequence variation, worthy of future investigation. Genes in cellulose, fatty acids, and energy-associated processes could be the key candidate genes for the dwarf phenotype. This study provides genetic clues for further understanding of the genetic control of dwarfism in soybean. The genetic resources could help to inbreed new cultivars with a desirable dwarf characteristic.
PMID: 36479521
Front Plant Sci , IF:5.753 , 2022 , V13 : P1077229 doi: 10.3389/fpls.2022.1077229
Functional characterization of a terpene synthase responsible for (E)-beta-ocimene biosynthesis identified in Pyrus betuleafolia transcriptome after herbivory.
Department of Entomology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.; General Station of Agricultural Technology Extension, Xinjiang Production and Construction Corps, Urumqi, China.; Key Laboratory of Oasis Agricultural Pest Management and Plant Protection Resources Utilization, Xinjiang Uygur Autonomous Region, College of Agriculture, Shihezi University, Shihezi, China.; Institute of Grain Crops, XinJiang Academy of Agricultural Sciences, Urumqi, China.
(E)-beta-ocimene, a ubiquitous monoterpene volatile in plants, is emitted from flowers to attract pollinators and/or from vegetative tissues as part of inducible defenses mediated by complex signaling networks when plants are attacked by insect herbivores. Wild pear species Pyrus betuleafolia used worldwide as rootstock generally displays valuable pest-resistant traits and is a promising genetic resource for pear breeding. In the current study, transcriptional changes in this wild pear species infested with a polyphagous herbivore Spodoptera litura and the underlying molecular mechanisms were fully investigated. A total of 3,118 differentially expressed genes (DEGs) were identified in damaged pear leaf samples. Spodoptera litura larvae infestation activated complex phytohormonal signaling networks in which jasmonic acid, ethylene, brassinosteroids, cytokinin, gibberellic acid and auxin pathways were induced, whereas salicylic acid and abscisic acid pathways were suppressed. All DEGs associated with growth-related photosynthesis were significantly downregulated, whereas most DEGs involved in defense-related early signaling events, transcription factors, green leaf volatiles and volatile terpenes were significantly upregulated. The PbeOCS (GWHGAAYT028729), a putative (E)-beta-ocimene synthase gene, was newly identified in P. betuleafolia transcriptome. The upregulation of PbeOCS in S. litura-infested pear leaves supports a potential role for PbeOCS in herbivore-induced plant defenses. In enzyme-catalyzed reaction, recombinant PbeOCS utilized only geranyl pyrophosphate but not neryl diphosphate, farnesyl pyrophosphate or geranylgeranyl diphosphate as a substrate, producing (E)-beta-ocimene as the major product and a trace amount of (Z)-beta-ocimene. Moreover, as a catalytic product of PbeOCS, (E)-beta-ocimene showed repellent effects on larvae of S. litura in dual-choice bioassays. What is more, (E)-beta-ocimene increased mortalities of larvae in no-choice bioassays. These findings provide an overview of transcriptomic changes in wild pears in response to chewing herbivores and insights into (E)-beta-ocimene biosynthesis in pear plants, which will help elucidate the molecular mechanisms underlying pear-insect interactions.
PMID: 36479507
Front Plant Sci , IF:5.753 , 2022 , V13 : P1019427 doi: 10.3389/fpls.2022.1019427
Local auxin synthesis mediated by YUCCA4 induced during root-knot nematode infection positively regulates gall growth and nematode development.
Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan.; International Research Organization for Advanced Science and Technology (IROAST), Kumamoto University, Kumamoto, Japan.; Dormancy and Adaptation Research Unit, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan.; Facultad de Ciencias Ambientales y Bioquimica, Area de Fisiologia Vegetal, Universidad de Castilla-La Mancha, Toledo, Spain.; International Research Center for Agricultural & Environmental Biology, Kumamoto University, Kumamoto, Japan.
Parasites and pathogens are known to manipulate the host's endogenous signaling pathways to facilitate the infection process. In particular, plant-parasitic root-knot nematodes (RKN) are known to elicit auxin response at the infection sites, to aid the development of root galls as feeding sites for the parasites. Here we describe the role of local auxin synthesis induced during RKN infection. Exogenous application of auxin synthesis inhibitors decreased RKN gall formation rates, gall size and auxin response in galls, while auxin and auxin analogues produced the opposite effects, re-enforcing the notion that auxin positively regulates RKN gall formation. Among the auxin biosynthesis enzymes, YUCCA4 (YUC4) was found to be dramatically up-regulated during RKN infection, suggesting it may be a major contributor to the auxin accumulation during gall formation. However, yuc4-1 showed only very transient decrease in gall auxin levels and did not show significant changes in RKN infection rates, implying the loss of YUC4 is likely compensated by other auxin sources. Nevertheless, yuc4-1 plants produced significantly smaller galls with fewer mature females and egg masses, confirming that auxin synthesized by YUC4 is required for proper gall formation and RKN development within. Interestingly, YUC4 promoter was also activated during cyst nematode infection. These lines of evidence imply auxin biosynthesis from multiple sources, one of them being YUC4, is induced upon plant endoparasitic nematode invasion and likely contribute to their infections. The coordination of these different auxins adds another layer of complexity of hormonal regulations during plant parasitic nematode interaction.
PMID: 36466293
Front Plant Sci , IF:5.753 , 2022 , V13 : P1043204 doi: 10.3389/fpls.2022.1043204
PIN1 regulates epidermal cells development under drought and salt stress using single-cell analysis.
State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, China.
Over the course of evolution, plants have developed plasticity to acclimate to environmental stresses such as drought and salt stress. These plant adaptation measures involve the activation of cascades of molecular networks involved in stress perception, signal transduction and the expression of stress related genes. Here, we investigated the role of the plasma membrane-localized transporter of auxin PINFORMED1 (PIN1) in the regulation of pavement cells (PCs) and guard cells (GCs) development under drought and salt stress conditions. The results showed that drought and salt stress treatment affected the development of PCs and GCs. Further analysis identified the different regulation mechanisms of PIN1 in regulating the developmental patterns of PCs and GCs under drought and salt stress conditions. Drought and salt stress also regulated the expression dynamics of PIN1 in pif1/3/4/5 quadruple mutants. Collectively, we revealed that PIN1 plays a crucial role in regulating plant epidermal cells development under drought and salt stress conditions, thus contributing to developmental rebustness and plasticity.
PMID: 36466268
Front Plant Sci , IF:5.753 , 2022 , V13 : P1012966 doi: 10.3389/fpls.2022.1012966
Integrated physiological and weighted gene co-expression network analysis reveals the hub genes engaged in nitrate-regulated alleviation of ammonium toxicity at the seedling stage in wheat (Triticum aestivum L.).
College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai'an, Shandong, China.
Wheat has a specific preference for NO(3) (-) and shows toxicity symptoms under high NH(4) (+) concentrations. Increasing the nitrate supply may alleviate ammonium stress. Nevertheless, the mechanisms underlying the nitrate regulation of wheat root growth to alleviate ammonium toxicity remain unclear. In this study, we integrated physiological and weighted gene co-expression network analysis (WGCNA) to identify the hub genes involved in nitrate alleviation of ammonium toxicity at the wheat seedling stage. Five NH(4) (+)/NO(3) (-) ratio treatments, including 100/0 (N(a)), 75/25 (N(r1)), 50/50 (N(r2)), 25/75 (N(r3)), and 0/100 (N(n)) were tested in this study. The results showed that sole ammonium treatment (N(a)) increased the lateral root number but reduced root biomass. Increasing the nitrate supply significantly increased the root biomass. Increasing nitrate levels decreased abscisic acid (ABA) content and increased auxin (IAA) content. Furthermore, we identified two modules (blue and turquoise) using transcriptome data that were significantly related to root physiological growth indicators. TraesCS6A02G178000 and TraesCS2B02G056300 were identified as hub genes in the two modules which coded for plastidic ATP/ADP-transporter and WRKY62 transcription factors, respectively. Additionally, network analysis showed that in the blue module, TraesCS6A02G178000 interacts with downregulated genes that coded for indolin-2-one monooxygenase, SRG1, DETOXIFICATION, and wall-associated receptor kinase. In the turquoise module, TraesCS2B02G056300 was highly related to the genes that encoded ERD4, ERF109, CIGR2, and WD40 proteins, and transcription factors including WRKY24, WRKY22, MYB30, and JAMYB, which were all upregulated by increasing nitrate supply. These studies suggest that increasing the nitrate supply could improve root growth and alleviate ammonium toxicity through physiological and molecular regulation networks, including ROS, hormonal crosstalk, and transcription factors.
PMID: 36466221
Front Plant Sci , IF:5.753 , 2022 , V13 : P1045270 doi: 10.3389/fpls.2022.1045270
Metabolome and transcriptome integration reveals insights into the process of delayed petal abscission in rose by STS.
School of Life Science ang Technology, Inner Mongolia University of Science and Technology, Baotou, China.
The abscission of plant organs plays an important role in ensuring the normal life activities. Rose is one of the most important ornamental plants, and its premature abscission of petal has seriously affected the quality and commercial value. Silver Thiosulfate (STS) is an ethylene inhibitor, which is often used preservative to delay the senescence of fresh cut flowers. To understand the regulatory mechanism of petal abscission in rose by STS, integrative analysis of the metabolome and transcriptome profiles was performed in abscission zone (AZ) tissues of rose under different treatments (MOCK, STS, ETH, STS+ETH). The results showed that STS significantly delayed the petal abscission in phenotype and reduced the activity of two enzymes (pectinase and cellulase) associated with cell wall degradation in physiological level. STS affected the contents of five metabolites (shikonin, jasmonic acid, gluconolactone, stachyose and D-Erythrose 4-phosphate), and involved changes in the expression of 39 differentially expressed genes (DEGs) associated with these five metabolites. Five DEGs (LOC112192149, LOC112196726, LOC112189737, LOC112188495, and LOC112188936) were probably directly associated with the biosynthesis of shikonin, jasmonic acid, and D-Erythrose 4-phosphate. Meanwhile, the effect of STS on the abscission process significantly involved in the pentose phosphate pathway and amino acid biosynthesis pathway. In addition, STS had a greater effect on the transcription factors, phytohormone related DEGs represented by auxin and ethylene, DEGs related to disease resistance and amino acid, etc. Above all, STS negatively influences petal abscission of rose, these results maybe provide a reference for subsequent studies on petal abscission of rose by STS.
PMID: 36457520
Front Plant Sci , IF:5.753 , 2022 , V13 : P1002703 doi: 10.3389/fpls.2022.1002703
Comparing adventitious root-formation and graft-unification abilities in clones of Argania spinosa.
The Institute of Plant Sciences, Agricultural Research Organization-The Volcani Institute, Rishon LeZion, Israel.; The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Argania spinosa trees have attracted attention in recent years due to their high resistance to extreme climate conditions. Initial domestication activities practiced in Morocco. Here we report on selection and vegetative propagation of A. spinosa trees grown in Israel. Trees yielding relatively high amounts of fruit were propagated by rooting of stem cuttings. High variability in rooting ability was found among the 30 clones selected. In-depth comparison of a difficult-to-root (ARS7) and easy-to-root (ARS1) clone revealed that the rooted cuttings of ARS7 have a lower survival rate than those of ARS1. In addition, histological analysis of the adventitious root primordia showed many abnormal fused primordia in ARS7. Hormone profiling revealed that while ARS1 accumulates more cytokinin, ARS7 accumulates more auxin, suggesting different auxin-to-cytokinin ratios underlying the different rooting capabilities. The hypothesized relationship between rooting and grafting abilities was addressed. Reciprocal grafting was performed with ARS1/ARS7 but no significant differences in the success of graft unification between the trees was detected. Accordingly, comparative RNA sequencing of the rooting and grafting zones showed more differentially expressed genes related to rooting than to grafting between the two trees. Clustering, KEGG and Venn analyses confirmed enrichment of genes related to auxin metabolism, transport and signaling, cytokinin metabolism and signaling, cell wall modification and cell division in both regions. In addition, the differential expression of some key genes in ARS1 vs. ARS7 rooting zones was revealed. Taken together, while both adventitious root-formation and graft-unification processes share response to wounding, cell reprogramming, cell division, cell differentiation and reconnection of the vasculature, there are similar, but also many different genes regulating the two processes. Therefore an individual genotype can have low rooting capacity but good graft-unification ability.
PMID: 36452103
Front Plant Sci , IF:5.753 , 2022 , V13 : P1045761 doi: 10.3389/fpls.2022.1045761
Gibberellin delays metabolic shift during tomato ripening by inducing auxin signaling.
Postharvest Research Division, National Institute of Horticultural and Herbal Science, Wanju-gun, South Korea.
Fruit ripening involves the dynamic interaction of phytohormones. Ethylene (ET) and gibberellin (GA) antagonistically affect fruit ripening. However, the mechanism of GA and its potential interaction with ET during fruit ripening remain unknown. To identify the potential molecular mechanism of ET and GA interplay in tomato (Solanum lycopersicum L.) fruit ripening, transcriptome and metabolomic profiling was carried out in tomato fruit treated with GA, ET or the combination of the two hormones (GA+ET). ET accelerated fruit ripening with the simultaneous repression of auxin signaling. In contrast, gibberellin delayed ripening by the upregulation of auxin signaling. ET signaling and response was inhibited by GA or combined with ET. At the metabolite level, while GA treatment inhibited metabolite shift during ripening, ET treatment promoted. In the combined hormone treatment, ET reduced or recovered GA inhibitory effect on specific metabolites. This study provided insight into ET and GA interaction, highlighting the importance of auxin signaling in metabolic shifts during tomato ripening progression.
PMID: 36452096
Front Plant Sci , IF:5.753 , 2022 , V13 : P1011596 doi: 10.3389/fpls.2022.1011596
An Asp376Glu substitution in ALS gene and enhanced metabolism confers high tribenuron-methyl resistance in Sinapis alba.
Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain.; Plant Protection Department, Scientific and Technological Research Centre of Extremadura (CICYTEX), Guadajira, Badajoz, Spain.; Department of Hortofructiculture, Botany and Gardening, Agrotecnio-CERCA Center, University of Lleida, Lleida, Spain.; Biosciences Department, Polytechnic Institute of Beja, Beja, Portugal.
Acetolactate synthase (ALS) inhibiting herbicides (group 2) have been widely applied for the last 20 years to control Sinapis alba in cereal crops from southern Spain. In 2008, a tribenuron-methyl (TM) resistant (R) S. alba population was first reported in a cereal field in Malaga (southern Spain). In 2018, three suspected R S. alba populations (R1, R2 and R3) to TM were collected from three different fields in Granada (southern Spain, 100 km away from Malaga). The present work aims to confirm the putative resistance of these populations to TM and explore their resistance mechanisms. Dose-response assays showed that the R1, R2 and R3 populations ranging between 57.4, 44.4 and 57.1 times more resistance to TM than the susceptible population (S). A mutation in the ALS gene (Asp376Glu) was detected in the Rs S. alba populations. (14)C-metabolism studies show that metabolites and TM were changing significantly faster in the R than in the S plants. Alternative chemical control trials showed that 2,4-D and MCPA (auxin mimics), glyphosate (enolpyruvyl shikimate phosphate synthase,EPSPS, inhibitor-group 9), metribuzin (PSII inhibitors/Serine 264 Binders, -group 5) and mesotrione (hydroxyphenyl pyruvate dioxygenase, HPPD, inhibitor-group 27) presented a high control of the four populations of S. alba tested, both S and R. Based on these results, it is the first case described where the Asp376Glu mutation and P450-mediated metabolism participates in resistance to TM in S. alba. Comparing these results with those found in the S. alba population in Malaga in 2008, where the resistance was TSR type (Pro197Ser), we can suggest that despite the geographical proximity (over 100 km), the resistance in these cases was due to different evolutionary events.
PMID: 36438121
Front Plant Sci , IF:5.753 , 2022 , V13 : P1052659 doi: 10.3389/fpls.2022.1052659
Identification of GOLDEN2-like transcription factor genes in soybeans and their role in regulating plant development and metal ion stresses.
Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China.; College of Life Sciences, South China Agricultural University (SCAU), Guangzhou, Guangdong, China.; Guangdong Subcenter of the National Center for Soybean Improvement, South China Agricultural University (SCAU), Guangzhou, Guangdong, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University (SCAU), Guangzhou, Guangdong, China.
The Golden 2-Like (G2-like or GLK) transcription factors are essential for plant growth, development, and many stress responses as well as heavy metal stress. However, G2-like regulatory genes have not been studied in soybean. This study identified the genes for 130 G2-Like candidates' in the genome of Glycine max (soybean). These GLK genes were located on all 20 chromosomes, and several of them were segmentally duplicated. Most GLK family proteins are highly conserved in Arabidopsis and soybean and were classified into five major groups based on phylogenetic analysis. These GmGLK gene promoters share cis-acting elements involved in plant responses to abscisic acid, methyl jasmonate, auxin signaling, low temperature, and biotic and abiotic stresses. RNA-seq expression data revealed that the GLK genes were classified into 12 major groups and differentially expressed in different tissues or organs. The co-expression network complex revealed that the GmGLK genes encode proteins involved in the interaction of genes related to chlorophyll biosynthesis, circadian rhythms, and flowering regulation. Real-time quantitative PCR analysis confirmed the expression profiles of eight GLK genes in response to cadmium (Cd) and copper (Cu) stress, with some GLK genes significantly induced by both Cd and Cu stress treatments, implying a functional role in defense responsiveness. Thus, we present a comprehensive perspective of the GLK genes in soybean and emphasize their important role in crop development and metal ion stresses.
PMID: 36438095
Front Plant Sci , IF:5.753 , 2022 , V13 : P1022696 doi: 10.3389/fpls.2022.1022696
Arbuscular mycorrhiza mitigates zinc stress on Eucalyptus grandis through regulating metal tolerance protein gene expression and ionome uptake.
Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China.
Arbuscular mycorrhizal (AM) fungi are symbionts of most terrestrial plants and enhance their adaptability in metal-contaminated soils. In this study, mycorrhized and non-mycorrhized Eucalyptus grandis were grown under different Zn treatments. After 6 weeks of treatment, the growing status and ionome content of plants as well as the expression patterns of metal tolerance proteins and auxin biosynthesis-related genes were measured. In this study, mycorrhized E. grandis showed higher biomass and height at a high level of Zn compared with non-mycorrhized plants. In addition, AM plants accumulated P, Mg, and Mn in roots and P, Fe, and Cu in shoots, which indicate that AM fungi facilitate the uptake of ionome nutrients to promote plant growth. In addition, mycorrhiza upregulated the expression of EgMTP1 and EgMTP7, whose encoding proteins were predicted to be located at the vacuolar membrane. Meanwhile, Golgi membrane transporter EgMTP5 was also induced in AM shoot. Our results suggest that AM likely mitigates Zn toxicity through sequestrating excess Zn into vacuolar and Golgi. Furthermore, the expression of auxin biosynthesis-related genes was facilitated by AM, and this is probably another approach for Zn tolerance.
PMID: 36420037
Front Plant Sci , IF:5.753 , 2022 , V13 : P1022961 doi: 10.3389/fpls.2022.1022961
Transcriptome and metabolome analyses of Shatian pomelo (Citrus grandis var. Shatinyu Hort) leaves provide insights into the overexpression of the gibberellin-induced gene CcGASA4.
Life Science and Technology School, Lingnan Normal University, Zhanjiang, China.; Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China.; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangzhou, China.; Key Laboratory of Tropical and Subtropical of Fruit Tree Research, Science and Technology Department of Guangdong Province, Guangzhou, China.
The gibberellic acid (GA)-stimulated Arabidopsis (GASA) gene family is highly specific to plants and plays crucial roles in plant growth and development. CcGASA4 is a member of the GASA gene family in citrus plants; however, the current understanding of its function in citrus is limited. We used CcGASA4-overexpression transgenic citrus (OEGA) and control (CON) plants to study the role of CcGASA4 in Shatian pomelo. The RNA sequencing (RNA-seq) analysis showed that 3,522 genes, including 1,578 upregulated and 1,944 downregulated genes, were significantly differentially expressed in the CON versus OEGA groups. The Gene Ontology enrichment analysis showed that 178 of the differentially-expressed genes (DEGs) were associated with flowers. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the DEGs were enriched in 134 pathways, including "plant-pathogen interaction", "MAPK signaling pathway-plant", "phenylpropane biosynthesis", "plant hormone signal transduction", "phenylalanine, tyrosine and tryptophan biosynthesis", and "flavonoid and flavonol biosynthesis". The most significantly-enriched pathway was "plant-pathogen interaction", in which 203 DEGs were enriched (126 DEGs were upregulated and 78 were downregulated). The metabolome analysis showed that 644 metabolites were detected in the OEGA and CON samples, including 294 differentially-accumulated metabolites (DAMs; 83 upregulated versus 211 downregulated in OEGA compared to CON). The metabolic pathway analysis showed that these DAMs were mainly involved in the metabolic pathways of secondary metabolites, such as phenylpropanoids, phenylalanine, flavone, and flavonol biosynthesis. Thirteen flavonoids and isoflavones were identified as DAMs in OEGA and CON. We also discovered 25 OEGA-specific accumulated metabolites and found 10 that were associated with disease resistance. CcGASA4 may therefore play a functional role in activating the expression of MAPK signaling transduction pathway and disease resistance genes, inhibiting the expression of auxin- and ethylene-related genes, and activating or inhibiting the expression of brassinosteroid biosynthesis- and abscisic acid-related genes. CcGASA4 may also play a role in regulating the composition and abundance of flavonoids, isoflavones, amino acids, purines, and phenolic compounds. This study provides new insights into the molecular mechanisms of action of CcGASA4 in citrus plants.
PMID: 36407630
Front Plant Sci , IF:5.753 , 2022 , V13 : P1021297 doi: 10.3389/fpls.2022.1021297
Identification and comprehensive analysis of MIPSs in Rosaceae and their expression under abiotic stresses in rose (Rosa chinensis).
Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
The Myo-Inositol-1-phosphate synthase (MIPS) gene family is involved in the myo-inositol synthesis and plays a significant role in signal transduction, membrane biogenesis, oligosaccharides synthesis, auxin storage and transport, programmed cell death and abiotic stress tolerance in plants. This study comprehensively identified the MIPS genes in Rosaceae plant species, and 51 MIPS genes were identified from 26 Rosaceae species. The phylogenetic analysis divided the MIPSs into two clades (clade I; subfamily Amygdaloideae specific, and clade II; subfamily Rosoideae specific). MIPS genes of all 26 Rosaceae species consist of similar gene structure, motif and domain composition, which shows their conserved nature. The cis-regulatory elements (CREs) analysis revealed that most Rosaceae MIPS genes play a role in growth, development, and stress responses. Furthermore, the qRT-PCR analysis also revealed the involvement of RcMIPS gene in plant development and response to abiotic stresses, including drought and heat. The results of the present study contribute to the understanding of the biological function of Rosaceae MIPS genes, and that could be used in further functional validations.
PMID: 36407582
Front Plant Sci , IF:5.753 , 2022 , V13 : P1025969 doi: 10.3389/fpls.2022.1025969
First experimental evidence suggests use of glucobrassicin as source of auxin in drought-stressed Arabidopsis thaliana.
Institute of Botany, Leibniz University Hannover, Hannover, Germany.; Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, University of Gottingen, Gottingen, Germany.; Gottingen Center for Molecular Biosciences (GZMB), Service Unit for Metabolomics and Lipidomics, University of Gottingen, Gottingen, Germany.; Gottingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Gottingen, Gottingen, Germany.
The synthesis of indole-3-acetonitrile (IAN) from the indolic glucosinolate (iGSL) glucobrassicin (GB) is a unique trait of members of the Brassicales. To assess the contribution of this pathway to indole-3-acetic acid (IAA) synthesis under stress conditions, drought stress (DS) experiments with Arabidopsis thaliana were performed in vitro. Analysis of GSLs in DS plants revealed higher contents of GB in shoots and roots compared to control plants. Deuterium incorporation experiments showed the highest turnover of GB compared to all other GSLs during drought conditions. Evidence suggests the involvement of the thioglucosidase BGLU18 in the degradation of GB. The nitrile specifier proteins NSP1 and NSP5 are known to direct the GSL hydrolysis towards formation of IAN. Nitrilases like NIT2 are able to subsequently synthesize IAA from IAN. Expression of BGLU18, NSP1, NSP5 and NIT2 and contents of GB, IAN and IAA were significantly elevated in DS plants compared to control plants suggesting the increased use of GB as IAA source. Significantly higher contents of reactive oxygen species in DS bglu18 and epithionitrile specifier protein (esp) mutants compared to Col-0 indicate higher stress levels in these mutants highlighting the need for both proteins in DS plants. Furthermore, GB accumulation in leaves was higher in both mutants during DS when compared to Col-0 indicating enhanced synthesis of GB due to a lack of breakdown products. This work provides the first evidence for the breakdown of iGSLs to IAN which seems to be used for synthesis of IAA in DS A. thaliana plants.
PMID: 36388588
Front Plant Sci , IF:5.753 , 2022 , V13 : P1023739 doi: 10.3389/fpls.2022.1023739
FveARF2 negatively regulates fruit ripening and quality in strawberry.
Liaoning Key Laboratory of Strawberry Breeding and Cultivation, College of Horticulture, Shenyang Agricultural University, Shenyang, China.; Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, China.
Auxin response factors (ARFs) are transcription factors that play important roles in plants. ARF2 is a member of the ARF family and participates in many plant growth and developmental processes. However, the role of ARF2 in strawberry fruit quality remains unclear. In this study, FveARF2 was isolated from the woodland strawberry 'Ruegen' using reverse transcription-polymerase chain reaction (RT-PCR), which showed that FveARF2 expression levels were higher in the stem than in other organs of the 'Ruegen' strawberry. Moreover, FaARF2 was higher in the white fruit stage of cultivated strawberry fruit than in other stage. Subcellular localization analysis showed that FveARF2 is located in the nucleus, while transcriptional activation assays showed that FveARF2 inhibited transcription in yeast. Silencing FveARF2 in cultivated strawberry fruit revealed earlier coloration and higher soluble solid, sugar, and anthocyanin content in the transgenic fruit than in the control fruit, overexpression of FveARF2 in strawberry fruit delayed ripening and lower soluble solid, sugar, and anthocyanin content compared to the control fruit. Gene expression analysis indicated that the transcription levels of the fruit ripening genes FaSUT1, FaOMT, and FaCHS increased in FveARF2-RNAi fruit and decreased in FveARF2-OE fruit, when compared with the control. Furthermore, yeast one-hybrid (Y1H) and GUS activity experiments showed that FveARF2 can directly bind to the AuxRE (TGTCTC) element in the FaSUT1, FaOMT, and FaCHS promoters in vitro and in vivo. Potassium ion supplementation improved the quality of strawberry fruit, while silencing FveARF2 increased potassium ion content in transgenic fruit. The Y1H and GUS activity experiments also confirmed that FveARF2 could directly bind to the promoter of FveKT12, a potassium transporter gene, and inhibited its expression. Taken together, we found that FveARF2 can negatively regulate strawberry fruit ripening and quality, which provides new insight for further study of the molecular mechanism of strawberry fruit ripening.
PMID: 36388474
Theor Appl Genet , IF:5.699 , 2022 Dec , V135 (12) : P4457-4468 doi: 10.1007/s00122-022-04231-8
BSA‑seq and genetic mapping identified candidate genes for branching habit in peanut.
Institute of Crop Germplasm Resources (Institute of Biotechnology), Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, People's Republic of China.; College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China.; College of Agricultural Science and Technology, Shandong Agriculture and Engineering University, Jinan, 250100, People's Republic of China.; Cash Crop Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, 530007, China.; Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, 450002, People's Republic of China.; Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, India.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA, Australia.; Institute of Crop Germplasm Resources (Institute of Biotechnology), Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, People's Republic of China. xingjunw@hotmail.com.; College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China. xingjunw@hotmail.com.; Institute of Crop Germplasm Resources (Institute of Biotechnology), Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, People's Republic of China. chuanzhiz@126.com.; College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China. chuanzhiz@126.com.
The candidate gene AhLBA1 controlling lateral branch angel of peanut was fine-mapped to a 136.65-kb physical region on chromosome 15 using the BSA-seq and QTL mapping. Lateral branch angel (LBA) is an important plant architecture trait of peanut, which plays key role in lodging, peg soil penetration and pod yield. However, there are few reports of fine mapping and quantitative trait loci (QTLs)/cloned genes for LBA in peanut. In this project, a mapping population was constructed using a spreading variety Tifrunner and the erect variety Fuhuasheng. Through bulked segregant analysis sequencing (BSA-seq), a major gene related to LBA, named as AhLBA1, was preliminarily mapped at the region of Chr.15: 150-160 Mb. Then, using traditional QTL approach, AhLBA1 was narrowed to a 1.12 cM region, corresponding to a 136.65-kb physical interval of the reference genome. Of the nine genes housed in this region, three of them were involved in hormone metabolism and regulation, including one "F-box protein" and two "2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase (2OG oxygenase)" encoding genes. In addition, we found that the level of some classes of cytokinin (CK), auxin and ethylene showed significant differences between spreading and erect peanuts at the junction of main stem and lateral branch. These findings will aid further elucidation of the genetic mechanism of LBA in peanut and facilitating marker-assisted selection (MAS) in the future breeding program.
PMID: 36181525
J Agric Food Chem , IF:5.279 , 2022 Dec , V70 (51) : P16229-16240 doi: 10.1021/acs.jafc.2c07072
Novel Plant Growth Regulator Guvermectin from Plant Growth-Promoting Rhizobacteria Boosts Biomass and Grain Yield in Rice.
Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China.; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.; Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Science, Huzhou University, Huzhou 313000, China.; Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China.
Food is a fundamental human right, and global food security is threatened by crop production. Plant growth regulators (PGRs) play an essential role in improving crop yield and quality, and this study reports on a novel PGR, termed guvermectin (GV), isolated from plant growth-promoting rhizobacteria, which can promote root and coleoptile growth, tillering, and early maturing in rice. GV is a nucleoside analogue like cytokinin (CK), but it was found that GV significantly promoted root and hypocotyl growth, which is different from the function of CK in Arabidopsis. The Arabidopsis CK receptor triple mutant ahk2-2 ahk3-3 cre1-12 still showed a GV response. Moreover, GV led different growth-promoting traits from auxin, gibberellin (GA), and brassinosteroid (BR) in Arabidopsis and rice. The results from a four-year field trial involving 28 rice varieties showed that seed-soaking treatment with GV increased the yields by 6.2 to 19.6%, outperforming the 4.0 to 10.8% for CK, 1.6 to 16.9% for BR, and 2.2 to 7.1% for GA-auxin-BR mixture. Transcriptome analysis demonstrated that GV induced different transcriptome patterns from CK, auxin, BR, and GA, and SAUR genes may regulate GV-mediated plant growth and development. This study suggests that GV represents a novel PGR with a unique signal perception and transduction pathway in plants.
PMID: 36515163
J Agric Food Chem , IF:5.279 , 2022 Dec , V70 (49) : P15380-15389 doi: 10.1021/acs.jafc.2c05908
Identification of a Novel 2,4-D Metabolic Detoxification Pathway in 2,4-D-Resistant Waterhemp (Amaranthus tuberculatus).
Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado 80523, United States.; Department of Chemistry, Materials and Molecular Analysis Center, Colorado State University, Fort Collins, Colorado 80523, United States.
A 2,4-dichlorophenoxyactic acid (2,4-D)-resistant population of Amaranthus tuberculatus (common waterhemp) from Nebraska, USA, was previously found to have rapid metabolic detoxification of the synthetic auxin herbicide 2,4-D. We purified the main 2,4-D metabolites from resistant and susceptible plants, solved their structures by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS), and synthesized the metabolites to determine their in planta toxicity. Susceptible plants conjugated 2,4-D to aspartate to form 2,4-D-aspartic acid (2,4-D-Asp), while resistant plants had a unique metabolic profile where 2,4-D was hydroxylated into 5-OH-2,4-D, followed by conjugation into a sugar metabolite (2,4-D-5-O-d-glucopyranoside) and subsequent malonylation into 2,4-D-(6'-O-malonyl)-5-O-d-glucopyranoside. Toxicological studies on waterhemp and Arabidopsis thaliana confirmed that the hydroxylated metabolite lost its auxinic action and toxicity. In contrast, the 2,4-D-Asp metabolite found in susceptible plants retained some auxinic action and toxicity. These results demonstrate that 2,4-D-resistant A. tuberculatus evolved novel detoxification reactions not present in susceptible plants to rapidly metabolize 2,4-D, potentially mediated by cytochrome P450 enzymes that perform the initial 5-hydroxylation reaction. This novel mechanism is more efficient to detoxify 2,4-D and produces metabolites with lower toxicity compared to the aspartic acid conjugation found in susceptible waterhemp.
PMID: 36453610
Metabolites , IF:4.932 , 2022 Dec , V12 (12) doi: 10.3390/metabo12121231
In Vivo Low-Temperature Plasma Ionization Mass Spectrometry (LTP-MS) Reveals Regulation of 6-Pentyl-2H-Pyran-2-One (6-PP) as a Physiological Variable during Plant-Fungal Interaction.
Department of Biotechnology and Biochemistry, Center for Research and Advanced Studies (CINVESTAV), Irapuato 36824, Mexico.; UGA-Langebio, Center for Research and Advanced Studies (CINVESTAV) Irapuato, Km. 9.6 Libramiento Norte Carr. Irapuato-Leon, Irapuato 36824, Mexico.; Department of Biochemical Engineering, Nacional Technological Institute, Celaya 38010, Mexico.
Volatile organic compounds (VOCs) comprises a broad class of small molecules (up to ~300 g/mol) produced by biological and non-biological sources. VOCs play a vital role in an organism's metabolism during its growth, defense, and reproduction. The well-known 6-pentyl-alpha-pyrone (6-PP) molecule is an example of a major volatile biosynthesized by Trichoderma atroviride that modulates the expression of PIN auxin-transport proteins in primary roots of Arabidopsis thaliana during their relationship. Their beneficial relation includes lateral root formation, defense induction, and increased plant biomass production. The role of 6-PP has been widely studied due to its relevance in this cross-kingdom relationship. Conventional VOCs measurements are often destructive; samples require further preparation, and the time resolution is low (around hours). Some techniques enable at-line or real-time analyses but are highly selective to defined compounds. Due to these technical constraints, it is difficult to acquire relevant information about the dynamics of VOCs in biological systems. Low-temperature plasma (LTP) ionization allows the analysis of a wide range of VOCs by mass spectrometry (MS). In addition, LTP-MS requires no sample preparation, is solvent-free, and enables the detection of 6-PP faster than conventional analytical methods. Applying static statistical methods such as Principal Component Analysis (PCA) and Discriminant Factorial Analysis (DFA) leads to a loss of information since the biological systems are dynamic. Thus, we applied a time series analysis to find patterns in the signal changes. Our results indicate that the 6-PP signal is constitutively emitted by T. atroviride only; the signal shows high skewness and kurtosis. In A. thaliana grown alone, no signal corresponding to 6-PP is detected above the white noise level. However, during T. atroviride-A. thaliana interaction, the signal performance showed reduced skewness and kurtosis with high autocorrelation. These results suggest that 6-PP is a physiological variable that promotes homeostasis during the plant-fungal relationship. Although the molecular mechanism of this cross-kingdom control is still unknown, our study indicates that 6-PP has to be regulated by A. thaliana during their interaction.
PMID: 36557269
Plant Cell Physiol , IF:4.927 , 2022 Nov doi: 10.1093/pcp/pcac163
Mapping of the Classical Mutation Rosette Highlights a Role for Calcium in Wound-induced Rooting.
The Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, The Hebrew University Israel.; Instituto de Bioingenieria, Universidad Miguel Hernandez, 03202, Elche, Spain.; Departamento de Nutricion Vegetal, CEBAS-CSIC, 30100, Murcia, Spain.; Departamento de Biologia Vegetal (Fisiologia Vegetal), Universidad de Murcia, Murcia, Spain.
Removal of the root system induces the formation of new roots from the remaining shoot. This process is primarily controlled by the phytohormone auxin, which interacts with other signals in a yet unresolved manner. Here, we study the classical tomato mutation rosette (ro), which lacks shoot-borne roots. ro plants were severely inhibited in forming wound-induced roots and have reduced auxin transport rates. We mapped ro to the tomato ortholog of the Arabidopsis thaliana BIG and the mammalians UBR4/p600. RO/BIG is a large protein of unknown biochemical function. In A. thaliana, BIG was implicated in regulating auxin transport and calcium homeostasis. We show that exogenous calcium inhibits wound-induced root formation in tomato and A. thaliana ro/big mutants. Exogenous calcium antagonized the root-promoting effects of the auxin IAA but not of 2,4-D, an auxin analog that is not recognized by the polar transport machinery, and accumulation of the auxin transporter PIN1 was sensitive to calcium levels in the ro/big mutants. Consistent with a role for calcium in mediating auxin transport, both ro/big mutants and calcium-treated wild-type plants were hypersensitive to treatment with polar auxin transport inhibitors. Subcellular localization of BIG suggests that, like its mammalian ortholog, it is associated with the endoplasmic reticulum (ER). Analysis of subcellular morphology revealed that ro/big mutants exhibited disruption in cytoplasmic streaming. We suggest that RO/BIG maintain auxin flow by stabilizing PIN membrane localization, possibly by attenuating the inhibitory effect of Ca2+ on cytoplasmic streaming.
PMID: 36398993
Plant Cell Physiol , IF:4.927 , 2022 Nov doi: 10.1093/pcp/pcac155
Arrest, Senescence, and Death of Shoot Apical Stem Cells in Arabidopsis thaliana.
Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Shaoguan University, Shaoguan 512005, China.; Henry Fok School of Biology and Agriculture, Shaoguan University, Shaoguan 512005, China.; Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, 630-0192 Japan.
Shoot stem cells act as the source of the aboveground parts of flowering plants. A precise regulatory basis is required to ensure that plant stem cells show the right status during stages of proliferation, senescence and cell death. Over the past decades, the genetic circuits controlling stem cell fate, including the regulatory pathways of establishment, maintenance, and differentiation, have been largely revealed. However, the morphological changes and molecular mechanisms of the final stages of stem cells, which are represented by senescence and cell death, have been less studied. The senescence and death of shoot stem cells are under the control of a complex series of pathways that integrate multiple internal and external signals. Given the crucial roles of shoot stem cells in influencing plant longevity and crop yields, researchers have attempted to uncover details of stem cell senescence and death. Recent studies indicate that stem cell activity arrest is controlled by the FRUITFULL (FUL)-APETALA2 (AP2) pathway and the plant hormones auxin and cytokinin, while the features of senescent and dead shoot apical stem cells have also been described, with dynamic changes in reactive oxygen species (ROS) implicated in stem cell death. In this review, we highlight the recent breakthroughs that have enriched our understanding of senescence and cell death processes in plant stem cells.
PMID: 36331512
Plant Cell Physiol , IF:4.927 , 2022 Nov , V63 (11) : P1709-1719 doi: 10.1093/pcp/pcac126
The 5'-3' mRNA Decay Pathway Modulates the Plant Circadian Network in Arabidopsis.
Fundacion Instituto Leloir, Instituto de Investigaciones Bioquimicas de Buenos Aires-Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires C1405BWE, Argentina.; Department of Biochemistry, University of Otago, Dunedin 9016, New Zealand.
Circadian rhythms enable organisms to anticipate and adjust their physiology to periodic environmental changes. These rhythms are controlled by biological clocks that consist of a set of clock genes that regulate each other's expression. Circadian oscillations in messenger RNA (mRNA) levels require the regulation of mRNA production and degradation. While transcription factors controlling clock function have been well characterized from cyanobacteria to humans, the role of factors controlling mRNA decay is largely unknown. Here, we show that mutations in SM-LIKE PROTEIN 1 (LSM1) and exoribonucleases 4 (XRN4), components of the 5'-3' mRNA decay pathway, alter clock function in Arabidopsis. We found that lsm1 and xrn4 mutants display long-period phenotypes for clock gene expression. In xrn4, these circadian defects were associated with changes in circadian phases of expression, but not overall mRNA levels, of several core-clock genes. We then used noninvasive transcriptome-wide mRNA stability analysis to identify genes and pathways regulated by XRN4. Among genes affected in the xrn4 mutant at the transcriptional and posttranscriptional level, we found an enrichment in genes involved in auxin, ethylene and drought recovery. Large effects were not observed for canonical core-clock genes, although the mRNAs of several auxiliary clock genes that control the pace of the clock were stabilized in xrn4 mutants. Our results establish that the 5'-3' mRNA decay pathway constitutes a novel posttranscriptional regulatory layer of the circadian gene network, which probably acts through a combination of small effects on mRNA stability of several auxiliary and some core-clock genes.
PMID: 36066193
Pest Manag Sci , IF:4.845 , 2022 Dec doi: 10.1002/ps.7294
The differential binding and biological efficacy of auxin herbicides.
School of Life Sciences, University of Warwick, Coventry, UK.; Corteva Agriscience, Crop Protection Discovery & Development, Indianapolis, Indiana, USA.
BACKGROUND: Auxin herbicides have been used for selective weed control for 75 years and they continue to be amongst the most widely used weed control agents globally. The auxin herbicides fall into five chemical classes, with two herbicides not classified, and in all cases it is anticipated that recognition in the plant starts with binding to the Transport Inhibitor Response 1 (TIR1) family of auxin receptors. There is evidence that some classes of auxins act selectively with certain clades of receptors, although a comprehensive structure-activity relationship has not been available. RESULTS: Using purified receptor proteins to measure binding efficacy we have conducted quantitative structure activity relationship (qSAR) assays using representative members of the three receptor clades in Arabidopsis, TIR1, AFB2 and AFB5. Complementary qSAR data for biological efficacy at the whole-plant level using root growth inhibition and foliar phytotoxicity assays have also been analyzed for each family of auxin herbicides, including for the afb5-1 receptor mutant line. CONCLUSIONS: Comparisons of all these assays highlight differences in receptor selectivity and some systematic differences between results for binding in vitro and activity in vivo. The results could provide insights into weed spectrum differences between the different classes of auxin herbicides, as well as the potential resistance and cross-resistance implications for this herbicide class. (c) 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
PMID: 36458868
Appl Microbiol Biotechnol , IF:4.813 , 2022 Nov , V106 (21) : P7027-7037 doi: 10.1007/s00253-022-12194-5
In vitro production of atractylon and beta-eudesmol from Atractylodes chinensis by adventitious root culture.
Key Laboratory of Forest Plant Ecology, Ministry of Education, Heilongjiang Provincial Key Laboratory of Ecological Utilization of Forestry-Based Active Substances, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China.; College of Forest Science, Kim Il Sung University, Pyongyang, 999093, Democratic People's Republic of Korea.; College of Life Science, Kim Il Sung University, Pyongyang, 999093, Democratic People's Republic of Korea.; Key Laboratory of Forest Plant Ecology, Ministry of Education, Heilongjiang Provincial Key Laboratory of Ecological Utilization of Forestry-Based Active Substances, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China. wjwang225@hotmail.com.; Key Laboratory of Forest Plant Ecology, Ministry of Education, Heilongjiang Provincial Key Laboratory of Ecological Utilization of Forestry-Based Active Substances, College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China. whm0709@163.com.
Atractylodes chinensis is a medicinal plant widely used for the treatment of gastric disorders, and its main bioactive compounds are atractylon and beta-eudesmol. This study was purposed to establish the adventitious root culture system of A. chinensis for in vitro production of atractylon and beta-eudesmol. The main parameters in the adventitious root induction and suspension cultures were optimized to maximize the culture efficiency. Adventitious roots were induced most efficiently from leaf explants on Murashige and Skoog (MS) solid medium containing 1.5 mg/L naphthaleneacetic acid (NAA) and 30 g/L sucrose with the highest root induction rate of approximately 92% and 12.9 roots per explant. During the adventitious root suspension culture, the root biomass and the accumulated content of the target compounds simultaneously increased to reach the maximum values after 8 weeks of culture. The maximum yield of the target compounds (total concentration 3.38 mg/g DW, total yield 2.66 mg) was achieved in the roots cultured in (1/2) MS liquid medium supplemented with 2.0 mg/L IBA, 3.2 mg/L NAA, and 40 g/L sucrose with the inoculum density of 8 g/L. Through the central composite design experiment, it was found that the combined use of different types of auxins in the suspension culture could further improve root growth and metabolite accumulation than the application of only one type of auxin. This work provides a new possibility to have a promising candidate for the industrial production of A. chinensis pharmaceuticals without relying on wild resources or field cultivation. KEY POINTS: * The induction culture was optimized for efficient root induction. * Suspension culture was optimized for the atractylon and beta-eudesmol production. * Combined use of different auxins improves root growth and metabolite accumulation.
PMID: 36171502
Plant Sci , IF:4.729 , 2022 Nov , V327 : P111536 doi: 10.1016/j.plantsci.2022.111536
A 2-bp deletion in the protein kinase domain region of the ERECTA-like receptor kinase gene in cucumber results in short internode phenotype.
School of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu 225009, China.; School of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, Jiangsu 225009, China.; Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China.; School of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu 225009, China. Electronic address: xhchen@yzu.edu.cn.
Cucumber varieties with shortend internodes require less space than regular vining varieties, thus have great significance for germplasm improvement. Here, we found a novel spontaneous cucumber mutant si107 that exhibited short intenodes (si), smaller leaves, fruits, and seeds. The decrease in longitudinal cell length led to the shortened internodes of si107. The genetic analysis revealed a single recessive gene si-2 that was responsible for the mutation. Through multiple lines of evidence, we demonstrated that CsSI is the possible candidate gene for si-2, which encodes an ERECTA leucine-rich repeat receptor-like kinase. The shortened internode in si107 is attributed to a 2-bp deletion in the protein kinase domain region of this gene. The expression of CsSI was higher in the internodes, petioles, and fruit peels of si107 than in the wild type (WT). The transcriptome analysis between the si107 mutant and WT indicated that differentially expressed genes were significantly enriched in the plant hormone signal transduction pathway, in which auxin signal genes comprised the largest group, and all were downregulated in si107. Phytohormone quantitation confirmed that endogenous auxin levels in the stems of si107 were decreased. Our results provide new insights into the molecular mechanisms underlying the internode length control in cucumber.
PMID: 36402238
Plant Sci , IF:4.729 , 2023 Jan , V326 : P111522 doi: 10.1016/j.plantsci.2022.111522
Transcription factor NtWRKY33a modulates the biosynthesis of polyphenols by targeting NtMYB4 and NtHCT genes in tobacco.
China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.; Technology Center, China Tobacco Hunan Industrial Co., Ltd., Changsha 410007, China.; Technology Center, China Tobacco Hunan Industrial Co., Ltd., Changsha 410007, China. Electronic address: hpj3508@126.com.; China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China. Electronic address: yangjun@ztri.com.cn.
There are abundant polyphenols in tobacco leaves mainly including chlorogenic acid (CGA), rutin, and scopoletin, which not only influence plant growth, development, and environmental adaptation, but also have a great impact on the industrial utilization of tobacco leaves. Few transcription factors regulating the biosynthesis of polyphenols have been identified in tobacco so far. In this study, two NtWRKY33 genes were identified from N. tabacum genome. NtWRKY33a showed higher transcriptional activity than NtWRKY33b, and encoded a nuclear localized protein. Overexpression and knock-out of NtWRKY33a gene revealed that NtWRKY33a inhibited the accumulation of rutin, scopoletin, and total polyphenols, but meanwhile promoted the biosynthesis of CGA. Chromatin immunoprecipitation and Dual-Luc assays indicated that NtWRKY33a could directly bind to the promoters of NtMYB4 and NtHCT, and thus induced the transcription of these two genes. The contents of polyphenols in ntwrky33a, ntmy4, and ntwrky33a/ntmyb4 mutants further confirmed that the repression of NtWRKY33a on the biosynthesis of rutin, scopoletin, and total polyphenols depends on the activity of NtMYB4. Moreover, the promotion of NtHCT by NtWRKY33a modulates the distribution of metabolism flux into the synthesis of CGA. Ectopic expression of NtWRKY33a inhibit the expression of NtSAUR14, NtSAUR59, NtSAUR66, NtIAA4, NtIAA17, and NtIAA19 genes, indicating that NtWRKY33a might be involved in the regulation of plant auxin response. Our study revealed new functions of NtWRKY33a in regulating the synthesis of polyphenols, and provided a promising target for manipulating polyphenols contents in tobacco.
PMID: 36332766
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111500 doi: 10.1016/j.plantsci.2022.111500
Molecular hydrogen positively influences lateral root formation by regulating hydrogen peroxide signaling.
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.; College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China. Electronic address: wbshenh@njau.edu.cn.
Although a previous study discovered that exogenous molecular hydrogen (H(2)) supplied with hydrogen-rich water (HRW) can mediate lateral root (LR) development, whether or how endogenous H(2) influences LR formation is still elusive. In this report, mimicking the induction responses in tomato seedlings achieved by HRW or exogenous hydrogen peroxide (H(2)O(2); a positive control), transgenic Arabidopsis that overexpressed the hydrogenase1 gene (CrHYD1) from Chlamydomonas reinhardtii not only stimulated endogenous hydrogen peroxide (H(2)O(2)) production, but also markedly promoted LR formation. Above H(2) and H(2)O(2) responses were abolished by the removal of endogenous H(2)O(2). Moreover, the changes in transcriptional patterns of representative cell cycle genes and auxin signaling-related genes during LR development in both tomato and transgenic Arabidopsis thaliana matched with above phenotypes. The alternations in the levels of GUS transcripts driven by the CYCB1 promoter and expression of PIN1 protein further indicated that H(2)O(2) synthesis was tightly linked to LR formation achieved by endogenous H(2), and cell cycle regulation and auxin-dependent pathway might be their targets. There results might provide a reference for molecular mechanism underlying the regulation of root morphogenesis by H(2).
PMID: 36257409
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111462 doi: 10.1016/j.plantsci.2022.111462
Overexpression of SmLAC25 promotes lignin accumulation and decreases salvianolic acid content in Salvia miltiorrhiza.
Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, College of Life Science, Shaanxi Normal University, Xi'an 710062, China.; College of Life Science and Food Engineering, Shaanxi Xueqian Normal University, Xi'an 710100, China.; Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, College of Life Science, Shaanxi Normal University, Xi'an 710062, China. Electronic address: Zhuxj2018@snnu.edu.cn.; Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, College of Life Science, Shaanxi Normal University, Xi'an 710062, China. Electronic address: caoxiaoyan@snnu.edu.cn.
Laccase (LAC) is a blue multicopper oxidase that contains four copper ions, which is involved in lignin polymerization and flavonoid biosynthesis in plants. Although dozens of LAC genes have been identified in Salvia miltiorrhiza Bunge (a model medicinal plant), most have not been functionally characterized. Here, we explored the expression patterns and the functionality of SmLAC25 in S. miltiorrhiza. SmLAC25 has a higher expression level in roots and responds to methyl jasmonate, auxin, abscisic acid, and gibberellin stimuli. The SmLAC25 protein is localized in the cytoplasm and chloroplasts. Recombinant SmLAC25 protein could oxidize coniferyl alcohol and sinapyl alcohol, two monomers of G-lignin and S-lignin. To investigate its function, we generated SmLAC25-overexpressed S. miltiorrhiza plantlets and hairy roots. The lignin content increased significantly in all SmLAC25-overexpressed plantlets and hairy roots, compared with the controls. However, the concentrations of rosmarinic acid and salvianolic acid B decreased significantly in all the SmLAC25-overexpressed lines. Further studies revealed that the transcription levels of some key enzyme genes in the lignin synthesis pathway (e.g., SmCCR and SmCOMT) were significantly improved in the SmLAC25-overexpressed lines, while the expression levels of multiple enzyme genes in the salvianolic acid biosynthesis pathway were inhibited. We speculated that the overexpression of SmLAC25 promoted the metabolic flux of lignin synthesis, which resulted in a decreased metabolic flux to the salvianolic acid biosynthesis pathway.
PMID: 36126879
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111461 doi: 10.1016/j.plantsci.2022.111461
Dissection of transcriptome and metabolome insights into the isoquinoline alkaloid biosynthesis during stem development in Phellodendron amurense (Rupr.).
Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China; State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 15004, China. Electronic address: lx2016bjfu@163.com.; State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 15004, China. Electronic address: ckwnefu@163.com.; Linjiang Forestry Bureau of Jilin Province, Linjiang 134600, China. Electronic address: 38047646@qq.com.; Linjiang Forestry Bureau of Jilin Province, Linjiang 134600, China. Electronic address: 67651509@qq.com.; Linjiang Forestry Bureau of Jilin Province, Linjiang 134600, China. Electronic address: 18314591710@163.com.; Linjiang Forestry Bureau of Jilin Province, Linjiang 134600, China. Electronic address: 893483624@qq.com.; Linjiang Forestry Bureau of Jilin Province, Linjiang 134600, China. Electronic address: 1604861006@qq.com.; Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China. Electronic address: xiaonapei2020@163.com.; Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China; State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 15004, China. Electronic address: zhaoxyphd@163.com.
Phellodendron amurense (Rupr.) is a well-known medicinal plant with high medicinal value, and its various tissues are enriched in various active pharmaceutical ingredients. Isoquinoline alkaloids are the primary medicinal component of P. amurense and have multiple effects, such as anti-inflammation, antihypertension, and antitumor effects. However, the potential regulatory mechanism of isoquinoline alkaloid biosynthesis during stem development in P. amurense is still poorly understood. In the present study, a total of eight plant hormones for each stem development stage were detected; of those, auxin, gibberellins and brassinosteroids were significantly highly increased in perennial stems and played key roles during stem development in P. amurense. We also investigated the content and change pattern of secondary metabolites and comprehensively identified some key structural genes involved in the isoquinoline alkaloid biosynthesis pathway by combining the transcriptome and metabolomics. A total of 39,978 DEGs were identified in the present study, and six of those had candidate structural genes (NCS, GOT2, TYNA, CODM, TYR, TAT and PSOMT1) that were specifically related to isoquinoline alkaloid biosynthesis in P. amurense. Corydalmine, cyclanoline, dehydroyanhunine, (S)-canadine and corybulbine were the most significantly upregulated metabolites among the different comparative groups. Three differentially expressed metabolites, dopamine, (S)-corytuberine and (S)-canadine, were enriched in the isoquinoline alkaloid biosynthesis pathway. Furthermore, bHLH and WRKY transcription factors play key roles in the isoquinoline alkaloid biosynthesis pathway in P. amurense. The results not only provide comprehensive genetic information for understanding the molecular mechanisms of isoquinoline alkaloid biosynthesis but also lay a foundation for the combinatory usage of the medicinal active ingredient of P. amurense.
PMID: 36122814
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111459 doi: 10.1016/j.plantsci.2022.111459
ZmDWF1 regulates leaf angle in maize.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.; College of Agronomy, National Key Laboratory of Wheat and Maize Crop Science and Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, No. 15 Longzihu University Park, Zhengdong New Area, Zhengzhou, Henan 450046, China; Henan Academy of Agricultural Science, Zhengzhou, Henan 450002, China.; College of Agronomy, National Key Laboratory of Wheat and Maize Crop Science and Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, No. 15 Longzihu University Park, Zhengdong New Area, Zhengzhou, Henan 450046, China.; College of Agronomy, National Key Laboratory of Wheat and Maize Crop Science and Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, No. 15 Longzihu University Park, Zhengdong New Area, Zhengzhou, Henan 450046, China. Electronic address: kulixia0371@163.com.
Leaf angle (LA) is a critical agronomic trait enhancing grain yield under high-density planting in maize. A number of researches have been conducted in recent years to investigate the quantitative trait loci/genes responsible for LA variation, while only a few genes were identified through map-based cloning. Here we cloned the ZmDWF1 gene, which was previously reported to encode Delta24-sterol reductase in the brassinosteroids (BRs) biosynthesis pathway. Overexpression of ZmDWF1 resulted in enlarged LA, indicating that ZmDWF1 is a positive regulator of LA in maize. To reveal the regulatory framework of ZmDWF1, we conducted RNA-Sequencing and yeast-two hybrid (Y2H) screening analysis. RNA-Sequencing analyzing results indicate ZmDWF1 mainly affected expression level of genes involved in cell wall associated metabolism and hormone metabolism including BR, gibberellin, and auxin. Y2H screening with Bi-FC assay confirmed three proteins (ZmPP2C-1, ZmROF1, and ZmTWD1) interacting with ZmDWF1. We revealed a new regulatory network of ZmDWF1 gene in controlling plant architecture in maize.
PMID: 36113675
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111456 doi: 10.1016/j.plantsci.2022.111456
The cytokinin type-B response regulator PeRR12 is a negative regulator of adventitious rooting and salt tolerance in poplar.
Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China. Electronic address: HaoranQi@njfu.edu.cn.; Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China; Institute of Pomology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. Electronic address: hengcai@njfu.edu.cn.; Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China. Electronic address: chicta@163.com.; Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China. Electronic address: sianliu@yzu.edu.cn.; State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China. Electronic address: changjunding@caf.ac.cn.; Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China. Electronic address: xum@njfu.edu.cn.
Adventitious root (AR) development is an ecologically and economically important biological process that maintains ecological balance, improves plant survivability, and allows for massive vegetative propagation, but its genetic mechanisms are not well understood. Here, eight Arabidopsis response regulator (ARR) genes were cloned and identified in poplar, most of which were detected in the AR, phloem, and xylem and showed remarkable induction at different time points during AR development. Subcellular localization indicated that most of these PeRR genes are in the nucleus. Based on qRT-PCR expression analysis of some genes related to AR development, we inferred that overexpression of PeRR12 (OE_PeRR12) may inhibited AR formation by suppressing the transcription of PeWOX11, PeWOX5, PePIN1 and PePIN3 in poplar while promoting type-A RR transcripts. Correspondingly, exogenous auxin partially restored the rooting of OE_PeRR12 poplar by inhibiting PeRR12 expression. Moreover, the activities of the antioxidant systems of OE_PeRR12 poplars were lower than those of wild-type poplars under salt stress conditions, indicating that PeRR12 may acts as a repressor that mediates salt tolerance by suppressing the expression of PeHKT1;1. Altogether, these results suggest that PeRR12 plays essential roles in mediating AR formation and salinity tolerance in poplar.
PMID: 36087886
Plant Sci , IF:4.729 , 2022 Nov , V324 : P111421 doi: 10.1016/j.plantsci.2022.111421
AtHB40 modulates primary root length and gravitropism involving CYCLINB and auxin transporters.
Instituto de Agrobiotecnologia del Litoral (CONICET, Universidad Nacional del Litoral, FBCB), Colectora Ruta Nacional 168, km 0, 3000 Santa Fe, Argentina.; Centro Nacional de Biotecnologia (CNB) - CSIC, Madrid, Spain.; Instituto de Agrobiotecnologia del Litoral (CONICET, Universidad Nacional del Litoral, FBCB), Colectora Ruta Nacional 168, km 0, 3000 Santa Fe, Argentina. Electronic address: rchan@fbcb.unl.edu.ar.
Gravitropism is a finely regulated tropistic response based on the plant perception of directional cues. Such perception allows them to direct shoot growth upwards, above ground, and root growth downwards, into the soil, anchoring the plant to acquire water and nutrients. Gravity sensing occurs in specialized cells and depends on auxin distribution, regulated by influx/efflux carriers. Here we report that AtHB40, encoding a transcription factor of the homeodomain-leucine zipper I family, was expressed in the columella and the root tip. Athb40 mutants exhibited longer primary roots. Enhanced primary root elongation was in agreement with a higher number of cells in the transition zone and the induction of CYCLINB transcript levels. Moreover, athb40 mutants and AtHB40 overexpressors displayed enhanced and delayed gravitropistic responses, respectively. These phenotypes were associated with altered auxin distribution and deregulated expression of the auxin transporters LAX2, LAX3, and PIN2. Accordingly, lax2 and lax3 mutants also showed an altered gravitropistic response, and LAX3 was identified as a direct target of AtHB40. Furthermore, AtHB40 is induced by AtHB53 when the latter is upregulated by auxin. Altogether, these results indicate that AtHB40 modulates cell division and auxin distribution in the root tip thus altering primary root length and gravitropism.
PMID: 35995111
Environ Geochem Health , IF:4.609 , 2022 Nov , V44 (11) : P3743-3764 doi: 10.1007/s10653-021-01179-4
The role of auxins and auxin-producing bacteria in the tolerance and accumulation of cadmium by plants.
Posgrado en Ciencias Quimicas, Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Avenida Dr. Manuel Nava 6, Zona Universitaria, 78210, San Luis Potosi, San Luis Potosi, Mexico.; Facultad de Estudios Profesionales Zona Huasteca, Universidad Autonoma de San Luis Potosi, Romualdo del Campo 501, Fraccionamiento Rafael Curiel, 79060, Ciudad Valles, San Luis Potosi, Mexico.; Secretaria de Investigacion y Posgrado, Centro Nayarita de Innovacion y Transferencia de Tecnologia (CENITT), Universidad Autonoma de Nayarit, Tepic, Nayarit, Mexico.; Facultad de Quimica, Universidad Autonoma de Queretaro, Santiago de Queretaro, Queretaro, Mexico.; Colegio de Postgraduados Campus Campeche, Campeche, Campeche, Mexico.; Posgrado en Ciencias Quimicas, Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Avenida Dr. Manuel Nava 6, Zona Universitaria, 78210, San Luis Potosi, San Luis Potosi, Mexico. alejandro.hernandez@uaslp.mx.; Facultad de Estudios Profesionales Zona Huasteca, Universidad Autonoma de San Luis Potosi, Romualdo del Campo 501, Fraccionamiento Rafael Curiel, 79060, Ciudad Valles, San Luis Potosi, Mexico. alejandro.hernandez@uaslp.mx.
Cadmium (Cd) is one of the most toxic heavy metals for plant physiology and development. This review discusses Cd effects on auxin biosynthesis and homeostasis, and the strategies for restoring plant growth based on exogenous auxin application. First, the two well-characterized auxin biosynthesis pathways in plants are described, as well as the effect of exogenous auxin application on plant growth. Then, review describes the impacts of Cd on the content, biosynthesis, conjugation, and oxidation of endogenous auxins, which are related to a decrease in root development, photosynthesis, and biomass production. Finally, compelling evidence of the beneficial effects of auxin-producing rhizobacteria in plants exposed to Cd is showed, focusing on photosynthesis, oxidative stress, and production of antioxidant compounds and osmolytes that counteract Cd toxicity, favoring plant growth and improve phytoremediation efficiency. Expanding our understanding of the positive effects of exogenous auxins application and the interactions between bacteria and plants growing in Cd-polluted environments will allow us to propose phytoremediation strategies for restoring environments contaminated with this metal.
PMID: 35022877
Front Genet , IF:4.599 , 2022 , V13 : P984720 doi: 10.3389/fgene.2022.984720
Genome-wide association studies reveal putative QTLs for physiological traits under contrasting phosphorous conditions in wheat (Triticum aestivum L.).
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.; ICAR- National Institute for Plant Biotechnology, New Delhi, India.; Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.; Division of Environment Science, ICAR-Indian Agricultural Research Institute, New Delhi, India.; Centre for Quantitative Genetics and Genomics (QGG), Aarhus University, Aarhus, Denmark.
A Genome-wide association (GWAS) study was conducted for phosphorous (P)-use responsive physiological traits in bread wheat at the seedling stage under contrasting P regimes. A panel of 158 diverse advanced breeding lines and released varieties, and a set of 10,800 filtered single nucleotide polymorphism (SNP) markers were used to study marker-trait associations over the eight shoot traits. Principle component analysis separated the two environments (P regimes) because of the differential response of the traits indicating the essentiality of the separate breeding programmes for each environment. Significant variations for genotypic, environmental, and genotype x environment (GEI) effects were observed for all the traits in the combined analysis of variance with moderately high broad sense heritability traits (0.50-0.73). With the different algorithms of association mapping viz., BLINK, FarmCPU, and MLM, 38 unique QTLs under non-limiting P (NLP) and 45 QTLs for limiting P (LP) conditions for various shoot traits were identified. Some of these QTLs were captured by all three algorithms. Interestingly, a Q.iari.dt.sdw.1 on chromosome 1D was found to explain the significant variations in three important physiological traits under non-limiting phosphorus (NLP) conditions. We identified the putative candidate genes for QTLs namely Q.iari.dt.chl.1, Q.iari.dt.sdw.16, Q.iari.dt.sdw.9 and Q.iari.dt.tpc.1 which are potentially involved in the mechanism regulating phosphorus use efficiency through improved P absorption due to improved root architectural traits and better mobilization such as sulfotransferase involved in postembryonic root development, WALLS ARE THIN1 (WAT1), a plant-specific protein that facilitates auxin export; lectin receptor-like kinase essentially involved in plant development, stress response during germination and lateral root development and F-box component of the SKP-Cullin-F box E3 ubiquitin ligase complex and strigolactone signal perception. Expression profiling of putative genes located in identified genomic regions against the wheat expression atlas revealed their significance based on the expression of these genes for stress response and growth development processes in wheat. Our results thus provide an important insight into understanding the genetic basis for improving PUE under phosphorus stress conditions and can shape the future breeding programme by developing and integrating molecular markers for these difficult-to-score important traits.
PMID: 36437925
Plant Cell Rep , IF:4.57 , 2022 Dec doi: 10.1007/s00299-022-02965-9
The Aux/IAA protein TaIAA15-1A confers drought tolerance in Brachypodium by regulating abscisic acid signal pathway.
College of Agronomy, Liaocheng University, Liaocheng, 252059, People's Republic of China. pssu2014@163.com.; College of Agronomy, Liaocheng University, Liaocheng, 252059, People's Republic of China.; College of Agronomy, Liaocheng University, Liaocheng, 252059, People's Republic of China. guoshangjing@lcu.edu.cn.
Overexpression of the Aux/IAA protein TaIAA15-1A from wheat improves drought tolerance by regulating the ABA signalling pathway in transgenic Brachypodium. Drought is a major abiotic stress that causes severe crop yield loss. Aux/IAA genes have been shown to be involved in drought stress responses. However, to the best of our knowledge, there has been little research on the molecular mechanism of the wheat Aux/IAA gene in the context of drought tolerance. In this study, we found that expression of the wheat Aux/IAA gene TaIAA15-1A was upregulated by PEG6000, NaCl, SA, JA, IAA and ABA. Transgenic plants overexpressing TaIAA15-1A showed higher drought tolerance than wild-type (WT) plants. The physiological analyses showed that the transgenic lines exhibited a higher survival rate, shoot length, and relative water content than the WT plants. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were enhanced in transgenic lines, causing a reduction in the hydrogen peroxide (H(2)O(2)) and superoxide anion radical (O(2)(-)) contents. Transcriptome analysis showed that TaIAA15-1A overexpression alters the expression of these genes involved in the auxin signalling pathway, ABA signalling pathway, phenolamides and antioxidant pathways. The results of exogenous ABA treatment suggested that TaIAA15-1A overexpression increased sensitivity to ABA at the germination and postgermination stages compared to WT plants. These results indicate that TaIAA15-1A plays a positive role in plant drought tolerance by regulating ABA-related genes and improving antioxidative stress ability and has potential application in genetically modified crops.
PMID: 36566287
Plant Cell Rep , IF:4.57 , 2022 Dec doi: 10.1007/s00299-022-02956-w
Auxin and CmAP1 regulate the reproductive development of axillary buds in Chinese chestnut (Castanea mollissima).
Engineering and Technology Research Center for Chestnut of National Forestry and Grassland Administration, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China) of Ministry of Agriculture, Beijing Engineering Research Center for Deciduous Fruit Trees, Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Ruiwangfeng No. 12, Haidian, Beijing, 100093, China.; College of Forestry, Shenyang Agriculture University, Shenyang, 110866, Liaoning, China.; Engineering and Technology Research Center for Chestnut of National Forestry and Grassland Administration, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China) of Ministry of Agriculture, Beijing Engineering Research Center for Deciduous Fruit Trees, Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Ruiwangfeng No. 12, Haidian, Beijing, 100093, China. lanyanping2000@126.com.
Auxin accumulation upregulates the expression of APETALA1 (CmAP1) and subsequently activates inflorescence primordium development in axillary buds of chestnut. The architecture of fruiting branches is a key determinant of chestnut yield. Normally, axillary buds at the top of mother fruiting branches develop into flowering shoots and bear fruits, and the lower axillary buds develop into vegetative shoots. Decapitation of the upper axillary buds induces the lower buds to develop into flowering shoots. How decapitation modulates the tradeoff between vegetative and reproductive development is unclear. We detected inflorescence primordia within both upper and lower axillary buds on mother fruiting branches. The level of the phytohormones 3-indoleacetic acid (IAA) and trans-zeatin (tZ) increased in the lower axillary buds in response to decapitation. Exogenous application of the synthetic analogues 1-naphthylacetic acid (NAA) or 6-benzyladenine (6-BA) blocked or promoted, respectively, the development of the inflorescence primordia in axillary buds. The transcript levels of the floral identity gene CmAP1 increased in axillary buds following decapitation. An auxin response element TGA-box is present in the CmAP1 promoter and influenced the CmAP1 promoter-driven expression of beta-glucuronidase (GUS) in floral organs in Arabidopsis, suggesting that CmAP1 is induced by auxin. We propose that decapitation releases axillary bud outgrowth from inhibition caused by apical dominance. During this process, decapitation-induced accumulation of auxin induces CmAP1 expression, subsequently promoting the reproductive development of axillary buds.
PMID: 36528704
Plant Cell Rep , IF:4.57 , 2022 Dec doi: 10.1007/s00299-022-02963-x
The AP2/ERF transcription factor SlERF.J2 functions in hypocotyl elongation and plant height in tomato.
Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China. chenguoping@cqu.edu.cn.; Room 523, Bioengineering College, Chongqing University, Campus B, 174 Shapingba Main Street, Chongqing, 400030, People's Republic of China. chenguoping@cqu.edu.cn.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China. huzongli71@163.com.; Room 521, Bioengineering College, Chongqing University, Campus B, 174 Shapingba Main Street, Chongqing, 400030, People's Republic of China. huzongli71@163.com.
Our findings indicated that the SlERF.J2-IAA23 module integrates hormonal signals to regulate hypocotyl elongation and plant height in tomato. Light and phytohormones can synergistically regulate photomorphogenesis-related hypocotyl elongation and plant height in tomato. AP2/ERF family genes have been extensively demonstrated to play a role in light signaling and various hormones. In this study, we identified a novel AP2/ERF family gene in tomato, SlERF.J2. Overexpression of SlERF.J2 inhibits hypocotyl elongation and plant height. However, the plant height in the slerf.j2(ko) knockout mutant was not significantly changed compared with the WT. we found that hypocotyl cell elongation and plant height were regulated by a network involving light, auxin and gibberellin signaling, which is mediated by regulatory relationship between SlERF.J2 and IAA23. SlERF.J2 protein could bind to IAA23 promoter and inhibit its expression. In addition, light-dark alternation can activate the transcription of SlERF.J2 and promote the function of SlERF.J2 in photomorphogenesis. Our findings indicated that the SlERF.J2-IAA23 module integrates hormonal signals to regulate hypocotyl elongation and plant height in tomato.
PMID: 36512035
Plant Cell Rep , IF:4.57 , 2022 Dec , V41 (12) : P2415-2422 doi: 10.1007/s00299-022-02932-4
Ectopic expression of WOX5 promotes cytokinin signaling and de novo shoot regeneration.
Department of Chemistry, Seoul National University, Seoul, 08826, Korea.; Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, Korea.; Division of Horticultural Biotechnology, School of Biotechnology, Hankyong National University, Anseong, 17579, Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea.; Division of Horticultural Biotechnology, School of Biotechnology, Hankyong National University, Anseong, 17579, Korea. yuyu1216@hknu.ac.kr.; Department of Chemistry, Seoul National University, Seoul, 08826, Korea. pjseo1@snu.ac.kr.; Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, Korea. pjseo1@snu.ac.kr.; Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea. pjseo1@snu.ac.kr.
WOX5 has a potential in activating cytokinin signaling and shoot regeneration, in addition to its role in pluripotency acquisition. Thus, overexpression of WOX5 maximizes plant regeneration capacity during tissue culture. In vitro plant regeneration involves two steps: callus formation and de novo shoot organogenesis. The WUSCHEL-RELATED HOMEOBOX 5 (WOX5) homeodomain transcription factor is known to be mainly expressed during incubation on callus-inducing medium (CIM) and involved in pluripotency acquisition in callus, but whether WOX5 also affects de novo shoot regeneration on cytokinin-rich shoot-inducing medium (SIM) remains unknown. Based on the recent finding that WOX5 promotes cytokinin signaling, we hypothesized that ectopic expression of WOX5 beyond CIM would further enhance overall plant regeneration capacity, because intense cytokinin signaling is particularly required for shoot regeneration on SIM. Here, we found that overexpression of the WOX5 gene on SIM drastically promoted de novo shoot regeneration from callus with the repression of type-A ARABIDOPSIS RESPONSE REGULATOR (ARR) genes, negative regulators of cytokinin signaling. The enhanced shoot regeneration phenotypes were indeed dependent on cytokinin signaling, which were partially suppressed in the progeny derived from crossing WOX5-overexpressing plants with cytokinin-insensitive 35S:ARR7 plants. The function of WOX5 in enhancing cytokinin-dependent shoot regeneration is evolutionarily conserved, as conditional overexpression of OsWOX5 on SIM profoundly enhanced shoot regeneration in rice callus. Overall, our results provide the technical advance that maximizes in vitro plant regeneration by constitutively expressing WOX5, which unequivocally promotes both callus pluripotency and de novo shoot regeneration.
PMID: 36219248
Plant Cell Rep , IF:4.57 , 2022 Dec , V41 (12) : P2363-2378 doi: 10.1007/s00299-022-02928-0
Switching cell fate by the actin-auxin oscillator in Taxus: cellular aspects of plant cell fermentation.
Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany.; Institute of Pharmacy, Martin-Luther-University, Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany.; Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131, Karlsruhe, Germany. peter.nick@kit.edu.
Paclitaxel synthesis in Taxus cells correlates with a cell-fate switch that leads to vacuoles of a glossy appearance and vermiform mitochondria. This switch depends on actin and apoplastic respiratory burst. Plant cell fermentation, the production of valuable products in plant cell culture, has great potential as sustainable alternative to the exploitation of natural resources for compounds of pharmaceutical interest. However, the success of this approach has remained limited, because the cellular aspects of metabolic competence are mostly unknown. The production of the anti-cancer alkaloid Paclitaxel has been, so far, the most successful case for this approach. In the current work, we map cellular aspects of alkaloid synthesis in cells of Taxus chinensis using a combination of live-cell imaging, quantitative physiology, and metabolite analysis. We show evidence that metabolic potency correlates with a differentiation event giving rise to cells with large vacuoles with a tonoplast that is of a glossy appearance, agglomerations of lipophilic compounds, and multivesicular bodies that fuse with the plasma membrane. Cellular features of these glossy cells are bundled actin, more numerous peroxisomes, and vermiform mitochondria. The incidence of glossy cells can be increased by aluminium ions, and this increase is significantly reduced by the actin inhibitor Latrunculin B, and by diphenylene iodonium, a specific inhibitor of the NADPH oxidase Respiratory burst oxidase Homologue (RboH). It is also reduced by the artificial auxin Picloram. This cellular fingerprint matches the implications of a model, where the differentiation into the glossy cell type is regulated by the actin-auxin oscillator that in plant cells acts as dynamic switch between growth and defence.
PMID: 36214871
Plant Cell Rep , IF:4.57 , 2022 Dec , V41 (12) : P2293-2303 doi: 10.1007/s00299-022-02921-7
Disruption of transcription factor RhMYB123 causes the transformation of stamen to malformed petal in rose (Rosa hybrida).
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, China.; School of Applied Chemistry and Biotechnology, Shenzhen Polytechnic, Shenzhen, China.; Yunnan Yuntianhua Modern Agriculture Development Co., Ltd, Kunming, China.; College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.; Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, China. zhouxiaofeng@cau.edu.cn.
We find that the R2R3 MYB transcription factor RhMYB123 has a novel function to regulate stamen-petal organ specification in rose. Rose is one of the ornamental plants with economic importance worldwide. Malformed flower seriously affects the ornamental value and fertility of rose. However, the regulatory mechanism is largely unknown. In this work, we identified a R2R3 MYB transcription factor RhMYB123 from rose, the expression of which significantly decreased from flower differentiation stage to floral organ development stage. Phylogenetic analysis indicated that it belongs to the same subgroup as MYB123 of Arabidopsis and located in nucleus. In addition, RhMYB123 was confirmed to have transcriptional activation function by dual luciferase assay. Silencing RhMYB123 using Virus-Induced Gene Silencing (VIGS) in rose could increase the number of malformed petaloid stamen. Furthermore, we identified 549 differential expressed genes (DEGs) in TRV-RhMYB123 lines compared to TRV controls by RNA-seq of floral buds (flower differentiation stage). Among of those genes, expression of 3 MADS box family genes related to floral organ development reduced in TRV-RhMYB123 lines, including AGAMOUS (RhAG), AGAMOUS LIKE 15 (RhAGL15), and SHATTERPROOF 1 (RhSHP1). Given, previous studies have shown that auxin plays a crucial role in floral meristem initiation and stamen-petal organ specification. We also found 6 DEGs were involved in auxin signal transduction, of which five were reduced expression in TRV-RhMYB123. Taken together, our findings suggested that RhMYB123 may govern the development of malformed petaloid stamen by regulating the expressions of some MADS box family members and auxin signaling pathway elements.
PMID: 35999377
Physiol Plant , IF:4.5 , 2022 Nov , V174 (6) : Pe13805 doi: 10.1111/ppl.13805
Transcriptome analysis of perennial ryegrass reveals the regulatory role of Aspergillus aculeatus under salt stress.
Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, Shandong, China.; CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan, China.
Perennial ryegrass (Lolium perenne) is an important turf grass and forage grass with moderately tolerant to salinity stress. Aspergillus aculeatus has been documented to involved in salt stress response of perennial ryegrass, while the A. aculeatus-mediated molecular mechanisms are unclear. Therefore, to investigate the molecular mechanisms underlying A. aculeatus-mediated salt tolerance, the comprehensive transcriptome analysis of the perennial ryegrass roots was performed. Twelve cDNA libraries from roots were constructed after 12 h of plant-fungus cocultivation under 300 mM salt stress concentrations. A total of 21,915 differentially expressed genes (DEGs) were identified through pairwise comparisons. Enrichment analysis revealed that potentially important A. aculeatus-induced salt responsive genes belonging to specific categories, such as hormonal metabolism (auxin and salicylic acid metabolism related genes), secondary metabolism (flavonoid's metabolism related genes) and transcription factors (MYB, HSF and AP2/EREBP family). In addition, weighted gene co-expression network analysis (WGCNA) showed that blue and black modules were significantly positively correlated with the peroxidase activity and proline content, then the hub genes within these two modules were further identified. Taken together, we found the categories of A. aculeatus-induced salt responsive genes, revealing underlying fungus-induced molecular mechanisms of salt stress response in perennial ryegrass roots. Besides, fungus-induced salt-tolerant hub genes represent a foundation for further exploring the molecular mechanisms.
PMID: 36270788
Nitric Oxide , IF:4.427 , 2023 Jan , V130 : P36-57 doi: 10.1016/j.niox.2022.11.004
Say "NO" to plant stresses: Unravelling the role of nitric oxide under abiotic and biotic stress.
Department of Zoology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India. Electronic address: deepdhaka415@gmail.com.; Department of Zoology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India. Electronic address: ohri_puja_11@rediffmail.com.
Nitric oxide (NO) is a diatomic gaseous molecule, which plays different roles in different strata of organisms. Discovered as a neurotransmitter in animals, NO has now gained a significant place in plant signaling cascade. NO regulates plant growth and several developmental processes including germination, root formation, stomatal movement, maturation and defense in plants. Due to its gaseous state, it is unchallenging for NO to reach different parts of cell and counterpoise antioxidant pool. Various abiotic and biotic stresses act on plants and affect their growth and development. NO plays a pivotal role in alleviating toxic effects caused by various stressors by modulating oxidative stress, antioxidant defense mechanism, metal transport and ion homeostasis. It also modulates the activity of some transcriptional factors during stress conditions in plants. Besides its role during stress conditions, interaction of NO with other signaling molecules such as other gasotransmitters (hydrogen sulfide), phytohormones (abscisic acid, salicylic acid, jasmonic acid, gibberellin, ethylene, brassinosteroids, cytokinins and auxin), ions, polyamines, etc. has been demonstrated. These interactions play vital role in alleviating plant stress by modulating defense mechanisms in plants. Taking all these aspects into consideration, the current review focuses on the role of NO and its interaction with other signaling molecules in regulating plant growth and development, particularly under stressed conditions.
PMID: 36460229
Sci Rep , IF:4.379 , 2022 Dec , V12 (1) : P21124 doi: 10.1038/s41598-022-25731-z
Characteristics of rhizosphere and endogenous bacterial community of Ulleung-sanmaneul, an endemic plant in Korea: application for alleviating salt stress.
Division of Biotechnology, Jeonbuk National University, 79 Gobong-ro, Iksan-si, Jeollabuk-do, 54596, Republic of Korea.; Wild Plants and Seeds Conservation Department, Baekdudaegan National Arboretum, Bonghwa-gun, Gyeongsangbuk-do, 36209, Republic of Korea.; Division of Biotechnology, Jeonbuk National University, 79 Gobong-ro, Iksan-si, Jeollabuk-do, 54596, Republic of Korea. yonghoonlee@jbnu.ac.kr.; Advanced Institute of Environment and Bioscience, Plant Medical Research Center, and Institute of Bio-Industry, Jeonbuk National University, Jeonju-si, Republic of Korea. yonghoonlee@jbnu.ac.kr.
Microbes influence plant growth and fitness. However, the structure and function of microbiomes associated with rare and endemic plants remain underexplored. To investigate the bacterial community structure of Ulleung-sanmaneul (U-SMN), an endemic plant in Korea, samples were collected from natural and cultivated habitats, and their 16S rDNA was sequenced. The root bacterial community structure differed from those of bulk soil and rhizosphere in both habitats. Endogenous bacteria in cultivated plants were less diverse than wild plants, but Luteibacter rhizovicinus, Pseudomonas fulva, and Sphingomonas pruni were shared. Co-inoculation of Pseudoxanthomonas sp. JBCE485 and Variovorax paradoxus JBCE486 promoted growth and induced salt stress resistance in Arabidopsis and chive. Changes in growth promotion and phenotypes of plants by co-inoculation were mediated by increased auxin production. Each strain colonized the roots without niche competition. The results indicated that host selectivity was influential than environmental factors in formulating endophytic bacterial composition, and domestication simplified the bacterial community diversity. Our results will contribute to the growth and maintenance of endemic U-SMN plants.
PMID: 36476722
Sci Rep , IF:4.379 , 2022 Dec , V12 (1) : P20771 doi: 10.1038/s41598-022-25132-2
Comparative transcriptomics reveals commonalities and differences in the genetic underpinnings of a floral dimorphism.
Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland. giacomo.potente@uzh.ch.; BaseClear BV, Leiden, The Netherlands. giacomo.potente@uzh.ch.; Zurich-Basel Plant Science Center, Zurich, Switzerland. giacomo.potente@uzh.ch.; Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland.; BaseClear BV, Leiden, The Netherlands.; Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.; Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland. peter.szoevenyi@systbot.uzh.ch.; Zurich-Basel Plant Science Center, Zurich, Switzerland. peter.szoevenyi@systbot.uzh.ch.; Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland. elena.conti@systbot.uzh.ch.; Zurich-Basel Plant Science Center, Zurich, Switzerland. elena.conti@systbot.uzh.ch.
Distyly, a floral dimorphism associated with heteromorphic self-incompatibility and controlled by the S-locus supergene, evolved independently multiple times. Comparative analyses of the first transcriptome atlas for the main distyly model, Primula veris, with other distylous species produced the following findings. A set of 53 constitutively expressed genes in P. veris did not include any of the housekeeping genes commonly used to normalize gene expression in qPCR experiments. The S-locus gene CYP(T) acquired its role in controlling style elongation via a change in expression profile. Comparison of genes differentially expressed between floral morphs revealed that brassinosteroids and auxin are the main hormones controlling style elongation in P. veris and Fagopyrum esculentum, respectively. Furthermore, shared biochemical pathways might underlie the expression of distyly in the distantly related P. veris, F. esculentum and Turnera subulata, suggesting a degree of correspondence between evolutionary convergence at phenotypic and molecular levels. Finally, we provide the first evidence supporting the previously proposed hypothesis that distyly supergenes of distantly related species evolved via the recruitment of genes related to the phytochrome-interacting factor (PIF) signaling network. To conclude, this is the first study that discovered homologous genes involved in the control of distyly in distantly related taxa.
PMID: 36456708
Sci Rep , IF:4.379 , 2022 Nov , V12 (1) : P18436 doi: 10.1038/s41598-022-22986-4
In vitro regeneration and its histological characteristics of Dioscorea nipponica Makino.
College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, China.; College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, China. sxndgrm@163.com.
Dioscorea nipponica Makino is an optimal candidate to develop the diosgenin industry in North China. Due to its increasing demand in the medicine industry, it is urgent to apply new biotechnological tools to foster breeds with desirable traits and enhanced secondary metabolite production. The production of useful metabolites by the in vitro cultured rhizomes can be explored successfully for utilization by various food and drug industries. In this study, we reported callus formation and plantlet regeneration of the medicinal plant D. nipponica. Explants of leaves, stem segments and rhizomes of aseptic seedlings were cultured on Murashige and Skoog (MS) medium containing various combinations of auxin and cytokinin to find the optimal PGRs of each type of explant for callus induction and shoot regeneration of D. nipponica. The paraffin section technique was also used to observe of the morphogenesis of callus and adventitious bud. Explants of seeds and rhizomes formed calli at high frequency in all lines we examined. However, the explant of leaves rarely formed callus. Three kinds of callus were detected during the induction phase. Here, we describe three types of callus (Callus I-III) with different structure characteristics. Greenish in color and a nodule-like protrusion surface (Callus type III) were arranged more closely of cells with less interstitial substance, cell differentiation ability stronger than other callus types. The optimum combination was the maximum shoot differentiation frequency of 90% in callus derived from seeds cultured on MS medium with 2.0 mg L(-1)6-BA + 0.2 mg L(-1)NAA. The shoot differentiation frequency (88.57%) of rhizome-induced callus was obtained by the combination of MS medium supplemented with 3.0 mg L(-1)6-BA + 2.0 mg L(-1)NAA. 1/2 MS medium plus 0.5 mg L(-1)NAA resulted in a higher root regeneration frequency of 86.70%. In vitro propagated plantlets with healthy roots were domesticated and transplanted into small plastic pots containing sterile soil rite under greenhouse conditions with 80% survivability. Bud differentiation is mostly of exogenous origin, mostly occurring on the near callus surface. Therefore, it may be surmised that in vitro morphogenesis of D. nipponica is mainly caused by indirect organogenesis (adventitious bud).
PMID: 36319819
Ann Bot , IF:4.357 , 2022 Dec doi: 10.1093/aob/mcac161
Specificity in root domain-accumulation of Phytoglobin1 and nitric oxide (NO) determines meristematic viability in water-stressed Brassica napus roots.
Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.; Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
BACKGROUND AND AIMS: Drought reduces plant productivity, especially in the susceptible species Brassica napus. Water stress, mimicked by applications of 10% polyethylene glycol (PEG), elevates nitric oxide (NO) in root cells after a few hours contributing to the degradation of the root apical meristems (RAMs), the function of which relies on auxin and brassinosteroids (BRs). Phytoglobins (Pgbs) are effective NO scavengers induced by the stress. This work examines the effects of BnPgb1 dysregulation in dehydrating B. napus roots, and the spatiotemporal relationship between Pgb1 and activities of auxin and BRs in the regulation of the RAM. METHODS: B. napus lines over-expressing [BnPgb1(S)] or down-regulating [BnPgb1(RNAi)] BnPgb1 were exposed to polyethylene glycol (PEG)-induced water stress. The localization of BnPgb1, NO, auxin and PIN1 were analyzed during the first 48h, while the expression level of biosynthetic auxin and BR genes was measured during the first 24h. Pharmacological treatments were conducted to assess the requirement of auxin and BR in dehydrating roots. KEY RESULTS: During the stress, BnPgb1 protein accumulated preferentially in the peripheral domains of the root elongation zone, exposing the meristem to NO, which inhibits polar auxin transport (PAT), likely by interfering with PIN1 localization and the synthesis of auxin. Diminished auxin at the root tip depressed the synthesis of BR and caused the degradation of the RAMs. The strength of BnPgb1 signal in the elongation zone was increased in BnPgb1(S) roots, where NO was confined to the most apical cells. Consequently, PAT and auxin synthesis were retained, and the definition of RAMs was maintained. The auxin preservation of the RAM required BRs, although BRs alone was not sufficient to fully rescue drought-damaged RAMs in auxin depleted environments. CONCLUSIONS: The tissue-specific localization of BnPgb1 and NO are determinant for B. napus root response to water stress. A model is proposed where auxin and BRs act as downstream components of BnPgb1 signalling in the preservation of RAMs in dehydrating roots.
PMID: 36571296
Ann Bot , IF:4.357 , 2022 Dec , V130 (6) : P869-882 doi: 10.1093/aob/mcac122
Cytokinins and auxins in organs of aquatic carnivorous plants: what do they reflect?
Institute of Botany of the Czech Academy of Sciences, Dukelska 135, CZ-379 01 Trebon, Czech Republic.; Laboratory of Growth Regulators, Faculty of Science, Palacky University & Institute of Experimental Botany AS CR, Slechtitelu 27, 78371 Olomouc, Czech Republic.; Department of Chemical Biology, Faculty of Science, Palacky University, Slechtitelu 27, 78371 Olomouc, Czech Republic.
BACKGROUND AND AIMS: Aquatic carnivorous plants have typical rootless linear shoots bearing traps and exhibit steep physiological polarity with rapid apical growth. The aim was to analyse auxin and cytokinin metabolites in traps, leaves/shoots and shoot apices in several species of genera Aldrovanda and Utricularia to elucidate how the hormonal profiles reflect the specific organ functions and polarity. METHODS: The main auxin and cytokinin metabolites were analysed in miniature samples (>2 mg dry weight) of different organs of Aldrovanda vesiculosa and six Utricularia species using ultraperformance liquid chromatography coupled with triple quadrupole mass spectrometry. KEY RESULTS: Total contents of biologically active forms (free bases, ribosides) of all four main endogenously occurring cytokinin types were consistently higher in traps than in leaves in four Utricularia species with monomorphic shoots and/or higher than in shoots in two Utricularia species with dimorphic shoots. In Aldrovanda traps, the total content of different cytokinin forms was similar to or lower than that in shoots. In U. australis leaves, feeding on prey increased all cytokinin forms, while no consistent differences occurred in Aldrovanda. In four aquatic Utricularia species with monomorphic shoots, the content of four auxin forms was usually higher in traps than in leaves. Zero IAA content was determined in U. australis leaves from a meso-eutrophic site or when prey-fed. CONCLUSIONS: Different cytokinin and auxin profiles estimated in traps and leaves/shoots of aquatic carnivorous plants indicate an association with different dominant functions of these organs: nutrient uptake by traps versus photosynthetic function of traps. Interplay of cytokinins and auxins regulates apical dominance in these plants possessing strong polarity.
PMID: 36215097
Plant Physiol Biochem , IF:4.27 , 2022 Dec , V194 : P685-695 doi: 10.1016/j.plaphy.2022.12.018
The plant specific SHORT INTERNODES/STYLISH (SHI/STY) proteins: Structure and functions.
School of Life Sciences, Jiangsu University, Zhenjiang, 212013, Jiangsu, China.; School of Life Sciences, Jiangsu University, Zhenjiang, 212013, Jiangsu, China. Electronic address: cjinfor@163.com.
Plant specific SHORT INTERNODES/STYLISH (SHI/STY) protein is a transcription factor involved in the formation and development of early lateral organs in plants. However, research on the SHI/STY protein family is not focused enough. In this article, we review recent studies on SHI/STY genes and explore the evolution and structure of SHI/STY. The biological functions of SHI/STYs are discussed in detail in this review, and the application of each biological function to modern agriculture is discussed. All SHI/STY proteins contain typical conserved RING-like zinc finger domain and IGGH domain. SHI/STYs are involved in the formation and development of lateral root, stem extension, leaf morphogenesis, and root nodule development. They are also involved in the regulation of pistil and stamen development and flowering time. At the same time, the regulation of some GA, JA, and auxin signals also involves these family proteins. For each aspect, unanswered or poorly understood questions were identified to help define future research areas. This review will provide a basis for further functional study of this gene family.
PMID: 36565613
Plant Physiol Biochem , IF:4.27 , 2022 Nov , V194 : P182-192 doi: 10.1016/j.plaphy.2022.11.018
Nitric oxide acts as an inducer of Strategy-I responses to increase Fe availability and mobilization in Fe-starved broccoli (Brassica oleracea var. oleracea).
Department of Genetics, University of Georgia, GA 30602, USA; Molecular Plant Physiology Laboratory, University of Rajshahi, Rajshahi, 6205, Bangladesh. Electronic address: ahmad.kabir@uga.edu.; Molecular Plant Physiology Laboratory, University of Rajshahi, Rajshahi, 6205, Bangladesh.; Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Cheonan, 31000, Republic of Korea.; Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Iron (Fe) deficiency causes reduced growth and yield in broccoli. This study elucidates how sodium nitroprusside (SNP), known as nitric oxide (NO) donor, mitigates the retardation caused by Fe deficiency in broccoli. The SNP caused substantial nitric oxide accumulation in the roots of Fe-deficient plants, which resulted in a significant improvement in chlorophyll levels, photosynthetic efficiency, and morphological growth parameters, showing that it has a favorable influence on recovering broccoli health. Ferric reductase activity and the expression of BoFRO1 (ferric chelate reductase) gene in roots were consistently increased by SNP under Fe deficiency, which likely resulted in increased Fe mobilization. Furthermore, proton (H(+)) extrusion and BoHA2 (H(+)-ATPase 2) expression were significantly increased, suggesting that they may be involved in lowering rhizospheric pH to restore Fe mobilization in roots of bicarbonate-treated broccoli plants. The levels of Fe in root and shoot tissues and the expression of BoIRT1 (Fe-regulated transporter) both increased dramatically after SNP supplementation under Fe deprivation. Furthermore, SNP-induced increase in citrate and malate concentrations suggested a role of NO in improved Fe chelation in Fe-deficient broccoli. A NO scavenger (cPTIO) ceased the elevated FCR activity and IAA (indole-3-acetic acid) concentration in Fe-starved plants treated with SNP. These findings suggest that SNP may play a role in initiating Fe availability by elevated IAA concentration and BoEIR1 (auxin efflux carrier) expression in the roots of broccoli during Fe shortage. Therefore, SNP may improve Fe availability and mobilization by increasing Strategy-I Fe uptake pathways, which may help broccoli tolerate Fe deficiency.
PMID: 36423388
Plant Physiol Biochem , IF:4.27 , 2022 Nov , V191 : P89-98 doi: 10.1016/j.plaphy.2022.09.022
Advances towards understanding the responses of root cells to acidic stress.
Instituto de Ciencias Biologicas, Departamento de Botanica, Plant Physiology Laboratory, Federal University of Minas Gerais, Antonio Carlos, 6627, Bloco I-2, 316, Belo Horizonte, MG, 31270-901, Brazil. Electronic address: jonathasgracas@gmail.com.; Laboratoire de Recherche en Sciences Vegetales, Universite de Toulouse, CNRS, UPS, Toulouse-INP 24, chemin de Borde Rouge 31320 Auzeville-Tolosane, France. Electronic address: jamet@lrsv.ups-tlse.fr.; Instituto de Ciencias Biologicas, Departamento de Botanica, Plant Physiology Laboratory, Federal University of Minas Gerais, Antonio Carlos, 6627, Bloco I-2, 316, Belo Horizonte, MG, 31270-901, Brazil. Electronic address: jonilima@icb.ufmg.br.
"Acid soil syndrome" is a worldwide phenomenon characterized by low pH (pH < 5.5), scarce nutrient availability (K(+), Ca(2+), Mg(2+), P), and mineral toxicity such as those caused by soluble aluminium (Al) forms. Regardless of the mineral toxicity, the low pH by itself is detrimental to crop development causing striking sensitivity responses such as root growth arrest. However, low pH-induced responses are still poorly understood and underrated. Here, we review and discuss the core evidence about the action of low pH upon specific root zones, distinct cell types, and possible cellular targets (cell wall, plasma membrane, and alternative oxidase). The role of different players in signaling processes leading to low pH-induced responses, such as the STOP transcription factors, the reactive oxygen species (ROS), auxin, ethylene, and components of the antioxidant system, is also addressed. Information at the molecular level is still lacking to link the low pH targets and the subsequent actors that trigger the observed sensitivity responses. Future studies will have to combine genetic tools to identify the signaling processes triggered by low pH, unraveling not only the mechanisms by which low pH affects root cells but also finding new ways to engineer the tolerance of domesticated plants to acidic stress.
PMID: 36195036
Plant Physiol Biochem , IF:4.27 , 2022 Nov , V190 : P1-10 doi: 10.1016/j.plaphy.2022.08.020
Liriodendron chinense LcMAX1 regulates primary root growth and shoot branching in Arabidopsis thaliana.
Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China. Electronic address: Winnie@njfu.edu.cn.; Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China. Electronic address: zhonghuatu@njfu.edu.cn.; Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China. Electronic address: lmwei@njfu.edu.cn.; Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China. Electronic address: hgli@njfu.edu.cn.
Strigolactones (SLs) play prominent roles in regulating shoot branching and root architecture in model plants. However, their roles in non-model (particularly woody) plants remain unclear. Liriodendron chinense is a timber tree species widely planted in southern China. The outturn percentage and wood quality of L. chinense are greatly affected by the branching characteristics of its shoot, and the rooting ability of the cuttings is key for its vegetative propagation. Here, we isolated and analyzed the function of the MORE AXILLARY GROWTH 1 (LcMAX1) gene, which is involved in L. chinense SL biosynthesis. RT-qPCR showed that LcMAX1 was highly expressed in the roots and axillary buds. LcMAX1 was located in the endoplasmic reticulum (ER) and nucleus. LcMAX1 ectopic expression promoted primary root growth, whereas there were no phenotypic differences in shoot branching between transgenic and wild-type (WT) A. thaliana plants. LcMAX1 overexpression in the max1 mutant restored them to the WT A. thaliana phenotypes. Additionally, AtPIN1, AtPIN2, and AtBRC1 expressions were significantly upregulated in transgenic A. thaliana and the max1 mutant. It was therefore speculated that LcMAX1 promotes primary root growth by regulating expression of auxin transport-related genes in A. thaliana, and LcMAX1 inhibits shoot branching by upregulating expression of AtBRC1 in the max1 mutant. Altogether, these results demonstrated that the root development and shoot branching functions of LcMAX1 were similar to those of AtMAX1. Our findings provide a foundation for obtaining further insights into root and branch development in L. chinense.
PMID: 36084353
BMC Plant Biol , IF:4.215 , 2022 Dec , V22 (1) : P567 doi: 10.1186/s12870-022-03963-5
Comparative transcriptome profiling of resistant and susceptible foxtail millet responses to Sclerospora graminicola infection.
College of Plant Protection, Shanxi Agricultural University, Taigu, 030801, Shanxi, China.; College of Agriculture, Shanxi Agricultural University, Taigu, 030801, Shanxi, China.; College of Agriculture, Shanxi Agricultural University, Taigu, 030801, Shanxi, China. hanyuanhuai@sxau.edu.cn.; Shanxi Key Laboratory of Germplasm Innovation and Molecular Breeding of Minor Crop, Taiyuan, 030031, China. hanyuanhuai@sxau.edu.cn.; College of Plant Protection, Shanxi Agricultural University, Taigu, 030801, Shanxi, China. jm.w@163.com.
BACKGROUND: Downy mildew of foxtail millet, which is caused by the biotrophic oomycete Sclerospora graminicola (Sacc.) Schroeter, is one of the most disruptive diseases. The foxtail millet-S. graminicola interaction is largely unexplored. Transcriptome sequencing technology can help to reveal the interaction mechanism between foxtail millet and its pathogens. RESULTS: Transmission electron microscopy observations of leaves infected with S. graminicola showed that the structures of organelles in the host cells gradually became deformed and damaged, or even disappeared from the 3- to 7-leaf stages. However, organelles in the leaves of resistant variety were rarely damaged. Moreover, the activities of seven cell wall degrading enzymes in resistant and susceptible varieties were also quite different after pathogen induction and most of enzymes activities were significantly higher in the susceptible variety JG21 than in the resistant variety G1 at all stages. Subsequently, we compared the transcriptional profiles between the G1 and JG21 in response to S. graminicola infection at 3-, 5-, and 7-leaf stages using RNA-Seq technology. A total of 473 and 1433 differentially expressed genes (DEGs) were identified in the resistant and susceptible varieties, respectively. The pathway analysis of the DEGs showed that the highly enriched categories were related to glutathione metabolism, plant hormone signalling, phenylalanine metabolism, and cutin, suberin and wax biosynthesis. Some defence-related genes were also revealed in the DEGs, including leucine-rich protein kinase, Ser/Thr protein kinase, peroxidase, cell wall degrading enzymes, laccases and auxin response genes. Our results also confirmed the linkage of transcriptomic data with qRT-PCR data. In particular, LRR protein kinase encoded by Seita.8G131800, Ser/Thr protein kinase encoded by Seita.2G024900 and Seita. 2G024800, which have played an essential resistant role during the infection by S. graminicola. CONCLUSIONS: Transcriptome sequencing revealed that host resistance to S. graminicola was likely due to the activation of defence-related genes, such as leucine-rich protein kinase and Ser/Thr protein kinase. Our study identified pathways and genes that contribute to the understanding of the interaction between foxtail millet and S. graminicola at the transcriptomic level. The results will help us better understand the resistance mechanism of foxtail millet against S. graminicola.
PMID: 36471245
BMC Plant Biol , IF:4.215 , 2022 Dec , V22 (1) : P562 doi: 10.1186/s12870-022-03918-w
Leaf transcriptome analysis of Medicago ruthenica revealed its response and adaptive strategy to drought and drought recovery.
Key Laboratory of Grassland Resources of the Ministry of Education, College of Grassland Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.; Key Laboratory of Grassland Resources of the Ministry of Education, College of Grassland Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China. nmczysfl@126.com.
BACKGROUND: Drought is one of the main causes of losses in forage crop yield and animal production. Medicago ruthenica (L.) cv. Zhilixing is a high-yielding alfalfa cultivar also known for its high tolerance to drought. We analyzed the transcriptome profile of this cultivar throughout drought stress and recovery and we were able to describe its phased response through the expression profiles of overlapping gene networks and drought-specific genes. RESULTS: The ABA and auxin signal transduction pathways are overlapping pathways in response to drought and drought recovery in forage crops. Medicago ruthenica (L.) cv. Zhilixing adopts different strategies at different degrees of drought stress. On the 9th day of drought, transcriptional regulations related to osmoregulation are enhanced mainly through increased activities of carbohydrate and amino acid metabolism, while photosynthetic activities were reduced to slow down growth. With drought prolonging, on the 12th day of drought, the synthesis of proline and other stored organic substances was suppressed in general. After recovery, Medicago ruthenica synthesizes flavonoids through the flavonoid biosynthesis pathway to remove accumulated ROS and repair the oxidative damage from water stress. In addition, the regulation of circadian rhythm seems to accelerate the drought recovery process. CONCLUSIONS: Medicago ruthenica adapts to drought by regulating the osmoregulatory system and photosynthesis, which appears to involve the ABA and auxin signaling pathways as key regulators. Furthermore, the synthesis of flavonoids and the regulation of the circadian rhythm can accelerate the recovery process. These results enriched our knowledge of molecular responses to drought and drought recovery in Medicago ruthenica and provide useful information for the development of new legume forage grass varieties with improved adaptability to drought stress.
PMID: 36460952
BMC Plant Biol , IF:4.215 , 2022 Nov , V22 (1) : P531 doi: 10.1186/s12870-022-03910-4
Identification of key gene networks related to the freezing resistance of apricot kernel pistils by integrating hormone phenotypes and transcriptome profiles.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.; State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. wlibing@caf.ac.cn.
BACKGROUND: Apricot kernel, a woody oil tree species, is known for the high oil content of its almond that can be used as an ideal feedstock for biodiesel production. However, apricot kernel is vulnerable to spring frost, resulting in reduced or even no yield. There are no effective countermeasures in production, and the molecular mechanisms underlying freezing resistance are not well understood. RESULTS: We used transcriptome and hormone profiles to investigate differentially responsive hormones and their associated co-expression patterns of gene networks in the pistils of two apricot kernel cultivars with different cold resistances under freezing stress. The levels of auxin (IAA and ICA), cytokinin (IP and tZ), salicylic acid (SA) and jasmonic acid (JA and ILE-JA) were regulated differently, especially IAA between two cultivars, and external application of an IAA inhibitor and SA increased the spring frost resistance of the pistils of apricot kernels. We identified one gene network containing 65 hub genes highly correlated with IAA. Among these genes, three genes in auxin signaling pathway and three genes in brassinosteroid biosynthesis were identified. Moreover, some hub genes in this network showed a strong correlation such as protein kinases (PKs)-hormone related genes (HRGs), HRGs-HRGs and PKs-Ca(2+) related genes. CONCLUSIONS: Ca(2+), brassinosteroid and some regulators (such as PKs) may be involved in an auxin-mediated freezing response of apricot kernels. These findings add to our knowledge of the freezing response of apricot kernels and may provide new ideas for frost prevention measures and high cold-resistant apricot breeding.
PMID: 36380302
BMC Plant Biol , IF:4.215 , 2022 Nov , V22 (1) : P523 doi: 10.1186/s12870-022-03888-z
Exogenous ABA and IAA modulate physiological and hormonal adaptation strategies in Cleistocalyx operculatus and Syzygium jambos under long-term waterlogging conditions.
School of Ecological and Environmental Sciences, Hainan University, Haikou, 570228, China.; School of Life Sciences, Hainan University, Haikou, 570228, China.; School of Plant Protection, Hainan University, Haikou, 570228, China.; School of Ecological and Environmental Sciences, Hainan University, Haikou, 570228, China. yangfan@hainanu.edu.cn.; Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou, 570228, China. yangfan@hainanu.edu.cn.
BACKGROUND: The mechanisms of abscisic acid (ABA) and auxin (IAA) in inducing adventitious root (AR) formation, biomass accumulation, and plant development under long-term waterlogging (LT-WL) conditions are largely unexplored. This study aimed to determine the roles of exogenous application of ABA and IAA in two woody plants (Cleistocalyx operculatus and Syzygium jambos) under LT-WL conditions. A pot experiment was conducted using a complete randomized design with two factors: (i) LT-WL and (ii) application of exogenous phytohormones (ABA and IAA) for 120 d. RESULTS: Results revealed that exogenous ABA and IAA promoted LT-WL tolerance in both species. In C. operculatus and S. jambos, plant height, the number of blades, leaf area, and fresh shoot weight were increased by exogenous IAA under LT-WL. However, exogenous ABA affected more the adventitious and primary root in C. operculatus compared to S. jambos. LT-WL decreased drastically the photosynthetic activities in both species, but adding moderate amounts of exogenous ABA or IAA protected the photosynthesis apparatus under LT-WL. Exogenous phytohormones at certain levels decreased the superoxide anion level and malondialdehyde accumulation in plants under LT-WL. Also, the increase of the peroxidases and superoxide dismutase activities by exogenous phytohormones was more marked in C. operculatus compared to S. jambos. Meanwhile, the catalase activity was down-regulated in both species by exogenous phytohormones. Exogenous ABA or IAA positively regulated the jasmonic acid content in ARs under LT-WL. Moderate application of exogenous ABA or IAA in plants under LT-WL decreased the ABA content in the leaves. Lower accumulation of IAA and ABA in the leaves of C. operculatus under LT-WL was positively correlated with a decrease in antioxidant activity. CONCLUSIONS: Lastly, C. operculatus which has greater morphology indexes was more tolerant to waterlogging than S. jambos. Moreover, the adaptive strategies via exogenous ABA were more built around the below-ground biomass indexes particularly in C. operculatus, while exogenous IAA backed the above-ground biomass in both species. Overall, the exogenous hormones applied (spraying or watering) influenced differentially the plant's responses to LT-WL. The phytohormonal profile of plants exposed to waterlogging stress varied depending on the species' tolerance level.
PMID: 36357840
BMC Plant Biol , IF:4.215 , 2022 Nov , V22 (1) : P521 doi: 10.1186/s12870-022-03908-y
Poly-gamma-glutamic acid promoted maize root development by affecting auxin signaling pathway and the abundance and diversity of rhizosphere microbial community.
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China.; School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, Shandong, PR China.; State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China. txia@qlu.edu.cn.; School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, Shandong, PR China. txia@qlu.edu.cn.
BACKGROUND: The root systems of higher plants play an important role in plant growth and development. In our present study, it was found that poly-gamma-glutamic acid (gamma-PGA), an environmentally friendly biomacromolecule, significantly improved root development in maize. RESULTS: After treatment with gamma-PGA for 7 days, the fresh weight of maize roots was significantly increased and the differences between gamma-PGA treated group and control group were mainly caused by the number (higher by 71.87% compared to the control) and length of lateral roots. RNAseq and RT-PCR analyses showed that gamma-PGA treatment upregulated the expression of genes related to the synthesis of auxins and auxin signal in maize roots. In addition, gamma-PGA promoted the accumulation of plant growth-promoting bacteria, such as Azospirillum, Azohydromonas, Ramlibacter, and Sphingobium (Proteobacteria), Streptomyces (Actinobacteria), Parasegetibacter (Bacteroidetes), and Gemmatimonas (Gemmatimonadetes) in rhizosphere soil and the secretion of auxins. The results of this study deepened our understanding of the effects and mechanism of gamma-PGA on maize root development, and as well as highlighted the possibility of using gamma-PGA to improve crop growth and soil environment. CONCLUSIONS: gamma-PGA promotes early growth and development of maize roots by inducing the secretion and accumulation of auxin in roots and in rhizosphere soil, and increasing the abundance of plant growth promoting bacteria.
PMID: 36352394
Tree Physiol , IF:4.196 , 2022 Nov , V42 (11) : P2306-2318 doi: 10.1093/treephys/tpac073
A genotype-specific architectural and physiological profile is involved in the flowering regularity of apple trees.
AGAP Institut, University of Montpellier, CIRAD, INRAE, Institut Agro, TA A-108/01 Avenue d'Agropolis, 34398 Montpellier Cedex 5, France.; ITK, 34830, Clapiers, France.
In polycarpic plants, meristem fate varies within individuals in a given year. In perennials, the proportion of floral induction (FI) in meristems also varies between consecutive years and among genotypes of a given species. Previous studies have suggested that FI of meristems could be determined by the within-plant competition for carbohydrates and by hormone signaling as key components of the flowering pathway. At the genotypic level, variability in FI was also associated with variability in architectural traits. However, the part of genotype-dependent variability in FI that can be explained by either tree architecture or tree physiology is still not fully understood. This study aimed at deciphering the respective effect of architectural and physiological traits on FI variability within apple trees by comparing six genotypes with contrasted architectures. Shoot type demography as well as the flowering and fruit production patterns were followed over 6 years and characterized by different indexes. Architectural morphotypes were then defined based on architectural traits using a clustering approach. For two successive years, non-structural starch content in leaf, stem and meristems, and hormonal contents (gibberellins, cytokinins, auxin and abscisic acid) in meristems were quantified and correlated to FI within-tree proportions. Based on a multi-step regression analysis, cytokinins and gibberellins content in meristem, starch content in leaves and the proportion of long shoots in tree annual growth were shown to contribute to FI. Although the predictive linear model of FI was common to all genotypes, each of the explicative variables had a different weight in FI determination, depending on the genotype. Our results therefore suggest both a common determination model and a genotype-specific architectural and physiological profile linked to its flowering behavior.
PMID: 35951430
Tree Physiol , IF:4.196 , 2022 Dec , V42 (12) : P2627-2639 doi: 10.1093/treephys/tpac089
The dark septate endophyte Phialocephala sphaeroides suppresses conifer pathogen transcripts and promotes root growth of Norway spruce.
College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Department of Forest Sciences, University of Helsinki, PO Box 27, Helsinki FIN-00014, Finland.
Plant-associated microbes including dark septate endophytes (DSEs) of forest trees play diverse functional roles in host fitness including growth promotion and increased defence. However, little is known about the impact on the fungal transcriptome and metabolites during tripartite interaction involving plant host, endophyte and pathogen. To understand the transcriptional regulation of endophyte and pathogen during co-infection, Norway spruce (Picea abies) seedlings were infected with DSE Phialocephala sphaeroides, or conifer root-rot pathogen Heterobasidion parviporum, or both. Phialocephala sphaeroides showed low but stable transcripts abundance (a decrease of 40%) during interaction with Norway spruce and conifer pathogen. By contrast, H. parviporum transcripts were significantly reduced (92%) during co-infection. With RNA sequencing analysis, P. sphaeroides experienced a shift from cell growth to anti-stress and antagonistic responses, while it repressed the ability of H. parviporum to access carbohydrate nutrients by suppressing its carbohydrate/polysaccharide-degrading enzyme machinery. The pathogen on the other hand secreted cysteine peptidase to restrict free growth of P. sphaeroides. The expression of both DSE P. sphaeroides and pathogen H. parviporum genes encoding plant growth promotion products were equally detected in both dual and tripartite interaction systems. This was further supported by the presence of tryptophan-dependent indolic compound in liquid culture of P. sphaeroides. Norway spruce and Arabidopsis seedlings treated with P. sphaeroides culture filtrate exhibited auxin-like phenotypes, such as enhanced root hairs, and primary root elongation at low concentration but shortened primary root at high concentration. The results suggested that the presence of the endophyte had strong repressive or suppressive effect on H. parviporum transcripts encoding genes involved in nutrient acquisition.
PMID: 35878416
Microorganisms , IF:4.128 , 2022 Dec , V10 (12) doi: 10.3390/microorganisms10122472
Bacillus velezensis BY6 Promotes Growth of Poplar and Improves Resistance Contributing to the Biocontrol of Armillaria solidipes.
Heilongjiang Provincial Key Laboratory of Forest Sustainable Management and Environmental Microbial Engineering, Northeast Forestry University, Harbin 150040, China.
To improve the application of endophyte Bacillus velezensis BY6 from the xylem of poplar, the effect of BY6 on the growth of diseased Populus davidiana x Populus. alba var. pyramidalis Louche (Pdpap poplar) seedlings and the biological control effect on the pathogen Armillaria solidipes were tested using a plant split-root experiment. After applying BY6 to the roots of diseased Pdpap poplar seedlings, the results show that plant growth indicators (dry mass, fresh mass, and plant height) were significantly increased (p < 0.05), and genes related to auxin hormone signal transcription were activated. BY6 indicated a surprising control effect after the inoculation of diseased Pdpap poplar seedlings. Compared to the infected control group, the treated disease index of the diseased Pdpap poplar seedlings in the treatment group were reduced by 49.53% on the 20th day. The relative staining areas of diaminobenzidine (DAB) and Trypan blue decreased by 3.37 and 7.31 times, respectively. The physiological indicators (soluble sugar and protein) and oxidase indicators were significantly increased (p < 0.05). The expression levels of defense genes related to salicylic acid (SA) and jasmonic acid (JA) signaling pathways were significantly increased (p < 0.05). Amazingly, the results indicate that BY6 simultaneously activates induced systemic resistance (ISR) and systemic acquired resistance (SAR) in diseased Pdpap poplar seedlings and promotes growth. The results indicate that BY6 is a promising candidate for developing forest tree biofertilizers and biopesticides.
PMID: 36557725
Microorganisms , IF:4.128 , 2022 Nov , V10 (12) doi: 10.3390/microorganisms10122341
The Friend Within: Endophytic Bacteria as a Tool for Sustainability in Strawberry Crops.
Biology Department, Federal University of Lavras, Lavras 37200-900, Brazil.; Phytopathology Department, Federal University of Lavras, Lavras 37200-900, Brazil.; Phytopathology Department, Federal University of Vicosa, Vicosa 36570-900, Brazil.; Plant Genetics Department, Federal University of Lavras, Lavras 37200-900, Brazil.; Genetic Department, Federal University of Parana, Curitiba 81531-980, Brazil.; Agriculture Department, Federal University of Lavras, Lavras 37200-900, Brazil.
Strawberry (Fragaria x ananassa, Duch.) is an important crop worldwide. However, since it is a highly demanding crop in terms of the chemical conditions of the substrate, a large part of strawberry production implies the application of large amounts of fertilizers in the production fields. This practice can cause environmental problems, in addition to increases in the fruit's production costs. In this context, applying plant growth-promoting bacteria in production fields can be an essential strategy, especially thanks to their ability to stimulate plant growth via different mechanisms. Therefore, this study aimed to test in vitro and in vivo the potential of bacteria isolated from strawberry leaves and roots to directly promote plant growth. The isolates were tested in vitro for their ability to produce auxins, solubilize phosphate and fix nitrogen. Isolates selected in vitro were tested on strawberry plants to promote plant growth and increase the accumulation of nitrogen and phosphorus in the leaves. The tested isolates showed an effect on plant growth according to biometric parameters. Among the tested isolates, more expressive results for the studied variables were observed with the inoculation of the isolate MET12M2, belonging to the species Brevibacillus fluminis. In general, bacterial inoculation induced strain-dependent effects on strawberry growth. In vitro and in vivo assays showed the potential use of the B. fluminis MET12M2 isolate as a growth promoter for strawberries.
PMID: 36557594
Planta , IF:4.116 , 2022 Dec , V257 (1) : P23 doi: 10.1007/s00425-022-04058-z
Auxin homeostasis in maize (Zea mays) is regulated via 1-O-indole-3-acetyl-myo-inositol synthesis at early stages of seedling development and under abiotic stress.
Department of Biochemistry, Nicolaus Copernicus University, Lwowska 1, 87-100, Torun, Poland. anciar@umk.pl.; Department of Biochemistry, Nicolaus Copernicus University, Lwowska 1, 87-100, Torun, Poland.; Department of Plant Physiology and Biotechnology, Nicolaus Copernicus University, Lwowska 1, 87-100, Torun, Poland.
Indole-3-acetyl-myo-inositol biosynthesis is regulated during maize seedling development and in response to drought and cold stress. The main purpose of this pathway is maintenance of auxin homeostasis. Indole-3-acetic acid (IAA) conjugation to myo-inositol is a part of a mechanism controlling free auxin level in maize. In this work, we investigated changes in the indole-3-acetyl-myo-inositol (IAInos) biosynthesis pathway in 3-d- and 6-d-old maize seedlings and germinating seeds as well as in seedlings subjected to drought and cold stress to evaluate a role of this pathway in maize development and stress response. In germinating seeds, activity of the enzymes involved in IAInos biosynthesis remains unchanged between 3-d- and 6-d-old material but increases in coleoptiles and radicles of the seedlings. Under cold stress, in germinating seeds and in coleoptiles, activity of the enzymes decreases and increases, respectively; however, it does not entail changes in auxin level. In drought-exposed germinating maize seeds, totally diminished activities of IAInos synthesis pathway enzymes resulted in almost twofold increase of free IAA content. Similar increase of auxin level was observed in radicles of drought-subjected seedlings together with lack of catalytic activity of the first enzyme of the pathway. Exogenous IAInos has no effect on the level of non-enzymatic antioxidant, ascorbate. It has also either no effect on the protein carbonylation and lipid peroxidation, or it affects it in a similar way as exogenously applied IAA and myo-inositol, which are products of IAInos hydrolysis. Thus, IAInos biosynthesis pathway acts in maize development and stress responses by regulation of free IAA concentration, as IAInos itself does not appear to have a distinct role in these processes.
PMID: 36539632
Planta , IF:4.116 , 2022 Nov , V256 (6) : P113 doi: 10.1007/s00425-022-04009-8
The source, level, and balance of nitrogen during the somatic embryogenesis process drive cellular differentiation.
Centro de Investigacion Cientifica de Yucatan, Unidad de Bioquimica y Biologia Molecular de Plantas, Merida, Yucatan, Mexico.; Instituto Politecnico Nacional, Centro Interdisciplinario de Investigacion para el Desarrollo Integral Regional, Unidad Oaxaca, Santa Cruz Xoxocotlan, C.P., 71230, Oaxaca, Oaxaca, Mexico.; Centro de Investigacion Cientifica de Yucatan, Unidad de Bioquimica y Biologia Molecular de Plantas, Merida, Yucatan, Mexico. vmloyola@cicy.mx.
Since the discovery of somatic embryogenesis (SE), it has been evident that nitrogen (N) metabolism is essential during morphogenesis and cell differentiation. Usually, N is supplied to cultures in vitro in three forms, ammonium (NH(4)(+)), nitrate (NO(3)(-)), and amino N from amino acids (AAs). Although most plants prefer NO(3)(-) to NH(4)(+), NH(4)(+) is the primary form route to be assimilated. The balance of NO(3)(-) and NH(4)(+) determines if the morphological differentiation process will produce embryos. That the N reduction of NO(3)(-) is needed for both embryo initiation and maturation is well-established in several models, such as carrot, tobacco, and rose. It is clear that N is indispensable for SE, but the mechanism that triggers the signal for embryo formation remains unknown. Here, we discuss recent studies that suggest an optimal endogenous concentration of auxin and cytokinin is closely related to N supply to plant tissue. From a molecular and biochemical perspective, we explain N's role in embryo formation, hypothesizing possible mechanisms that allow cellular differentiation by changing the nitrogen source.
PMID: 36367589
Genes (Basel) , IF:4.096 , 2022 Nov , V13 (12) doi: 10.3390/genes13122216
CsIAGLU Regulates the Angle of Leaf Petiole by Affecting Endogenous Content of Auxin in Cucumber (Cucumis sativus L.).
State Key Laboratories of Agrobiotechnology, Joint International Research Laboratory of Crop Molecular Breeding, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural University, Beijing 100193, China.
The leaf angle is an important factor determining plant shoot architecture that may boost crop yield by increasing photosynthetic efficiency and facilitating high-density planting. Auxin is an important phytohormone involved in leaf angle regulation. Here, we identified two Single-Nucleotide Polymorphisms (SNPs) in the Indoleacetic Acid (IAA) glucosyltransferase gene CsIAGLU in 80 re-sequenced cucumber lines, of which the CsIAGLU(717G,1234T) is the dominant allele associated with a small leaf pedicle angle (LPA), whereas CsIAGLU(717C,1234A) is linked with a large LPA. CsIAGLU was highly expressed in leaves and petioles. In natural cucumber populations, the expression of CsIAGLU was negatively correlated with the LPA. The mutation of CsIAGLU induced by the CRISPR-Cas9 system resulted in elevated free IAA levels and enlarged cell expansion on the adaxial side of the petiole base, thus producing a greater LPA. Consistently, exogenous IAA treatment led to increased LPA and cell size. Therefore, our findings suggest that CsIAGLU functions as a negative regulator of LPA development via auxin-mediated cell expansion in cucumber, providing a valuable strategy for cucumber breeding with small LPAs.
PMID: 36553483
Genes (Basel) , IF:4.096 , 2022 Nov , V13 (11) doi: 10.3390/genes13112121
Analysis of the Small Auxin-Up RNA (SAUR) Genes Regulating Root Growth Angle (RGA) in Apple.
College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China.; College of Agriculture and Bioengineering, Heze University, Heze 274000, China.; College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
Small auxin upregulated RNAs (SAURs) are primary auxin response genes; the function of regulating root growth angle (RGA) is unclear in the apple rootstock. We firstly identified 96 MdSAUR genes families from new apple genome GDDH13 using the resequence database of 'Baleng Crab (BC)' and 'M9'. A total of 25 MdSAUR genes, regulating the formation of RGA, were screened for the expression profiles in stems and roots and the allelic variants of quantitative trait loci (QTL). Finally, through the joint analysis of network and protein-protein interaction, MdSAUR2, MdSAUR29, MdSAUR60, MdSAUR62, MdSAUR69, MdSAUR71, and MdSAUR84 were screened as the main candidate genes for regulating RGA. This study provides a new insight for further revealing the regulatory mechanism of RGA in apple dwarf rootstocks.
PMID: 36421796
Plant Mol Biol , IF:4.076 , 2022 Dec doi: 10.1007/s11103-022-01318-0
High temporal-resolution transcriptome landscapes of maize embryo sac and ovule during early seed development.
State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing, People's Republic of China.; Department of Plant Genetics and Breeding, National Maize Improvement Center, China Agricultural University, Beijing, People's Republic of China.; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, People's Republic of China.; Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, Beijing, People's Republic of China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, People's Republic of China.; State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing, People's Republic of China. jianchen@cau.edu.cn.; Department of Plant Genetics and Breeding, National Maize Improvement Center, China Agricultural University, Beijing, People's Republic of China. jianchen@cau.edu.cn.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, People's Republic of China. jianchen@cau.edu.cn.
Here we provided a high temporal-resolution transcriptome atlas of maize embryo sac and ovule to reveal the gene activity dynamic during early seed development. The early maize (Zea mays) seed development is initiated from double fertilization in the embryo sac and needs to undergo a highly dynamic and complex development process to form the differentiated embryo and endosperm. Despite the importance of maize seed for food, feed, and biofuel, many regulators responsible for controlling its early development are not known yet. Here, we reported a high temporal-resolution transcriptome atlas of embryo sac and ovule based on 44 time point samples collected within the first four days of seed development. A total of 25,187 genes including 1598 transcription factors (TFs) involved in early seed development were detected. Global comparisons of the expressions of these genes revealed five distinct development stages of early seed, which are mainly related to double fertilization, asymmetric cell division of the zygote, as well as coenocyte formation, cellularization and differentiation in endosperm. We identified 3327 seed-specific genes, which more than one thousand seed-specific genes with main expressions during early seed development were newly identified here, including 859 and 186 genes predominantly expressed in the embryo sac and ovule, respectively. Combined with the published transcriptome data of seed, we uncovered the dominant auxin biosynthesis, transport and signaling related genes at different development stages and subregions of seed. These results are helpful for understanding the genetic control of early seed development.
PMID: 36508138
Plant Mol Biol , IF:4.076 , 2022 Dec , V110 (6) : P531-543 doi: 10.1007/s11103-022-01304-6
Combined analysis of mRNA and miRNA reveals the banana potassium absorption regulatory network and validation of miRNA160a.
Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China.; Institute of Fruit Tree ResearchKey Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural AffairsGuangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.; School of Agriculture and Environment, The UWA Institute of Agriculture, The University of Western Australia, Perth, 6009 WA, Australia.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. w_mingyuan@163.com.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. 907153549@qq.com.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. yuhailing1989@163.com.
Potassium (K) has an important effect on the growth and development of plants. Banana contains higher K content than many other fruits, and its plant requires more K nutrient in soil. However, the soil in the banana-producing areas in China is generally deficient in K. Therefore, understanding the mechanism of banana K absorption may assist in providing effective strategy to solve this problem. This study used two banana varieties with contrasting K tolerance, 'Guijiao No. 1' (low-K tolerant), and 'Brazilian banana' (low-K sensitive)to investigate K absorption mechanisms in response to low-K stress through miRNA and mRNA sequencing analysis. Under low-K condition, 'Guijiao No.1' showed higher plant height, dry weight, tissue K content and ATPase activity. Analysis of transcription factors showed that they were mainly in the types or classes of MYB, AP-EREBP, bHLH, etc. The sequencing results showed that 'Guijiao No. 1' had 776 differentially expressed genes (DEGs) and 27 differentially expressed miRNAs (DEMs), and 'Brazilian banana' had 71 DEGs and 14 DEMs between normal and low K treatments. RT-qPCR results showed that all miRNAs and mRNAs showed similar expression patterns with RNA-Seq and transcriptome. miRNA regulatory network was constructed by integrated analysis of miRNA-mRNA data. miR160a was screened out as a key miRNA, and preliminary functional validation was performed. Arabidopsis overexpressing miR160a showed reduced tolerance to low K, and inhibited phenotypic traits such as shorter root length, and reduced K accumulation. The overexpressed miR160a had a targeting relationship with ARF10 and ARF16 in Arabidopsis. These results indicate that miR160a may regulate K absorption in bananas through the auxin pathway. This study provides a theoretical basis for further study on the molecular mechanism of banana response to low potassium stress.
PMID: 35962899
Phytochemistry , IF:4.072 , 2023 Feb , V206 : P113531 doi: 10.1016/j.phytochem.2022.113531
Labdane diterpenoids from the heartwood of Leucosceptrum canum that impact on root growth and seed germination of Arabidopsis thaliana.
State Key Laboratory of Southwestern Chinese Medicine Resources, and Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China.; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, PR China.; State Key Laboratory of Southwestern Chinese Medicine Resources, and Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, PR China. Electronic address: shli@cdutcm.edu.cn.
Eleven undescribed diterpenoids possessing labdane, 3,18-cyclo-labdane, 19 (4 --> 3)-labdane and 12-nor-labdane skeletons, named leucolactones A-K, were isolated from the heartwood of a large woody Lamiaceae plant, Leucosceptrum canum. Their structures were determined by NMR, MS, and in the case of leucolactones A by single crystal X-ray diffraction analysis. Plausible biosynthetic pathway of leucolactones were proposed. Leucolactones showed significant inhibitory effects against seed germination and root elongation of Arabidopsis thaliana in the Petri dish bioassay. Among them, the diastereomeric leucolactones G and H were the most potent, with EC(50) values for root elongation of 6.53 +/- 1.35 and 9.75 +/- 1.25 muM, respectively. The preliminary structure-activity relationship of leucolactones was discussed. The increase of auxin reporter activity in A. thaliana DR5::GUS roots by leucolactone H was observed, indicating that leucolactones altered auxin accumulation and distribution. These findings suggested that leucolactones might be involved in regulation of plant growth and development through altering auxin accumulation and distribution, presumably contributing to the heartwood formation in L. canum.
PMID: 36464100
BMC Genomics , IF:3.969 , 2022 Dec , V23 (1) : P846 doi: 10.1186/s12864-022-09078-3
Transcriptomic analysis reveals the formation mechanism of anemone-type flower in chrysanthemum.
Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Education Ministry, School of Landscape Architecture, National Engineering Research Center for Floriculture, Beijing Forestry University, Beijing, 100083, China.; National Bot Garden, Beijing, 100093, China.; Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Education Ministry, School of Landscape Architecture, National Engineering Research Center for Floriculture, Beijing Forestry University, Beijing, 100083, China. 101navy@163.com.
BACKGROUND: The ray and disc florets on the chrysanthemum capitulum are morphologically diverse and have remarkably abundant variant types, resulting in a rich variety of flower types. An anemone shape with pigmented and elongated disk florets is an important trait in flower shape breeding of chrysanthemums. The regulatory mechanism of their anemone-type disc floret formation was not clear, thus limiting the directional breeding of chrysanthemum flower types. In this study, we used morphological observation, transcriptomic analysis, and gene expression to investigate the morphogenetic processes and regulatory mechanisms of anemone-type chrysanthemum. RESULT: Scanning electron microscopy (SEM) observation showed that morphological differences between non-anemone-type disc florets and anemone-type disc florets occurred mainly during the petal elongation period. The anemone-type disc florets elongated rapidly in the later stages of development. Longitudinal paraffin section analysis revealed that the anemone-type disc florets were formed by a great number of cells in the middle layer of the petals with vigorous division. We investigated the differentially expressed genes (DEGs) using ray and disc florets of two chrysanthemum cultivars, 082 and 068, for RNA-Seq and their expression patterns of non-anemone-type and anemone-type disc florets. The result suggested that the CYCLOIDEA2 (CYC2s), MADS-box genes, and phytohormone signal-related genes appeared significantly different in both types of disc florets and might have important effects on the formation of anemone-type disc florets. In addition, it is noteworthy that the auxin and jasmonate signaling pathways might play a vital role in developing anemone-type disc florets. CONCLUSIONS: Based on our findings, we propose a regulatory network for forming non-anemone-type and anemone-type disc florets. The results of this study lead the way to further clarify the mechanism of the anemone-type chrysanthemum formation and lay the foundation for the directive breeding of chrysanthemum petal types.
PMID: 36544087
BMC Genomics , IF:3.969 , 2022 Dec , V23 (1) : P814 doi: 10.1186/s12864-022-09039-w
A comparative transcriptomic analysis reveals a coordinated mechanism activated in response to cold acclimation in common vetch (Vicia sativa L.).
Department of Grassland Science, College of Animal Science, Guizhou University, Guiyang, China.; Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University, Guiyang, China.; School of Tropical Crops, Hainan University, Haikou, China.; State Key Laboratory of Grassland Agro-ecosystems, China, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.; Grassland Technology Experiment and Extension Station, Guiyang, China.; College of Agriculture, Guizhou University, Guiyang, China. hejin0811@163.com.
BACKGROUND: Due to its strong abiotic stress tolerance, common vetch is widely cultivated as a green manure and forage crop in grass and crop rotation systems. The comprehensive molecular mechanisms activated in common vetch during cold adaptation remain unknown. RESULTS: We investigated physiological responses and transcriptome profiles of cold-sensitive (Lanjian No. 1) and cold-tolerant (Lanjian No. 3) cultivars during cold acclimation to explore the molecular mechanisms of cold acclimation. In total, 2681 and 2352 differentially expressed genes (DEGs) were identified in Lanjian No. 1 and Lanjian No. 3, respectively; 7532 DEGs were identified in both lines. DEGs involved in "plant hormone signal transduction" were significantly enriched during cold treatment, and 115 DEGs involved in cold-processed hormone signal transduction were identified. Common vetch increased the level of indoleacetic acid (IAA) by upregulating the transcriptional regulator Aux/IAA and downregulating GH3, endowing it with stronger cold tolerance. An auxin-related DEG was overexpressed in yeast and shown to possess a biological function conferring cold tolerance. CONCLUSION: This study identifies specific genes involved in Ca(2+) signaling, redox regulation, circadian clock, plant hormones, and transcription factors whose transcriptional differentiation during cold acclimation may improve cold tolerance and contributes to the understanding of common and unique molecular mechanisms of cold acclimation in common vetch. The candidate genes identified here also provide valuable resources for further functional genomic and breeding studies.
PMID: 36482290
BMC Genomics , IF:3.969 , 2022 Nov , V23 (1) : P778 doi: 10.1186/s12864-022-09022-5
Integrative physiological and transcriptome analyses provide insights into the Cadmium (Cd) tolerance of a Cd accumulator: Erigeron canadensis.
School of Life Sciences, Guizhou Normal University, Guiyang, 550025, People's Republic of China.; School of Advanced Agriculture and Bioengineering, Yangtze Normal University, Chongqing, 408100, People's Republic of China.; School of Life Sciences, Guizhou Normal University, Guiyang, 550025, People's Republic of China. zhugg130@126.com.
Cadmium (Cd) is a highly toxic pollutant in soil and water that severely hampers the growth and reproduction of plants. Phytoremediation has been presented as a cost-effective and eco-friendly method for addressing heavy metal pollution. However, phytoremediation is restricted by the limited number of accumulators and the unknown mechanisms underlying heavy metal tolerance. In this study, we demonstrated that Erigeron canadensis (Asteraceae), with its strong adaptability, is tolerant to intense Cd stress (2 mmol/L CdCl(2) solution). Moreover, E. canadensis exhibited a strong ability to accumulate Cd(2+) when treated with CdCl(2) solution. The activity of some antioxidant enzymes, as well as the malondialdehyde (MDA) level, was significantly increased when E. canadensis was treated with different CdCl(2) solutions (0.5, 1, 2 mmol/L CdCl(2)). We found high levels of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities under 1 mmol/L CdCl(2) treatment. Comparative transcriptomic analysis identified 5,284 differentially expressed genes (DEGs) in the roots and 3,815 DEGs in the shoots after E. canadensis plants were exposed to 0.5 mM Cd. Functional annotation of key DEGs indicated that signal transduction, hormone response, and reactive oxygen species (ROS) metabolism responded significantly to Cd. In particular, the DEGs involved in auxin (IAA) and ethylene (ETH) signal transduction were overrepresented in shoots, indicating that these genes are mainly involved in regulating plant growth and thus likely responsible for the Cd tolerance. Overall, these results not only determined that E. canadensis can be used as a potential accumulator of Cd but also provided some clues regarding the mechanisms underlying heavy metal tolerance.
PMID: 36443662
BMC Genomics , IF:3.969 , 2022 Nov , V23 (1) : P753 doi: 10.1186/s12864-022-08979-7
Identification of LsPIN1 gene and its potential functions in rhizome turning of Leymus secalinus.
School of Biological Science and Technology, University of Jinan, Jinan, 250022, China.; School of Biological Science and Technology, University of Jinan, Jinan, 250022, China. ramonsantosbermudez@gmail.com.; School of Biological Science and Technology, University of Jinan, Jinan, 250022, China. 163.hwx@163.com.
BACKGROUND: Continuous tilling and the lateral growth of rhizomes confer rhizomatous grasses with the unique ability to laterally expand, migrate and resist disturbances. They play key roles especially in degraded grasslands, deserts, sand dunes, and other fragile ecological system. The rhizomatous plant Leymus secalinus has both rhizome buds and tiller buds that grow horizontally and upward at the ends of rhizome differentiation and elongation, respectively. The mechanisms of rhizome formation and differentiation in L. secalinus have not yet been clarified. RESULTS: In this study, we found that the content of gibberellin A3 (GA(3)) and indole-3-acetic acid (IAA) were significantly higher in upward rhizome tips than in horizontal rhizome tips; by contrast, the content of methyl jasmonate and brassinolide were significantly higher in horizontal rhizome tips than in upward rhizome tips. GA(3) and IAA could stimulate the formation and turning of rhizomes. An auxin efflux carrier gene, LsPIN1, was identified from L. secalinus based on previous transcriptome data. The conserved domains of LsPIN1 and the relationship of LsPIN1 with PIN1 genes from other plants were analyzed. Subcellular localization analysis revealed that LsPIN1 was localized to the plasma membrane. The length of the primary roots (PRs) and the number of lateral roots (LRs) were higher in Arabidopsis thaliana plants overexpressing LsPIN1 than in wild-type (Col-0) plants. Auxin transport was altered and the gravitropic response and phototropic response were stronger in 35S:LsPIN1 transgenic plants compared with Col-0 plants. It also promoted auxin accumulation in root tips. CONCLUSION: Our findings indicated that LsPIN1 plays key roles in auxin transport and root development. Generally, our results provide new insights into the regulatory mechanisms underlying rhizome development in L. secalinus.
PMID: 36384450
Pestic Biochem Physiol , IF:3.963 , 2022 Nov , V188 : P105226 doi: 10.1016/j.pestbp.2022.105226
Tribenuron-methyl metabolism and the rare Pro197Phe double mutation together with 2,4-D metabolism and reduced absorption can evolve in Papaver rhoeas with multiple and cross herbicide resistance to ALS inhibitors and auxin mimics.
Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Cordoba, UCO-CeiA3, 14014 Cordoba, Spain.; Biosciences Department, Polytechnic Institute of Beja, 7800-295 Beja, Portugal; VALORIZA-Research Centre for Endogenous Resource Valorization, Polytechnic Institute of Portalegre, 7300-555 Portalegre, Portugal.; Plant Protection Department, Extremadura Scientific and Technological Research Center (CICYTEX), Ctra. de AV, km 372, Badajoz, 06187, Guadajira, Spain.; Department of Hortofructiculture, Botany and Gardening, Agrotecnio-CERCA Center, University of Lleida, 25198 Lleida, Spain. Electronic address: joel.torra@udl.cat.; Institute for Plant Molecular and Cellular Biology (IBMCP), Polytechnic University of Valencia (UPV), Spanish National Research Council (CSIC), ES-46022, Valencia, Spain.; Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan 4918943464, Iran.
Multiple resistance mechanisms to ALS inhibitors and auxin mimics in two Papaver rhoeas populations were investigated in wheat fields from Portugal. Dose-response trials, also with malathion (a cytochrome P450 inhibitor), cross-resistance patterns for ALS inhibitors and auxin mimics, alternative herbicides tests, 2,4-D and tribenuron-methyl absorption, translocation and metabolism experiments, together with ALS activity, gene sequencing and enzyme modelling and ligand docking were carried out. Results revealed two different resistant profiles: one population (R1) multiple resistant to tribenuron-methyl and 2,4-D, the second (R2) only resistant to 2,4-D. In R1, several target-site mutations in Pro197 and enhanced metabolism (cytochrome P450-mediated) were responsible of tribenuron-methyl resistance. For 2,4-D, reduced transport was observed in both populations, while cytochrome P450-mediated metabolism was also present in R1 population. Moreover, this is the first P. rhoeas population with enhanced tribenuron-methyl metabolism. This study reports the first case for P. rhoeas of the amino acid substitution Pro197Phe due to a double nucleotide change. This double mutation could cause reduced enzyme sensitivity to most ALS inhibitors according to protein modelling and ligand docking. In addition, this study reports a P. rhoeas population resistant to 2,4-D, apparently, with reduced transport as the sole resistance mechanism.
PMID: 36464346
Plants (Basel) , IF:3.935 , 2022 Dec , V11 (24) doi: 10.3390/plants11243572
Histone Acetyltransferase GCN5 Affects Auxin Transport during Root Growth by Modulating Histone Acetylation and Gene Expression of PINs.
Department of Botany, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.; Postgraduate Program Studies "Applications of Biology-Biotechnology, Molecular and Microbial Analysis of Food and Products", School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.; Natural Products Research Centre of Excellence (NatPro-AUTh), Center of Interdisciplinary Research and Innovation of Aristotle University of Thessaloniki (CIRI-AUTh), 57001 Thessaloniki, Greece.
General Control Non-Derepressible 5 (GCN5) is a histone acetyltransferase that targets multiple genes and is essential for the acetylation of Lysine residues in the N-terminal tail of histone H3 in Arabidopsis. GCN5 interacts with the transcriptional coactivator Alteration/Deficiency in Activation 2b (ADA2b), which enhances its activity functioning in multiprotein complexes, such as the Spt-Ada-Gcn5-Acetyltransferase complex (SAGA). Mutations in GCN5 and ADA2b result in pleiotropic phenotypes, including alterations in the growth of roots. Auxin is known to regulate root development by modulating gene expression patterns. Auxin moves polarly during plant growth via the Pin-formed (PIN) auxin efflux transport proteins. The effect of GCN5 and ADA2b on auxin distribution at different stages of early root growth (4 to 7 days post-germination) was studied using the reporter lines DR5rev::GFP and PIN1::PIN1-GFP. In wild-type plants, auxin efflux transporter PIN1 expression increases from the fourth to the seventh day of root growth. The PIN1 expression was reduced in the roots of gcn5-1 and ada2b-1 compared to the wild type. The expression of PIN1 in ada2b-1 mutants is confined only to the meristematic zone, specifically in the stele cells, whereas it is almost abolished in the elongation zone. Gene expression analysis showed that genes associated with auxin transport, PIN1, PIN3 and PIN4, are downregulated in gcn5-1 and ada2b-1 mutants relative to the wild type. As a result, auxin accumulation was also reduced in gcn5-1 and ada2b-1 compared to wild-type roots. Furthermore, acetylation of Lysine 14 of histone H3 (H3K14) was also affected in the promoter and coding region of PIN1, PIN3 and PIN4 genes during root growth of Arabidopsis in gcn5 mutants. In conclusion, GCN5 acts as a positive regulator of auxin distribution in early root growth by modulating histone H3 acetylation and the expression of auxin efflux transport genes.
PMID: 36559684
Plants (Basel) , IF:3.935 , 2022 Dec , V11 (24) doi: 10.3390/plants11243555
Comparative Transcriptome and Co-Expression Network Analyses Reveal the Molecular Mechanism of Calcium-Deficiency-Triggered Tipburn in Chinese Cabbage (Brassica rapa L. ssp. Pekinensis).
Institute of Vegetables, Shandong Key Laboratory of Greenhouse Vegetable Biology, Shandong Branch of National Vegetable Improvement Center, Huanghuai Region Vegetable Scientific Station of Ministry of Agriculture (Shandong), Shandong Academy of Agricultural Sciences, Jinan 250100, China.; Columbian College of Arts & Sciences, Phillips Hall, The George Washington University, 801 22nd St. NW., Washington, DC 20052, USA.; College of Life Sciences, Shandong Normal University, Jinan 250061, China.; College of Life Science, Huangshan University, Huangshan 245061, China.
Chinese cabbage tipburn is characterized by the formation of necrotic lesions on the margin of leaves, including on the insides of the leafy head. This physiological disorder is associated with a localized calcium deficiency during leaf development. However, little information is available regarding the molecular mechanisms governing Ca-deficiency-triggered tipburn. This study comprehensively analysed the transcriptomic comparison between control and calcium treatments (CK and 0 mM Ca) in Chinese cabbage to determine its molecular mechanism in tipburn. Our analysis identified that the most enriched gene ontology (GO) categories are photosynthesis, thylakoid and cofactor binding. Moreover, the KEGG pathway was most enriched in photosynthesis, carbon metabolism and carbon fixation. We also analyzed the co-expression network by functional categories and identified ten critical hub differentially expressed genes (DEGs) in each gene regulatory network (GRN). These DEGs might involve abiotic stresses, developmental processes, cell wall metabolism, calcium distribution, transcription factors, plant hormone biosynthesis and signal transduction pathways. Under calcium deficiency, CNX1, calmodulin-binding proteins and CMLs family proteins were downregulated compared to CK. In addition, plant hormones such as GA, JA, BR, Auxin and ABA biosynthesis pathways genes were downregulated under calcium treatment. Likewise, HATs, ARLs and TCP transcription factors were reported as inactive under calcium deficiency, and potentially involved in the developmental process. This work explores the specific DEGs' significantly different expression levels in 0 mM Ca and the control involved in plant hormones, cell wall developments, a light response such as chlorophylls and photosynthesis, transport metabolism and defence mechanism and redox. Our results provide critical evidence of the potential roles of the calcium signal transduction pathway and candidate genes governing Ca-deficiency-triggered tipburn in Chinese cabbage.
PMID: 36559667
Plants (Basel) , IF:3.935 , 2022 Dec , V11 (24) doi: 10.3390/plants11243512
The Role of gamma-Aminobutyric Acid (GABA) in the Occurrence of Adventitious Roots and Somatic Embryos in Woody Plants.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, The Chinese Academy of Forestry, Beijing 100091, China.; College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China.; Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, The Chinese Academy of Forestry, Beijing 100091, China.
The occurrence of adventitious roots and somatic embryos is a crucial step in micropropagation that frequently limits the application of this technique in woody plants. Recent studies demonstrated that they can be negatively or positively regulated with gamma-aminobutyric acid (GABA), which is a four-carbon non-proteinous amino acid that not only acts as a main inhibitory neurotransmitter in mammals. It has been reported that GABA affects plant growth and their response to stress although its mode of action is still unclear. This review dealt with the effects of GABA on adventitious root formation and growth as well as on somatic embryogenesis. Furthermore, we focused on discussing the interaction of GABA with phytohormones, such as auxin, ethylene, abscisic acid, and gibberellin, as well as with the carbon and nitrogen metabolism during adventitious root development. We suggested that research on GABA will contribute to the application of micropropagation in the recalcitrant fruit and forest species.
PMID: 36559624
Plants (Basel) , IF:3.935 , 2022 Dec , V11 (24) doi: 10.3390/plants11243486
Transcriptomics Analysis Reveals a Putative Role for Hormone Signaling and MADS-Box Genes in Mature Chestnut Shoots Rooting Recalcitrance.
Mision Biologica de Galicia, Consejo Superior de Investigaciones Cientificas, 15780 Santiago de Compostela, Spain.; Department of Horticulture, University of Sirnak, 73100 Sirnak, Turkey.
Maturation imposes several changes in plants, which are particularly drastic in the case of trees. In recalcitrant woody species, such as chestnut (Castanea sativa Mill.), one of the major maturation-related shifts is the loss of the ability to form adventitious roots in response to auxin treatment as the plant ages. To analyze the molecular mechanisms underlying this phenomenon, an in vitro model system of two different lines of microshoots derived from the same field-grown tree was established. While juvenile-like shoots root readily when treated with exogenous auxin, microshoots established from the crown of the tree rarely form roots. In the present study, a transcriptomic analysis was developed to compare the gene expression patterns in both types of shoots 24 h after hormone and wounding treatment, matching the induction phase of the process. Our results support the hypothesis that the inability of adult chestnut tissues to respond to the inductive treatment relies in a deep change of gene expression imposed by maturation that results in a significant transcriptome modification. Differences in phytohormone signaling seem to be the main cause for the recalcitrant behavior of mature shoots, with abscisic acid and ethylene negatively influencing the rooting ability of the chestnut plants. We have identified a set of related MADS-box genes whose expression is modified but not suppressed by the inductive treatment in mature shoots, suggesting a putative link of their activity with the rooting-recalcitrant behavior of this material. Overall, distinct maturation-derived auxin sensibility and homeostasis, and the related modifications in the balance with other phytohormones, seem to govern the outcome of the process in each type of shoots.
PMID: 36559597
Plants (Basel) , IF:3.935 , 2022 Dec , V11 (24) doi: 10.3390/plants11243457
Combined Transcriptomic and Metabolomic Analysis Reveals Insights into Resistance of Arabidopsis bam3 Mutant against the Phytopathogenic Fungus Fusarium oxysporum.
Laboratory of Mycology, Scientific Department of Phytopathology, Benaki Phytopathological Institute, 8 St. Delta Street, 145 61 Athens, Greece.; Laboratory of Pesticide Science, Agricultural University of Athens, 75 Iera Odos Street, 118 55 Athens, Greece.; Laboratory of Plant Pathology, Agricultural University of Athens, 75 Iera Odos Street, 118 55 Athens, Greece.
The wilt-inducing strains of Fusarium oxysporum are responsible for severe damage to many economically important plant species. The most cost-effective and environmentally safe method for the management of Fusarium wilt is the use of resistant cultivars when they are available. In the present study, the Arabidopsis genotype with disruptions in the beta-amylase 3 (BAM3) gene, which encodes the major hydrolytic enzyme that degrades starch to maltose, had significantly lower susceptibility to Fusarium oxysporum f. sp. raphani (For) compared to wild-type (wt) plants. It showed the lowest disease severity and contained reduced quantities of fungal DNA in the plant vascular tissues when analyzed with real-time PCR. Through metabolomic analysis using gas chromatography (GC)-mass spectrometry (MS) and gene-expression analysis by reverse-transcription quantitative PCR (RT-qPCR), we observed that defense responses of Arabidopsis bam3 mutants are associated with starch-degradation enzymes, the corresponding modification of the carbohydrate balance, and alterations in sugar (glucose, sucrose, trehalose, and myo-inositol) and auxin metabolism.
PMID: 36559570
Plants (Basel) , IF:3.935 , 2022 Nov , V11 (23) doi: 10.3390/plants11233301
Transcriptome Dynamics of Rooting Zone and Leaves during In Vitro Adventitious Root Formation in Eucalyptus nitens.
Laboratorio de Biotecnologia Aplicada y Genomica Funcional, Instituto de Botanica del Nordeste (IBONE-CONICET), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste, Sgto. Cabral 2131, Corrientes W3402BKG, Argentina.; Mejoramiento Genetico Forestal, INTA-EEA Concordia, CC 34, Concordia E3200AQK, Argentina.; Instituto de Biotecnologia, CICVyA (INTA), Nicolas Repetto y de los Reseros s/n, Hurlingham, Buenos Aires B1686IGC, Argentina.
Wood properties and agronomic traits associated with fast growth and frost tolerance make Eucalyptus nitens a valuable forest alternative. However, the rapid age-related decline in the adventitious root (AR) formation (herein, meaning induction, initiation, and expression stages) limits its propagation. We analyzed transcriptomic profile variation in leaves and stem bases during AR induction of microcuttings to elucidate the molecular mechanisms involved in AR formation. In addition, we quantified expressions of candidate genes associated with recalcitrance. We delimited the ontogenic phases of root formation using histological techniques and Scarecrow and Short-Root expression quantification for RNA sequencing sample collection. We quantified the gene expressions associated with root meristem formation, auxin biosynthesis, perception, signaling, conjugation, and cytokinin signaling in shoots harvested from 2- to 36-month-old plants. After IBA treatment, 702 transcripts changed their expressions. Several were involved in hormone homeostasis and the signaling pathways that determine cell dedifferentiation, leading to root meristem formation. In part, the age-related decline in the rooting capacity is attributable to the increase in the ARR1 gene expression, which negatively affects auxin homeostasis. The analysis of the transcriptomic variation in the leaves and rooting zones provided profuse information: (1) To elucidate the auxin metabolism; (2) to understand the hormonal and signaling processes involved; (3) to collect data associated with their recalcitrance.
PMID: 36501341
Plants (Basel) , IF:3.935 , 2022 Nov , V11 (23) doi: 10.3390/plants11233289
PGP-Bacterium Pseudomonas protegens Improves Bread Wheat Growth and Mitigates Herbicide and Drought Stress.
Ufa Institute of Biology of Ufa Federal Research Centre of Russian Academy of Sciences, 450054 Ufa, Russia.
The reaction of plants to simultaneous stress action and treatment with biological stimulants still remains poorly studied. Laboratory and field experiments have been conducted to study the growth and yield of bread wheat (Triticum aestivum L.) of the variety Ekada 113; stress markers and quantitative ratios of phytohormones in plants under insufficient soil moisture; the effects of spraying with herbicide containing 2,4-D and dicamba and growth-stimulating bacterium Pseudomonas protegens DA1.2; and combinations of these factors. Under water shortage conditions, spraying plants with Chistalan reduced their growth compared to non-sprayed plants, which was associated with inhibition of root growth and a decrease in the content of endogenous auxins in the plants. Under conditions of combined stress, the treatment of plants with the strain P. protegens DA1.2 increased the IAA/ABA ratio and prevented inhibition of root growth by auxin-like herbicide, ensuring water absorption by the roots as well as increased transpiration. As a result, the content of malondialdehyde oxidative stress marker was reduced. Bacterization improved the water balance of wheat plants under arid field conditions. The addition of bacterium P. protegens DA1.2 to the herbicide Chistalan increased relative water content in wheat leaves by 11% compared to plants treated with herbicide alone. Application of the bacterial strain P. protegens DA1.2 increased the amount of harvested grain from 2.0-2.2 t/ha to 3.2-3.6 t/ha. Thus, auxin-like herbicide Chistalan and auxin-producing bacterium P. protegens DA1.2 may affect the balance of phytohormones in different ways. This could be the potential reason for the improvement in wheat plants' growth during dry periods when the bacterium P. protegens DA1.2 is included in mixtures for weed control.
PMID: 36501327
Plants (Basel) , IF:3.935 , 2022 Nov , V11 (23) doi: 10.3390/plants11233251
The Physiological Responses of Wheat and Maize Seedlings Grown under Water Deficit Are Modulated by Pre-Application of Auxin-Type Plant Growth Regulators.
Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.; Nature Research Centre, Laboratory of Plant Physiology, Institute of Botany, 2 Akademijos Str., 08412 Vilnius, Lithuania.
The physiological responses of wheat and maize seedlings to exogenous auxin-type compounds 1-[2-chloroethoxycarbonyl-methyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxicarbonylmethyl]naphthalene chlormethylate (TA-14) application prior to polyethyleneglycol-6000 (PEG) treatment were studied. PEG treatment inhibited seedlings growth and caused alterations in their antioxidant defence which was crop-specific. PEG increased the non-enzymatic antioxidants along with inhibition of enzymatic antioxidant activity in wheat, while in maize the opposite effects were found. The TA-12 and TA-14 applied alone increased most of the growth parameters measured in both crops, as well as the catalase activity and protein content of wheat. The growth of PEG-treated wheat and maize plants was improved by foliar spray with TA-compounds (TAs). Application of TAs before PEG treatment maintained low-molecular weight thiol-containing compounds and protein contents, and catalase and peroxidase activities close to the control levels. This was better expressed in maize than in wheat seedlings. The results showed that the preliminary application of TA-12 and TA-14 can reduce the adverse effects of moderate water deficit by crop-specific adjustment of the antioxidant defence to counteract stress.
PMID: 36501291
Plants (Basel) , IF:3.935 , 2022 Nov , V11 (22) doi: 10.3390/plants11223136
Nematicidal, Acaricidal and Plant Growth-Promoting Activity of Enterobacter Endophytic Strains and Identification of Genes Associated with These Biological Activities in the Genomes.
CENID-Salud Animal e Inocuidad, Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias, Jiutepec 62550, Mexico.; Division Agroalimentaria, Universidad Tecnologica de la Selva, Carretera Ocosingo-Altamirano, km 0.5, Ocosingo 29950, Mexico.; National Center for Disciplinary Research in Animal Health and Safety (INIFAP), Km 11 Federal Road Cuernavaca-Cuautla, Jiutepec 62550, Mexico.; Centro de Ciencias Genomicas, Universidad Nacional Autonoma de Mexico, AP565-A, Cuernavaca 62210, Mexico.; Facultad de Ciencias Agricolas, Universidad Autonoma de Chiapas, Huehuetan 30660, Mexico.; National Institute of Forestry Agricultural and Livestock Research (INIFAP), Campo Experimental Rosario Izapa, Tuxtla Chico 30870, Mexico.; Departamento de Agronomia, Division Ciencias de la Vida, Campus Irapuato-Salamanca, Universidad de Guanajuato, Irapuato 36500, Mexico.; Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Carretera Federal Cuernavaca-Cuautla No. 8534, Colonia Progreso, Jiutepec 62550, Mexico.; Centro de Investigacion en Biotecnologia, Universidad Autonoma del Estado de Morelos, Cuernavaca 62209, Mexico.; Centro de Investigaciones Biologicas, Universidad Autonoma del Estado de Morelos, Cuernavaca 62209, Mexico.
In the present study, the nematicidal and acaricidal activity of three Enterobacter endophytic strains isolated from Mimosa pudica nodules was evaluated. The percentages of mortality of Enterobacter NOD4 against Panagrellus redivivus was 81.2%, and against Nacobbus aberrans 70.1%, Enterobacter NOD8 72.4% and 62.5%, and Enterobacter NOD10 64.8% and 58.7%, respectively. While against the Tyrophagus putrescentiae mite, the mortality percentages were 68.2% due to Enterobacter NOD4, 64.3% due to Enterobacter NOD8 and 77.8% due to Enterobacter NOD10. On the other hand, the ability of the three Enterobacter strains to produce indole acetic acid and phosphate solubilization, characteristics related to plant growth-promoting bacteria, was detected. Bioinformatic analysis of the genomes showed the presence of genes related to IAA production, phosphate solubilization, and nitrogen fixation. Phylogenetic analyzes of the recA gene, phylogenomics, and average nucleotide identity (ANI) allowed us to identify the strain Enterobacter NOD8 related to E. mori and Enterobacter NOD10 as E. asburiae, while Enterobacter NOD4 was identified as a possible new species of this species. The plant growth-promoting, acaricidal and nematicidal activity of the three Enterobacter strains makes them a potential agent to include in biocontrol alternatives and as growth-promoting bacteria in crops of agricultural interest.
PMID: 36432865
Plants (Basel) , IF:3.935 , 2022 Nov , V11 (21) doi: 10.3390/plants11212995
Expression of Genes Involved in ABA and Auxin Metabolism and LEA Gene during Embryogenesis in Hemp.
Department of Botany, Faculty of Science, Palacky University Olomouc, 783 71 Olomouc, Czech Republic.
The level of phytohormones such as abscisic acid (ABA) and auxins (Aux) changes dynamically during embryogenesis. Knowledge of the transcriptional activity of the genes of their metabolic pathways is essential for a deeper understanding of embryogenesis itself; however, it could also help breeding programs of important plants, such as Cannabis sativa, attractive for the pharmaceutical, textile, cosmetic, and food industries. This work aimed to find out how genes of metabolic pathways of Aux (IAA-1, IAA-2, X15-1, X15-2) and ABA (PP2C-1) alongside one member of the LEA gene family (CanLea34) are expressed in embryos depending on the developmental stage and the embryo cultivation in vitro. Walking stick (WS) and mature (M) cultivated and uncultivated embryos of C. sativa cultivars 'KC Dora' and 'USO 31' were analyzed. The RT-qPCR results indicated that for the development of immature (VH) embryos, the genes (IAA-1, IAA-2) are likely to be fundamental. Only an increased expression of the CanLea34 gene was characteristic of the fully maturated (M) embryos. In addition, this feature was significantly increased by cultivation. In conclusion, the cultivation led to the upsurge of expression of all studied genes.
PMID: 36365448
Am J Bot , IF:3.844 , 2022 Nov : Pe16102 doi: 10.1002/ajb2.16102
What determines root-sprouting ability: Injury or phytohormones?
Department of Experimental and Functional Morphology, Institute of Botany of the Czech Academy of Sciences, Dukelska 135, CZ-379 82, Trebon, Czech Republic.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 263, 165 02 Prague 6, Czech Republic.; Department of Ecology and Environmental Sciences, Palacky University, Slechtitelu 241/27, CZ-783 71, Olomouc, Czech Republic.; Department of Botany, Faculty of Science, Charles University, Benatska 2, CZ-128 01 Praha 2, Czech Republic.
PREMISE: Root-sprouting (RS) is an evolutionarily independent alternative to axillary stem branching for a plant to attain its architecture. Root-sprouting plants are better adapted to disturbance than non-RS plants, and their vigor is frequently boosted by biomass removal. Nevertheless, RS plants are rarer than plants that are not root-sprouters, possibly because they must overcome developmental barriers such as intrinsic phytohormonal balance or because RS ability is conditioned by injury to the plant body. The objective of this study was to identify whether phytohormones or injury enable RS. METHODS: In a greenhouse experiment, growth variables, root respiration, and phytohormones were analyzed in two closely related clonal herbs that differ in RS ability (spontaneously RS Inula britannica and rhizomatous non-RS I. salicina) with and without severe biomass removal. RESULTS: As previously reported, I. britannica is a root-sprouter, but injury did not boost its RS ability. Root respiration did not differ between the two species and decreased continuously with time irrespectively of injury, but their phytohormone profiles differed significantly. In RS species, the auxins-to-cytokinins ratio was low, and injury further decreased it. CONCLUSIONS: This first attempt to test drivers behind different plant growth forms suggests that intrinsic phytohormone regulation, especially the auxins-to-cytokinins ratio, might be behind RS ability. Injury, causing a phytohormonal imbalance, seems to be less important in spontaneously RS species than expected for RS species in general.
PMID: 36371783
Life (Basel) , IF:3.817 , 2022 Nov , V12 (11) doi: 10.3390/life12111782
Gravi-Sensitivity of Mosses and Their Gravity-Dependent Ontogenetic Adaptations.
Institute of Ecology of the Carpathians, National Academy of Sciences of Ukraine, Kozelnytska Str. 4, 79005 Lviv, Ukraine.; M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Tereschenkivska Str. 2, 01601 Kyiv, Ukraine.; Paragon Space Development Corporation, 3400 East Britannia Drive, Tucson, AZ 85706, USA.
Gravi-morphoses affect the variability of plants and are the morphogenetic adaptation to different environmental conditions. Gravity-dependent phenotypic plasticity of gametophytes as well as gravi-sensitivity of moss protonemata in microgravity and simulated microgravity conditions are discussed. The moss protonema, a filamentous multicellular system, representing a juvenile stage of moss development, develops as a result of the elongation and division of the apical cell. This apical cell of the protonema is a unique object for research on moss gravi-sensitivity, as graviperception and gravitropic growth occur within the same single cell. Attention is focused on the influence of gravity on bryophyte ontogenesis, including the gravitropic reactivity of moss protonemata, gravi-sensitivity at the stage of leafy shoot development and sporogonium formation, gravity-influenced morphogenesis of apical cell budding, and gravity-dependent spiral growth patterns. The role of gravireceptors in the growth processes of mosses at the cellular level under microgravity conditions are being discussed, as well as the involvement of auxin transport, Ca2+-induced gravitropism and the cytoskeleton in gravitropic reactions.
PMID: 36362937
Gene , IF:3.688 , 2023 Jan , V851 : P146982 doi: 10.1016/j.gene.2022.146982
Molecular characterization of the GH3 family in alfalfa under abiotic stress.
Hainan Key Laboratory for the Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou 570228, People's Republic of China; School of Tropical Crops, Hainan University, Haikou 570228, People's Republic of China.; College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, People's Republic of China.; Hainan Key Laboratory for the Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou 570228, People's Republic of China.; Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT), Cali 763537, Colombia.; Hainan University Archives, Haikou 570228, People's Republic of China.; Hainan Key Laboratory for the Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou 570228, People's Republic of China; School of Tropical Crops, Hainan University, Haikou 570228, People's Republic of China. Electronic address: zhangrui@hainanu.edu.cn.; Hainan Key Laboratory for the Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou 570228, People's Republic of China. Electronic address: yhchen@hainanu.edu.cn.
The phytohormone auxin plays a pivotal role in regulating plant growth, development, and abiotic stress responses by promptly controlling the expression of auxin response genes. The Gretchen Hagen3 (GH3) genes are a major early auxin response gene family that contribute to auxin homeostasis by conjugating excess auxins to amino acids. To our knowledge, a genome-wide investigation of the GH3 genes in alfalfa has never been reported. Here, we present a comprehensive bioinformatics analysis of the MsGH3 gene family, including chromosomal locations, phylogenetic relationships, gene structures, conserved motifs and Gene Ontology annotation. Interestingly, the analysis revealed 31 MsGH3 genes in the alfalfa genome. These genes were classified phylogenetically into the GH3-I, GH3-II, and GH3-III subgroups. Additionally, the data analysis showed that most MsGH3 genes are tissue specific and responsive to environmental stress-related hormones. Furthermore, the analysis of cis elements and potential biological functions revealed that the MsGH3 genes play potential roles in various stress responses. Notably, qRT-PCR results following exposure to high temperature, drought, and salt treatments demonstrated that most of the MsGH3 family genes, especially MsGH3-12, MsGH3-13, and MsGH3-15, play important roles in stress responses. These findings provide invaluable insight for future practical analyses and genetic improvement of alfalfa abiotic stress tolerance.
PMID: 36270456
J Plant Physiol , IF:3.549 , 2022 Dec , V280 : P153891 doi: 10.1016/j.jplph.2022.153891
The nitrification inhibitor 1,9-decanediol from rice roots promotes root growth in Arabidopsis through involvement of ABA and PIN2-mediated auxin signaling.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. Electronic address: yflu@issas.ac.cn.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.; School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.; Amway (China) Botanical R&D Center, Wuxi, 214115, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: wmshi@issas.ac.cn.
1,9-decanediol (1,9-D) is a biological nitrification inhibitor secreted in roots, which effectively inhibits soil nitrifier activity and reduces nitrogen loss from agricultural fields. However, the effects of 1,9-D on plant root growth and the involvement of signaling pathways in the plant response to 1,9-D have not been investigated. Here, we report that 1,9-D, in the 100-400 muM concentration range, promotes primary root length in Arabidopsis seedlings at 3d and 5d, by 10.1%-33.3% and 6.9%-32.6%, and, in a range of 50-200 muM, leads to an increase in the number of lateral roots. 150 muM 1,9-D was found optimum for the positive regulation of root growth. qRT-PCR analysis reveals that 1,9-D can significantly increase AtABA3 gene expression and that a mutation in ABA3 results in insensitivity of root growth to 1,9-D. Moreover, through pharmacological experiments, we show that exogenous addition of ABA (abscisic acid) with 1,9-D enhances primary root length by 23.5%-63.3%, and an exogenous supply of 1,9-D with the ABA inhibitor Flu reduces primary root length by 1.0%-14.3%. Primary root length of the pin2/eir1-1 is shown to be insensitive to both exogenous addition of 1,9-D and ABA, indicating that the auxin carrier PIN2/EIR1 is involved in promotion of root growth by 1,9-D. These results suggest a novel for 1,9-D in regulating plant root growth through ABA and auxin signaling.
PMID: 36495813
Funct Integr Genomics , IF:3.41 , 2022 Dec , V23 (1) : P14 doi: 10.1007/s10142-022-00928-7
Leaf rust responsive miRNA and their target genes in wheat.
Division of Genetics, ICAR-Indian Agricultural Research Institute (IARI), New Delhi, 110012, India.; Regional Station, ICAR-Indian Institute of Wheat and Barley Research, Flowerdale, Shimla, 171002, India.; Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, 250004, India.; Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, 250004, India. pkgupta36@gmail.com.
Small RNA sequencing (sRNA-seq) and degradome analysis were used for the identification of miRNAs and their target host genes in a pair of near-isogenic lines (NILs), which differed for the presence of leaf rust resistance gene Lr28. The study led to identification of (i) 506 known and 346 novel miRNAs; and (ii) 5054 target genes including 4557 in silico predicted and 497 degradome-based genes using 105 differentially expressed (DE) miRNAs. A subset of 128 targets (67 in silico + 61 degradome-based) was differentially expressed in RNA-seq data that was generated by us earlier using the same pair of NILs; among these 128 targets, 58 target genes exhibited an inverse relationship with the DE miRNAs (expression of miRNAs and activation/suppression of target genes). Eight miRNAs which belonged to the conserved miRNA families and were known to be induced in response to fungal diseases in plants included the following: miR156, miR158, miR159, miR168, miR169, miR172, miR319, miR396. The target genes belonged to the following classes of genes known to be involved in downstream disease resistance pathways; peroxidases, sugar transporters, auxin response signaling, oxidation-reduction, etc. It was also noticed that although a majority of miRNAs and target genes followed the above classical inverse relationship, there were also examples, where no such relationship was observed. Among the target genes, there were also 51 genes that were not only regulated by miRNAs, but were also differentially methylated at sequences including the following segments: promotors, introns, TSS, exons. The results of the present study suggest a complex interplay among miRNA genes, target genes, and various epigenetic controls, which regulate the expression of genes involved in downstream pathways for disease resistance.
PMID: 36550370
Protoplasma , IF:3.356 , 2022 Nov doi: 10.1007/s00709-022-01826-2
Phytotoxicity and the molecular response in yttrium oxide nanoparticle-treated Arabidopsis thaliana seedlings.
Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China.; Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. jinlin_feng@163.com.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. jinlin_feng@163.com.; Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. hhwrsl@163.com.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. hhwrsl@163.com.
Due to the widespread application of rare earth oxide nanoparticles in various fields, their release into the environment is inevitable, and their potential toxicity and ecological impact have become a concern. Yttrium oxide nanoparticles are important rare earth oxide nanoparticles; however, their impact on plants and the molecular mechanism underlying their influence on plant growth and development are unclear. In this study, we found that yttrium oxide nanoparticles at concentrations exceeding 2 mM significantly inhibited the growth of Arabidopsis seedlings. Using Arabidopsis marker lines for auxin signaling, we found that the application of yttrium oxide nanoparticles resulted in disordered auxin signaling in root cells. Auxin signaling in the cells of the quiescent center and columella stem cells decreased, while auxin signaling in the cells of the stele was enhanced. In addition, trypan blue staining showed that yttrium oxide nanoparticles induced root cell death. Transcriptome analysis showed that the nanoparticles specifically inhibited the expression of lignin synthesis-related genes, activated the MAPK signaling pathway, and enhanced the ethylene and abscisic acid signaling pathways in plants. This study demonstrates the phytotoxicity of yttrium oxide nanoparticles at the molecular level in Arabidopsis, and it provides a new perspective on how plants respond to rare earth oxide stress.
PMID: 36445485
PLoS One , IF:3.24 , 2022 , V17 (11) : Pe0277701 doi: 10.1371/journal.pone.0277701
Transcriptome analysis reveals the regulatory mode by which NAA promotes the growth of Armillaria gallica.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China.; Planting Department of Zhaoyang District Bureau of Agriculture, Zhaotong, China.
A symbiotic relationship is observed between Armillaria and the Chinese herbal medicine Gastrodia elata (G. elata). Armillaria is a nutrient source for the growth of G. elata, and its nutrient metabolism efficiency affects the growth and development of G. elata. Auxin has been reported to stimulate Armillaria species, but the molecular mechanism remains unknown. We found that naphthalene acetic acid (NAA) can also promote the growth of A. gallica. Moreover, we identified a total of 2071 differentially expressed genes (DEGs) by analyzing the transcriptome sequencing data of A. gallica at 5 and 10 hour of NAA treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that these unigenes were significantly enriched in the metabolism pathways of arginine, proline, propanoate, phenylalanine and tryptophan. The expression levels of the general amino acid permease (Gap), ammonium transporter (AMT), glutamate dehydrogenase (GDH), glutamine synthetase (GS), Zn(II) 2Cys6 and C2H2 transcription factor genes were upregulated. Our transcriptome analysis showed that the amino acid and nitrogen metabolism pathways in Armillaria were rapidly induced within hours after NAA treatment. These results provide valuable insights into the molecular mechanisms by which NAA promotes the growth of Armillaria species.
PMID: 36409681
Plant Biol (Stuttg) , IF:3.081 , 2022 Nov doi: 10.1111/plb.13489
Cold stress triggers freezing tolerance in wheat (Triticum aestivum L.) via hormone regulation and transcription of related genes.
College of Life Science, Northeast Agricultural University, Harbin, China.
Low temperatures limit the geographic distribution and yield of plants. Hormones play an important role in coordinating the growth and development of plants and their tolerance to low temperatures. However, the mechanisms by which hormones affect plant resistance to extreme cold stress in the natural environment are still unclear. In this study, two winter wheat varieties with different cold resistances, Dn1 and J22, were used to conduct targeted plant hormone metabolome analysis on the tillering nodes of winter wheat at 5 degrees C, -10 degrees C and -25 degrees C using an LC-ESI-MS/MS system. We screened 39 hormones from 88 plant hormone metabolites and constructed a partial regulatory network of auxin, jasmonic acid and cytokinin. GO analysis and enrichment of KEGG pathways in different metabolites showed that the 'plant hormone signal transduction' pathway was the most common. Our study showed that extreme low temperature increased the most levels of auxin, cytokinin and salicylic acid, and decreased levels of jasmonic acid and abscisic acid, and that levels of auxin, jasmonic acid and cytokinin in Dn1 were higher than those in J22. These changes in hormone levels were associated with changes in gene expression in synthesis, catabolism, transport and signal transduction pathways. These results differ from the previous hormone regulation mechanisms, which were mostly obtained at 4 degrees C. Our results provide a basis for further understanding the molecular mechanisms by which plant endogenous hormones regulate plant freezing stress tolerance.
PMID: 36385725
Plant Direct , IF:3.038 , 2022 Dec , V6 (12) : Pe465 doi: 10.1002/pld3.465
Opposing effects of trans- and cis-cinnamic acid during rice coleoptile elongation.
Department of Plant Biotechnology and Bioinformatics Ghent University Ghent Belgium.; VIB-UGent Center for Plant Systems Biology Ghent Belgium.; Laboratory of Plant Growth Analysis Ghent University Global Campus Incheon South Korea.; VIB Metabolomics Core Ghent Ghent Belgium.; Department of Biotechnology Ghent University Ghent Belgium.; Department of Green Chemistry and Technology Ghent University Ghent Belgium.
The phenylpropanoid cinnamic acid (CA) is a plant metabolite that can occur under a trans- or cis-form. In contrast to the proven bioactivity of the cis-form (c-CA), the activity of trans-CA (t-CA) is still a matter of debate. We tested both compounds using a submerged rice coleoptile assay and demonstrated that they have opposite effects on cell elongation. Notably, in the tip of rice coleoptile t-CA showed an inhibiting and c-CA a stimulating activity. By combining transcriptomics and (untargeted) metabolomics with activity assays and genetic and pharmacological experiments, we aimed to explain the underlying mechanistic processes. We propose a model in which c-CA treatment activates proton pumps and stimulates acidification of the apoplast, which in turn leads to the loosening of the cell wall, necessary for elongation. We hypothesize that c-CA also inactivates auxin efflux transporters, which might cause a local auxin accumulation in the tip of the coleoptile. For t-CA, the phenotype can partially be explained by a stimulation of cell wall polysaccharide feruloylation, leading to a more rigid cell wall. Metabolite profiling also demonstrated that salicylic acid (SA) derivatives are increased upon t-CA treatment. As SA is a known antagonist of auxin, the shift in SA homeostasis provides an additional explanation of the observed t-CA-mediated restriction on cell growth.
PMID: 36545006
Ecotoxicology , IF:2.823 , 2022 Dec doi: 10.1007/s10646-022-02613-8
Pea root responses under naproxen stress: changes in the formation of structural barriers in the primary root in context with changes of auxin and abscisic acid levels.
Section of Experimental Plant Biology, Department of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlarska 2, 611 37, Brno, Czech Republic.; Section of Experimental Plant Biology, Department of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlarska 2, 611 37, Brno, Czech Republic. zezulka@sci.muni.cz.; Department of Plant Physiology, Faculty of Natural Science, Comenius University in Bratislava, Mlynska dolina B2, 842 15, Bratislava, Slovakia.; Institute of Plant Biology, Faculty of Agronomy, Mendel University Brno, Zemedelska 1, 613 00, Brno, Czech Republic.; Laboratory of Metabolomics and Isotope Analyses, Global Change Research Institute, Czech Academy of Sciences, Belidla 986/4a, 603 00, Brno, Czech Republic.
Pharmaceuticals belong to pseudo-persistent pollutants because of constant entry into the environment and hazardous potential for non-target organisms, including plants, in which they can influence biochemical and physiological processes. Detailed analysis of results obtained by microscopic observations using fluorescent dyes (berberine hemisulphate, Fluorol Yellow 088), detection of phytohormone levels (radioimmunoassay, enzyme-linked immune sorbent assay) and thermogravimetric analysis of lignin content proved that the drug naproxen (NPX) can stimulate the formation of root structural barriers. In the primary root of plants treated with 0.5, 1, and 10 mg/L NPX, earlier Casparian strip formation and development of the whole endodermis circle closer to its apex were found after five days of cultivation (by 9-20% as compared to control) and after ten days from 0.1 mg/L NPX (by 8-63%). Suberin lamellae (SL) were deposited in endodermal cells significantly closer to the apex under 10 mg/L NPX by up to 75%. Structural barrier formation under NPX treatment can be influenced indirectly by auxin-supported cell division and differentiation caused by its eight-times higher level under 10 mg/L NPX and directly by stimulated SL deposition induced by abscisic acid (higher from 0.5 mg/L NPX), as proved by the higher proportion of cells with SL in the primary root base (by 8-44%). The earlier modification of endodermis in plant roots can help to limit the drug transfer and maintain the homeostasis of the plant.
PMID: 36542231
J Theor Biol , IF:2.691 , 2022 Nov , V553 : P111261 doi: 10.1016/j.jtbi.2022.111261
Modeling phyllotaxis: From the inhibition potential to the real plant.
Laboratoire de Thermodynamique des Milieux Ioniques et Biologiques, Universite Paris Cite, 45 cours Lassus, 66000 Perpignan, France. Electronic address: jpwalch511@gmail.com.
We developed a new parametrization of the classic Douady and Couder model of phyllotaxis based on the inhibition potential: it allowed us to accurately reproduce the vegetative meristem of Linum usitatissimum displaying Fibonacci phyllotaxis, and the reproductive meristem of Ranunculus repens. We calculated the inhibition potential within the meristem and the auxin concentration at the front. We show that phyllotaxis modes and the convergence of the divergence angles towards "noble" angles are the consequence of minimizing the inhibitory potential under the constraint of decreasing plastochron ratios. Our approach, which gives a physicochemical basis to the van Iterson diagram, produces the same results as approaches based on mechanical constraints, suggesting these are two facets of the same botanical reality.
PMID: 36037857
Arch Microbiol , IF:2.552 , 2022 Dec , V205 (1) : P45 doi: 10.1007/s00203-022-03358-y
Molecular identification and characterization of phytobeneficial osmotolerant endophytic bacteria inhabiting root nodules of the Saharan tree Vachellia tortilis subsp. raddiana.
Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco.; Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco. jamal.aurag@fsr.um5.ac.ma.
Nodular endophytes of drought-tolerant legumes are understudied. For this reason, we have isolated and studied non-symbiotic endophytic bacteria from nodules of Vachellia tortilis subsp. raddiana, a leguminous tree adapted to the harsh arid climate of Southern Morocco. Rep-PCR analysis followed by 16S rDNA sequencing revealed two main genera, Pseudomonas and Bacillus. Isolates responded variably to salt and water stresses, and mostly produced exopolysaccharides. Differences concerned also plant growth-promoting activities: phosphate, potassium, and zinc solubilization; biological nitrogen fixation; auxin, siderophore, ammonia, and HCN production; and ACC deaminase activity. Some strains exhibited antagonistic activities against phytopathogenic fungi (Fusarium oxysporum and Botrytis cinerea) and showed at least two enzymatic activities (cellulase, protease, chitinase). Four selected strains inoculated to vachellia plants under controlled conditions have shown significant positive impacts on plant growth parameters. These strains are promising bio-inoculants for vachellia plants to be used in reforestation programs in arid areas increasingly threatened by desertification.
PMID: 36576567
Braz J Microbiol , IF:2.476 , 2022 Nov doi: 10.1007/s42770-022-00874-3
Bacillus subtilis and Bacillus licheniformis promote tomato growth.
Departamento de Fitopatologia, Universidade Federal de Lavras, Lavras, MG, 37200-900, Brazil.; Chr-Hansen Industria E Comercio Ltda, Valinhos, SP, 13278-327, Brazil.; Embrapa Meio Ambiente, Rod. SP-340 Km 1275, 13.918-110, Jaguariuna, SP, Brazil. wagner.bettiol@embrapa.br.
Bacillus spp. are widely marketed and used in agricultural systems as antagonists to various phytopathogens, but it can also benefit the plant as plant growth promoters. Therefore, the longer presence of the bacterium in the rhizosphere would result in a prolonged growth-promoting benefit, but little is yet known about its persistence in the rhizosphere after seed coating. The objectives of this study were to evaluate the tomato growth promotion mediated by Bacillus licheniformis FMCH001 and Bacillus subtilis FMCH002 and the survival rate of these bacteria both in shoots and in the rhizosphere. The Bacillus strains used throughout this study were obtained from Quartzo(R) produced by Chr. Hansen. The application of a mixture of B. subtilis and B. licheniformis (Quartzo(R)) at concentrations 1 x 10(8), 1 x 10(9), and 1 x 10(10) CFU mL(-1), as well as the application of B. subtilis and B. licheniformis individually at concentration 1 x 10(8) CFU mL(-1), increased fresh and dry masses of shoot and root system, volume of root system, and length of roots of tomato plants when compared to control. Both Bacillus strains produced IAA after 48 h of in vitro. Bacillus colonies obtained from plant sap were morphologically similar to colonies of B. subtilis and B. licheniformis strains and were detected in inoculated on plants and not detected in control ones. A similar pattern was obtained through DNA-based detection (qPCR). Therefore, B. subtilis and B. licheniformis were able to produce auxin, promote tomato growth, and colonize and persist in the rhizosphere.
PMID: 36422850
Biol Open , IF:2.422 , 2022 Dec , V11 (12) doi: 10.1242/bio.059668
Reevaluating the relationship between EGL-43 (EVI1) and LIN-12 (Notch) during C. elegans anchor cell invasion.
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA.; Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA.
Development of the Caenorhabditis elegans reproductive tract is orchestrated by the anchor cell (AC). This occurs in part through a cell invasion event that connects the uterine and vulval tissues. Several key transcription factors regulate AC invasion, such as EGL-43, HLH-2, and NHR-67. Specifically, these transcription factors function together to maintain the post-mitotic state of the AC, a requirement for AC invasion. Recently, a mechanistic connection has been made between loss of EGL-43 and AC cell-cycle entry. The current model states that EGL-43 represses LIN-12 (Notch) expression to prevent AC proliferation, suggesting that Notch signaling has mitogenic effects in the invasive AC. To reexamine the relationship between EGL-43 and LIN-12, we first designed and implemented a heterologous co-expression system called AIDHB that combines the auxin-inducible degron (AID) system of plants with a live cell-cycle sensor based on human DNA helicase B (DHB). After validating AIDHB using AID-tagged GFP, we sought to test it by using AID-tagged alleles of egl-43 and lin-12. Auxin-induced degradation of either EGL-43 or LIN-12 resulted in the expected AC phenotypes. Lastly, we seized the opportunity to pair AIDHB with RNAi to co-deplete LIN-12 and EGL-43, respectively, which revealed that LIN-12 is not required for AC proliferation following loss of EGL-43.
PMID: 36445013
Can J Microbiol , IF:2.419 , 2022 Nov doi: 10.1139/cjm-2022-0181
Bacterial secondary metabolites: Possible mechanism for weed suppression in wheat.
The Islamia University of Bahawalpur Pakistan, 54735, Department of Soil Science, Bahawalpur, Pakistan; abubakar.dar@iub.edu.pk.; University of Hohenheim, 26558, Institute of Agricultural Sciences in the Tropics , Stuttgart, Germany; vnwere@gmail.com.; University of Hohenheim, 26558, Institute of Agricultural Sciences in the Tropics, Stuttgart, Baden-Wurttemberg, Germany; Thomas.Hilger@uni-hohenheim.de.; University of Agriculture Faisalabad, 66724, Institute of Soil & Environmental Sciences, Faisalabad, Punjab, Pakistan; zazahir@uaf.edu.pk.; The Islamia University of Bahawalpur Pakistan, 54735, Department of Soil Science, Bahawalpur, Punjab, Pakistan; makshoof.ahmad@iub.edu.pk.; The Islamia University of Bahawalpur Pakistan, 54735, Department of Soil Science, Bahawalpur, Pakistan; azharhaseen@gmail.com.; University of Hohenheim, 26558, Institute of Agricultural Sciences in the Tropics, Stuttgart, Germany; frank.rasche@uni-hohenheim.de.
Chemical weed control is an effective method, but has proved hazardous for humans, environment, and soil biodiversity. Use of allelopathic bacteria (AB), may be more efficient and sustainable weed control measure. The bacterial inoculants never studied in context of their interaction with weed root exudates and precursor-dependent production of the natural phytotoxins (cyanide, cytolytic enzymes and auxin) by these stains to understand their weed suppression and wheat growth promotion abilities. Therefore, root exudates of Avena fatua, Phalaris minor, Rumex dentatus and wheat were quantified and their role in microbial root colonization and secondary metabolites production i.e. cyanide, cytolitic enzymes, phenolics and elevated auxin concentration was studied. The results depicted L-tryptophan and glycine as major contributor of elevated cyanide and elevated levels in weed rhizosphere by the studied Pseudomonas strains, through their higher root colonization ability in weeds as compared to wheat. Furthermore, the higher root colonization also enhanced p-coumaric acid (photosynthesis inhibitor by impairing cytochrome c oxidase activity in plants), and cytolytic enzymes (root cell wall degradation) concentration in weed rhizosphere. In conclusion, the differential root colonization of wheat and weeds by these strains is responsible for enhancing weed suppression (enhancing phytotoxic effect) and wheat growth promotion (lowering phytotoxic effect).
PMID: 36379032
3 Biotech , IF:2.406 , 2022 Nov , V12 (11) : P326 doi: 10.1007/s13205-022-03392-z
Identification, characterization, and genome sequencing of Brevibacterium sediminis MG-1 isolate with growth-promoting properties.
Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region), Federal University, Kazan, Russia. GRID: grid.77268.3c. ISNI: 0000 0004 0543 9688; Laboratory of Agrobioengineering, Institute of Fundamental Medicine and Biology, Kazan (Volga Region), Federal University, Kazan, Russia. GRID: grid.77268.3c. ISNI: 0000 0004 0543 9688; Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA. GRID: grid.137628.9. ISNI: 0000 0004 1936 8753; Research Center Regulatory Genomics, Institute of Fundamental Medicine and Biology, Kazan (Volga Region), Federal University, Kazan, Russia. GRID: grid.77268.3c. ISNI: 0000 0004 0543 9688; Department of Breeding and Biotechnology of Potatoes, Tatar Research Institute of Agriculture, Federal Research Center "Kazan Scientific Center of Russian Academy of Sciences", Kazan, Russia. GRID: grid.465285.8. ISNI: 0000 0004 0637 9007
In recent years, plant growth-promoting rhizobacteria (PGPR) have received increased attention due to their prospective use as biofertilizers for the enhancement of crop growth and yields. However, there is a growing need to identify new PGPR isolates with additional beneficial properties. In this paper, we describe the identification of a new strain of a non-sporulating Gram-positive bacterium isolated from the rhizosphere of potato plants, classified as Brevibacterium sediminis MG-1 based on whole-genome sequencing. The bacteria are aerobic; they grow in a pH range of 6.0-10.0 (optimum 6.0), and a temperature range of 20-37 degrees C (optimum 30 degrees C). At 96 h of cultivation, strain MG-1 synthesizes 28.65 microg/ml of indole-3-acetic acid (IAA) when 500 microg/ml of l-tryptophan is added. It is a producer of catechol-type siderophores and ACC deaminase (213 +/- 12.34 ng/ml) and shows halotolerance. Treatment of pea, rye, and wheat seeds with a suspension of MG-1 strain cells resulted in the stimulation of stem and root biomass accumulation by 12-26% and 6-25% (P < 0.05), respectively. Treatment of seeds with bacteria in the presence of high salt concentration reduced the negative effects of salt stress on plant growth by 18-50%. The hypothetical gene lin, encoding the bacteriocin Linocin-M18, RIPP-like proteins, and polyketide synthase type III (T3PKS) loci, gene clusters responsible for iron acquisition and metabolism of siderophores, as well as gene clusters responsible for auxin biosynthesis, were identified in the B. sediminis MG-1 genome. Thus, the rhizosphere-associated strain B. sediminis MG-1 has growth-stimulating properties and can be useful for the treatment of plants grown on soils with high salinity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03392-z.
PMID: 36276447
Physiol Mol Biol Plants , IF:2.391 , 2022 Dec , V28 (11-12) : P1997-2009 doi: 10.1007/s12298-022-01268-3
Volatile organic compounds from Lysinibacillus macroides regulating the seedling growth of Arabidopsis thaliana.
College of Life Sciences, Shandong Agricultural University, Tai'an, 271018 China. GRID: grid.440622.6. ISNI: 0000 0000 9482 4676; Shandong Key Laboratory of Agricultural Microbiology, Tai'an, 271018 China.; Shandong Engineering Research Center of Plant-Microbia Restoration for Saline-Alkali Land, Tai'an, 271018 China.
Volatile organic compounds (VOCs) have the characteristics of long distance propagation, low concentration, perception, and indirect contact between organisms. In this experiment, Lysinibacillus macroides Xi9 was isolated from cassava residue, and the VOCs produced by this strain were analyzed by the SPME-GC-MS method, mainly including alcohols, esters, and alkanes. By inoculation of L. macroides Xi9, VOCs can promote the growth and change the root-system architecture of Arabidopsis seedlings. The results showed that the number of lateral roots, root density, and fresh weight of Arabidopsis seedlings were significantly higher (p
PMID: 36573143
Mol Biol Rep , IF:2.316 , 2022 Nov doi: 10.1007/s11033-022-07999-6
Phylogeny, gene structures, and expression patterns of the auxin response factor (GhARF2) in upland cotton (Gossypium hirsutum L.).
College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China.; Postdoctoral Research Base, Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China.; State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, 271018, China.; College of Agronomy, Henan Agricultural University, Zhengzhou, 450046, China. tangjihua1@163.com.; Postdoctoral Research Base, Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China. wangql985@163.com.
BACKGROUND: Auxin response factors (ARFs) are a class of transcription factors that regulate the expression of auxin-responsive genes and play important functions in plant growth and development. To understand the biological functions of the auxin response factor GhARF2 gene in upland cotton, the coding sequence (CDS) of GhARF2 gene was cloned, and its protein sequence, evolutionary relationship, subcellular localization and expression pattern were analysed. METHODS: The CDS sequence of GhARF2 gene was cloned from upland cotton variety Baimian No.1, and its protein sequence was analyzed by bioinformatics method. The subcellular localization of GhARF2 protein was detected by tobacco epidermal transient transformation system, and the tissue expression and stress expression pattern of GhARF2 were analyzed by quantitative Real‑Time PCR (qRT-PCR). RESULTS: The full-length CDS of GhARF2 gene was 2583 bp, encoded 860 amino acids, and had a molecular weight and an isoelectric point of 95.46 KDa and 6.02, respectively. The GhARF2 protein had multiple phosphorylation sites, no transmembrane domain, and secondary structures dominated by random coils and alpha helix. The GhARF2 protein had 3 conserved typical domains of ARF gene family members, including the B3 DNA binding domain, the Auxin_resp domain, and the Aux/IAA domain. Phylogenetic analysis revealed that ARF2 proteins in different species were clustered in the Group A subgroup, in which GhARF2 was closely related to TcARF2 of Theobroma cacao L. (Malvaceae). The subcellular localization results showed that the GhARF2 protein was localized in the nucleus. Analysis of tissue expression pattern showed that the GhARF2 gene was expressed in all tested tissues, with the highest expression levels in sepal, followed by leaf, and the lowest expression levels in fiber. Further stress expression analysis showed that the GhARF2 gene was induced by drought, high-temperature, low-temperature and salt stress, and had different expression patterns under different stress conditions. CONCLUSION: These results established a foundation for understanding the functions of GhARF2 and breeding varieties with high-stress tolerance in cotton.
PMID: 36399242
Mol Biol Rep , IF:2.316 , 2022 Dec , V49 (12) : P11273-11280 doi: 10.1007/s11033-022-07712-7
Determination of genotoxic damages of picloram and dicamba with comet assay in Allium cepa rooted in tissue culture and distilled water.
Faculty of Gazi Education, Department of Biology Education, Gazi University, Ankara, Turkey. cigdemozel@gazi.edu.tr.; Science Faculty, Department of Biology, Gazi University, Ankara, Turkey.; Vocational School of Technical Sciences, Amasya University, Amasya, Turkey.; Faculty of Gazi Education, Department of Biology Education, Gazi University, Ankara, Turkey.
BACKGROUND: Many genotoxicity tests allow us to understand the mechanism of damages on genetic material occurring in living organisms against various physical and chemical agents. One of them is the Comet test. The current study aimed to evaluate genotoxic caused by picloram and dicamba to root meristems of Allium cepa utilizing comet assay. METHODS: Two different protocols were used for rooting and auxin/pesticide application. (i) A. cepa bulbs were rooted in MS medium and then treated with Murashige and Skoog (MS) medium (control) and 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba using aseptic tissue culture techniques. (ii) A. cepa bulbs were then rooted in bidistilled water and treated with 0 (control), 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba in distilled water. The A. cepa root tip cells in both treatment groups were examined using comet test to find the possible DNA damaging effects of picloram and dicamba. RESULTS: The results obtained at all the concentrations were statistically compared with their control groups. Almost at all the concentrations of Picloram and dicamba increased comet tail intensity (%) and tail moment in roots treated in MS medium. Two highest concentrations revealed toxic effect. On the other hand, DNA damaging effect of both auxins was only noted on the highest (> 4.02 mg/L) in roots treated in distilled water. CONCLUSIONS: This study approve and confirm genotoxic effects of how growth regulators on plants. These findings give an evidence of DNA damage in A. cepa. Therefore, both picloram and dicamba should only be used in appropriate and recommended concentrations in agriculture to conserve ecosystem and to pose minimum threat to life.
PMID: 35804213
J Basic Microbiol , IF:2.281 , 2022 Nov doi: 10.1002/jobm.202200463
Transcriptome analysis of Armillaria gallica 012 m in response to auxin.
Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University, Kunming, China.; Department of Chemistry, School of Chemistry and Environment, Yunnan Minzu University, Kunming, China.; Life Science College, Southwest Forestry University, Kunming, China.; Kunming Xianghao Technology Co. Ltd., Kunming, China.
Gastrodia elata is an achlorophyllous and fully mycoheterotrophic orchid which obtains carbon and other nutrients from Armillaria species in its life cycle. Many researchers suggested that plant hormones, as signing molecules, play a central role in the plant-fungi interaction. In the process of Armillaria gallica 012 m cultivation, both exogenous indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) distinctly stimulated the growth of mycelia in solid media. The differential expression genes (DEGs) of A. gallica 012 m with IAA versus blank control (BK) and IBA versus BK were investigated. The results showed that more than 80% of DEGs of the IAA group were coincident with the DEGs of the IBA group, and more than half of upregulated DEGs and most of the downregulated DEGs of the IAA group coincided with those DEGs of the IBA group. Above research implied that A. gallica 012 m could perceive IAA and IBA, and possess similar responses and signaling pathways to IAA and IBA. The overlapping differential genes of the IAA group and IBA group were analyzed by GO term, and the results showed that several DEGs identified were related to biological processes including positive regulation of the biological process and biological process. The downregulated NmrA-like and FKBP_C genes might be benefit to the growth of mycelia. Those results can explain that exiguous IAA and IBA improved the growth of A. gallica to some extent. We speculate that IAA and IBA are signaling molecules, and regulate the expression of growth-related genes of A. gallica 012 m by the same signaling pathway.
PMID: 36449692
Antonie Van Leeuwenhoek , IF:2.271 , 2022 Dec doi: 10.1007/s10482-022-01800-1
Devosia oryzisoli sp. nov., a novel moderately halotolerant bacterium isolated from the roots of rice plants and genome mining revealed the biosynthesis potential as plant growth promoter.
Department of Life Science, Dongguk University-Seoul, 10326, Goyang, South Korea.; Department of Life Science, Dongguk University-Seoul, 10326, Goyang, South Korea. tseo@dongguk.edu.
A Gram-stain-negative, halotolerant bacterium designated as PTR5(T) was isolated from the roots of rice plants, collected in Ilsan, South Korea. Cells were, aerobic, asporogenous, motile, rod-shaped, white in color, and grew at 5-38 degrees C (optimum 30 degrees C), at pH 5.0-0-8.0 (optimum, 7.0) and tolerates up to 10% (w/v) NaCl (optimum, 0% NaCl). According to the EZbioCloud server the most closely related Devosia species to strain PTR5(T) based on 16 S rRNA gene sequence comparison are Devosia crocina (97.4%), followed by D. soli (97.2%), D. lucknowensis (96.9%) and D. marina (96.5%). The respiratory quinone was identified as Q-10. The major polar lipids were phosphatidylglycerol and diphosphatidylglycerol. C(16:0), C(18:1) omega7c 11-methyl and summed feature 8 (comprising C(18:1) omega7c/C(18:1) omega6c) constituted the main cellular fatty acids. The draft genome sequence of strain PTR5(T) was 3,689,283 bp in size. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH) and amino acid identity (AAI) values between strain PTR5(T) and its close relative were 72.8-76.8%, 19-20.7% and 70.3-75%, respectively. The G + C content was 63.7%. Strain PTR5(T) was able to produce siderophore and indole acetic acid (IAA) in the presence of L-tryptophan. Genes for siderophore production, auxin responsive and tryptophan biosynthesis were present in the genome of novel strain. Also, gene clusters involved in detoxification of various metal pollutants and antibiotics were also revealed in the genome of novel strain PTR5(T), this suggest that novel strain can facilitate bioremediation of heavy metals and antibiotics in contaminated areas. This study aimed to determine the detailed taxonomic position of the strain PTR5(T) using the modern polyphasic approach. On the basis of evidence presented in this study, strain PTR5(T) is considered to represent a novel species of the genus Devosia, for which the name Devosia oryzisoli sp. nov. (type strain PTR5(T) (KCTC 82691(T) = TBRC 15163(T)) is proposed.
PMID: 36525157
Plant Signal Behav , IF:2.247 , 2022 Dec , V17 (1) : P2096780 doi: 10.1080/15592324.2022.2096780
GIGANTEA regulates lateral root formation by modulating auxin signaling in Arabidopsis thaliana.
Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
Lateral root (LR) formation is a vital organogenetic process that determines the root architecture in plants. The number of root branches governs the degree of anchorage, efficiency of nutrients acquisition, and water uptake. The molecular pathways involved in LR formation have been extensively studied in Arabidopsis thaliana (At). A plant hormone, Auxin, is a key regulator of root development and promotes LR formation in plants. A plethora of Arabidopsis genes have been identified to regulate LR initiation, patterning, and emergence processes. Recently, the involvement of flowering time control pathways and circadian clock pathways in LR development has come to light, but the connecting link between these processes is still missing. We have established that GIGANTEA (GI), a key component of photoperiodic flowering, can regulate the formation of LRs in Arabidopsis. GI is known to be involved in red light signaling and circadian clock signaling pathways. Here, we report that over-expression of GI enhances LR formation in red light in At. Real-time PCR analysis shows that GI positively regulates the transcription of TRANSPORT INHIBITOR RESPONSE 1 (TIR1) which is an upstream component of auxin signaling. Furthermore, gi-100 mutant downregulates the LR initiation signaling gene, AUXIN RESPONSE FACTOR 7 (ARF7), and its downstream target gene, LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16). Hence, GI acts as a positive regulator of IAA14-ARF7-LBD16 modules during LR initiation. We have also checked the effect of GI on the expression of NAC1 and AIR3 genes which are controlled by TIR1 during LR formation. Our results show that GI induces the NAC1 transcription and its downstream gene, AIR3 expression, which leads to the enhancement of LR initiation. Taken together, our results suggest that GI controls the expression of TIR1 to govern auxin signaling during LR formation in presence of red light and GI can act as a link between circadian clock signaling, flowering time control pathways, light signaling, and lateral root development pathways.
PMID: 35822517
Plant Signal Behav , IF:2.247 , 2022 Dec , V17 (1) : P2095143 doi: 10.1080/15592324.2022.2095143
Chemically defined elicitors activate priming in tomato seedlings.
Department of Research and Development, Zero Gravity Solutions, Inc., Boca Raton, FL, USA.
Tomato (Solanum lycopersicum L.) is an important crop that possesses about 35,000 genes. The treatment of plants with elicitors or pathogen attacks causes a cascade of defense reactions. We investigated tomato responses to the BamFX(TM) solution containing Zn and Cu elicitors and report the results of comparative transcriptome analysis of tomato seeds treated with Zn and Cu elicitors. The seeds were treated with optimum concentrations of Bam-FX solutions and subjected to cold methanolic extraction methods to obtain the secondary metabolites produced within them at different time intervals post-Bam-FX treatment. The metabolite mixture was analyzed using gas chromatography-mass spectrometry (GCMS). In transcriptome sequencing, GO and KEGG analyses revealed that the majority of the DEGs in BamFx-treated tomato was associated with primary and secondary metabolism, plant hormone signal transduction, TF regulation, transport, and responses to stimuli.The secondary metabolites found in the BamFX treated tomato seedlings - Esters of Fumaric acid, Succinic acid etc. The transcript levels of most auxin transporter-encoding genes changed significantly in the BamFX-treated seedlings (e.g., Solyc01g007010.3, a RING-type E3 ubiquitin transferase). The gene Solyc07g061720.3 for Gibberellin 2-oxidase and the Phorbol-ester/DAG-type domain-containing protein (Solyc02g068680.1) associated with the intracellular signaling genes were found upregulated in the BamFx-treated seeds. The time-dependent effect of the BamFX (1:500 for 60 min) was found to be regulating Abscisic acid signaling pathway genes (Solyc09g015380.1). This study identified many candidate genes for future functional analyses and laid a theoretical foundation for an improved understanding of the molecular mechanisms involved in the BamFx treatment of tomatoes to improve stress resistance.
PMID: 35770510
Plant Signal Behav , IF:2.247 , 2022 Dec , V17 (1) : P2065432 doi: 10.1080/15592324.2022.2065432
Functional redundancy of OsPIN1 paralogous genes in regulating plant growth and development in rice.
Institute of Plant Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.; Agricultural Experiment Station of Zhejiang University, Hangzhou, Zhejiang, China.
The OsPIN1 paralogous genes (OsPIN1a-1d) are important for root and panicle development in rice (Oryza sativa L.). However, the specific role of OsPIN1 paralogous genes is still not clear. To understand the specific roles of PIN1 paralogs in rice, we generated pin1 triple and quadruple mutants by crossing the pin1a pin1b and pin1c pin1d double mutants which we previously created. Compared with the 7-day-old wild type, the pin1a pin1c pin1d and pin1b pin1c pin1d triple mutants showed no obvious phenotype variation except that the pin1a pin1c pin1d triple mutant had shorter primary root and shoot. The pin1a pin1b pin1c and pin1a pin1b pin1d triple mutants exhibited a series of developmental abnormalities, including shorter primary roots, longer root hairs, fewer crown roots and lateral roots, shorter and curved shoots. Furthermore, the pin1a pin1b pin1c pin1d quadruple mutant displayed more severe phenotypic defects which was lethal. In addition, the expression levels of some hormone signal transduction and crown root development related genes, such as OsIAAs, OsARFs, OsRRs, and OsCRLs, were significantly altered in the stem base of all examined pin1 multiple mutants. Taken together, our results demonstrated that the four OsPIN1 paralogous genes function redundantly in regulating rice growth and development.
PMID: 35442849
Plant Signal Behav , IF:2.247 , 2022 Dec , V17 (1) : P2031784 doi: 10.1080/15592324.2022.2031784
The epigenetic regulator ULTRAPETALA1 suppresses de novo root regeneration from Arabidopsis leaf explants.
Key Laboratory of Saline-Alkali Vegetation Ecology Restoration Ministry of Education, Northeast Forestry University, Harbin, China.; College of Life Science, Institute of Genetics, Northeast Forestry University, Harbin, China.; Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, China.
Plants have the potency to regenerate adventitious roots from aerial organs after detachment. In Arabidopsis thaliana, de novo root regeneration (DNRR) from leaf explants is triggered by wounding signaling that rapidly induces the expression of the ETHYLENE RESPONSE FACTOR (ERF) transcription factors ERF109 and ABR1 (ERF111). In turn, the ERFs promote the expression of ASA1, an essential enzyme of auxin biosynthesis, which contributes to rooting by providing high levels of auxin near the wounding side of the leaf. Here, we show that the loss of the epigenetic regulator ULTRAPETALA1 (ULT1), which interacts with Polycomb and Trithorax Group proteins, accelerates and reinforces adventitious root formation. Expression of ERF109 and ASA1 was increased in ult1 mutants, whereas ABR1 was not significantly changed. Cultivation of explants on media with exogenous auxin equates adventitious root formation in wild-type with ult1 mutants, suggesting that ULT1 negatively regulates DNRR by suppressing auxin biosynthesis. Based on these findings, we propose that ULT1 is involved in a novel mechanism that prevents overproliferation of adventitious roots during DNRR.
PMID: 35164655
Folia Microbiol (Praha) , IF:2.099 , 2022 Dec , V67 (6) : P899-911 doi: 10.1007/s12223-022-00985-2
Predicting interactions of the frass-associated yeast Hyphopichia heimii with Olea europaea subsp. cuspidata and twig-boring bark beetles.
Department of Microbiology, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.; Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, 7602, South Africa.; Department of Microbiology, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa. abo@sun.ac.za.
Bark beetles are destructive insect pests known to form symbioses with different fungal taxa, including yeasts. The aim of this study was to (1) determine the prevalence of the rare yeast Hyphopichia heimii in bark beetle frass from wild olive trees in South Africa and to (2) predict the potential interaction of this yeast with trees and bark beetles. Twenty-eight culturable yeast species were isolated from frass in 35 bark beetle galleries, including representatives of H. heimii from nine samples. Physiological characterization of H. heimii isolates revealed that none was able to degrade complex polymers present in hemicellulose; however, all were able to assimilate sucrose and cellobiose, sugars associated with an arboreal habitat. All isolates were able to produce the auxin indole acetic acid, indicative of a potential symbiosis with the tree. Sterol analysis revealed that the isolates possessed ergosterol quantities ranging from 3.644 +/- 0.119 to 13.920 +/- 1.230 mg/g dry cell weight, which suggested that H. heimii could serve as a source of sterols in bark beetle diets, as is known for other bark beetle-associated fungi. In addition, gas chromatography-mass spectrometry demonstrated that at least one of the isolates, Hyphopichia heimii CAB 1614, was able to convert the insect pheromone cis-verbenol to the anti-aggregation pheromone verbenone. This indicated that H. heimii could potentially influence beetle behaviour. These results support the contention of a tripartite symbiosis between H. heimii, olive trees, and bark beetles.
PMID: 35767213
Heliyon , 2022 Dec , V8 (12) : Pe11969 doi: 10.1016/j.heliyon.2022.e11969
Prediction of In vitro organogenesis of Bacopa monnieri using artificial neural networks and regression models.
Agricultural Research Station, Fort Valley State University, Fort Valley, GA 31030, USA.; Department of Bioinformatics, Boston University, Boston, MA 02115, USA.; Houston County High School, Warner Robins, GA 31088, USA.; Department of Agricultural Sciences, College of Agriculture, Family Sciences and Technology, Fort Valley State University, Fort Valley, GA 31030, USA.
This study was conducted to determine if artificial neural networks (ANN) can be used to accurately predict in vitro organogenesis of Bacopa monnieri compared with statistical regression. Prediction models were developed for shoot and root organogenesis (outputs) on two culture media (Murashige and Skoog and Gamborg B5) affected by two explant types (leaf and node) and two cytokinins (6-Benzylaminopurine and Thidiazuron at 1.0, 5.0, and 10.0 muM levels) with and without the addition of auxin (1-Naphthaleneacetic acid 0.1 muM) (inputs). Categorical data were encoded in numeric form using one-hot encoding technique. Backpropagation (BP) and Kalman filter (KF) learning algorithms were used to develop nonparametric models between inputs and outputs. Correlations between predicted and observed outputs (validation dataset) were similar in both ANN-BP (R values = 0.77, 0.71, 0.68, and 0.48), and ANN-KF (R values = 0.79, 0.68, 0.75, and 0.49), and were higher than regression (R values = 0.13, 0.48, 0.39, and 0.37) models for shoots and roots from leaf and node explants, respectively. Because ANN models have the ability to interpolate from unseen data, they could be used as an effective tool in accurately predicting the in vitro growth kinetics of Bacopa cultures.
PMID: 36544836
Biotechnol Genet Eng Rev , 2022 Dec : P1-22 doi: 10.1080/02648725.2022.2157949
Comparison of diversity and zinc solubilizing efficiency of rhizobacteria obtained from solanaceous crops under polyhouse and open field conditions.
Department of Biotechnology, Chandigarh University, Mohali, Punjab, India.; Department of Agricultural Sciences, Chandigarh University, Mohali, Punjab, India.; Department of Chemistry, University Institute of Science, Chandigarh University, Mohali, Punjab, India.; Department of Environmental Science, Veer Bahadur Singh Purvanchal University, Jaunpur, Uttar Pradesh, India.; Biotechnology Program, Dr. Rammanohar Lohia Avadh University, Ayodhya, Uttar Pradesh, India.
Zinc-solubilizing bacteria (Zn-SB) play a crucial role in regulating soil fertility and plant health by maintaining Zn availability in the rhizosphere. It is uncertain how the Zn-SB population fluctuates across various cultivation systems since varied land-use patterns for agricultural aims may affect microbial activity and plant development effectiveness. The current study aims to examine the Zn-SB potential of various farming systems using Solanum lycopersicum, Solanum melongena, and Capsicum annuum grown in polyhouse soil (PS) and open fields (OF). Only twenty rhizobacterial isolates from PS and two isolates from OF out of 80 showed a strong ability to solubilize Zn, which was evaluated using Atomic Absorption Spectroscopy. Bacterial strain-PS4 solubilized 253.06 ppm of ZnO and produced a high quantity of lactic acid (168.62 g/ml) and acetic acid (470.5 g/ml), whereas bacterial strain OF1 solubilized 16.02 ppm of ZnO by releasing glycolic acid (42.89 g/ml), lactic acid (22.30 g/ml), formic acid (106.03 g/ml), and acetic acid (48.5 microg/ml). Further, in vitro studies demonstrated higher production of auxin, gibberellic acid and siderophore by PS1 as compared to OF1 strain. A large diversity of Zn-SB in the soil was indicated by biochemical analysis, which revealed that isolates belonged to the families Enterobacteriaceae, Bacillaceae, Burkholderiaceae, Streptococcaceae, Paenibacillaceae, Micrococcaceae, Morganellaceae, and Dietziaceae. The isolates PS4 and OF1 were identified as Bacillus cereus and Enterobacter hormaechei, respectively, using 16S rRNA sequencing. The findings show that soil from polyhouses has a greater diversity of Zn-solubilization rhizobacteria than soil from open areas. The findings suggested a potential land-use method for enhancing crop yields by employing microorganisms and polyhouse technology, which could be useful in the future study.
PMID: 36544391
Heliyon , 2022 Dec , V8 (12) : Pe11959 doi: 10.1016/j.heliyon.2022.e11959
Impacts of plant growth regulators in strawberry plant: A review.
G.P. Koirala College of Agriculture and Research Centre (GPCAR), Gothgaun, Morang, Nepal.; Nepal Polytechnic Institute (NPI), Chitwan, Nepal.
Strawberry (Fragaria x ananassa), the family Rosaceae, is a small fruit that has great importance. It is triggered by a number of physiological, genetic, and biochemical processes. Phytohormones or plant growth regulators are organic substances produced naturally in many plants and responsible for controlling growth and other physiological functions. Therefore, plant growth regulators such as Gibberellin, NAA (auxin) and triacontanol, and chlormequat are essential factors that cause strawberry ripening, maturity indices, and determine the quality of fruits. Moreover, Gibberellin stimulates cell division and breaks dormancy whereas NAA (auxin) stimulates root growth. Similarly, triacontanol plays a special role in plant growth and development. Additionally, chlormequat is effective in controlling the height of the plant. The main objective of this review is to study the effect of various plant growth regulators that have a great potential effect on growth, development, and fruit yield.
PMID: 36466575
Methods Mol Biol , 2023 , V2581 : P43-56 doi: 10.1007/978-1-0716-2784-6_4
An In vitro Assay to Recapitulate Hormone-Triggered and SCF-Mediated Protein Ubiquitylation.
Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale), Germany.; Molecular Signal Processing Department, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale), Germany. LuzIrina.Calderon@ipb-halle.de.; KWS Gateway Research Center, LLC, BRDG Park at the Danforth Plant Science Center, St. Louis, MO, USA. LuzIrina.Calderon@ipb-halle.de.
Signaling proteins trigger a sequence of molecular switches in the cell, which permit development, growth, and rapid adaptation to changing environmental conditions. SCF-type E3 ubiquitin ligases recognize signaling proteins prompting changes in their fate, one of these being ubiquitylation followed by degradation by the proteasome. SCFs together with their ubiquitylation targets (substrates) often serve as phytohormone receptors, responding and/or assembling in response to fluctuating intracellular hormone concentrations. Tracing and understanding phytohormone perception and SCF-mediated ubiquitylation of proteins could provide powerful clues on the molecular mechanisms utilized for plant adaptation. Here, we describe an adaptable in vitro system that uses recombinant proteins and enables the study of hormone-triggered SCF-substrate interaction and the dynamics of protein ubiquitylation. This system can serve to predict the requirements for protein recognition and to understand how phytohormone levels have the power to control protein fate.
PMID: 36413309
Plant Commun , 2022 Nov , V3 (6) : P100456 doi: 10.1016/j.xplc.2022.100456
A chromosome-level genome assembly for Dracaena cochinchinensis reveals the molecular basis of its longevity and formation of dragon's blood.
Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education & National Engineering Laboratory for Breeding of Endangered Medicinal Materials, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China.; Novogene Bioinformatics Institute, Beijing 100083, China.; Yunnan Key Laboratory of Southern Medicine Utilization, Yunnan Branch of the Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Jinghong 666100, China.; Hainan Branch of the Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Haikou 570311, China.; Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.; Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education & National Engineering Laboratory for Breeding of Endangered Medicinal Materials, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China; Hainan Branch of the Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Haikou 570311, China. Electronic address: wjianh@263.net.
Dracaena, a remarkably long-lived and slowly maturing species of plant, is world famous for its ability to produce dragon's blood, a precious traditional medicine used by different cultures since ancient times. However, there is no detailed and high-quality genome available for this species at present; thus, the molecular mechanisms that underlie its important traits are largely unknown. These factors seriously limit the protection and regeneration of this rare and endangered plant resource. Here, we sequenced and assembled the genome of Dracaena cochinchinensis at the chromosome level. The D. cochinchinensis genome covers 1.21 Gb with a scaffold N50 of 50.06 Mb and encodes 31 619 predicted protein-coding genes. Analysis showed that D. cochinchinensis has undergone two whole-genome duplications and two bursts of long terminal repeat insertions. The expansion of two gene classes, cis-zeatin O-glucosyltransferase and small auxin upregulated RNA, were found to account for its longevity and slow growth. Two transcription factors (bHLH and MYB) were found to be core regulators of the flavonoid biosynthesis pathway, and reactive oxygen species were identified as the specific signaling molecules responsible for the injury-induced formation of dragon's blood. Our study provides high-quality genomic information relating to D. cochinchinensis and significant insight into the molecular mechanisms responsible for its longevity and formation of dragon's blood. These findings will facilitate resource protection and sustainable utilization of Dracaena.
PMID: 36196059