Nat Rev Mol Cell Biol , IF:94.444 , 2022 Oct , V23 (10) : P680-694 doi: 10.1038/s41580-022-00479-6
Plant hormone regulation of abiotic stress responses.
Institute of Technology, University of Tartu, Tartu, Estonia.; Institut fur Biologie und Biotechnologie der Pflanzen, Westfalische Wilhelms-Universitat Munster, Munster, Germany.; Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.; Graduate School of Environmental and Life Science, Okayama University, Tsushima-Naka, Okayama, Japan.; Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA. jischroeder@ucsd.edu.
Plant hormones are signalling compounds that regulate crucial aspects of growth, development and environmental stress responses. Abiotic stresses, such as drought, salinity, heat, cold and flooding, have profound effects on plant growth and survival. Adaptation and tolerance to such stresses require sophisticated sensing, signalling and stress response mechanisms. In this Review, we discuss recent advances in understanding how diverse plant hormones control abiotic stress responses in plants and highlight points of hormonal crosstalk during abiotic stress signalling. Control mechanisms and stress responses mediated by plant hormones including abscisic acid, auxin, brassinosteroids, cytokinins, ethylene and gibberellins are discussed. We discuss new insights into osmotic stress sensing and signalling mechanisms, hormonal control of gene regulation and plant development during stress, hormone-regulated submergence tolerance and stomatal movements. We further explore how innovative imaging approaches are providing insights into single-cell and tissue hormone dynamics. Understanding stress tolerance mechanisms opens new opportunities for agricultural applications.
PMID: 35513717
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
Cell Res , IF:25.617 , 2022 Oct , V32 (10) : P931-945 doi: 10.1038/s41422-022-00711-0
A spontaneous thermo-sensitive female sterility mutation in rice enables fully mechanized hybrid breeding.
Department of Biology, Hong Kong Baptist University, Hong Kong, China.; School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.; Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Agriculture, Hunan Agricultural University, Changsha, Hunan, China.; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, USA.; Division of Plant and Microbial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 2-1-2 Kannondai Tsukuba, Ibaraki, Japan.; Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong, China.; College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, China.; The Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, China.; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, USA. xuemei.chen@ucr.edu.; Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Agriculture, Hunan Agricultural University, Changsha, Hunan, China. nye@hunau.edu.cn.; Department of Biology, Hong Kong Baptist University, Hong Kong, China. jzhang@hkbu.edu.hk.; School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China. jzhang@hkbu.edu.hk.; Department of Biology, Hong Kong Baptist University, Hong Kong, China. gqwang@link.cuhk.edu.hk.; School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China. gqwang@link.cuhk.edu.hk.
Male sterility enables hybrid crop breeding to increase yields and has been extensively studied. But thermo-sensitive female sterility, which is an ideal property that may enable full mechanization in hybrid rice breeding, has rarely been investigated due to the absence of such germplasm. Here we identify the spontaneous thermo-sensitive female sterility 1 (tfs1) mutation that confers complete sterility under regular/high temperature and partial fertility under low temperature as a point mutation in ARGONAUTE7 (AGO7). AGO7 associates with miR390 to form an RNA-Induced Silencing Complex (RISC), which triggers the biogenesis of small interfering RNAs (siRNAs) from TRANS-ACTING3 (TAS3) loci by recruiting SUPPRESSOR OF GENE SILENCING (SGS3) and RNA-DEPENDENT RNA POLYMERASE6 (RDR6) to TAS3 transcripts. These siRNAs are known as tasiR-ARFs as they act in trans to repress auxin response factor genes. The mutant TFS1 (mTFS1) protein is compromised in its ability to load the miR390/miR390* duplex and eject miR390* during RISC formation. Furthermore, tasiR-ARF levels are reduced in tfs1 due to the deficiency in RDR6 but not SGS3 recruitment by mTFS1 RISC under regular/high temperature, while low temperature partially restores mTFS1 function in RDR6 recruitment and tasiR-ARF biogenesis. A miR390 mutant also exhibits female sterility, suggesting that female fertility is controlled by the miR390-AGO7 module. Notably, the tfs1 allele introduced into various elite rice cultivars endows thermo-sensitive female sterility. Moreover, field trials confirm the utility of tfs1 as a restorer line in fully mechanized hybrid rice breeding.
PMID: 36068348
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 , 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
Nucleic Acids Res , IF:16.971 , 2022 Oct , V50 (18) : P10544-10561 doi: 10.1093/nar/gkac798
Phosphorylation of the auxin signaling transcriptional repressor IAA15 by MPKs is required for the suppression of root development under drought stress in Arabidopsis.
Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Republic of Korea.
Since plants are sessile organisms, developmental plasticity in response to environmental stresses is essential for their survival. Upon exposure to drought, lateral root development is suppressed to induce drought tolerance. However, the molecular mechanism by which the development of lateral roots is inhibited by drought is largely unknown. In this study, the auxin signaling repressor IAA15 was identified as a novel substrate of mitogen-activated protein kinases (MPKs) and was shown to suppress lateral root development in response to drought through stabilization by phosphorylation. Both MPK3 and MPK6 directly phosphorylated IAA15 at the Ser-2 and Thr-28 residues. Transgenic plants overexpressing a phospho-mimicking mutant of IAA15 (IAA15DD OX) showed reduced lateral root development due to a higher accumulation of IAA15. In addition, MPK-mediated phosphorylation strongly increased the stability of IAA15 through the inhibition of polyubiquitination. Furthermore, IAA15DD OX plants showed the transcriptional downregulation of two key transcription factors LBD16 and LBD29, responsible for lateral root development. Overall, this study provides the molecular mechanism that explains the significance of the MPK-Aux/IAA module in suppressing lateral root development in response to drought.
PMID: 36161329
Nat Plants , IF:15.793 , 2022 Nov 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
Nat Commun , IF:14.919 , 2022 Oct , V13 (1) : P5940 doi: 10.1038/s41467-022-33648-4
Variation in the fruit development gene POINTED TIP regulates protuberance of tomato fruit tip.
Key Laboratory of Horticultural Plant Biology (MOE) and National Center for Vegetable Improvement (Central China), Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; Department of Plant Sciences, University of Idaho, Moscow, ID, 83844, USA.; Key Laboratory of Horticultural Plant Biology (MOE) and National Center for Vegetable Improvement (Central China), Huazhong Agricultural University, Wuhan, 430070, China. zhangjunhng@mail.hzau.edu.cn.; Hubei Hongshan Laboratory, Wuhan, 430070, China. zhangjunhng@mail.hzau.edu.cn.
The domestication of tomato has led to striking variations in fruit morphology. Here, we show a genome-wide association study (GWAS) to understand the development of the fruit tip and describe a POINTED TIP (PT) gene that encodes a C2H2-type zinc finger transcription factor. A single nucleotide polymorphism is found to change a histidine (H) to an arginine (R) in the C2H2 domain of PT and the two alleles are referred to as PT(H) and PT(R). Knocking out PT(H) leads to development of pointed tip fruit. PT(H) functions to suppress pointed tip formation by downregulating the transcription of FRUTFULL 2 (FUL2), which alters the auxin transport. Our evolutionary analysis and previous studies by others suggest that the PT(R) allele likely hitch-hiked along with other selected loci during the domestication process. This study uncovers variation in PT and molecular mechanism underlying fruit tip development in tomato.
PMID: 36209204
Trends Biochem Sci , IF:13.807 , 2022 Oct , V47 (10) : P865-874 doi: 10.1016/j.tibs.2022.06.004
Intrinsic and extrinsic regulators of Aux/IAA protein degradation dynamics.
Department of Biology, Duke University, Durham, NC, USA.; Department of Biology, Duke University, Durham, NC, USA. Electronic address: lucia.strader@duke.edu.
The plant hormone auxin acts through regulated degradation of Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) proteins to regulate transcriptional events. In this review, we examine the composition and function of each Aux/IAA structural motif. We then focus on recent characterization of Aux/IAA N-terminal disordered regions, formation of secondary structure within these disordered regions, and post-translational modifications (PTMs) that affect Aux/IAA function and stability. We propose how structural variations between Aux/IAA family members may be tuned for differential transcriptional repression and degradation dynamics.
PMID: 35817652
Mol Plant , IF:13.164 , 2022 Nov 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 Nov 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
Mol Plant , IF:13.164 , 2022 Oct , V15 (10) : P1543-1557 doi: 10.1016/j.molp.2022.08.008
The regeneration factors ERF114 and ERF115 regulate auxin-mediated lateral root development in response to mechanical cues.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium.; Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas alle 5, 756 51 Uppsala, Sweden.; Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), University of Tubingen, 72076 Tubingen, Germany.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium. Electronic address: lieven.deveylder@psb.vib-ugent.be.
Plants show an unparalleled regenerative capacity, allowing them to survive severe stress conditions, such as injury, herbivory attack, and harsh weather conditions. This potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant bodies. Despite the intertwined nature of development and regeneration, common upstream cues and signaling mechanisms are largely unknown. Here, we demonstrate that in addition to being activators of regeneration, ETHYLENE RESPONSE FACTOR 114 (ERF114) and ERF115 govern developmental growth in the absence of wounding or injury. Increased ERF114 and ERF115 activity enhances auxin sensitivity, which is correlated with enhanced xylem maturation and lateral root formation, whereas their knockout results in a decrease in lateral roots. Moreover, we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions. Antagonistically, cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions. Taken together, our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114- and ERF115-mediated auxin signaling.
PMID: 36030378
EMBO J , IF:11.598 , 2022 Oct , V41 (19) : Pe110988 doi: 10.15252/embj.2022110988
ARF2-PIF5 interaction controls transcriptional reprogramming in the ABS3-mediated plant senescence pathway.
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China.; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA; Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA.; Department of Genetics, Harvard Medical School, Boston, MA, USA.; Institute of Future Agriculture, Northwest A&F University, Yangling, China.
One of the hallmarks of plant senescence is the global transcriptional reprogramming coordinated by a plethora of transcription factors (TFs). However, mechanisms underlying the interactions between different TFs in modulating senescence remain obscure. Previously, we discovered that plant ABS3 subfamily MATE transporter genes regulate senescence and senescence-associated transcriptional changes. In a genetic screen for mutants suppressing the accelerated senescence phenotype of the gain-of-function mutant abs3-1D, AUXIN RESPONSE FACTOR 2 (ARF2) and PHYTOCHROME-INTERACTING FACTOR 5 (PIF5) were identified as key TFs responsible for transcriptional regulation in the ABS3-mediated senescence pathway. ARF2 and PIF5 (as well as PIF4) interact directly and function interdependently to promote senescence, and they share common target genes such as key senescence promoting genes ORESARA 1 (ORE1) and STAY-GREEN 1 (SGR1) in the ABS3-mediated senescence pathway. In addition, we discovered reciprocal regulation between ABS3-subfamily MATEs and the ARF2 and PIF5/4 TFs. Taken together, our findings reveal a regulatory paradigm in which the ARF2-PIF5/4 functional module facilitates the transcriptional reprogramming in the ABS3-mediated senescence pathway.
PMID: 35942625
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
Plant Cell , IF:11.277 , 2022 Oct doi: 10.1093/plcell/koac297
The RAC/ROP GTPase Activator OsRopGEF10 functions in crown root development by regulating cytokinin signaling in rice.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China.; Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.; Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003.
RAC/ROP GTPases are major molecular switches that control diverse signaling cascades for plant growth, development, and defense. Here we discovered a signaling node that connects RAC/ROPs to cytokinins. Rice (Oryza sativa) plants develop a fibrous root system mainly composed of crown roots. Cytokinin signaling via a phosphorelay system is critical for crown root development. We show that OsRopGEF10, which activates RAC/ROPs, acts upstream of the cytoplasmic-nuclear shuttling phosphotransfer proteins AHPs of the cytokinin signaling pathway to promote crown root development. Mutations of OsRopGEF10 induced hypersensitivity to cytokinin, whereas overexpressing this gene reduced the cytokinin response. Loss of OsRopGEF10 function reduced the expression of the response regulator gene OsRR6, a repressor of cytokinin signaling, and impaired crown root development. Mutations in OsAHP1/2 led to increased crown root production and rescued the crown root defect of Osropgef10. Furthermore, auxin activates the ROP GTPase OsRAC3, which attenuates cytokinin signaling for crown root initiation. Molecular interactions between OsRopGEF10, OsRAC3 and OsAHP1/2 implicate a mechanism whereby OsRopGEF10-activated OsRAC3 recruits OsAHP1/2 to the cortical cytoplasm, sequestering them from their phosphorelay function in the nucleus. Together, our findings uncover the OsRopGEF10-OsRAC3-OsAHP1/2 signaling module, establish a link between RAC/ROPs and cytokinin, and reveal molecular crosstalk between auxin and cytokinin during crown root development.
PMID: 36190337
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4583-4599 doi: 10.1093/plcell/koac266
The localization of PHRAGMOPLAST ORIENTING KINESIN1 at the division site depends on the microtubule-binding proteins TANGLED1 and AUXIN-INDUCED IN ROOT CULTURES9 in Arabidopsis.
Graduate Group in Biochemistry and Molecular Biology, University of California, Riverside, California, USA.; Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, California, USA.
Proper plant growth and development require spatial coordination of cell divisions. Two unrelated microtubule-binding proteins, TANGLED1 (TAN1) and AUXIN-INDUCED IN ROOT CULTURES9 (AIR9), are together required for normal growth and division plane orientation in Arabidopsis (Arabidopsis thaliana). The tan1 air9 double mutant has synthetic growth and division plane orientation defects, while single mutants lack obvious defects. Here we show that the division site-localized protein, PHRAGMOPLAST ORIENTING KINESIN1 (POK1), was aberrantly lost from the division site during metaphase and telophase in the tan1 air9 mutant. Since TAN1 and POK1 interact via the first 132 amino acids of TAN1 (TAN11-132), we assessed the localization and function of TAN11-132 in the tan1 air9 double mutant. TAN11-132 rescued tan1 air9 mutant phenotypes and localized to the division site during telophase. However, replacing six amino-acid residues within TAN11-132, which disrupted the POK1-TAN1 interaction in the yeast-two-hybrid system, caused loss of both rescue and division site localization of TAN11-132 in the tan1 air9 mutant. Full-length TAN1 with the same alanine substitutions had defects in phragmoplast guidance and reduced TAN1 and POK1 localization at the division site but rescued most tan1 air9 mutant phenotypes. Together, these data suggest that TAN1 and AIR9 are required for POK1 localization, and yet unknown proteins may stabilize TAN1-POK1 interactions.
PMID: 36005863
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4409-4427 doi: 10.1093/plcell/koac262
Auxin and abscisic acid antagonistically regulate ascorbic acid production via the SlMAPK8-SlARF4-SlMYB11 module in tomato.
Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 400044, China.; College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
Ascorbic acid (AsA) is a multifunctional phytonutrient that is essential for the human diet as well as plant development. While much is known about AsA biosynthesis in plants, how this process is regulated in tomato (Solanum lycopersicum) fruits remains unclear. Here, we found that auxin treatment inhibited AsA accumulation in the leaves and pericarps of tomato. The auxin response factor gene SlARF4 is induced by auxin to mediate auxin-induced inhibition of AsA accumulation. Specifically, SlARF4 transcriptionally inhibits the transcription factor gene SlMYB11, thereby modulating AsA accumulation by regulating the transcription of the AsA biosynthesis genes l-galactose-1-phosphate phosphatase, l-galactono-1,4-lactone dehydrogenase, and dehydroascorbate. By contrast, abscisic acid (ABA) treatment increased AsA accumulation in tomato under drought stress. ABA induced the expression of the mitogen-activated protein kinase gene SlMAPK8. We demonstrate that SlMAPK8 phosphorylates SlARF4 and inhibits its transcriptional activity, whereas SlMAPK8 phosphorylates SlMYB11 and activates its transcriptional activity. SlMAPK8 functions in ABA-induced AsA accumulation and drought stress tolerance. Moreover, ABA antagonizes the effects of auxin on AsA biosynthesis. Therefore, auxin- and ABA-induced regulation of AsA accumulation is mediated by the SlMAPK8-SlARF4-SlMYB11 module in tomato during fruit development and drought stress responses, shedding light on the roles of phytohormones in regulating AsA accumulation to mediate stress tolerance.
PMID: 36000899
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4124-4125 doi: 10.1093/plcell/koac258
A case of identity: Activation of auxin biosynthesis drives cell reprogramming.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
PMID: 35977390
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4388-4408 doi: 10.1093/plcell/koac254
A SlCLV3-SlWUS module regulates auxin and ethylene homeostasis in low light-induced tomato flower abscission.
College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China.; Crops Pathology and Genetic Research Unit, United States Department of Agriculture Agricultural Research Service, Albany, California 95616, USA.; Department of Plant Sciences, University of California, Los Angeles, California 95616, USA.
Premature abscission of flowers and fruits triggered by low light stress can severely reduce crop yields. However, the underlying molecular mechanism of this organ abscission is not fully understood. Here, we show that a gene (SlCLV3) encoding CLAVATA3 (CLV3), a peptide hormone that regulates stem cell fate in meristems, is highly expressed in the pedicel abscission zone (AZ) in response to low light in tomato (Solanum lycopersicum). SlCLV3 knockdown and knockout lines exhibit delayed low light-induced flower drop. The receptor kinases SlCLV1 and BARELY ANY MERISTEM1 function in the SlCLV3 peptide-induced low light response in the AZ to decrease expression of the transcription factor gene WUSCHEL (SlWUS). DNA affinity purification sequencing identified the transcription factor genes KNOX-LIKE HOMEDOMAIN PROTEIN1 (SlKD1) and FRUITFULL2 (SlFUL2) as SlWUS target genes. Our data reveal that low light reduces SlWUS expression, resulting in higher SlKD1 and SlFUL2 expression in the AZ, thereby perturbing the auxin response gradient and causing increased ethylene production, eventually leading to the initiation of abscission. These results demonstrate that the SlCLV3-SlWUS signaling pathway plays a central role in low light-induced abscission by affecting auxin and ethylene homeostasis.
PMID: 35972422
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4366-4387 doi: 10.1093/plcell/koac250
Rice EIL1 interacts with OsIAAs to regulate auxin biosynthesis mediated by the tryptophan aminotransferase MHZ10/OsTAR2 during root ethylene responses.
State Key Lab of Plant Genomics, Institute of Genetics and Developmental Biology, 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.; College of Agriculture, South China Agricultural University, Guangzhou 510642, China.; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.
Ethylene plays essential roles in adaptive growth of rice (Oryza sativa). Understanding of the crosstalk between ethylene and auxin (Aux) is limited in rice. Here, from an analysis of the root-specific ethylene-insensitive rice mutant mao hu zi 10 (mhz10), we identified the tryptophan aminotransferase (TAR) MHZ10/OsTAR2, which catalyzes the key step in indole-3-pyruvic acid-dependent Aux biosynthesis. Genetically, OsTAR2 acts downstream of ethylene signaling in root ethylene responses. ETHYLENE INSENSITIVE3 like1 (OsEIL1) directly activated OsTAR2 expression. Surprisingly, ethylene induction of OsTAR2 expression still required the Aux pathway. We also show that Os indole-3-acetic acid (IAA)1/9 and OsIAA21/31 physically interact with OsEIL1 and show promotive and repressive effects on OsEIL1-activated OsTAR2 promoter activity, respectively. These effects likely depend on their EAR motif-mediated histone acetylation/deacetylation modification. The special promoting activity of OsIAA1/9 on OsEIL1 may require both the EAR motifs and the flanking sequences for recruitment of histone acetyltransferase. The repressors OsIAA21/31 exhibit earlier degradation upon ethylene treatment than the activators OsIAA1/9 in a TIR1/AFB-dependent manner, allowing OsEIL1 activation by activators OsIAA1/9 for OsTAR2 expression and signal amplification. This study reveals a positive feedback regulation of ethylene signaling by Aux biosynthesis and highlights the crosstalk between ethylene and Aux pathways at a previously underappreciated level for root growth regulation in rice.
PMID: 35972379
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4348-4365 doi: 10.1093/plcell/koac218
Transcriptional activation of auxin biosynthesis drives developmental reprogramming of differentiated cells.
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.; Center for Sustainable Resource Science, RIKEN, Yokohama 230-0045, Japan.; Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, Kasugai 487-8501, Japan.; Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki 444-8585, Japan.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium.; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium.
Plant cells exhibit remarkable plasticity of their differentiation states, enabling regeneration of whole plants from differentiated somatic cells. How they revert cell fate and express pluripotency, however, remains unclear. In this study, we demonstrate that transcriptional activation of auxin biosynthesis is crucial for reprogramming differentiated Arabidopsis (Arabidopsis thaliana) leaf cells. Our data show that interfering with the activity of histone acetyltransferases dramatically reduces callus formation from leaf mesophyll protoplasts. Histone acetylation permits transcriptional activation of PLETHORAs, leading to the induction of their downstream YUCCA1 gene encoding an enzyme for auxin biosynthesis. Auxin biosynthesis is in turn required to accomplish initial cell division through the activation of G2/M phase genes mediated by MYB DOMAIN PROTEIN 3-RELATED (MYB3Rs). We further show that the AUXIN RESPONSE FACTOR 7 (ARF7)/ARF19 and INDOLE-3-ACETIC ACID INDUCIBLE 3 (IAA3)/IAA18-mediated auxin signaling pathway is responsible for cell cycle reactivation by transcriptionally upregulating MYB3R4. These findings provide a mechanistic model of how differentiated plant cells revert their fate and reinitiate the cell cycle to become pluripotent.
PMID: 35922895
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Oct , V119 (40) : Pe2205757119 doi: 10.1073/pnas.2205757119
Modulation of receptor-like transmembrane kinase 1 nuclear localization by DA1 peptidases in Arabidopsis.
Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom.; State Key Laboratory of Plant Cell and Chromosome Engineering, CAS Centre for Excellence in Molecular Plant Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; University of Chinese Academy of Sciences, Beijing 100039, China.
The cleavage of intracellular domains of receptor-like kinases (RLKs) has an important functional role in the transduction of signals from the cell surface to the nucleus in many organisms. However, the peptidases that catalyze protein cleavage during signal transduction remain poorly understood despite their crucial roles in diverse signaling processes. Here, we report in the flowering plant Arabidopsis thaliana that members of the DA1 family of ubiquitin-regulated Zn metallopeptidases cleave the cytoplasmic kinase domain of transmembrane kinase 1 (TMK1), releasing it for nuclear localization where it represses auxin-responsive cell growth during apical hook formation by phosphorylation and stabilization of the transcriptional repressors IAA32 and IAA34. Mutations in DA1 family members exhibited reduced apical hook formation, and DA1 family-mediated cleavage of TMK1 was promoted by auxin treatment. Expression of the DA1 family-generated intracellular kinase domain of TMK1 by an auxin-responsive promoter fully restored apical hook formation in a tmk1 mutant, establishing the function of DA1 family peptidase activities in TMK1-mediated differential cell growth and apical hook formation. DA1 family peptidase activity therefore modulates TMK1 kinase activity between a membrane location where it stimulates acid cell growth and initiates an auxin-dependent kinase cascade controlling cell proliferation in lateral roots and a nuclear localization where it represses auxin-mediated gene expression and growth.
PMID: 36161927
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 , 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
Extra-nuclear auxin signaling: a new insight into auxin's versatility.
Institute of Integrated Genome Biology and Department of Botany and Plant Sciences, 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 co-receptor proteins, i.e., the TIR1/AFBs and AUX/IAAs. Recent evidence has suggested transcription-independent roles of TIR1/AFBs localized outside the nucleus and TMK-based auxin signaling occurring in the plasma membrane. Furthermore, emerging evidence supports a coordinated action of the intra- and extra-nuclear 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 extra-nuclear 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 , 2022 Oct doi: 10.1111/nph.18570
Root architecture plasticity in response to endoparasitic cyst nematodes is mediated by damage signaling.
Laboratory of Nematology, Wageningen University & Research, 6708, PB, Wageningen, the Netherlands.; Laboratory of Molecular Biology, Cluster of Plant Developmental Biology, Wageningen University & Research, 6708, PB, Wageningen, the Netherlands.; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Institute of Crop Science and Resource Conservation (INRES), Molecular Phytomedicine, University of Bonn, INRES, 53115, Bonn, Germany.
Plant root architecture plasticity in response to biotic stresses has not been thoroughly investigated. Infection by the endoparasitic cyst nematodes induces root architectural changes that involve the formation of secondary roots at infection sites. However, the molecular mechanisms regulating secondary root formation in response to cyst nematode infection remain largely unknown. We first assessed whether secondary roots form in a nematode-density dependent manner by challenging wildtype Arabidopsis plants with increasing numbers of cyst nematodes (Heterodera schachtii). Next, by using jasmonate-related reporter lines and knock-out mutants, we tested if tissue damage by nematodes triggers jasmonate-dependent secondary root formation. Finally, we verified whether damage-induced secondary root formation depends on local auxin biosynthesis at nematode infection sites. Intracellular host invasion by H. schachtii triggers a transient local increase in jasmonates, which activates the expression of ERF109 in a COI1-dependent manner. Knock-out mutations in COI1 and ERF109 disrupt the nematode-density dependent increase of secondary roots observed in wildtype plants. Furthermore, ERF109 regulates secondary root formation upon H. schachtii infection via local auxin biosynthesis. Host invasion by H. schachtii triggers secondary root formation via the damage-induced jasmonate-dependent ERF109 pathway. This points at a novel mechanism underlying plant root plasticity in response to biotic stress.
PMID: 36285401
New Phytol , IF:10.151 , 2022 Oct 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 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 , 2022 Oct 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 , 2022 Oct 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 , 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 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 Oct doi: 10.1093/plphys/kiac497
The Auxin response factor TaARF15-A1 negatively regulates senescence in common wheat (Triticum aestivum L.).
Key Laboratory of Crop Gene Resources and Germplasm Enhancement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang Hebei 050000, China.; Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang Henan 455000, China.; Institute of Wheat Research, State Key Laboratory of Sustainable Dryland Agriculture, Shanxi Agricultural University, Linfen Shanxi 041000, China.
Auxin plays an important role in regulating leaf senescence. Auxin response factors (ARFs) are crucial components of the auxin signaling pathway; however, their roles in leaf senescence in cereal crops are unknown. In this study, we identified TaARF15-A1 as a negative regulator of senescence in wheat (Triticum aestivum L.) by analyzing TaARF15-A1 overexpression and RNA interference lines and CRISPR/Cas9-based arf15 mutants. Overexpression of TaARF15-A1 delayed senescence, whereas knockdown lines and knockout mutants showed accelerated leaf senescence and grain ripening. RNA-seq analysis revealed that TaARF15-A1 delays leaf senescence by negatively regulating senescence-promoting processes and positively modulating senescence-delaying genes including senescence-associated phytohormone biosynthesis and metabolism genes as well as transcription factors. We also demonstrated that TaARF15-A1 physically interacts with TaMYC2, a core jasmonic acid (JA) signaling transcription factor that positively modulates wheat senescence. Furthermore, TaARF15-A1 suppressed the expression of TaNAM-1 (TaNAM-A1 and TaNAM-D1) via protein-protein interaction and competition with TaMYC2 for binding to its promoter to regulate senescence. Finally, we identified two haplotypes of TaARF15-A1 in global wheat collections. Association analysis revealed that TaARF15-A1-HapI has undergone strong selection during wheat breeding in China, likely owing to its earlier maturity. Thus, we identify TaARF15-A1 as a negative regulator of senescence in common wheat and present another perspective on the crosstalk between auxin and JA signaling pathways in regulating plant senescence.
PMID: 36282536
Plant Physiol , IF:8.34 , 2022 Oct doi: 10.1093/plphys/kiac464
Transition to ripening in tomato requires hormone-controlled genetic reprogramming initiated in gel tissue.
Laboratoire de Recherche en Sciences Vegetales - Genomique et Biotechnologie des Fruits -UMR5546, Universite de Toulouse, CNRS, UPS, Toulouse-INP, Toulouse, France.; Universite de Toulouse, INRAe/INP Toulouse, Genomique et Biotechnologie des Fruits-UMR990, Castanet-Tolosan, France.; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China.; Institute of Biosciences, Department of Botany, Universidade de Sao Paulo, Sao Paulo, 11461 Brazil.; Metatoul-AgromiX platform, LRSV, Universite de Toulouse, CNRS, UPS, Toulouse INP, France.; MetaboHUB-MetaToul, National Infrastructure of Metabolomics and Fluxomics, Toulouse, 31077, France.
Ripening is the last stage of the developmental program in fleshy fruits. During this phase, fruits become edible and acquire their unique sensory qualities and post-harvest potential. Although our knowledge of the mechanisms that regulate fruit ripening has improved considerably over the past decades, the processes that trigger the transition to ripening remain poorly deciphered. While transcriptomic profiling of tomato (Solanum lycopersicum L.) fruit ripening to date has mainly focused on the changes occurring in pericarp tissues between the Mature Green and Breaker stages, our study addresses the changes between the Early Mature Green and Late Mature Green stages in the gel and pericarp separately. The data showed that the shift from an inability to initiate ripening to the capacity to undergo full ripening requires extensive transcriptomic reprogramming that takes place first in the locular tissues before extending to the pericarp. Genome-wide transcriptomic profiling revealed the wide diversity of transcription factor families engaged in the global reprogramming of gene expression and identified those specifically regulated at the Mature Green stage in the gel but not in the pericarp, thereby providing potential targets towards deciphering the initial factors and events that trigger the transition to ripening. The study also uncovered an extensive reformed homeostasis for most plant hormones, highlighting the multi-hormonal control of ripening initiation. Our data unveil the antagonistic roles of ethylene and auxin during the onset of ripening and show that auxin treatment delays fruit ripening via impairing the expression of genes required for System-2 autocatalytic ethylene production that is essential for climacteric ripening. This study unveils the detailed features of the transcriptomic reprogramming associated with the transition to ripening of tomato fruit and shows that the first changes occur in the locular gel before extending to pericarp and that a reformed auxin homeostasis is essential for the ripening to proceed.
PMID: 36200876
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 Oct doi: 10.1093/plphys/kiac462
Factor of DNA Methylation 1 affects woodland strawberry plant stature and organ size via DNA methylation.
Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; College of Horticulture, Anhui Agricultural University, Hefei, 230036, China.; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA.
RNA-directed DNA methylation (RdDM) is an epigenetic process that directs silencing to specific genomic regions and loci. The biological functions of RdDM are not well studied in horticultural plants. Here, we isolated the EMS mutant reduced organ size (ros) producing small leaves, flowers, and fruits in woodland strawberry (Fragaria vesca) due to reduced cell numbers compared with that in the wild type. The candidate mutation causes a premature stop codon in FvH4_6g28780, which shares high similarity to Arabidopsis (Arabidopsis thaliana) FACTOR OF DNA METHYLATION1 (FDM1) encoding an RdDM pathway component and was named FveFDM1. Consistently, the fvefdm1CR mutants generated by CRISPR/Cas9 also produced smaller organs. Overexpressing FveFDM1 in an Arabidopsis fdm1-1 fdm2-1 double mutant restored DNA methylation at the RdDM target loci. FveFDM1 acts in a protein complex with its homologue INVOLVED IN DE NOVO 2 (FveIDN2). Furthermore, whole genome bisulfite sequencing revealed that DNA methylation, especially in the CHH context, was remarkably reduced throughout the genome in fvefdm1. Common and specific differentially expressed genes were identified in different tissues of fvefdm1 compared to in wild-type tissues. DNA methylation and expression levels of several gibberellic acid (GA) biosynthesis and cell cycle genes were validated. Moreover, the contents of GA and auxin were substantially reduced in the young leaves of fvefdm1 compared to in the wild type. However, exogenous application of GA and auxin could not recover the organ size of fvefdm1. In addition, expression levels of FveFDM1, FveIDN2, NUCLEAR RNA POLYMERASE D1 (FveNRPD1), DOMAINS REARRANGED METHYLASE 2 (FveDRM2), and cell cycle genes were greatly induced by GA treatment. Overall, our work demonstrated the critical roles of FveFDM1 in plant growth and development via RdDM-mediated DNA methylation in horticultural crops.
PMID: 36200851
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
Sci Total Environ , IF:7.963 , 2022 Oct , V841 : P156486 doi: 10.1016/j.scitotenv.2022.156486
Impact of arsenic on microbial community structure and their metabolic potential from rice soils of West Bengal, India.
Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.; Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India. Electronic address: psar@bt.iitkgp.ac.in.
Paddy soil is a heterogenous ecosystem that harbours diverse microbial communities critical for maintaining ecosystem sustainability and crop yield. Considering the importance of soil in crop production and recent reports on its contamination with arsenic (As) across the South East Asia, its microbial community composition and biogeochemical functions remained inadequately studied. We have characterized the microbial communities of rice soil from eleven paddy fields of As-contaminated sites from West Bengal (India), through metagenomics and amplicon sequencing. 16S rRNA gene sequencing showed considerable bacterial diversity [over 0.2 million Operational Taxonomic Units (OTUs)] and abundance (upto 1.6 x 10(7) gene copies/g soil). Existence of a core-microbiome (261 OTUs conserved out of a total 141,172 OTUs) across the samples was noted. Most of the core-microbiome members were also found to represent the abundant taxa of the soil. Statistical analyses suggested that the microbial communities were highly constrained by As, Fe K, N, PO(4)(3-), SO(4)(2-) and organic carbon (OC). Members of Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Planctomycetes and Thaumarchaeota constituted the core-microbiome. Co-occurrence network analysis displayed significant interaction among diverse anaerobic, SO(4)(2-) and NO(3)(-) reducing, cellulose and other organic matter or C1 compound utilizing, fermentative and aerobic/facultative anaerobic bacteria and archaea. Correlation analysis suggested that taxa which were positively linked with soil parameters that maintain soil health and productivity (e.g., N, K, PO(4)(3-) and Fe) were adversely impacted by increasing As concentration. Shotgun metagenomics highlighted major metabolic pathways controlling the C (3-hydroxypropionate bicycle), N (Denitrification, dissimilatory NO(3)(-) reduction to ammonium), and S (assimilatory SO(4)(2-) reduction and sulfide oxidation) cycling, As homeostasis (methylation and reduction) and plant growth promotion (polyphosphate hydrolysis and auxin biosynthesis). All these major biogeochemical processes were found to be catalyzed by the members of most abundant/core-community.
PMID: 35667424
Curr Opin Plant Biol , IF:7.834 , 2022 Oct , V69 : P102293 doi: 10.1016/j.pbi.2022.102293
Reactive oxygen species function as signaling molecules in controlling plant development and hormonal responses.
Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27101, USA; Department of Biology and the Center for Molecular Signaling, Wake Forest University, Winston-Salem, NC, 27109, USA.; Department of Biology and the Center for Molecular Signaling, Wake Forest University, Winston-Salem, NC, 27109, USA.; Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27101, USA; Department of Biology and the Center for Molecular Signaling, Wake Forest University, Winston-Salem, NC, 27109, USA. Electronic address: muday@wfu.edu.
Reactive oxygen species (ROS) serve as second messengers in plant signaling pathways to remodel plant growth and development. New insights into how enzymatic ROS-producing machinery is regulated by hormones or localized during development have provided a framework for understanding the mechanisms that control ROS accumulation patterns. Signaling-mediated increases in ROS can then modulate the activity of proteins through reversible oxidative modification of specific cysteine residues. Plants also control the synthesis of antioxidants, including plant-specialized metabolites, to further define when, where, and how much ROS accumulate. The availability of sophisticated imaging capabilities, combined with a growing tool kit of ROS detection technologies, particularly genetically encoded biosensors, sets the stage for improved understanding of ROS as signaling molecules.
PMID: 36099672
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 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, 450001, China.; School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China.
Wheat is a staple upland crop grown worldwide, including in saline-alkali soils with a high pH and excess salt content. Wheat plants are thus ubiquitously simultaneously exposed to salinity (NaCl) and limited iron (Fe) availability caused by soil saline-alkalization. Seminal root growth in cereal crops is fundamental for the early establishment of seedlings and grain yield. Through this study, we found that both low Fe and NaCl severely inhibited the growth of seminal roots in wheat (Triticum aestivum L.) seedlings; however, sufficient Fe (+Fe) caused greater cessation of seminal root growth than low Fe (-Fe) under salt stress. Low Fe improved the division activity of the meristematic zone but it did not alter the cell size in the elongation region of the root tips compared with sufficient Fe under salt stress. Foliar Fe spray and split-root experiments showed that the low Fe-mediated alleviation of 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 sufficient Fe and low Fe conditions under salt stress. Phytohormone profiling and high-resolution metabolite fingerprints revealed salinity-induced overaccumulation of ACC/ethylene and tryptophan/auxin in the roots under sufficient Fe than under low Fe. Furthermore, genome-wide transcriptomics-assisted differential gene expression, exogenous application of various pharmacological inhibitors and the root growth performance of transgenic wheat plants revealed that TaPIN2-7D mediated 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 understanding of Fe involved nutrient interactions and the modulation of root growth under salt stress orchestration the ethylene-auxin homeostasis in crop species. This article is protected by copyright. All rights reserved.
PMID: 36358019
Plant Cell Environ , IF:7.228 , 2022 Oct 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
J Integr Plant Biol , IF:7.061 , 2022 Oct doi: 10.1111/jipb.13392
Advances in structure and function of auxin response factor in plants.
School of Life Sciences, Inner Mongolia University, Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, Hohhot, 010000, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Auxin is a crucial phytohormone that has various effects on the regulators of plant growth and development. Auxin signal transduction is mainly controlled by two gene families: auxin response factor (ARF) and auxin/indole-3-acetic acid (Aux/IAA). ARFs are plant-specific transcription factors that bind directly to auxin response elements in the promoters of auxin-responsive genes. ARF proteins contain three conserved regions: a conserved N-terminal B3 DNA-binding domain, a variable intermediate middle region domain that functions in activation or repression, and a C-terminal domain including the Phox and Bem1p region for dimerization, similar to the III and IV elements of Aux/IAA, which facilitate protein-protein interaction through homodimerization of ARF proteins or heterodimerization of ARF and Aux/IAA proteins. In the two decades following the identification of the first ARF, 23 ARF members have been identified and characterized in Arabidopsis. Using whole-genome sequencing, 22, 25, 23, 25, and 36 ARF genes have been identified in tomato, rice, wheat, sorghum, and maize, respectively, in addition to which the related biofunctions of some ARFs have been reported. ARFs play crucial roles in regulating the growth and development of roots, leaves, flowers, fruits, seeds, responses to biotic and abiotic stresses, and phytohormone signal crosstalk. In this review, we summarize the research progress on the structures and functions of ARFs in Arabidopsis, tomato, and cereal crops, to provide clues for future basic research on phytohormone signaling and the molecular design breeding of crops. This article is protected by copyright. All rights reserved.
PMID: 36263892
J Integr Plant Biol , IF:7.061 , 2022 Oct 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 Integr Plant Biol , IF:7.061 , 2022 Oct , V64 (10) : P1916-1934 doi: 10.1111/jipb.13341
The unconventional prefoldin RPB5 interactor mediates the gravitropic response by modulating cytoskeleton organization and auxin transport in Arabidopsis.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, 253023, China.; Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; Faculty of Biology, Institute of Biology II/Molecular Plant Physiology, Albert-Ludwigs-University of Freiburg, Schanzlestrasse 1, Freiburg, D-79104, Germany.; 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), Shanghai, 200032, China.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.
Gravity-induced root curvature involves the asymmetric distribution of the phytohormone auxin. This response depends on the concerted activities of the auxin transporters such as PIN-FORMED (PIN) proteins for auxin efflux and AUXIN RESISTANT 1 (AUX1) for auxin influx. However, how the auxin gradient is established remains elusive. Here we identified a new mutant with a short root, strong auxin distribution in the lateral root cap and an impaired gravitropic response. The causal gene encoded an Arabidopsis homolog of the human unconventional prefoldin RPB5 interactor (URI). AtURI interacted with prefoldin 2 (PFD2) and PFD6, two beta-type PFD members that modulate actin and tubulin patterning in roots. The auxin reporter DR5(rev) :GFP showed that asymmetric auxin redistribution after gravistimulation is disordered in aturi-1 root tips. Treatment with the endomembrane protein trafficking inhibitor brefeldin A indicated that recycling of the auxin transporter PIN2 is disrupted in aturi-1 roots as well as in pfd mutants. We propose that AtURI cooperates with PFDs to recycle PIN2 and modulate auxin distribution.
PMID: 35943836
J Integr Plant Biol , IF:7.061 , 2022 Oct , V64 (10) : P1901-1915 doi: 10.1111/jipb.13336
FERONIA is involved in phototropin 1-mediated blue light phototropic growth in Arabidopsis.
School of Life Sciences, Central South University, Changsha, 410078, China.; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, 410082, China.; Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.; Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.; State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, China.
Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates, the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.
PMID: 35924740
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 , 2022 Oct doi: 10.1093/jxb/erac430
The locoweed endophyte Alternaria oxytropis affects root development in Arabidopsis in vitro through auxin signaling and polar transport.
Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, China.; Qinling National Botanical Garden, Xi'an, China.; Shaanxi Institute for Food and Drug, Xi'an, China.; Provincial Key Laboratory of Biotechnology of Shaanxi Province, College of Life Sciences, Northwest University, Xi'an, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; Hubei Hongshan Laboratory, Wuhan, China.; Institute of Biology, Environmental and Rural Science, Aberystwyth University, Aberystwyth SY23 3FL, UK.; Key Laboratory of Grassland Resources of Ministry of Education, Inner Mongolia Agricultural University, Hohhot, China.
Locoweeds are leguminous forbs known for their toxicity to livestock caused by the endophytic fungi Alternaria sect. Undifilum. Unlike the defensive mutualism reported in many toxin producing endophytes and their plant hosts, the benefits that A. sect. Undifilum can confer to it host plants has been unclear. Here we conducted physiological and genetic analyses to show that A. (sect. Undifilum) oxytropis influences the growth, especially root development in its locoweed host and Arabidopsis. A. oxytropis significantly decreased primary root length while increasing the number of lateral roots and root hairs, plant leaf area and fresh weight. It enhanced the levels of plant endogenous auxin, and the expression of key genes in auxin biosynthesis, signaling and transport. Such influence on root development was abolished in auxin signaling and polar transport mutants. A. oxytropis down-regulated PIN1 but increased PIN2, PIN7, and AUX1, which may reflect altered spatial auxin accumulation responsible for the change in root architecture. Plant growth was also insensitive to A. oxytropis when NPA (naphthylphthalamic acid) was applied. Our findings indicate a function of A. oxytropis in promoting the growth and development of Arabidopsis via the regulation of auxin. This suggests the possible role of A. oxytropis to benefit its locoweed hosts, via a process irrelevant to its toxin production.
PMID: 36306203
J Exp Bot , IF:6.992 , 2022 Oct 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.; Horticultural Sciences Department, University of Florida, Gainesville, FL.; Department of Chemistry, University of Florida, Gainesville, FL.; Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, Gainesville, FL.; Department of Microbiology & Cell Science, Gainesville, FL.; UF Genetics Institute, University of Florida, Gainesville, FL.; Florida Center for Renewable Chemicals and Fuels, University of Florida, Gainesville, FL.
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 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 , 2022 Oct doi: 10.1093/jxb/erac416
GhROP6 GTPase promotes cell-specific GhPIN3a degradation in cotton fibers by regulating GhPIN3a localization.
Biotechnology Research Center, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing, 400715, P. R. China.; Academy of Agricultural Sciences, Southwest University, Chongqing, P. R. China.; Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Southwest University, Chongqing, P. R. 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 , 2022 Oct doi: 10.1093/jxb/erac406
RsCLE22a Regulates the Taproot Growth through 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, P.R.China.; College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
CLAVATA3/EMBRYO SURROUNDING REGION-related (CLE) peptides are a class of small polypeptide molecules involved in plant growth and development. Although radish is an important root vegetable crop worldwide, the functions of CLE peptides in 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 exogenous supplement of RsCLE22 peptide (CLE22p) was shown the similar phenotypes in radish. 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 (Y1H) and dual-luciferase assay (DLA) showed that the RsWOX4 (WUSCHEL-RELATED HOMEOBOX 4) gene binds to RsCLE22a promoter and activated its transcription. Meanwhile, the expression level of RsWOX4 was related to vascular cambial activity and regulated by auxin. Furthermore, a RsCLE22a-RsWOX4 module was proposed to regulate taproot vascular cambium activity through auxin signaling-related pathway in radish. These findings provided novel insight into the regulation of root growth in horticultural crops.
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
J Exp Bot , IF:6.992 , 2022 Oct , V73 (18) : P6255-6271 doi: 10.1093/jxb/erac280
Actin isovariant ACT7 controls root meristem development in Arabidopsis through modulating auxin and ethylene responses.
Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, Japan.; The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Japan.; Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada.
The meristem is the most functionally dynamic part in a plant. The shaping of the meristem requires constant cell division and elongation, which are influenced by hormones and the cytoskeletal component, actin. Although the roles of hormones in modulating meristem development have been extensively studied, the role of actin in this process is still elusive. Using the single and double mutants of the vegetative class actin, we demonstrate that actin isovariant ACT7 plays an important role in root meristem development. In the absence of ACT7, but not ACT8 and ACT2, depolymerization of actin was observed. Consistently, the act7 mutant showed reduced cell division, cell elongation, and meristem length. Intracellular distribution and trafficking of auxin transport proteins in the actin mutants revealed that ACT7 specifically functions in the root meristem to facilitate the trafficking of auxin efflux carriers PIN1 and PIN2, and consequently the transport of auxin. Compared with act7, the act7act8 double mutant exhibited slightly enhanced phenotypic response and altered intracellular trafficking. The altered distribution of auxin in act7 and act7act8 affects the response of the roots to ethylene, but not to cytokinin. Collectively, our results suggest that ACT7-dependent auxin-ethylene response plays a key role in controlling Arabidopsis root meristem development.
PMID: 35749807
J Exp Bot , IF:6.992 , 2022 Oct , V73 (18) : P6272-6291 doi: 10.1093/jxb/erac281
MAX2-dependent competence for callus formation and shoot regeneration from Arabidopsis thaliana root explants.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark, Ghent, Belgium.; Center for Plant Systems Biology, VIB, Technologiepark, Ghent, Belgium.; Laboratory of Plant Growth Analysis, Ghent University Global Campus, Songdomunhwa-Ro, Yeonsu-Gu, Incheon, Korea.; Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Universite Paris-Sud, Universite Paris-Saclay, Avenue de la Terrasse, Gif-sur-Yvette, France.; Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Valentin Vaerwyckweg, Ghent, Belgium.
Although the division of the pericycle cells initiates both lateral root development and root-derived callus formation, these developmental processes are affected differently in the strigolactone and karrikin/KARRIKIN INSENSITIVE 2 (KAI2) ligand signalling mutant more axillary growth 2 (max2). Whereas max2 produces more lateral roots than the wild type, it is defective in the regeneration of shoots from root explants. We suggest that the decreased shoot regeneration of max2 originates from delayed formation of callus primordium, yielding less callus material to regenerate shoots. Indeed, when incubated on callus-inducing medium, the pericycle cell division was reduced in max2 and the early gene expression varied when compared with the wild type, as determined by a transcriptomics analysis. Furthermore, the expression of the LATERAL ORGAN BOUNDARIES DOMAIN genes and of callus-induction genes was modified in correlation with the max2 phenotype, suggesting a role for MAX2 in the regulation of the interplay between cytokinin, auxin, and light signalling in callus initiation. Additionally, we found that the in vitro shoot regeneration phenotype of max2 might be caused by a defect in KAI2, rather than in DWARF14, signalling. Nevertheless, the shoot regeneration assays revealed that the strigolactone biosynthesis mutants max3 and max4 also play a minor role.
PMID: 35738874
J Exp Bot , IF:6.992 , 2022 Oct , V73 (18) : P6334-6351 doi: 10.1093/jxb/erac253
Stress-induced higher vein density in the C3-C4 intermediate Moricandia suffruticosa under drought and heat stress.
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, People's Republic of China.; Hubei Hongshan Laboratory, Wuhan, Hubei, People's Republic of China.
The evolution of C4 photosynthesis involved multiple anatomical and physiological modifications, yet our knowledge of the genetic regulation involved remains elusive. In this study, systematic analyses were conducted comparing the C3-C4 intermediate Moricandia suffruticosa and its C3 relative Brassica napus (rapeseed). We found that the leaves of M. suffruticosa had significantly higher vein density than those of B. napus, and the vein density was further increased in M. suffruticosa under drought and heat stress. Moreover, the bundle sheath distance, as the mean distance from the outer wall of one bundle sheath to the outer wall of an adjacent one, decreased and the number of centripetal chloroplasts in bundle sheath cells was found to be altered in M. suffruticosa leaves under drought and heat treatments. These results suggest that abiotic stress can induce a change in an intermediate C3-C4 anatomy towards a C4-like anatomy in land plants. By integrating drought and heat factors, co-expression network and comparative transcriptome analyses between M. suffruticosa and B. napus revealed that inducible auxin signaling regulated vascular development, and autophagy-related vesicle trafficking processes were associated with this stress-induced anatomical change. Overexpressing three candidate genes, MsERF02, MsSCL01, and MsDOF01, increased leaf vein density and/or enhanced photosynthetic assimilation and drought adaptability in the transgenic lines. The findings of this study may improve our understanding of the genetic regulation and evolution of C4 anatomy.
PMID: 35675763
J Exp Bot , IF:6.992 , 2022 Sep , V73 (17) : P5874-5885 doi: 10.1093/jxb/erac111
Phytomelatonin as a central molecule in plant disease resistance.
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Crops, Hainan University, Haikou, Hainan province, 570228, China.; Department of Cellular and Structural Biology, UT Health San Antonio, Long School of Medicine, San Antonio, TX, USA.
Melatonin is an essential phytohormone in the regulation of many plant processes, including during plant development and in response to stress. Pathogen infections cause serious damage to plants and reduce agricultural production. Recent studies indicate that melatonin plays important roles in alleviating bacterial, fungal, and viral diseases in plants and post-harvest fruits. Herein, we summarize information related to the effects of melatonin on plant disease resistance. Melatonin, reactive oxygen species, and reactive nitrogen species form a complex loop in plant-pathogen interaction to regulate plant disease resistance. Moreover, crosstalk of melatonin with other phytohormones including salicylic acid, jasmonic acid, auxin, and abscisic acid further activates plant defense genes. Melatonin plays an important role not only in plant immunity but also in alleviating pathogenicity. We also summarize the known processes by which melatonin mediates pathogenicity via negatively regulating the expression levels of genes related to cell viability as well as virulence-related genes. The multiple mechanisms underlying melatonin influences on both plant immunity and pathogenicity support the recognition of the essential nature of melatonin in plant-pathogen interactions, highlighting phytomelatonin as a critical molecule in plant immune responses.
PMID: 35298631
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 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 signalling 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 signalling in roots to regulate meristem size. The rav1 mutants have prominently longer primary roots, with a meristem that is significantly enlarged and contain higher cell numbers, compared to 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 signalling. 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 signalling, is transcriptionally repressed by RAV1 to promote cytokinin response in roots. Further associating RAV1 with cytokinin signalling, 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 signalling. 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, 38098, San Michele all'Adige, Italy.; C3A Center Agriculture Food Environment, University of Trento, Trento, Italy.; The New Zealand Institute for Plant and Food Research Limited, New Zealand.; Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Jena, Germany.; Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences and Palacky University, Olomouc, 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 CRISPR/Cas9-mediated genome editing. To this end, we conducted transcriptomic and metabolic analyses of MdPGT1 RNAi knockdown and genome-edited lines. Knockdown lines exhibited characteristic impairment of plant growth and leaf morphology, whilst genome-edited lines exhibited normal growth despite reduced foliar phloridzin. RNA-Seq 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 get insight into their role in the phenotypes observed. We found that salicylic and jasmonic acid were increased in dwarf lines, whilst auxin and abscisic acid showed no correlation with the growth phenotype. Furthermore, bioactive brassinosteroids (BRs) were commonly upregulated, whereas gibberellin GA(4) was distinctively altered, showing a sharp decrease in RNAi knockdown lines. qRT-PCR expression analysis further confirmed transcriptional regulation of key factors involved in BR and GA interaction. These findings suggest that a differential modulation of phytohormones may be involved in the contrasting effects on growth following phloridzin reduction. This 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 Nov 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
Plant J , IF:6.417 , 2022 Oct , V112 (2) : P476-492 doi: 10.1111/tpj.15960
Bioenergy sorghum stem growth regulation: intercalary meristem localization, development, and gene regulatory network analysis.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77843-2128, USA.; ABQMR, Inc., 2301 Yale Blvd. SE, Suite C2, Albuquerque, New Mexico, 87106, USA.; Department of Plant Biology, University of Illinois, Champaign-Urbana, Illinois, 61801, USA.
Bioenergy sorghum is a highly productive drought tolerant C(4) grass that accumulates 80% of its harvestable biomass in approximately 4 m length stems. Stem internode growth is regulated by development, shading, and hormones that modulate cell proliferation in intercalary meristems (IMs). In this study, sorghum stem IMs were localized above the pulvinus at the base of elongating internodes using magnetic resonance imaging, microscopy, and transcriptome analysis. A change in cell morphology/organization occurred at the junction between the pulvinus and internode where LATERAL ORGAN BOUNDARIES (SbLOB), a boundary layer gene, was expressed. Inactivation of an AGCVIII kinase in DDYM (dw2) resulted in decreased SbLOB expression, disrupted IM localization, and reduced internode cell proliferation. Transcriptome analysis identified approximately 1000 genes involved in cell proliferation, hormone signaling, and other functions selectively upregulated in the IM compared with a non-meristematic stem tissue. This cohort of genes is expressed in apical dome stem tissues before localization of the IM at the base of elongating internodes. Gene regulatory network analysis identified connections between genes involved in hormone signaling and cell proliferation. The results indicate that gibberellic acid induces accumulation of growth regulatory factors (GRFs) known to interact with ANGUSTIFOLIA (SbAN3), a master regulator of cell proliferation. GRF:AN3 was predicted to induce SbARF3/ETT expression and regulate SbAN3 expression in an auxin-dependent manner. GRFs and ARFs regulate genes involved in cytokinin and brassinosteroid signaling and cell proliferation. The results provide a molecular framework for understanding how hormone signaling regulates the expression of genes involved in cell proliferation in the stem IM.
PMID: 36038985
Antioxidants (Basel) , IF:6.312 , 2022 Oct , V11 (10) doi: 10.3390/antiox11102035
Mitochondrial HSC70-1 Regulates Polar Auxin Transport through ROS Homeostasis in Arabidopsis Roots.
Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.; National 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 200032, China.; College of Life Sciences, Hengshui University, Hengshui 053000, China.
Arabidopsis mitochondrial-localized heat shock protein 70-1 (mtHSC70-1) modulates vegetative growth by assisting mitochondrial complex IV assembly and maintaining reactive oxygen species (ROS) homeostasis. In addition, mtHSC70-1 affects embryo development, and this effect is mediated by auxin. However, whether mtHSC70-1 regulates vegetative growth through auxin and knowledge of the link between ROS homeostasis and auxin distribution remain unclear. Here, we found that mtHSC70-1 knockout seedlings (mthsc70-1a) displayed shortened roots, decreased fresh root weight and lateral root number, increased root width and abnormal root morphology. The introduction of the mtHSC70-1 gene into mthsc70-1a restored the growth and development of roots to the level of the wild type. However, sugar and auxin supplementation could not help the mutant roots restore to normal. Moreover, mthsc70-1a seedlings showed a decrease in meristem length and activity, auxin transport carrier (PINs and AUX1) and auxin abundances in root tips. The application of exogenous reducing agents upregulated the levels of PINs in the mutant roots. The introduction of antioxidant enzyme genes (MSD1 or CAT1) into the mthsc70-1a mutant rescued the PIN and local auxin abundances and root growth and development. Taken together, our data suggest that mtHSC70-1 regulates polar auxin transport through ROS homeostasis in Arabidopsis roots.
PMID: 36290758
Commun Biol , IF:6.268 , 2022 Sep , V5 (1) : P1043 doi: 10.1038/s42003-022-03998-2
The RPN12a proteasome subunit is essential for the multiple hormonal homeostasis controlling the progression of leaf senescence.
Department of Plant Physiology, Umea Plant Science Centre, Umea University, SE-901 87, Umea, Sweden.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, SE-901 83, Umea, Sweden.; Department of Plant Physiology, Umea Plant Science Centre, Umea University, SE-901 87, Umea, Sweden. olivier.keech@umu.se.
The 26S proteasome is a conserved multi-subunit machinery in eukaryotes. It selectively degrades ubiquitinated proteins, which in turn provides an efficient molecular mechanism to regulate numerous cellular functions and developmental processes. Here, we studied a new loss-of-function allele of RPN12a, a plant ortholog of the yeast and human structural component of the 19S proteasome RPN12. Combining a set of biochemical and molecular approaches, we confirmed that a rpn12a knock-out had exacerbated 20S and impaired 26S activities. The altered proteasomal activity led to a pleiotropic phenotype affecting both the vegetative growth and reproductive phase of the plant, including a striking repression of leaf senescence associate cell-death. Further investigation demonstrated that RPN12a is involved in the regulation of several conjugates associated with the auxin, cytokinin, ethylene and jasmonic acid homeostasis. Such enhanced aptitude of plant cells for survival in rpn12a contrasts with reports on animals, where 26S proteasome mutants generally show an accelerated cell death phenotype.
PMID: 36180574
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
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232113195
The Integration of Metabolomics and Transcriptomics Provides New Insights for the Identification of Genes Key to Auxin Synthesis at Different Growth Stages of Maize.
College of Life Sciences, Jilin Agricultural University, Changchun 130118, China.; Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Changchun 130118, China.; College of Agronomy, Jilin Agricultural University, Changchun 130118, China.
As a staple food crop, maize is widely cultivated worldwide. Sex differentiation and kernel development are regulated by auxin, but the mechanism regulating its synthesis remains unclear. This study explored the influence of the growth stage of maize on the secondary metabolite accumulation and gene expression associated with auxin synthesis. Transcriptomics and metabonomics were used to investigate the changes in secondary metabolite accumulation and gene expression in maize leaves at the jointing, tasseling, and pollen-release stages of plant growth. In total, 1221 differentially accumulated metabolites (DAMs) and 4843 differentially expressed genes (DEGs) were screened. KEGG pathway enrichment analyses of the DEGs and DAMs revealed that plant hormone signal transduction, tryptophan metabolism, and phenylpropanoid biosynthesis were highly enriched. We summarized the key genes and regulatory effects of the tryptophan-dependent auxin biosynthesis pathways, giving new insights into this type of biosynthesis. Potential MSTRG.11063 and MSTRG.35270 and MSTRG.21978 genes in auxin synthesis pathways were obtained. A weighted gene co-expression network analysis identified five candidate genes, namely TSB (Zm00001d046676 and Zm00001d049610), IGS (Zm00001d020008), AUX2 (Zm00001d006283), TAR (Zm00001d039691), and YUC (Zm00001d025005 and Zm00001d008255), which were important in the biosynthesis of both tryptophan and auxin. This study provides new insights for understanding the regulatory mechanism of auxin synthesis in maize.
PMID: 36361983
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232113037
Genome-Wide Identification and Characterization of YUCCA Gene Family in Mikania micrantha.
Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Bioindustry and Innovation Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Auxin is a general coordinator for growth and development throughout plant lifespan, acting in a concentration-dependent manner. Tryptophan aminotransferases (YUCCA) family catalyze the oxidative decarboxylation of indole-3-pyruvic acid (IPA) to form indole-3-acetic acid (IAA) and plays a critical role in auxin homeostasis. Here, 18 YUCCA family genes divided into four categories were identified from Mikania micrantha (M. micrantha), one of the world's most invasive plants. Five highly conserved motifs were characterized in these YUCCA genes (MmYUCs). Transcriptome analysis revealed that MmYUCs exhibited distinct expression patterns in different organs and five MmYUCs showed high expression levels throughout all the five tissues, implying that they may play dominant roles in auxin biosynthesis and plant development. In addition, MmYUC6_1 was overexpressed in DR5::GUS Arabidopsis line to explore its function, which resulted in remarkably increased auxin level and typical elevated auxin-related phenotypes including shortened roots and elongated hypocotyls in the transgenic plants, suggesting that MmYUC6_1 promoted IAA biosynthesis in Arabidopsis. Collectively, these findings provided comprehensive insight into the phylogenetic relationships, chromosomal distributions, expression patterns and functions of the MmYUC genes in M. micrantha, which would facilitate the study of molecular mechanisms underlying the fast growth of M. micrantha and preventing its invasion.
PMID: 36361840
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232112981
Identification of Key Genes during Ethylene-Induced Adventitious Root Development in Cucumber (Cucumis sativus L.).
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.; College of Science, Gansu Agricultural University, Lanzhou 730070, China.
Ethylene (ETH), as a key plant hormone, plays critical roles in various processes of plant growth and development. ETH has been reported to induce adventitious rooting. Moreover, our previous studies have shown that exogenous ETH may induce plant adventitious root development in cucumber (Cucumis sativus L.). However, the key genes involved in this process are still unclear. To explore the key genes in ETH-induced adventitious root development, we employed a transcriptome technique and revealed 1415 differentially expressed genes (DEGs), with 687 DEGs up-regulated and 728 DEGs down-regulated. Using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we further identified critical pathways that were involved in ETH-induced adventitious root development, including carbon metabolism (starch and sucrose metabolism, glycolysis/gluconeogenesis, citrate cycle (TCA cycle), oxidative phosphorylation, fatty acid biosynthesis, and fatty acid degradation), secondary metabolism (phenylalanine metabolism and flavonoid biosynthesis) and plant hormone signal transduction. In carbon metabolism, ETH reduced the content of sucrose, glucose, starch, the activity of sucrose synthase (SS), sucrose-phosphate synthase (SPS) and hexokinase (HK), and the expressions of CsHK2, pyruvate kinase2 (CsPK2), and CsCYP86A1, whereas it enhanced the expressions of beta-amylase 1 (CsBAM1) and beta-amylase 3 (CsBAM3). In secondary metabolism, the transcript levels of phenylalanine ammonia-lyase (CsPAL) and flavonoid 3'-monooxygenase (CsF3'M) were negatively regulated, and that of primary-amine oxidase (CsPAO) was positively regulated by ETH. Additionally, the indole-3-acetic acid (IAA) content and the expressions of auxin and ETH signaling transduction-related genes (auxin transporter-like protein 5 (CsLAX5), CsGH3.17, CsSUAR50, and CsERS) were suppressed, whereas the abscisic acid (ABA) content and the expressions of ABA and BR signaling transduction-related genes (CsPYL1, CsPYL5, CsPYL8, BRI1-associated kinase 1 (CsBAK1), and CsXTH3) were promoted by ETH. Furthermore, the mRNA levels of these genes were confirmed by real-time PCR (RT-qPCR). These results indicate that genes related to carbon metabolism, secondary metabolite biosynthesis, and plant hormone signaling transduction are involved in ETH-induced adventitious root development. This work identified the key pathways and genes in ETH-induced adventitious rooting in cucumber, which may provide new insights into ETH-induced adventitious root development and will be useful for investigating the molecular roles of key genes in this process in further studies.
PMID: 36361778
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232112776
Effects and Mechanism of Enhanced UV-B Radiation on the Flag Leaf Angle of Rice.
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.; College of Horticulture and Landscape, Yunnan Agricultural University, Kunming 650201, China.
Leaf angle is an influential agricultural trait that influences rice (Oryza sativa L.) plant type and yield, which results from the leaf bending from the vertical axis to the abaxial axis. UV-B radiation affects plant morphology, but the effects of varying UV-B intensities on rice flag leaves and the underlying molecular, cellular, and physiological mechanisms remain unknown. This experiment aims to examine the effect of natural light and field-enhanced UV-B radiation (2.5, 5.0, 7.5 kJ.m(-2)) on the leaf angle of the traditional rice variety Baijiaolaojing on Yuanyang terraces. In comparison with natural light, the content of brassinolide and gibberellin in rice flag leaves increased by 29.94% and 60.1%, respectively. The auxin content decreased by 17.3%. Compared with the natural light treatment, the cellulose content in the pulvini was reduced by 13.8% and hemicellulose content by 25.7% under 7.5 kJ.m(-2) radiation intensity. The thick-walled cell area and vascular bundle area of the leaf pulvini decreased with increasing radiation intensity, and the growth of mechanical tissue in the rice leaf pulvini was inhibited. The flag leaf angle of rice was greatest at 7.5 kJ.m(-2) radiation intensity, with an increase of 50.2%. There are two pathways by which the angle of rice flag leaves is controlled under high-intensity UV-B radiation. The leaf angle regulation genes OsBUL1, OsGSR1, and OsARF19 control hormone levels, whereas the ILA1 gene controls fiber levels. Therefore, as cellulose, hemicellulose, sclerenchyma, and vascular bundles weaken the mechanical support of the pulvini, the angle of the flag leaf increases.
PMID: 36361567
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (21) doi: 10.3390/ijms232112750
Genome-Wide Identification of Auxin-Responsive GH3 Gene Family in Saccharum and the Expression of ScGH3-1 in Stress Response.
Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Gretchen Hagen3 (GH3), one of the three major auxin-responsive gene families, is involved in hormone homeostasis in vivo by amino acid splicing with the free forms of salicylic acid (SA), jasmonic acid (JA) or indole-3-acetic acid (IAA). Until now, the functions of sugarcane GH3 (SsGH3) family genes in response to biotic stresses have been largely unknown. In this study, we performed a systematic identification of the SsGH3 gene family at the genome level and identified 41 members on 19 chromosomes in the wild sugarcane species, Saccharum spontaneum. Many of these genes were segmentally duplicated and polyploidization was the main contributor to the increased number of SsGH3 members. SsGH3 proteins can be divided into three major categories (SsGH3-I, SsGH3-II, and SsGH3-III) and most SsGH3 genes have relatively conserved exon-intron arrangements and motif compositions. Diverse cis-elements in the promoters of SsGH3 genes were predicted to be essential players in regulating SsGH3 expression patterns. Multiple transcriptome datasets demonstrated that many SsGH3 genes were responsive to biotic and abiotic stresses and possibly had important functions in the stress response. RNA sequencing and RT-qPCR analysis revealed that SsGH3 genes were differentially expressed in sugarcane tissues and under Sporisorium scitamineum stress. In addition, the SsGH3 homolog ScGH3-1 gene (GenBank accession number: OP429459) was cloned from the sugarcane cultivar (Saccharum hybrid) ROC22 and verified to encode a nuclear- and membrane-localization protein. ScGH3-1 was constitutively expressed in all tissues of sugarcane and the highest amount was observed in the stem pith. Interestingly, it was down-regulated after smut pathogen infection but up-regulated after MeJA and SA treatments. Furthermore, transiently overexpressed Nicotiana benthamiana, transduced with the ScGH3-1 gene, showed negative regulation in response to the infection of Ralstonia solanacearum and Fusarium solani var. coeruleum. Finally, a potential model for ScGH3-1-mediated regulation of resistance to pathogen infection in transgenic N. benthamiana plants was proposed. This study lays the foundation for a comprehensive understanding of the sequence characteristics, structural properties, evolutionary relationships, and expression of the GH3 gene family and thus provides a potential genetic resource for sugarcane disease-resistance breeding.
PMID: 36361540
Int J Mol Sci , IF:5.923 , 2022 Oct , V23 (20) doi: 10.3390/ijms232012495
Molecular Mechanisms of Diverse Auxin Responses during Plant Growth and Development.
Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education, Heilongjiang University, Harbin 150500, China.; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.; College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA.; Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region, School of Life Sciences, Heilongjiang University, Harbin 150080, China.
The plant hormone auxin acts as a signaling molecule to regulate numerous developmental processes throughout all stages of plant growth. Understanding how auxin regulates various physiological and developmental processes has been a hot topic and an intriguing field. Recent studies have unveiled more molecular details into how diverse auxin responses function in every aspect of plant growth and development. In this review, we systematically summarized and classified the molecular mechanisms of diverse auxin responses, and comprehensively elaborated the characteristics and multilevel regulation mechanisms of the canonical transcriptional auxin response. On this basis, we described the characteristics and differences between different auxin responses. We also presented some auxin response genes that have been genetically modified in plant species and how their changes impact various traits of interest. Finally, we summarized some important aspects and unsolved questions of auxin responses that need to be focused on or addressed in future research. This review will help to gain an overall understanding of and some insights into the diverse molecular mechanisms of auxin responses in plant growth and development that are instrumental in harnessing genetic resources in molecular breeding of extant plant species.
PMID: 36293351
Int J Mol Sci , IF:5.923 , 2022 Sep , V23 (19) doi: 10.3390/ijms231911580
Physiological and Comparative Transcriptome Analyses of the High-Tillering Mutant mtn1 Reveal Regulatory Mechanisms in the Tillering of Centipedegrass (Eremochloa ophiuroides (Munro) Hack.).
The National Forestry and Grassland Administration Engineering Research Center for Germplasm Innovation and Utilization of Warm-Season Turfgrasses, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
Tillering is a key factor that determines the reproductive yields of centipedegrass, which is an important perennial warm-season turfgrass. However, the regulatory mechanism of tillering in perennial plants is poorly understood, especially in perennial turfgrasses. In this study, we created and characterised a cold plasma-mutagenised centipedegrass mutant, mtn1 (more tillering number 1). Phenotypic analysis showed that the mtn1 mutant exhibited high tillering, short internodes, long seeds and a heavy 1000-seed weight. Then, a comparative transcriptomic analysis of the mtn1 mutant and wild-type was performed to explore the molecular mechanisms of centipedegrass tillering. The results revealed that plant hormone signalling pathways, as well as starch and sucrose metabolism, might play important roles in centipedegrass tillering. Hormone and soluble sugar content measurements and exogenous treatment results validated that plant hormones and sugars play important roles in centipedegrass tiller development. In particular, the overexpression of the auxin transporter ATP-binding cassette B 11 (EoABCB11) in Arabidopsis resulted in more branches. Single nucleotide polymorphisms (SNPs) were also identified, which will provide a useful resource for molecular marker-assisted breeding in centipedegrass. According to the physiological characteristics and transcriptional expression levels of the related genes, the regulatory mechanism of centipedegrass tillering was systematically revealed. This research provides a new breeding resource for further studies into the molecular mechanism that regulates tillering in perennial plants and for breeding high-tillering centipedegrass varieties.
PMID: 36232880
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 : 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 : P1050840 doi: 10.3389/fpls.2022.1050840
Combined full-length transcriptomic and metabolomic analysis reveals the regulatory mechanisms of adaptation to salt stress in asparagus.
Institute of Cash Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang, China.; Landscape Management and Protection Center, Shijiazhuang Bureau of Landscape Architecture, Shijiazhuang, China.; College of Biodiversity Conservation, Southwest Forestry University, Kunming, China.
Soil salinity is a very serious abiotic stressor that affects plant growth and threatens crop yield. Thus, it is important to explore the mechanisms of salt tolerance of plant and then to stabilize and improve crop yield. Asparagus is an important cash crop, but its salt tolerance mechanisms are largely unknown. Full-length transcriptomic and metabolomic analyses were performed on two asparagus genotypes: 'jx1502' (a salt-tolerant genotype) and 'gold crown' (a salt-sensitive genotype). Compared with the distilled water treatment (control), 877 and 1610 differentially expressed genes (DEGs) were identified in 'jx1502' and 'gold crown' under salt stress treatment, respectively, and 135 and 73 differentially accumulated metabolites (DAMs) were identified in 'jx1502' and 'gold crown' under salt stress treatment, respectively. DEGs related to ion transport, plant hormone response, and cell division and growth presented differential expression profiles between 'jx1502' and 'gold crown.' In 'jx1502,' 11 ion transport-related DEGs, 8 plant hormone response-related DEGs, and 12 cell division and growth-related DEGs were upregulated, while 7 ion transport-related DEGs, 4 plant hormone response-related DEGs, and 2 cell division and growth-related DEGs were downregulated. Interestingly, in 'gold crown,' 14 ion transport-related DEGs, 2 plant hormone response-related DEGs, and 6 cell division and growth-related DEGs were upregulated, while 45 ion transport-related DEGs, 13 plant hormone response-related DEGs, and 16 cell division and growth-related DEGs were downregulated. Genotype 'jx1502' can modulate K(+)/Na(+) and water homeostasis and maintain a more constant transport system for nutrient uptake and distribution than 'gold crown' under salt stress. Genotype 'jx1502' strengthened the response to auxin (IAA), as well as cell division and growth for root remodeling and thus salt tolerance. Therefore, the integration analysis of transcriptomic and metabolomic indicated that 'jx1502' enhanced sugar and amino acid metabolism for energy supply and osmotic regulatory substance accumulation to meet the demands of protective mechanisms against salt stress. This work contributed to reveal the underlying salt tolerance mechanism of asparagus at transcription and metabolism level and proposed new directions for asparagus variety improvement.
PMID: 36388563
Front Plant Sci , IF:5.753 , 2022 , V13 : P1053459 doi: 10.3389/fpls.2022.1053459
Genetic dissection of branch architecture in oilseed rape (Brassica napus L.) germplasm.
Oil Crops Research Institute of the Chinses Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, China.; Hubei Hongshan Laboratory, Wuhan, China.
Branch architecture is an important factor influencing rapeseed planting density, mechanized harvest, and yield. However, its related genes and regulatory mechanisms remain largely unknown. In this study, branch angle (BA) and branch dispersion degree (BD) were used to evaluate branch architecture. Branch angle exhibited a dynamic change from an increase in the early stage to a gradual decrease until reaching a stable state. Cytological analysis showed that BA variation was mainly due to xylem size differences in the vascular bundle of the branch junction. The phenotypic analysis of 327 natural accessions revealed that BA in six environments ranged from 24.3 degrees to 67.9 degrees , and that BD in three environments varied from 4.20 cm to 21.4 cm, respectively. A total of 115 significant loci were detected through association mapping in three models (MLM, mrMLM, and FarmCPU), which explained 0.53%-19.4% of the phenotypic variations. Of them, 10 loci were repeatedly detected in different environments and models, one of which qBAD.A03-2 was verified as a stable QTL using a secondary segregation population. Totally, 1066 differentially expressed genes (DEGs) were identified between branch adaxial- and abaxial- sides from four extremely large or small BA/BD accessions through RNA sequencing. These DEGs were significantly enriched in the pathways related to auxin biosynthesis and transport as well as cell extension such as indole alkaloid biosynthesis, other glycan degradation, and fatty acid elongation. Four known candidate genes BnaA02g16500D (PIN1), BnaA03g10430D (PIN2), BnaC03g06250D (LAZY1), and BnaC06g20640D (ARF17) were identified by both GWAS and RNA-seq, all of which were involved in regulating the asymmetric distribution of auxins. Our identified association loci and candidate genes provide a theoretical basis for further study of gene cloning and genetic improvement of branch architecture.
PMID: 36388516
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
Front Plant Sci , IF:5.753 , 2022 , V13 : P1025161 doi: 10.3389/fpls.2022.1025161
Tissue-specific transcriptome responses to Fusarium head blight and Fusarium root rot.
Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, England.
Fusarium head blight (FHB) and Fusarium root rot (FRR) are important diseases of small-grain cereals caused by Fusarium species. While host response to FHB has been subject to extensive study, very little is known about response to FRR and the transcriptome responses of FHB and FRR have not been thoroughly compared. Brachypodium distachyon (Bd) is an effective model for investigating host responses to both FHB and FRR. In this study the transcriptome response of Bd to F. graminearum (Fg) infection of heads and roots was investigated. An RNA-seq analysis was performed on both Bd FHB and FRR during the early infection. Additionally, an RNA-seq analysis was performed on in vitro samples of Fg for comparison with Fg gene expression in planta. Differential gene expression and gene-list enrichment analyses were used to compare FHB and FRR transcriptome responses in both Bd and Fg. Differential expression of selected genes was confirmed using RT-qPCR. Most genes associated with receptor signalling, cell-wall modification, oxidative stress metabolism, and cytokinin and auxin biosynthesis and signalling genes were generally upregulated in FHB or were downregulated in FRR. In contrast, Bd genes involved in jasmonic acid and ethylene biosynthesis and signalling, and antimicrobial production were similarly differentially expressed in both tissues in response to infection. A transcriptome analysis of predicted Fg effectors with the same infected material revealed elevated expression of core tissue-independent genes including cell-wall degradation enzymes and the gene cluster for DON production but also several tissue-dependent genes including those for aurofusarin production and cutin degradation. This evidence suggests that Fg modulates its transcriptome to different tissues of the same host.
PMID: 36352885
Front Plant Sci , IF:5.753 , 2022 , V13 : P1004590 doi: 10.3389/fpls.2022.1004590
Transcriptomic analysis of succulent stem development of Chinese kale (Brassica oleracea var. alboglabra Bailey) and its synthetic allotetraploid via RNA sequencing.
College of Horticulture Science, Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas of Zhejiang Province, Zhejiang A&F University, Hangzhou, China.; Institute of Crop Science, Hangzhou Academy of Agricultural Sciences, Hangzhou, China.; College of Modern Agriculture, Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, Zhejiang A&F University, Hangzhou, China.; Department of Health and Agriculture, Hangzhou Wanxiang Polytechnic, Hangzhou, China.
Chinese kale (Brassica oleracea var. alboglabra Bailey, CC) is a succulent stem vegetable in the Brassica family. Its allotetraploid (AACC) vegetable germplasm, which was synthesized via distant hybridization with the colloquially named 'yellow turnip' (B. rapa L. ssp. rapifera Matzg., AA), has a swelling stem similar to CC. To address the molecular mechanism of stem development for CC and AACC, RNA sequencing (RNA-seq) was used to investigate transcriptional regulation of their stem development at three key stages including 28 days, 42 days and the bolting stage (BS) after sowing. As a result, 32,642, 32,665, 33,816, 32,147, 32,293 and 32,275 genes were identified in six corresponding cDNA libraries. Among them, 25,459 genes were co-expressed, while 7,183, 7,206, 8,357, 6,688, 6,834 and 6,814 genes were specifically expressed. Additionally, a total of 29,222 differentially expressed genes (DEGs) were found for functional enrichment as well as many genes involved in plant hormones including gibberellin (GA), abscisic acid (ABA), cytokinin (CTK) and auxin (AUX). Based on gene expression consistency between CC and AACC, the gene families including DELLA, GID, PYR/PYL, PP2C, A-ARR and AUX/IAA might be related to stem development. Among these, eight genes including Bo00834s040, Bo5g093140, Bo6g086770, Bo9g070200, Bo7g116570, Bo3g054410, Bo7g093470 and Bo5g136600 may play important roles in stem development based on their remarkable expression levels as confirmed by qRT-PCR. These findings provide a new theoretical basis for understanding the molecular mechanism of stem development in Brassica vegetable stem breeding.
PMID: 36340371
Front Plant Sci , IF:5.753 , 2022 , V13 : P1023723 doi: 10.3389/fpls.2022.1023723
Indole pyruvate decarboxylase gene regulates the auxin synthesis pathway in rice by interacting with the indole-3-acetic acid-amido synthetase gene, promoting root hair development under cadmium stress.
Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.; Department of Plant Breeding and Genetics, The University of Haripur, Haripur, Pakistan.; Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.; Department of Agronomy, Institute of Food and Agricultural Sciences, Florida University, Gainesville, FL, United States.; Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan.; Institute of Environment and Ecology, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, China.; Department of Biotechnology, Chonnam National University, Yeosu, South Korea.
This research focused on cadmium (Cd), which negatively affects plant growth and auxin hemostasis. In plants, many processes are indirectly controlled through the expression of certain genes due to the secretion of bacterial auxin, as indole-3-acetic acid (IAA) acts as a reciprocal signaling molecule in plant-microbe interaction. The aim of current studies was to investigate responsible genes in rice for plant-microbe interaction and lateral root development due to the involvement of several metabolic pathways. Studies revealed that GH3-2 interacts with endogenous IAA in a homeostasis manner without directly providing IAA. In rice, indole-3-pyruvate decarboxylase (IPDC) transgenic lines showed a 40% increase in lateral roots. Auxin levels and YUCCA (auxin biosynthesis gene) expression were monitored in osaux1 mutant lines inoculated with Bacillus cereus exposed to Cd. The results showed an increase in root hairs (RHs) and lateral root density, changes in auxin levels, and expression of the YUCCA gene. B. cereus normalizes the oxidative stress caused by Cd due to the accumulation of O2- and H(2)O(2) in osaux1 mutant lines. Furthermore, the inoculation of B. cereus increases DR5:GUS expression, indicating that bacterial species have a positive role in auxin regulation. Thus, the current study suggests that B. cereus and IPDC transgenic lines increase the RH development in rice by interacting with IAA synthetase genes in the host plant, alleviating Cd toxicity and enhancing plant defense mechanisms.
PMID: 36340357
Front Plant Sci , IF:5.753 , 2022 , V13 : P1019334 doi: 10.3389/fpls.2022.1019334
The role of plant hormones on the reproductive success of red and brown algae.
Laboratory of Aquaculture Genetics and Genomics, Division of Marine Life Science, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan.
Seaweeds or macroalgae are important primary producers that serve as a habitat for functioning ecosystems. A sustainable production of macroalgae has been maintained by a diverse range of life cycles. Reproduction is the most dynamic change to occur during its life cycle, and it is a key developmental event to ensure the species' survival. There is gradually accumulating evidence that plant hormones, such as abscisic acid and auxin, have a role on the sporogenesis of brown alga (Saccharina japonica). Recent studies reported that 1-aminocylopropane-1-carboxylic acid, an ethylene precursor, regulates sexual reproduction in red alga (Neopyropia yezoensis) independently from ethylene. In addition, these macroalgae have an enhanced tolerance against abiotic and biotic stresses during reproduction to protect their gametes and spores. Herein, we reviewed the current understanding on the regulatory mechanisms of red and brown algae on their transition from vegetative to reproductive phase.
PMID: 36340345
Front Plant Sci , IF:5.753 , 2022 , V13 : P883970 doi: 10.3389/fpls.2022.883970
Plant mineral nutrition and disease resistance: A significant linkage for sustainable crop protection.
Department of Plant Pathology, College of Agriculture, G. B. Pant University of Agriculture and Technology, Pantnagar, India.; Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia.; ICAR - Central Citrus Research Institute, Nagpur, Nagpur, Maharashtra, India.; Division of Bioenergy, Biorefinery and Green Chemistry (BBC-BIC), Department of Energy Technologies and Renewable Resources (TERIN), Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Bari, Italy.; Faculty of Chemical Sciences, Benemerita, Autonomous University of Puebla, Puebla, Mexico.
Complete and balanced nutrition has always been the first line of plant defense due to the direct involvement of mineral elements in plant protection. Mineral elements affect plant health directly by modulating the activity of redox enzymes or improving the plant vigor indirectly by altering root exudates, and changing microflora population dynamics, rhizosphere soil nutrient content, pH fluctuation, lignin deposition, and phytoalexin biosynthesis. Nitrogen (N) is one of the most important macronutrients having a significant impact on the host-pathogen axis. N negatively affects the plant's physical defense along with the production of antimicrobial compounds, but it significantly alleviates defense-related enzyme levels that can eventually assist in systemic resistance. Potassium (K) is an essential plant nutrient, when it is present in adequate concentration, it can certainly increase the plant's polyphenolic concentrations, which play a critical role in the defense mechanism. Although no distinguished role of phosphorus (P) is observed in plant disease resistance, a high P content may increase the plant's susceptibility toward the invader. Manganese (Mn) is one of the most important micronutrients, which have a vital effect on photosynthesis, lignin biosynthesis, and other plant metabolic functions. Zinc (Zn) is a part of enzymes that are involved in auxin synthesis, infectivity, phytotoxin, and mycotoxin production in pathogenic microorganisms. Similarly, many other nutrients also have variable effects on enhancing or decreasing the host susceptibility toward disease onset and progression, thereby making integrative plant nutrition an indispensable component of sustainable agriculture. However, there are still many factors influencing the triple interaction of host-pathogen-mineral elements, which are not yet unraveled. Thereby, the present review has summarized the recent progress regarding the use of macro- and micronutrients in sustainable agriculture and their role in plant disease resistance.
PMID: 36340341
Front Plant Sci , IF:5.753 , 2022 , V13 : P1041068 doi: 10.3389/fpls.2022.1041068
Joint metabolome and transcriptome analysis of the effects of exogenous GA(3) on endogenous hormones in sweet cherry and mining of potential regulatory genes.
College of Horticulture, Sichuan Agricultural University, Chengdu, China.
Gibberellin (GA) is an important phytohormone that can participate in various developmental processes of plants. The study found that application of GA(3) can induce parthenocarpy fruit and improve fruit set. However, the use of GA(3) affects endogenous hormones in fruits, thereby affecting fruit quality. This study mainly investigates the effect of exogenous GA(3) on endogenous hormones in sweet cherries. The anabolic pathways of each hormone were analyzed by metabolome and transcriptome to identify key metabolites and genes that affect endogenous hormones in response to exogenous GA(3) application. Results showed that exogenous GA(3) led to a significant increase in the content of abscisic acid (ABA) and GA and affected jasmonic acid (JA) and auxin (IAA). At the same time, the key structural genes affecting the synthesis of various hormones were preliminarily determined. Combined with transcription factor family analysis, WRKY genes were found to be more sensitive to the use of exogenous GA(3), especially the genes belonging to Group III (PaWRKY16, PaWRKY21, PaWRKY38, PaWRKY52, and PaWRKY53). These transcription factors can combine with the promoters of NCED, YUCCA, and other genes to regulate the content of endogenous hormones. These findings lay the foundation for the preliminary determination of the mechanism of GA(3)'s effect on endogenous hormones in sweet cherry and the biological function of WRKY transcription factors.
PMID: 36330269
Front Plant Sci , IF:5.753 , 2022 , V13 : P954467 doi: 10.3389/fpls.2022.954467
De novo transcriptome based insights into secondary metabolite biosynthesis in Malaxis acuminata (Jeevak)-A therapeutically important orchid.
Biotechnology Division, Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.; Studio of Computational Biology & Bioinformatics, The Himalayan Centre for High-throughput Computational Biology (HiCHiCoB, A BIC supported by DBT, India), Council for Scientific and Industrial Research (CSIR)-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, Himachal Pradesh, India.; Agrotechnology and Rural Development Division (ARDD), CSIR-North East Institute of Science and Technology, Jorhat, Assam, India.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India.; Chemical Technology Division, Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.
Malaxis acuminata D. Don [=Crepidium acuminatum (D. Don) Szlach.] is an endangered medicinal orchid of the Ashtvarga group of plants in Ayurveda (Indian system of traditional medicine). Using a combination of aromatic cytokinin [meta-Topolin (mT)], plant biostimulant (chitosan), auxin [indole-3-butyric acid (IBA)], and a phenolic elicitor [phloroglucinol (PG)], plants of M. acuminata were regenerated in vitro for mass multiplication. The present research reveals the first-ever transcriptome of M. acuminata. A total of 43,111 transcripts encoding 23,951 unigenes were assembled de novo from a total of 815.02 million reads obtained from leaf and pseudobulb of in vitro raised M. acuminata. Expression analysis of genes associated with beta-sitosterol and eugenol biosynthesis in leaf and pseudobulb provided vital clues for differential accumulation of metabolites in M. acuminata. Ultra-performance liquid chromatography (UPLC) confirmed higher amounts of beta-sitosterol and eugenol content in the leaf as compared to the pseudobulb. Differential expression of transcripts related to starch and sucrose metabolism, plant hormone signal transduction, diterpenoid biosynthesis, phenylalanine metabolism, stilbenoid, diarylheptanoid, and gingerol biosynthesis suggested the operation of differential metabolic pathways in leaf and pseudobulb. The present research provides valuable information on the biosynthesis of secondary metabolites in M. acuminata, which could be used for advanced metabolite bioprospection using cell suspension culture and bioreactor-based approaches. Data also suggested that leaf tissues rather than pseudobulb can be used as an alternate source of bioactive metabolites thereby shifting the need for harvesting the pseudobulb. This will further facilitate the conservation and sustainable utilization of this highly valued medicinal orchid.
PMID: 36330257
Front Plant Sci , IF:5.753 , 2022 , V13 : P1020367 doi: 10.3389/fpls.2022.1020367
Combined analysis of transcriptome and metabolome reveals the molecular mechanism and candidate genes of Haloxylon drought tolerance.
School of Ecology and Environment, Xinjiang University, Urumqi, China.; Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China.; Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem, Ministry of Education, Jinghe, China.
Haloxylon ammodendron and Haloxylon persicum, as typical desert plants, show strong drought tolerance and environmental adaptability. They are ideal model plants for studying the molecular mechanisms of drought tolerance. Transcriptomic and metabolomic analyses were performed to reveal the response mechanisms of H. ammodendron and H. persicum to a drought environment at the levels of transcription and physiological metabolism. The results showed that the morphological structures of H. ammodendron and H. persicum showed adaptability to drought stress. Under drought conditions, the peroxidase activity, abscisic acid content, auxin content, and gibberellin content of H. ammodendron increased, while the contents of proline and malondialdehyde decreased. The amino acid content of H. persicum was increased, while the contents of proline, malondialdehyde, auxin, and gibberellin were decreased. Under drought conditions, 12,233 and 17,953 differentially expressed genes (DEGs) were identified in H. ammodendron and H. persicum , respectively, including members of multiple transcription factor families such as FAR1, AP2/ERF, C2H2, bHLH, MYB, C2C2, and WRKY that were significantly up-regulated under drought stress. In the positive ion mode, 296 and 452 differential metabolites (DEMs) were identified in H. ammodendron and H. persicum, respectively; in the negative ion mode, 252 and 354 DEMs were identified, primarily in carbohydrate and lipid metabolism. A combined transcriptome and metabolome analysis showed that drought stress promoted the glycolysis/gluconeogenesis pathways of H. ammodendron and H. persicum and increased the expression of amino acid synthesis pathways, consistent with the physiological results. In addition, transcriptome and metabolome were jointly used to analyze the expression changes of the genes/metabolites of H. ammodendron and H. persicum that were associated with drought tolerance but were regulated differently in the two plants. This study identified drought-tolerance genes and metabolites in H. ammodendron and H. persicum and has provided new ideas for studying the drought stress response of Haloxylon.
PMID: 36330247
Front Plant Sci , IF:5.753 , 2022 , V13 : P1018272 doi: 10.3389/fpls.2022.1018272
Defense mechanisms promoting tolerance to aggressive Phytophthora species in hybrid poplar.
Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Phytophthora Research Centre, Mendel University in Brno, Brno, Czechia.; Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Phytophthora Research Centre, Mendel University in Brno, Brno, Czechia.; Department of Forestry, University of Belgrade-Faculty of Forestry, Belgrade, Serbia.; Department of Phytology, Technical University in Zvolen, Zvolen, Slovakia.
Poplars are among the fastest-growing trees and significant resources in agriculture and forestry. However, rapid growth requires a large water consumption, and irrigation water provides a natural means for pathogen spread. That includes members of Phytophthora spp. that have proven to be a global enemy to forests. With the known adaptability to new hosts, it is only a matter of time for more aggressive Phytophthora species to become a threat to poplar forests and plantations. Here, the effects of artificial inoculation with two different representatives of aggressive species (P. cactorum and P. plurivora) were analyzed in the proteome of the Phytophthora-tolerant hybrid poplar clone T-14 [Populus tremula L. 70 x (Populus x canescens (Ait.) Sm. 23)]. Wood microcore samples were collected at the active necrosis borders to provide insight into the molecular processes underlying the observed tolerance to Phytophthora. The analysis revealed the impact of Phytophthora on poplar primary and secondary metabolism, including carbohydrate-active enzymes, amino acid biosynthesis, phenolic metabolism, and lipid metabolism, all of which were confirmed by consecutive metabolome and lipidome profiling. Modulations of enzymes indicating systemic response were confirmed by the analysis of leaf proteome, and sampling of wood microcores in distal locations revealed proteins with abundance correlating with proximity to the infection, including germin-like proteins, components of proteosynthesis, glutamate carboxypeptidase, and an enzyme that likely promotes anthocyanin stability. Finally, the identified Phytophthora-responsive proteins were compared to those previously found in trees with compromised defense against Phytophthora, namely, Quercus spp. and Castanea sativa. That provided a subset of candidate markers of Phytophthora tolerance, including certain ribosomal proteins, auxin metabolism enzymes, dioxygenases, polyphenol oxidases, trehalose-phosphate synthase, mannose-1-phosphate guanylyltransferase, and rhamnose biosynthetic enzymes. In summary, this analysis provided the first insight into the molecular mechanisms of hybrid poplar defense against Phytophthora and identified prospective targets for improving Phytophthora tolerance in trees.
PMID: 36325556
Front Plant Sci , IF:5.753 , 2022 , V13 : P1009895 doi: 10.3389/fpls.2022.1009895
The Arabidopsis ATP-Binding Cassette E protein ABCE2 is a conserved component of the translation machinery.
Instituto de Bioingenieria, Universidad Miguel Hernandez, Elche, Spain.; Area de Genetica, Universidad Miguel Hernandez, Alicante, Spain.; Centro Nacional de Biotecnologia, CNB-CSIC, Madrid, Spain.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umea, Sweden.
ATP-Binding Cassette E (ABCE) proteins dissociate cytoplasmic ribosomes after translation terminates, and contribute to ribosome recycling, thus linking translation termination to initiation. This function has been demonstrated to be essential in animals, fungi, and archaea, but remains unexplored in plants. In most species, ABCE is encoded by a single-copy gene; by contrast, Arabidopsis thaliana has two ABCE paralogs, of which ABCE2 seems to conserve the ancestral function. We isolated apiculata7-1 (api7-1), the first viable, hypomorphic allele of ABCE2, which has a pleiotropic morphological phenotype reminiscent of mutations affecting ribosome biogenesis factors and ribosomal proteins. We also studied api7-2, a null, recessive lethal allele of ABCE2. Co-immunoprecipitation experiments showed that ABCE2 physically interacts with components of the translation machinery. An RNA-seq study of the api7-1 mutant showed increased responses to iron and sulfur starvation. We also found increased transcript levels of genes related to auxin signaling and metabolism. Our results support for the first time a conserved role for ABCE proteins in translation in plants, as previously shown for the animal, fungal, and archaeal lineages. In Arabidopsis, the ABCE2 protein seems important for general growth and vascular development, likely due to an indirect effect through auxin metabolism.
PMID: 36325553
Front Plant Sci , IF:5.753 , 2022 , V13 : P995913 doi: 10.3389/fpls.2022.995913
Transcriptome analysis of Harumi tangor fruits: Insights into interstock-mediated fruit quality.
College of Horticulture, Sichuan Agricultural University, Chengdu, China.; Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu, China.
Harumi tangor fruit with Ponkan as an interstock contains significantly higher levels of total soluble solids compared to Harumi tangor fruit cv.with no interstock. Transcriptome analysis of two graft combinations (Harumi/Hongjv (HP) and cv. cv.Harumi/Ponkan/Hongjv (HPP)) was conducted to identify the genes related to use of the Ponkan interstock. Soluble sugars and organic acids were also measured in the two graft combinations. The results showed that the contents of sucrose, glucose, and fructose were higher in the fruits of HPP than in those of HP; additionally, the titratable acid levels were lower in grafts with interstocks than in grafts without interstocks. Transcriptome analysis of HPP and HP citrus revealed that the interstock regulated auxin and ethylene signals, sugar and energy metabolism, and cell wall metabolism. Trend and Venn analyses suggested that genes related to carbohydrate-, energy-, and hormone-metabolic activities were more abundant in HPP plants than in HP plants during different periods. Moreover, weighted gene co-expression network analysis demonstrated that carbohydrates, hormones, cell wall, and transcription factors may be critical for interstock-mediated citrus fruit development and ripening. The contents of ethylene, auxin, cytokinin, transcription factors, starch, sucrose, glucose, fructose, and total sugar in HPP plants differed considerably than those in HP fruits. Interstocks may help to regulate the early ripening and quality of citrus fruit through the above-mentioned pathways. These findings provide information on the effects of interstock on plant growth and development.
PMID: 36311145
Front Plant Sci , IF:5.753 , 2022 , V13 : P1043099 doi: 10.3389/fpls.2022.1043099
Transcriptome mining of hormonal and floral integrators in the leafless flowers of three cymbidium orchids.
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou, China.; College of Life Sciences, Fujian Normal University, Fuzhou, China.
Flowering is the most studied ornamental trait in orchids where long vegetative phase may span up to three years. Cymbidium orchids produce beautiful flowers with astonishing shapes and pleasant scent. However, an unusually long vegetative phase is a major drawback to their ornamental value. We observed that under certain culture conditions, three cymbidium species (Cymbidium ensifolium, C. goeringii and C. sinense) skipped vegetative growth phase and directly flowered within six months, that could be a breakthrough for future orchids with limited vegetative growth. Hormonal and floral regulators could be the key factors arresting vegetative phase. Therefore, transcriptomic analyses were performed for leafless flowers and normal vegetative leaves to ascertain differentially expressed genes (DEGs) related to hormones (auxin, cytokinin, gibberellin, abscisic acid and ethylene), floral integrators and MADS-box genes. A significant difference of cytokinin and floral regulators was observed among three species as compared to other hormones. The MADS-box genes were significantly expressed in the leafless flowers of C. sinense as compared to other species. Among the key floral regulators, CONSTANS and AGAMOUS-like genes showed the most differential expression in the leafless flowers as compared to leaves where the expression was negligible. However, CONSTANS also showed downregulation. Auxin efflux carriers were mainly downregulated in the leafless flowers of C. ensifolium and C. sinense, while they were upregulated in C. goeringii. Moreover, gibberellin and cytokinin genes were also downregulated in C. ensifolium and C. sinense flowers, while they were upregulated in C. goeringii, suggesting that species may vary in their responses. The data mining thus, outsources the valuable information to direct future research on orchids at industrial levels.
PMID: 36311107
Front Plant Sci , IF:5.753 , 2022 , V13 : P973471 doi: 10.3389/fpls.2022.973471
Screening of protonstatin-1 (PS-1) analogs for improved inhibitors of plant plasma membrane H(+)-ATPase activity.
College of Biological Sciences, China Agricultural University, Beijing, China.; Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
We previously identified protonstatin-1 (PS-1) as a selective inhibitor of plasma membrane H(+)-ATPase (PM H(+)-ATPase) activity and used it as a tool to validate the chemiosmotic model for polar auxin transport. Here, to obtain compounds with higher affinity than PS-1 for PM H(+)-ATPase, we synthesized 34 PS-1 analogs and examined their ability to inhibit PM H(+)-ATPase activity. The 34 analogs showed varying inhibitory effects on the activity of this enzyme. The strongest effect was observed for the small molecule PS-2, which was approximately five times stronger than PS-1. Compared to PS-1, PS-2 was also a stronger inhibitor of auxin uptake as well as acropetal and basipetal polar auxin transport in Arabidopsis thaliana seedlings. Because PS-2 is a more potent inhibitor of PM H(+)-ATPase than PS-1, we believe that this compound could be used as a tool to study the functions of this key plant enzyme.
PMID: 36311099
Front Plant Sci , IF:5.753 , 2022 , V13 : P932008 doi: 10.3389/fpls.2022.932008
IPT9, a cis-zeatin cytokinin biosynthesis gene, promotes root growth.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umea, Sweden.; Plant Sciences Core Facility, Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), and NCBR, Faculty of Science, Masaryk University, Brno, Czechia.; Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czechia.; Laboratory of Growth Regulators, Faculty of Science, Palacky University, Olomouc, Czechia.; Department of Life Sciences, Imperial College London, London, United Kingdom.; Department of Chemical Biology, Faculty of Science, Palacky University, Olomouc, Czechia.
Cytokinin and auxin are plant hormones that coordinate many aspects of plant development. Their interactions in plant underground growth are well established, occurring at the levels of metabolism, signaling, and transport. Unlike many plant hormone classes, cytokinins are represented by more than one active molecule. Multiple mutant lines, blocking specific parts of cytokinin biosynthetic pathways, have enabled research in plants with deficiencies in specific cytokinin-types. While most of these mutants have confirmed the impeding effect of cytokinin on root growth, the ipt29 double mutant instead surprisingly exhibits reduced primary root length compared to the wild type. This mutant is impaired in cis-zeatin (cZ) production, a cytokinin-type that had been considered inactive in the past. Here we have further investigated the intriguing ipt29 root phenotype, opposite to known cytokinin functions, and the (bio)activity of cZ. Our data suggest that despite the ipt29 short-root phenotype, cZ application has a negative impact on primary root growth and can activate a cytokinin response in the stele. Grafting experiments revealed that the root phenotype of ipt29 depends mainly on local signaling which does not relate directly to cytokinin levels. Notably, ipt29 displayed increased auxin levels in the root tissue. Moreover, analyses of the differential contributions of ipt2 and ipt9 to the ipt29 short-root phenotype demonstrated that, despite its deficiency on cZ levels, ipt2 does not show any root phenotype or auxin homeostasis variation, while ipt9 mutants were indistinguishable from ipt29. We conclude that IPT9 functions may go beyond cZ biosynthesis, directly or indirectly, implicating effects on auxin homeostasis and therefore influencing plant growth.
PMID: 36311087
Front Plant Sci , IF:5.753 , 2022 , V13 : P1005077 doi: 10.3389/fpls.2022.1005077
Histone methyltransferases SDG33 and SDG34 regulate organ-specific nitrogen responses in tomato.
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States.; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, United States.; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States.
Histone posttranslational modifications shape the chromatin landscape of the plant genome and affect gene expression in response to developmental and environmental cues. To date, the role of histone modifications in regulating plant responses to environmental nutrient availability, especially in agriculturally important species, remains largely unknown. We describe the functions of two histone lysine methyltransferases, SET Domain Group 33 (SDG33) and SDG34, in mediating nitrogen (N) responses of shoots and roots in tomato. By comparing the transcriptomes of CRISPR edited tomato lines sdg33 and sdg34 with wild-type plants under N-supplied and N-starved conditions, we uncovered that SDG33 and SDG34 regulate overlapping yet distinct downstream gene targets. In response to N level changes, both SDG33 and SDG34 mediate gene regulation in an organ-specific manner: in roots, SDG33 and SDG34 regulate a gene network including Nitrate Transporter 1.1 (NRT1.1) and Small Auxin Up-regulated RNA (SAUR) genes. In agreement with this, mutations in sdg33 or sdg34 abolish the root growth response triggered by an N-supply; In shoots, SDG33 and SDG34 affect the expression of photosynthesis genes and photosynthetic parameters in response to N. Our analysis thus revealed that SDG33 and SDG34 regulate N-responsive gene expression and physiological changes in an organ-specific manner, thus presenting previously unknown candidate genes as targets for selection and engineering to improve N uptake and usage in crop plants.
PMID: 36311072
Front Plant Sci , IF:5.753 , 2022 , V13 : P958816 doi: 10.3389/fpls.2022.958816
Genome-wide identification of the auxin response factor (ARF) gene family in Magnolia sieboldii and functional analysis of MsARF5.
Department of Forestry, Shenyang Agricultural University, Shenyang, China.; Biotechnology and Analysis Test Center, Liaoning Academy of Forest Science, Shenyang, China.
Auxin plays an essential role in flowering, embryonic development, seed dormancy, and germination. Auxin response factors (ARFs) are plant-specific key transcriptional factors in mediating the gene expression network of auxin signaling. Although ARFs in model plants such as Arabidopsis had been well characterized, their identities and potential roles in non-model plants are less studied. Here, we performed genome-wide identification of ARFs in Magnolia sieboldii K. Koch, a primitive species with high taxonomic importance and medicinal values. We found 25 ARF genes in M. sieboldii, which were widely distributed across multiple chromosomes. Based on sequence similarity, the encoded proteins could be either transcriptional repressors or activators. Gene expression analysis showed a dynamic pattern for many ARFs including MsARF5 during seed germination. In addition, overexpressing of MsARF5 showed that it restores many developmental defects in the Arabidopsis mutant. Moreover, two phenotypically distinct transgenic Arabidopsis lines were obtained, indicating a link between gene expression levels and developmental phenotypes. Taken together, we provided a systematic investigation of the ARF gene family in M. sieboldii and revealed an important role of MsARF5 in mediating auxin signaling.
PMID: 36275560
Front Plant Sci , IF:5.753 , 2022 , V13 : P964003 doi: 10.3389/fpls.2022.964003
A high trans-zeatin nucleoside concentration in corms may promote the multileaf growth of Amorphophallus muelleri.
Yunnan Urban Agricultural Engineering and Technological Research Center, College of Agronomy, Kunming University, Kunming, China.
Amorphophallus muelleri has a multileaf growth pattern different from that of other konjacs; however, the hormonal mechanism underlying this phenomenon is not clear. In this study, the levels of hormones closely related to the sprouting of the axillary bud, including five types of cytokinins, indole-3-acetic acid (IAA) and abscisic acid (ABA) were measured. In the second leaf sprouting stage, the content of trans-zeatin riboside (tZR) in corms increased more than 5000-fold over that in the dormancy period. Surprisingly, although the expression of CYP735A1 and CYP735A2, which synthesize the precursors for tZR was elevated at the second leaf sprouting stage, the expression of IPTs, which have key roles in cytokinin biosynthesis, did not change significantly. In addition, most cytokinin contents in leaves during the same period were significantly lower than those in corms. We speculate that the high cytokinin contents in the corms may not biosynthesized de novo in corms. In addition, the IAA content in the corms also considerably increased during the second leaf sprouting stage. Indole-3-acetaldehyde oxidase (AO1) and auxin efflux carrier PIN1A, presented relatively high expression levels in the same period. In contrast, ABA content, and the expression of NCED1, a rate-limiting enzyme in ABA biosynthesis, were suppressed at the second leaf sprouting stage. It is worth mentioning that N6-(Delta2-isopentenyl) adenosine (iP)-type cytokinins have a high content in corms in the dormant period that significantly decreases after the first leaf sprouting stage, which is completely different from the trend of tZR. By treating dormant corms with iP, the percentage of multibud plants increased, and the growth performance in terms of bud and root length was significantly higher than those of the control. This implies that iP-type cytokinins tend to play a role in promoting first seedling sprouting. Furthermore, there was a remarkable increase of the IAA content in both corms and roots under iP treatment but an inhibitory effect in buds. We speculate that the increase in the IAA content induced by iP is tissue specific. These results will assist in the understanding of the role of hormones, especially cytokinins, in the multileaf growth type of konjac.
PMID: 36275554
Front Plant Sci , IF:5.753 , 2022 , V13 : P979883 doi: 10.3389/fpls.2022.979883
Bacillus amyloliquefaciens GB03 augmented tall fescue growth by regulating phytohormone and nutrient homeostasis under nitrogen deficiency.
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou, China.; Guizhou Institute of Prataculture, Guizhou Academy of Agricultural Sciences, Guiyang, China.; School of Life Sciences, Guizhou Normal University, Guiyang, China.; State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Nitrogen is an important nutrient for plant growth and development. Soil microorganisms have been used to curb the imbalance between the limited content of natural environmental nitrogen and the pollution caused by increasing nitrogen fertilizer use in ecologically fragile areas. Bacillus amyloliquefaciens GB03 has been shown to confer growth promotion and abiotic stress tolerance in Arabidopsis thaliana. This study provided a new insight into the role of the plant growth-promoting rhizobacterium B. amyloliquefaciens GB03 as an initiator of defense against nitrogen deficiency in non-leguminous grass tall fescue (Festuca arundinacea). Two-week-old seedlings of tall fescue were grown with or without GB03 for 4 weeks under total nitrogen (3.75 mM NO(3) (-)) or low nitrogen (0.25 mM NO(3) (-)) treatment. Growth parameters, chlorophyll content, endogenous total nitrogen, total phosphorus content, and phytohormone content, including those of auxin indole-3-acetic acid, cytokinin, gibberellic acid, and abscisic acid, were determined at the time of harvest. Tall fescue grown in GB03-inoculated soil was more robust than the non-inoculated controls with respect to plant height, root length, plant biomass, chlorophyll concentration, and nutrient (total nitrogen and total phosphorus) contents under total nitrogen treatment. GB03 increased indole acetic acid content by 24.7%, whereas decreased cytokinin and abscisic acid contents by 28.4% and 26.9%, respectively, under a total nitrogen level. Remarkably, GB03 increased indole acetic acid content by more than 80% and inhibited abscisic acid production by nearly 70% under a low nitrogen level. These results showed, for the first time, that GB03 played a crucial role in mediating NO(3) (-)dependent regulation of tall fescue growth and development, especially revealing the mechanism of soil bacteria improve resistance to nitrogen deficiency stress in non-nitrogen-fixing species.
PMID: 36275534
Front Plant Sci , IF:5.753 , 2022 , V13 : P995815 doi: 10.3389/fpls.2022.995815
Morphological characterization and transcriptome analysis of leaf angle mutant bhlh112 in maize [Zea mays L.].
College of Agronomy, Gansu Agricultural University, Lanzhou, China.; Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, China.; Gansu Key Laboratory of Crop Improvement & Germplasm Enhancement, Gansu Agricultural University, Lanzhou, China.
Leaf angle is an important agronomic trait in maize [Zea mays L.]. The compact plant phenotype, with a smaller leaf angle, is suited for high-density planting and thus for increasing crop yields. Here, we studied the ethyl methane sulfonate (EMS)-induced mutant bhlh112. Leaf angle and plant height were significantly decreased in bhlh112 compared to the wild-type plants. After treatment of seedlings with exogenous IAA and ABA respectively, under the optimal concentration of exogenous hormones, the variation of leaf angle of the mutant was more obvious than that of the wild-type, which indicated that the mutant was more sensitive to exogenous hormones. Transcriptome analysis showed that the ZmbHLH112 gene was related to the biosynthesis of auxin and brassinosteroids, and involved in the activation of genes related to the auxin and brassinosteroid signal pathways as well as cell elongation. Among the GO enrichment terms, we found many differentially expressed genes (DEGs) enriched in the cell membrane and ribosomal biosynthesis, hormone biosynthesis and signaling pathways, and flavonoid biosynthesis, which could influence cell growth and the level of endogenous hormones affecting leaf angle. Therefore, ZmbHLH112 might regulate leaf angle development through the auxin signaling and the brassinosteroid biosynthesis pathways. 12 genes related to the development of leaf were screened by WGCNA; In GO enrichment and KEGG pathways, the genes were mainly enriched in rRNA binding, ribosome biogenesis, Structural constituent of ribosome; Arabidopsis ribosome RNA methyltransferase CMAL is involved in plant development, likely by modulating auxin derived signaling pathways; The free 60s ribosomes and polysomes in the functional defective mutant rice minute-like1 (rml1) were significantly reduced, resulting in plant phenotypic diminution, narrow leaves, and growth retardation; Hence, ribosomal subunits may play an important role in leaf development. These results provide a foundation for further elucidation of the molecular mechanism of the regulation of leaf angle in maize.
PMID: 36275532
Front Plant Sci , IF:5.753 , 2022 , V13 : P998664 doi: 10.3389/fpls.2022.998664
Transcriptome characteristics during cell wall formation of endosperm cellularization and embryo differentiation in Arabidopsis.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Embryonic and endosperm development are important biological events during Arabidopsis seed development, and are controlled by dynamic changes in a range of gene expression. Nevertheless, the regulatory mechanisms of endosperm cellularization and embryo differentiation remain unclear. Here, we characterized the early embryo and endosperm development of the naa15 mutant that had abnormal embryo differentiation and incomplete endosperm cellularization compared to WT of Arabidopsis, and comparatively investigated the changes of gene expressions in WT seeds at 3, 4, and 5 days after pollination (3W, 4W, and 5W) and the white homozygous aborted naa15 seeds at 5, 6, and 7 DAP (5M, 6M, and 7M) from naa15-1/+ siliques using RNA sequencing and qPCR assays. The transcriptome analyses showed that there were 2040 and 3630 differentially expressed genes (DEGs) in 4W (at endosperm cellularization initiation stage and heart embryo stage) vs 3W (at syncytium stage and globular embryo stage), and 5W (at end of endosperm cellularization stage and torpedo embryo stage) vs 4W, respectively. The KEGG and GO analyses showed that lipid metabolic processes and transmembrane transport related to cell wall biogenesis, cell division and differentiation, the plant hormone signaling pathway, photosynthesis, and transcription regulator activity were evidently enriched in WT and naa15. The heatmap and qPCR analyses showed that auxin response genes (ARFs), auxin transport genes (PINs) cytokinin synthesis genes (LOGs), cytokinin dehydrogenase genes (CKXs), cytokinin receptor, transcription factors (MYB, bHLH, MADS-box, and ERF) were significantly downregulated in naa15 compared to WT. A series of cell wall genes annotated to xyloglucan endotransglycosylase/hydrolase, pectin methyl esterase, and pectin methyl esterase inhibitor were also identified in these DEGs. Moreover, using an immunofluorescent assay, the features of cell walls displayed that cellulose fluorescence signals in the embryo and endosperm of naa15 were significantly decreased, and the signals of low- and high- methyl esterification of pectin were also obviously decreased in the endosperm of naa15. In summary, we identified a large number of DEGs and investigated the features of cell walls during endosperm cellularization and embryonic differentiation, which provided important information on transcription and gene expression to reveal their regulatory mechanisms.
PMID: 36262665
Front Plant Sci , IF:5.753 , 2022 , V13 : P979033 doi: 10.3389/fpls.2022.979033
OsARF4 regulates leaf inclination via auxin and brassinosteroid pathways in rice.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.; Hainan Yazhou Bay Seed Laboratory, Sanya, China.; Key Laboratory of Herbage and Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage and Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot, China.
Leaf inclination is a vital agronomic trait and is important for plant architecture that affects photosynthetic efficiency and grain yield. To understand the molecular mechanisms underlying regulation of leaf inclination, we constructed an auxin response factor (arf) rice mutant-osarf4-showing increased leaf inclination using CRISPR/Cas9 gene editing technology. OsARF4 encodes a nuclear protein that is expressed in the lamina joint (LJ) at different developmental stages in rice. Histological analysis indicated that an increase in cell differentiation on the adaxial side resulted in increased leaf inclination in the osarf4 mutants; however, OsARF4-overexpressing lines showed a decrease in leaf inclination, resulting in erect leaves. Additionally, a decrease in the content and distribution of indole-3-acetic acid (IAA) in osarf4 mutant led to a greater leaf inclination, whereas the OsARF4-overexpressing lines showed the opposite phenotype with increased IAA content. RNA-sequencing analysis revealed that the expression of genes related to brassinosteroid (BR) biosynthesis and response was different in the mutants and overexpressing lines, suggesting that OsARF4 participates in the BR signaling pathway. Moreover, BR sensitivity assay revealed that OsARF4-overexpressing lines were more sensitive to exogenous BR treatment than the mutants. In conclusion, OsARF4, a transcription factor in auxin signaling, participates in leaf inclination regulation and links auxin and BR signaling pathways. Our results provide a novel insight into l leaf inclination regulation, and have significant implications for improving rice architecture and grain yield.
PMID: 36247537
Theor Appl Genet , IF:5.699 , 2022 Oct 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
Theor Appl Genet , IF:5.699 , 2022 Oct , V135 (10) : P3611-3628 doi: 10.1007/s00122-022-04205-w
Genetic dissection of morphological variation in rosette leaves and leafy heads in cabbage (Brassica oleracea var. capitata).
Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, The Netherlands.; Centre for Crop Systems Analysis, Wageningen University and Research, PO Box 430, 6700 AK, Wageningen, The Netherlands.; Biometris, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, The Netherlands.; Plant Breeding, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, The Netherlands. guusje.bonnema@wur.nl.
Correlations between morphological traits of cabbage rosette leaves and heads were found. Genome-wide association studies of these traits identified 50 robust quantitative trait loci in multiple years. Half of these loci affect both organs. Cabbage (Brassica oleracea var. capitata) is an economically important vegetable crop cultivated worldwide. Cabbage plants go through four vegetative stages: seedling, rosette, folding and heading. Rosette leaves are the largest leaves of cabbage plants and provide most of the energy needed to produce the leafy head. To understand the relationship and the genetic basis of leaf development and leafy head formation, 308 cabbage accessions were scored for rosette leaf and head traits in three-year field trials. Significant correlations were found between morphological traits of rosette leaves and heads, namely leaf area with the head area, height and width, and leaf width with the head area and head height, when heads were harvested at a fixed number of days after sowing. Fifty robust quantitative trait loci (QTLs) for rosette leaf and head traits distributed over all nine chromosomes were identified with genome-wide association studies. All these 50 loci were identified in multiple years and generally affect multiple traits. Twenty-five of the QTL were associated with both rosette leaf and leafy head traits. We discuss thirteen candidate genes identified in these QTL that are expressed in heading leaves, with an annotation related to auxin and other phytohormones, leaf development, and leaf polarity that likely play a role in leafy head development or rosette leaf expansion.
PMID: 36057748
Theor Appl Genet , IF:5.699 , 2022 Oct , V135 (10) : P3497-3510 doi: 10.1007/s00122-022-04196-8
Integrated genetic mapping and transcriptome analysis reveal the BnaA03.IAA7 protein regulates plant architecture and gibberellin signaling in Brassica napus L.
College of Agronomy and Biotechnology, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing, 400715, China.; Biotechnology Research Center, Southwest University, Chongqing, 400715, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, 430070, China.; College of Agronomy and Biotechnology, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing, 400715, China. liezhao@swu.edu.cn.
A novel mutation in the BnaA03.IAA7 protein reduces plant height and enhances gibberellin signaling in Brassica napus L. Rapeseed (Brassica napus) is an excellent and important source for vegetable oil production, but its production is severely affected by lodging. Lodging hinders mechanization and decreases yield, and an ideal solution is semidwarf breeding. Limited by germplasm resources, semidwarf breeding developed slowly in rapeseed. In the current study, a mutant called sdA03 was isolated from EMS-mutagenized lines of Zhongshuang 11 (ZS11). The inheritance analysis showed that phenotypes of sdA03 were controlled by a single semidominant gene. Genetic mapping, RNA-seq and candidate gene analysis identified BnaA03.IAA7 as a candidate gene, and a function test confirmed that the mutated BnaA03.iaa7 regulates plant architecture in a dose-dependent manner. Yeast two-hybrid and transient expression experiments illustrated the P87L substitution in the GWPPV/I degron motif of BnaA03.iaa7 impaired the interaction between BnaA03.IAA7 and TIR1 proteins, and BnaA03.iaa7 prevented ARF from activating the auxin signaling pathway.The gibberellin (GA) content was higher in sdA03 hypocotyls than in those of ZS11. Further expression analysis showed more active gibberellin signaling in hypocotyl and richer expression of GA synthetic genes in root and cotyledon of sdA03 seedlings. Finally, a marker was developed based on the SNP found in BnaA03.iaa7 and used in molecular breeding. The study enriched our understanding of the architectural regulation of rapeseed and provided germplasm resources for breeding.
PMID: 35962210
Front Microbiol , IF:5.64 , 2022 , V13 : P996054 doi: 10.3389/fmicb.2022.996054
A novel PGPF Penicillium olsonii isolated from the rhizosphere of Aeluropus littoralis promotes plant growth, enhances salt stress tolerance, and reduces chemical fertilizers inputs in hydroponic system.
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.; Department of Plant Production, College of Food and Agricultural Science, King Saud University, Riyadh, Saudi Arabia.; Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Sciences of Sfax, University of Sfax, Sfax, Tunisia.; Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia.
The hydroponic farming significantly enhances the yield and enables multiple cropping per year. These advantages can be improved by using plant growth-promoting fungi (PGPF) either under normal or stress conditions. In this study, the fungal strain (A3) isolated from the rhizosphere of the halophyte plant Aeluropus littoralis was identified as Penicillium olsonii based on sequence homology of its ITS region. The A3 fungus was shown to be halotolerant (up to 1 M NaCl) and its optimal growth was at 27 degrees C, but inhibited at 40 degrees C. In liquid culture medium, the A3 produced indole acetic acid (IAA) especially in the presence of L-tryptophan. Tobacco plants grown under hydroponic farming system were used to evaluate the promoting activity of the direct effect of A3 mycelium (DE) and the indirect effect (IDE) of its cell-free culture filtrate (A3CFF). The results showed that for the two conditions (DE or IDE) the tobacco seedlings exhibited significant increase in their height, leaf area, dry weight, and total chlorophyll content. Interestingly, the A3CFF (added to the MS liquid medium or to nutrient solution (NS), prepared from commercial fertilizers) induced significantly the growth parameters, the proline concentration, the catalase (CAT) and the superoxide dismutase (SOD) activities of tobacco plants. The A3CFF maintained its activity even after extended storage at 4 degrees C for 1 year. Since the A3 is a halotolerant fungus, we tested its ability to alleviate salt stress effects. Indeed, when added at 1:50 dilution factor to NS in the presence of 250 mM NaCl, the A3CFF enhanced the plant salt tolerance by increasing the levels of total chlorophyll, proline, CAT, and SOD activities. In addition, the treated plants accumulated less Na(+) in their roots but more K(+) in their leaves. The A3CFF was also found to induce the expression of five salt stress related genes (NtSOS1, NtNHX1, NtHKT1, NtSOD, and NtCAT1). Finally, we proved that the A3CFF can reduce by half the chemical fertilizers inputs. Indeed, the tobacco plants grown in a hydroponic system using 0.5xNS supplemented with A3CFF (1:50) exhibited significantly higher growth than those grown in 0.5xNS or 1xNS. In an attempt to explain this mechanism, the expression profile of some growth related genes (nitrogen metabolism (NR1, NRT1), auxin (TRYP1, YUCCA6-like), and brassinosteroid (DET2, DWF4) biosynthesis) was performed. The results showed that all these genes were up-regulated following plant treatment with A3CFF. In summary the results revealed that the halotolerant fungus P. olsonii can stimulates tobacco plant growth, enhances its salt tolerance, and reduces by half the required chemical fertilizer inputs in a hydroponic farming system.
PMID: 36386667
FEBS J , IF:5.542 , 2022 Oct , V289 (20) : P6172-6186 doi: 10.1111/febs.16132
Meet your MAKR: the membrane-associated kinase regulator protein family in the regulation of plant development.
Department of Plant Molecular Biology, Biophore Building, University of Lausanne, Lausanne, Switzerland.; Institute of Cytology and Genetics, Novosibirsk, Russian Federation.; Novosibirsk State University, Novosibirsk, Russian Federation.; Department of Plant Systems Physiology, Institute for Water and Wetland Research, Faculty of Science, Radboud University, Nijmegen, The Netherlands.; Laboratoire Reproduction et Developpement des Plantes, CNRS, INRAE, Universite de Lyon, Ecole normale superieure de Lyon, Universite Claude Bernard Lyon 1, Lyon, France.
A small family composed of BRI1 KINASE INHIBITOR1 (BKI1) and MEMBRANE-ASSOCIATED KINASE REGULATORS (MAKRs) has recently captured the attention of plant biologists, due to their involvement in developmental processes downstream of hormones and Receptor-Like Kinases (RLK) signalling. BKI1/MAKRs are intrinsically disordered proteins (so-called unstructured proteins) and as such lack specific domains. Instead, they are defined by the presence of two conserved linear motifs involved in the interaction with lipids and proteins, respectively. Here, we first relate the discovery of the MAKR gene family. Then, we review the individual function of characterized family members and discuss their shared and specific modes of action. Finally, we explore and summarize the structural, comparative and functional genomics data available on this gene family. Together, this review aims at building a comprehensive reference about BKI1/MAKR protein function in plants.
PMID: 34288456
iScience , IF:5.458 , 2022 Oct , V25 (10) : P105062 doi: 10.1016/j.isci.2022.105062
PIN-FORMED1 polarity in the plant shoot epidermis is insensitive to the polarity of neighboring cells.
School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia.; European Molecular Biology Laboratory, Heidelberg 69117, Germany.
At the Arabidopsis shoot apex, epidermal cells are planar-polarized along an axis marked by the asymmetric localization patterns of several proteins including PIN-FORMED1 (PIN1), which facilitates the directional efflux of the plant hormone auxin to pattern phyllotaxis. While PIN1 polarity is known to be regulated non-cell autonomously via the MONOPTEROS (MP) transcription factor, how this occurs has not been determined. Here, we use mosaic expression of the serine threonine kinase PINOID (PID) to test whether PIN1 polarizes according to the polarity of neighboring cells. Our findings reveal that PIN1 is insensitive to the polarity of PIN1 in neighboring cells arguing against auxin flux or extracellular auxin concentrations acting as a polarity cue, in contrast to previous model proposals.
PMID: 36157591
J Cell Sci , IF:5.285 , 2022 Oct , V135 (19) doi: 10.1242/jcs.260127
Defects in division plane positioning in the root meristematic zone affect cell organization in the differentiation zone.
Graduate Group in Biochemistry and Molecular Biology.; Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521, USA.
Cell-division-plane orientation is critical for plant and animal development and growth. TANGLED1 (TAN1) and AUXIN-INDUCED IN ROOT CULTURES 9 (AIR9) are division-site-localized microtubule-binding proteins required for division-plane positioning. The single mutants tan1 and air9 of Arabidopsis thaliana have minor or no noticeable phenotypes, but the tan1 air9 double mutant has synthetic phenotypes including stunted growth, misoriented divisions and aberrant cell-file rotation in the root differentiation zone. These data suggest that TAN1 plays a role in non-dividing cells. To determine whether TAN1 is required in elongating and differentiating cells in the tan1 air9 double mutant, we limited its expression to actively dividing cells using the G2/M-specific promoter of the syntaxin KNOLLE (pKN:TAN1-YFP). Unexpectedly, in addition to rescuing division-plane defects, expression of pKN:TAN1-YFP rescued root growth and cell file rotation defects in the root-differentiation zone in tan1 air9 double mutants. This suggests that defects that occur in the meristematic zone later affect the organization of elongating and differentiating cells.
PMID: 36074053
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 Oct doi: 10.1093/pcp/pcac153
High Expression of ALTERNATIVE OXIDASE 2 in Latent Axillary Buds Suggests Its Key Role in Quiescence Maintenance in Rosebush.
University of Angers, Institut Agro Rennes-Angers, INRAE, IRHS, SFR QUASAV, Angers F-49000, France.
Most vegetative axes remain quiescent as dormant axillary buds until metabolic and hormonal signals, driven by environmental changes, trigger bud outgrowth. While the resumption of growth activity is well documented, the establishment and maintenance of quiescence is comparatively poorly understood, despite its major importance in the adaptation of plants to the seasonal cycle or in the establishment of their shape. Here, using the rosebush Rosa hybrida 'Radrazz' as plant model, we highlighted that the quiescent state was the consequence of an internal and active energy control of buds, under the influence of hormonal factors previously identified in the bud outgrowth process. We found that the quiescent state in the non-growing vegetative axis of dormant axillary buds displayed a low energy state along with a high expression of the ALTERNATIVE OXIDASE 2 (AOX2) and the accumulation of the corresponding protein. Conversely, AOX2 expression and protein amount strongly decreased during bud burst as energy status shifted to a high state, allowing growth. Since AOX2 can deviate electrons from the cytochrome pathway in the mitochondrial respiratory chain, it could drastically reduce the formation of ATP, which would result in a low energy status unfavorable for growth activities. We provided evidence that the presence/absence of AOX2 in quiescent/growing vegetative axes of buds was under hormonal control, and thus may constitute the mechanistic basis of both quiescence and sink strength manifestation, two important aspects of bud-break.
PMID: 36287074
Plant Cell Physiol , IF:4.927 , 2022 Oct doi: 10.1093/pcp/pcac150
Silicon Palliates Chromium Toxicity through the Formation of Root Hairs in Rice (Oryza Sativa) Mediated by GSH and IAA.
Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida-201313, India.; Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004 UP, India.; Department of Biology, Saint Joseph's University, University City Campus, 600 S. 43rd St., Philadelphia, PA 19104, USA.; Department of Biochemistry and Cell and Molecular Biology of Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas (CSIC), Profesor Albareda 1, 18008, Granada, Spain.; Plant Physiology Laboratory, Department of Botany, C.M.P. Degree College, A Constituent Post Graduate College of University of Allahabad, Prayagraj 211002, India.
Along with the rapidly increasing environmental contamination by heavy metals, the exposure of plants to chromium has also magnified, resulting in a declined productivity. Hexavalent chromium [Cr(VI)], the most toxic form of Cr, brings about changes in plant processes at morpho-physiological and biochemical levels. However, silicon (Si) is known to mitigate the impact of abiotic stresses in plants. Here, we demonstrate Si-mediated alleviation of Cr(VI) toxicity and its effects on root hair formation in rice seedlings. Glutathione (GSH) and indole-3 acetic acid (IAA, an important auxin) were assessed for their involvement in root hair formation after the application of Si to Cr(VI)-stressed plants, and our results confirmed their crucial significance in such developmental process. The expression analysis of genes involved in GSH biosynthesis (OsGS2) and regeneration (OsGR1); and auxin biosynthesis (OsTAA1 and OsYUCCA1) and transport (OsAUX1 andOsPIN1) corroborated their positive role in Si-mediated root hair formation in Cr(VI) stressed rice seedlings. Moreover, the results indicated that nitric oxide (NO) seems a probable but not a fundamental component in Si-mediated formation of roots in rice during exposure to Cr(VI) stress. In this study, the indispensable role of GSH and IAA, and redox homeostasis of GSH, IAA biosynthesis and transport are discussed with regard to Si-mediated formation of root hairs in rice under Cr(VI) stress. The results of the study suggests Si as a protective agent against Cr(VI) stress in rice and the findings can be used to develop Cr(VI) stress-tolerant varieties of rice with enhanced productivity.
PMID: 36264202
Plant Cell Physiol , IF:4.927 , 2022 Oct doi: 10.1093/pcp/pcac146
Auxin-induced WUSCHEL-RELATED HOMEOBOX13 Mediates Asymmetric Activity of Callus Formation upon Cutting.
Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, Japan.; Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-8551, Japan.; Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-8551, Japan.; Division of Biological Sciences, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara 630-0192, Japan.; Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka, Yokohama 244-0813, Japan.; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230-0045, Japan.; Department of Biological Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 119-0033, Japan.
Plants have the regenerative ability to reconnect cut organs, which is physiologically important to survive severe tissue damage. The ability to reconnect organs is utilized as grafting to combine two different individuals. Callus formation at the graft junction facilitates organ attachment and vascular reconnection. While it is well documented that local wounding signals provoke callus formation, how callus formation is differentially regulated at each cut end remains elusive. Here, we report that callus formation activity is asymmetrical between the top and bottom cut ends, and is regulated by differential auxin accumulation. Gene expression analyses revealed that cellular auxin response is preferentially up-regulated in the top part of the graft. Disruption of polar auxin transport inhibited callus formation from the top while external application of auxin was sufficient to induce callus formation from the bottom, suggesting that asymmetric auxin accumulation is responsible for active callus formation from the top end. We further found that the expression of a key regulator of callus formation, WUSCHEL-RELATED HOMEOBOX 13 (WOX13) is induced by auxin. The ectopic callus formation from the bottom end, which is triggered by locally supplemented auxin, requires WOX13 function, demonstrating that WOX13 plays a pivotal role in auxin-dependent callus formation. The asymmetric WOX13 expression is observed both in grafted petioles and incised inflorescence stems, underscoring the generality of our findings. We propose that efficient organ reconnection is achieved by a combination of local wounding stimuli and disrupted long-distance signaling.
PMID: 36263676
Plant Cell Physiol , IF:4.927 , 2022 Oct doi: 10.1093/pcp/pcac149
Integration of auxin, brassinosteroid and cytokinin in the regulation of rice yield.
Department of Life Sciences, POSTECH Biotech Center, Pohang University of Science and Technology, Pohang, Korea.; Department of Botany, Hindu Girls College, Maharshi Dayanand University, Sonipat 131001, India.; Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang, Vietnam.; Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
Crop varieties with a high yield are most desirable in the present context of the ever-growing human population. Mostly the yield traits are governed by a complex of numerous molecular and genetic facets modulated by various quantitative trait loci (QTLs). With the identification and molecular characterizations of yield-associated QTLs over recent years, the central role of phytohormones in regulating plant yield is becoming more apparent. Most often, different groups of phytohormones work in close association to orchestrate yield attributes. Understanding this crosstalk would thus provide new venues for phytohormone pyramiding by editing a single gene or QTL(s) for yield improvement. Here, we review a few important findings to integrate the knowledge on the roles of auxin, brassinosteroid and cytokinin and how a single gene or a QTL could govern crosstalk among multiple phytohormones to determine the yield traits.
PMID: 36255097
Plant Cell Physiol , IF:4.927 , 2022 Oct doi: 10.1093/pcp/pcac142
Loss of MYB34 transcription factor supports backward evolution of indole glucosinolate biosynthesis in a subclade of Camelineae tribe and releases feedback loop in this pathway in Arabidopsis.
Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.; Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, 60-479 Poznan, Poland.; Department of General Botany, Institute of Experimental Biology, Adam Mickiewicz University, 61-614 Poznan, Poland.
Glucosinolates are specialized defensive metabolites characteristic for the Brassicales order. Among them aliphatic and indolic glucosinolates (IGs) are usually highly abundant in the species from Brassicaceae family. The exception from this trend is constituted by species representing a subclade of Camelineae tribe, including Capsella and Camelina genera, which have reduced capacity to produce and metabolize IGs. Our study addresses contribution of specific glucosinolate-related MYB transcription factors to this unprecedented backward evolution of IG biosynthesis. To this end we performed phylogenomic and functional studies of respective MYB proteins. Obtained results revealed weakened conservation of glucosinolate-related MYB transcription factors, including loss of functional MYB34 protein, in the investigated species. We showed that introduction of functional MYB34 from Arabidopsis thaliana partially restores IG biosynthesis in Capsella rubella indicating that loss of this transcription factor contributes to the backward evolution of this metabolic pathway. Finally, we performed analysis of the impact of particular myb mutations on the feedback loop in IG biosynthesis, which drives auxin overproduction, metabolic dysregulation and strong growth retardation caused by mutations in IG biosynthetic genes. This uncovered unique function of MYB34 among IG-related MYBs in this feedback regulation and consequently in IG conservation in Brassicaceae plants.
PMID: 36222356
Plant Cell Physiol , IF:4.927 , 2022 Oct doi: 10.1093/pcp/pcac138
Auxin crosstalk with reactive oxygen and nitrogen species in plant development and abiotic stress.
D D Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, India.; Crop Nanobiology and Molecular Stress Physiology Lab,Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida-201313.; Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, India.; Plant Physiology Laboratory, Department of Botany, CMP, Degree Collage, University of Allahabad, India.; Institute of Botany, Technische Universitat Dresden, 01062 Dresden, Germany.; Department of Biochemistry, Cell and Molecular Biology, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas (CSIC), C/Professor Albareda, 1, 18008, Granada, Spain.
The phytohormone auxin acts as an important signaling molecule having regulatory functions during the growth and development of plants. Reactive oxygen species (ROS) are also known to perform signaling functions at low concentrations, however, over-accumulation of ROS due to various environmental stresses damages the biomolecules, cell structures and lead to cell death, therefore it can be said that ROS act as a double-edged sword. Nitric oxide (NO), a gaseous signaling molecule, performs a wide range of favourable roles in plants. NO displays its positive role in photo-morphogenesis, root growth, leaf expansion, seed germination, stomatal closure, senescence, fruit maturation, mitochondrial activity, and metabolism of iron. Studies have revealed the early existence of these crucial molecules during evolution. Moreover, auxin, ROS, and NO together show their involvement in various developmental processes and abiotic stress tolerance. Redox signaling is a primary response during exposure of plants to stresses and shows a link with auxin signaling. This review provides updated information related to crosstalk between auxin, ROS, and NO starting from their evolution during early earth periods and their interaction in plant growth and developmental processes as well as in the case of abiotic stresses to plants.
PMID: 36208156
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
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
J Chromatogr A , IF:4.759 , 2022 Oct , V1682 : P463497 doi: 10.1016/j.chroma.2022.463497
Quantification of six types of cytokinins: Integration of an ultra-performance liquid chromatographic-electrospray tandem mass spectrometric method with antibody based immunoaffinity columns equally recognizing cytokinins in free base and nucleoside forms.
College of Agronomy, China Agricultural University, Beijing 100193, People's Republic of China.; Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo 315211, People's Republic of China.; College of Agronomy, China Agricultural University, Beijing 100193, People's Republic of China. Electronic address: yangxiaolin429@cau.edu.cn.; College of Agronomy, China Agricultural University, Beijing 100193, People's Republic of China. Electronic address: wbaomin@263.net.
Cytokinins (CTKs) exist in various types in plants. The accurate quantification of free base and nucleoside types of cytokinins are helpful for better understanding their physiological role. In the present study, antibodies against trans-zeatin riboside (tZR) and N(6)-isopentenyladenine riboside (iPR) antibodies with equal recognition to free base and nucleoside cytokinins were developed. The cross-reactivity of tZR mAb 3G101G7 with tZR, trans-zeatin (tZ), dihydrozeatin riboside (DHZR), dihydrozeatin (DHZ), iPR, and N(6)-isopentenyladenine (iP) was 100.0%, 95.7%, 19.1%, 18.0%, 1.1%, and 0.7%, and that of iPR mAb 5C82F1 with above-mentioned 6 types of cytokinins was 1.5%, 1.4%, 5.7%, 3.1%, 100.0% and 92.6%, respectively. The obtained antibodies were used to prepare two immunoaffinity columns (IAC). The elution efficiencies of tZR 3G101G7-IAC for tZ and tZR, DHZ and DHZR and of iPR 5C82F1-IAC for iP and iPR were almost no difference with the same loading amount on their corresponding IACs. Subsequently, six types of cytokinins in mepiquat chloride (MC)-treated cotton (Gossypium hirsutum L.) roots were determined by IACs combined with ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS). The contents of tZR, iPR and DHZR were increased by 9.3 approximately 38.5%, 6.6 approximately 23.5%, and 30.1 approximately 110.0%, respectively, whereas those of tZ and iP were reduced by 5.3 approximately 20.0% and 27.7 approximately 32.1%, respectively. The decreased tZ and iP levels led to the ratio of auxin-to-active cytokinins increase to promote lateral root initiation in MC-treated cotton seeding. Integration of the IACs equally recognizing cytokinins in their free base and nucleoside forms with UPLC-ESI-MS/MS can accurately quantify different cytokinins in plant tissues.
PMID: 36166882
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 , 2022 Nov , 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
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111415 doi: 10.1016/j.plantsci.2022.111415
IbTLD modulates reactive oxygen species scavenging and DNA protection to confer salinity stress tolerance in tobacco.
Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan. Electronic address: tcch@ucdavis.edu.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: abslwert@gmail.com.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: r98b43022@gmail.com.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: jslin@dragon.nchu.edu.tw.
Plants accumulate reactive oxygen species (ROS) that may damage the cells under prolonged stress conditions. Reduction of the excessive ROS production can alleviate oxidative damage and enhance the survival rates under stress. TLDc-containing protein (TLD) was reported to confer tolerance to oxidative stress, but the regulatory mechanism of TLD remains unclear. In this study, we ectopically overexpressed the Ipomoea batatas TLDc gene (IbTLD) in tobacco and characterized its functions. RNA-sequencing analysis and Gene Ontology term enrichment analysis revealed that IbTLD up-regulates auxin-responsive genes in response to oxidative stress. Under salinity stress, the IbTLD transgenic lines showed higher germination rates, chlorophyll contents, and root lengths than wild type (W38). In addition, the IbTLD transgenic lines showed higher expression of ROS scavenging genes, nudix hydrolases, ROS scavenging enzyme activity, and lesser DNA damage compared to W38 under salinity stress. Therefore, our results suggest that IbTLD activates the expression of ROS scavenging genes and confers tolerance to salinity stress in planta.
PMID: 35963494
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111409 doi: 10.1016/j.plantsci.2022.111409
PpPIF8, a DELLA2-interacting protein, regulates peach shoot elongation possibly through auxin signaling.
College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China.; College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China. Electronic address: jcheng2007@163.com.; College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China. Electronic address: jcfeng@henau.edu.cn.
Rapid growth of branches in a peach tree restricts the light penetration and air ventilation within the orchard, which lowers fruit quality and promotes the occurrence of diseases and insects. Our previous works showed that PpDELLA1 and PpDELLA2 repress the rapid growth of annual shoots. Proteins that interact with DELLA are vital for its function. In this study, seven PpPIFs (PpPIF1, -2, -3, -4, -6, -7 and -8) were identified in the peach genome and contain a conserved bHLH domain. Among the seven PpPIFs, PpPIF8 interacted with PpDELLA2 through an unknown motif in the C-terminal and/or the bHLH domain. Overexpression of PpPIF8 in Arabidopsis promotes plant height and branch numbers. Hypocotyl elongation was significantly enhanced by PpPIF8 under weak light intensity. PpPIF8 overexpressed in Arabidopsis and transiently expressed in peach seedlings upregulated the transcription of YUCCA and SAUR19 and downregulated SHY1 and -2. Additionally, PpPIF4 and -8 were significantly induced by weak light. Phylogentic analysis and intron patterns of the bHLH domain strongly suggested that PIFs from six species could be divided into two groups of different evolutionary origins. These results lay a foundation for the further study of the repression of shoot growth by PpDELLA2 through protein interaction with PpPIF8 in peach.
PMID: 35934255
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111408 doi: 10.1016/j.plantsci.2022.111408
Overexpression of a SHORT-ROOT transcriptional factor enhances the auxin mediated formation of adventitious roots and lateral roots in poplar trees.
School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 2441909790@qq.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 1501661988@qq.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 18700944808@163.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: shaohuiyang77@tju.edu.cn.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: jiehuawang@tju.edu.cn.
SHORT-ROOT (SHR) defines root stem cells and maintains radial patterning, but its involvement in adventitious root (AR) formation has not been reported. In this study, we showed that PtSHR2 was transcriptionally upregulated by excision before the formation of AR and responded dynamically to auxin. PtSHR2 overexpression (SHR2B(OE)) in hybrid poplars resulted in an increased number of ARs with an initial delay. Despite a lower endogenous content in the stems than in wild-type plants, indole-3-acetic acid (IAA) content at the SHR2B(OE) basal stem increased rapidly after cutting and reached a higher maximum than in wild-type plants, which was accompanied by a more sustained and stronger induction of AR formation marker genes. In addition, the higher auxin content in SHR2B(OE) ARs resulted in more and longer lateral roots (LRs). Application of auxin abolished the early delay in the formation of AR and largely other AR phenotypes of SHR2B(OE) plants, whereas the polar auxin transport inhibitor N-1-naphthylphthalamic acid completely inhibited both AR and LR abnormalities. Since the enhanced rooting ability of SHR2B(OE) stem cuttings in hydroponics was clearly confirmed, our results suggest a novel role of poplar SHR2 as a positive regulator during the organogenesis of AR and LR by affecting local auxin homeostasis.
PMID: 35932828
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111401 doi: 10.1016/j.plantsci.2022.111401
The Citrus sinensis TILLER ANGLE CONTROL 1 (CsTAC1) gene regulates tree architecture in sweet oranges by modulating the endogenous hormone content.
Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA. Electronic address: manjul@ufl.edu.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA; Pomology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA; Department of Agricultural Botany, Faculty of Agriculture, Tanta University, Tanta 31512, Egypt.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA.
Citrus is a major fruit crop cultivated on a global scale. Citrus trees are long lived perennials with a large canopy. Understanding the genetic control of tree architecture could provide tools for breeding and selection of citrus cultivars suitable for high density planting with improved light exposure. Tree architecture is modulated by the TILLER ANGLE CONTROL 1 (TAC1) gene which plays an important role in the regulation of the shoot angle. Herein, we used CRISPR/Cas9 technology to knockout the CsTAC1 gene for the biochemical and molecular analysis of its function. Nine transgenic lines were obtained, and five edited plants were confirmed based on T7EI mismatch detection assay and Sanger sequencing. The transgenic citrus lines exhibited pleiotropic phenotypes, including differences in branch angle and stem growth. Additionally, silencing CsTAC1 led to enhanced CsLAZY1 transcript levels in the tested lines. Analysis of the phytohormonal profile revealed that TAC1-edited plants exhibited lower auxin contents and increased cytokinin levels in the leaves compared to the wild-type plants. The GA(7) gibberellin level was enhanced in most of the edited lines. Collectively, TAC1 affects branch angle in association with hormone signals in citrus.
PMID: 35905898
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
Front Genet , IF:4.599 , 2022 , V13 : P1034947 doi: 10.3389/fgene.2022.1034947
Identification of genomic regions of wheat associated with grain Fe and Zn content under drought and heat stress using genome-wide association study.
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.; ICAR- Indian Institute of Wheat and Barley Research, Karnal, India.
Wheat is the staple food crop of global importance for its grain nutrient quality. Grain iron and zinc content of the wheat grain is an important quantitatively inherited trait that is influenced by the environmental factors such as drought and heat stress. Phenotypic evaluation of 295 advanced breeding lines from the wheat stress breeding program of IARI was carried out under timely sown irrigated (IR), restricted irrigated, and late-sown conditions at New Delhi during the cropping season of 2020-21, and grain iron (GFeC) and zinc (GZnC) contents were estimated from both control and treatments. A statistically significant increase in GFeC and GZnC was observed under stress conditions compared to that of the control. Genotyping was carried out with the SNPs from the 35K Axiom Breeder's array, and marker-trait association was identified by GWAS analysis. Of the 23 MTAs identified, seven were linked with GFeC and sixteen were linked with GZnC. In silico analysis revealed a few important transcripts involved in various plant metabolism, growth, and development activities such as auxin response factor, root UVB sensitive proteins, potassium transporter, glycosyl transferase, COBRA, and F-box-like domain. The identified MTAs can be used for molecular breeding after validation and also for rapid development of micronutrient-rich varieties of wheat to mitigate hidden hunger.
PMID: 36338980
Front Genet , IF:4.599 , 2022 , V13 : P1013822 doi: 10.3389/fgene.2022.1013822
Genome-wide identification of Aux/IAA gene family and their expression analysis in Prunus mume.
Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, China.
AUXIN/INDOLE ACETIC ACIDs (Aux/IAAs), an early auxin-responsive gene family, is important for plant growth and development. To fully comprehend the character of Aux/IAA genes in woody plants, we identified 19 PmIAA genes in Prunus mume and dissected their protein domains, phylogenetic relationship, gene structure, promoter, and expression patterns during floral bud flushing, auxin response, and abiotic stress response. The study showed that PmIAA proteins shared conserved Aux/IAA domain, but differed in protein motif composition. 19 PmIAA genes were divided into six groups (Groups â… to â…¥) based on phylogenetic analysis. The gene duplication analysis showed that segmental and dispersed duplication greatly influenced the expansion of PmIAA genes. Moreover, we identified and classified the cis-elements of PmIAA gene promoters and detected elements that are related to phytohormone responses and abiotic stress responses. With expression pattern analysis, we observed the auxin-responsive expression of PmIAA5, PmIAA17, and PmIAA18 in flower bud, stem, and leaf tissues. PmIAA5, PmIAA13, PmIAA14, and PmIAA18 were possibly involved in abiotic stress responses in P. mume. In general, these results laid the theoretical foundation for elaborating the functions of Aux/IAA genes in perennial woody plant development.
PMID: 36313426
Front Genet , IF:4.599 , 2022 , V13 : P1001195 doi: 10.3389/fgene.2022.1001195
Integration of transcriptome and metabolome analyses reveals key lodging-resistance-related genes and metabolic pathways in maize.
Hebei Key Laboratory of Quality and Safety Analysis-Testing for Agro-Products and Food, Hebei North University, Zhangjiakou, China.; School of Medicine, Nankai University, Tianjin, China.
Stalk lodging, or breakage of the stalk at or below the ear, is one of the vital factors causing substantial yield losses in maize (Zea mays. L). Lodging affects maize plants' physiological and molecular processes, eventually impacting plant growth and productivity. Despite this known fact, few researchers have investigated the genetic architecture underlying lodging in maize. Herein, through integrated transcriptome, metabolome, and phenotypic analyses of stalks of three diverse hybrid cultivars (highly resistant JNK738, mildly resistant JNK728, and lowly resistant XY335) at the tasseling (10 days to silking, 10 DTS) stage, we identified key genes and metabolic pathways modulating lodging resistance in maize. Based on the RNA-Seq analysis, a total of 10093 differentially expressed genes (DEGs) were identified from the comparison of the three varieties in pairs. Additionally, key lodging resistance-related metabolic pathways were obtained by KEGG enrichment analysis, and the DEGs were found predominantly enriched in phenylpropanoid and secondary metabolites biosynthesis pathways in the L_vs._H and M_vs._H comparison groups. Moreover, K-means analysis clustered the DEGs into clear and distinct expression profiles for each cultivar, with several functional and regulatory genes involved in the cell wall assembly, lignin biosynthetic process and hormone metabolic process being identified in the special clusters related to lodging resistance. Subsequently, integrating metabolome and transcriptome analyses revealed nine key lignin-associated metabolites that showed different expression trends in the three hybrid cultivars, among which L-phenylalanine and p-coumaric acid were regarded as differentially changed metabolites (DCMs). These two DCMs belonged to phenylalanine metabolism and biosynthesis pathways and were also supported by the RNA-Seq data. Furthermore, plant hormone signal transduction pathway-related genes encoding auxin, abscisic acid, jasmonates, and salicylic acid were differentially expressed in the three comparisons of lodging resistance, indicating these DEGs were valuable potential targets for improving maize lodging resistance. Finally, comparative physiological and qRT-PCR analyses results supported our transcriptome-based findings. Our research not only provides a preliminary theoretical basis and experimental ideas for an in-depth study of the regulatory networks involved in maize lodging resistance regulation but also opens up new avenues for molecular maize stalk lodging resistance breeding.
PMID: 36299597
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
Plant Cell Rep , IF:4.57 , 2022 Oct , V41 (10) : P2089-2105 doi: 10.1007/s00299-022-02908-4
The strigolactone receptor SlDWARF14 plays a role in photosynthetic pigment accumulation and photosynthesis in tomato.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China.; Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT, 06269, USA.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. wuhan@njau.edu.cn.
Tomato DWARF14 regulates the development of roots, shoot branches and leaves, and also plays a role in photosynthetic pigment accumulation and photosynthetic capacity. Strigolactones (SLs) are a novel class of plant hormones. DWARF14 (D14) is the only SL receptor identified to date, but it is not functionally analyzed in tomato (Solanum lycopersicum). In the present study, we identified the potential SL receptor in tomato by bioinformatic analysis, which was designated as SlD14. SlD14 was expressed in roots, stems, flowers and developing fruits, with the highest expression level in leaves. sld14 mutant plants produced by the CRISPR/Cas9 system displayed reduced plant height and root biomass, increased shoot branching and altered leaf shape comparing with WT plants. The cytokinin biosynthetic gene ISOPENTENYLTRANSFERASE 3 (SlIPT3), auxin biosynthetic genes FLOOZY (SlFZY) and TRYPTOPHAN AMINOTRANSFERASE RELATED 1 (SlTAR1) and several auxin transport genes SlPINs, which are involved in branch formation, showed higher expression levels in the sld14 plant stem. In addition, sld14 plants exhibited light-green leaves, reduced chlorophyll and carotenoid contents, abnormal chloroplast structure and reduced photosynthetic capacity. Transcriptomic analysis showed that the transcript levels of six chlorophyll biosynthetic genes, three carotenoid biosynthetic genes and numerous chlorophyll a/b-binding protein genes were decreased in sld14 plants. These results suggest that tomato SL receptor gene SlD14 not only regulates the development of roots, shoot branches and leaves, but also plays a role in regulating photosynthetic pigment accumulation and photosynthetic capacity.
PMID: 35907035
Microb Ecol , IF:4.552 , 2022 Oct , V84 (3) : P643-675 doi: 10.1007/s00248-021-01849-x
Himalayan Microbiomes for Agro-environmental Sustainability: Current Perspectives and Future Challenges.
Department of Microbiology, Akal College of Basic Sciences, Eternal University, Sirmaur, Himachal Pradesh, India.; Uttarakhand Pollution Control Board, Regional Office, Kashipur, Uttarakhand, India.; Division of Crop Research, Research Complex for Eastern Region, Patna, Bihar, India.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China.; Forest Research Institute, Dehradun, 2480 06, India.; Rain Forest Research Institute, Jorhat, 785 010, India.; Department of Biotechnology, Invertis Institute of Engineering and Technology (IIET), Invertis University, Bareilly, 243123, Uttar Pradesh, India.; Department of Agricultural Microbiology, College of Agriculture, Indira Gandhi Krishi Vishwa Vidyalaya, Raipur, Chhattisgarh, India.; Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India.; Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.; Microbial Biotechnology Laboratory, Department of Biotechnology, Dr. Khem Singh Gill Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, Himachal Pradesh, India.; Microbial Biotechnology Laboratory, Department of Biotechnology, Dr. Khem Singh Gill Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, Himachal Pradesh, India. ajar@eternaluniversity.edu.in.
The Himalayas are one of the most mystical, yet least studied terrains of the world. One of Earth's greatest multifaceted and diverse montane ecosystems is also one of the thirty-four global biodiversity hotspots of the world. These are supposed to have been uplifted about 60-70 million years ago and support, distinct environments, physiography, a variety of orogeny, and great biological diversity (plants, animals, and microbes). Microbes are the pioneer colonizer of the Himalayas that are involved in various bio-geological cycles and play various significant roles. The applications of Himalayan microbiomes inhabiting in lesser to greater Himalayas have been recognized. The researchers explored the applications of indigenous microbiomes in both agricultural and environmental sectors. In agriculture, microbiomes from Himalayan regions have been suggested as better biofertilizers and biopesticides for the crops growing at low temperature and mountainous areas as they help in the alleviation of cold stress and other biotic stresses. Along with alleviation of low temperature, Himalayan microbes also have the capability to enhance plant growth by availing the soluble form of nutrients like nitrogen, phosphorus, potassium, zinc, and iron. These microbes have been recognized for producing plant growth regulators (abscisic acid, auxin, cytokinin, ethylene, and gibberellins). These microbes have been reported for bioremediating the diverse pollutants (pesticides, heavy metals, and xenobiotics) for environmental sustainability. In the current perspectives, present review provides a detailed discussion on the ecology, biodiversity, and adaptive features of the native Himalayan microbiomes in view to achieve agro-environmental sustainability.
PMID: 34647148
Physiol Plant , IF:4.5 , 2022 Oct : 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, P.R. 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. A. 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
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 Oct 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 (ACPs) 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 that in shoots or lower. 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 usually prevailed 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 ACPs indicate an association with different dominant functions of these organs: nutrient uptake by traps vs. 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 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 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
BMC Plant Biol , IF:4.215 , 2022 Oct , V22 (1) : P500 doi: 10.1186/s12870-022-03873-6
Comparison of anther transcriptomes in response to cold stress at the reproductive stage between susceptible and resistant Japonica rice varieties.
Rice Research Institute of Heilongjiang Academy of Agricultural Sciences, 154026, Jiamusi, Heilongjiang, China.; National Engineering Research Center of Plant Space Breeding, South China Agricultural University, 510642, Guangzhou, Guangdong, China.; Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences, 154007, Jiamusi, Heilongjiang, China. cai_lijun@yeah.net.; Crops Research Institute, Guangdong Academy of Agricultural Sciences, 510640, Guangzhou, Guangdong, China.; Jiamusi Longjing Seed Industry Co., LTD, 154026, Jiamusi, Heilongjiang, China.; Qiqihar Branch of Heilongjiang Academy of Agricultural Sciences, 161006, Qiqihar, Heilongjiang, China.; Rice Research Institute of Heilongjiang Academy of Agricultural Sciences, 154026, Jiamusi, Heilongjiang, China. zixuanfeng2008@163.com.; Rice Research Institute of Heilongjiang Academy of Agricultural Sciences, 154026, Jiamusi, Heilongjiang, China. liuchuanxue2007@163.com.; Rice Research Institute of Heilongjiang Academy of Agricultural Sciences, 154026, Jiamusi, Heilongjiang, China. panguojun777@163.com.
BACKGROUND: Rice is one of the most important cereal crops in the world but is susceptible to cold stress (CS). In this study, we carried out parallel transcriptomic analysis at the reproductive stage on the anthers of two Japonica rice varieties with contrasting CS resistance: cold susceptible Longjing11 (LJ11) and cold resistant Longjing25 (LJ25). RESULTS: According to the obtained results, a total of 16,762 differentially expressed genes (DEGs) were identified under CS, including 7,050 and 14,531 DEGs in LJ25 and LJ11, respectively. Examining gene ontology (GO) enrichment identified 35 up- and 39 down-regulated biological process BP GO terms were significantly enriched in the two varieties, with 'response to heat' and 'response to cold' being the most enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified 33 significantly enriched pathways. Only the carbon metabolism and amino acid biosynthesis pathways with down-regulated DEGs were enriched considerably in LJ11, while the plant hormone signal transduction pathway (containing 153 DEGs) was dramatically improved. Eight kinds of plant hormones were detected in the pathway, while auxin, abscisic acid (ABA), salicylic acid (SA), and ethylene (ETH) signaling pathways were found to be the top four pathways with the most DEGs. Furthermore, the protein-protein interaction (PPI) network analysis identified ten hub genes (co-expressed gene number >/= 30), including six ABA-related genes. Various DEGs (such as OsDREB1A, OsICE1, OsMYB2, OsABF1, OsbZIP23, OsCATC, and so on) revealed distinct expression patterns among rice types when the DEGs between LJ11 and LJ25 were compared, indicating that they are likely responsible for CS resistance of rice in cold region. CONCLUSION: Collectively, our findings provide comprehensive insights into complex molecular mechanisms of CS response and can aid in CS resistant molecular breeding of rice in cold regions.
PMID: 36284279
BMC Plant Biol , IF:4.215 , 2022 Oct , V22 (1) : P484 doi: 10.1186/s12870-022-03861-w
Functional analysis revealed the involvement of ZmABCB15 in resistance to rice black-streaked dwarf virus infection.
Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China.; Weihai Academy of Agricultural Sciences, Weihai, China.; Henan Academy of Agricultural Sciences Zhengzhou, Zhengzhou, China. tieshaugngui308@126.com.; Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China. mengzhd981@126.com.
BACKGROUND: Maize rough dwarf disease (MRDD), caused by rice black-streaked dwarf virus (RBSDV) belonging to the Fijivirus genus, seriously threatens maize production worldwide. Three susceptible varieties (Ye478, Zheng 58, and Zhengdan 958) and two resistant varieties (P138 and Chang7-2) were used in our study. RESULTS: A set of ATP-binding cassette subfamily B (ABCB) transporter genes were screened to evaluate their possible involvements in RBSDV resistance. In the present study, ZmABCB15, an ABCB transporter family member, was cloned and functionally identified. Expression analysis showed that ZmABCB15 was significantly induced in the resistant varieties, not in the susceptible varieties, suggesting its involvement in resistance to the RBSDV infection. ZmABCB15 gene encodes a putative polar auxin transporter containing two trans-membrane domains and two P-loop nucleotide-binding domains. Transient expression analysis indicated that ZmABCB15 is a cell membrance localized protein. Over-expression of ZmABCB15 enhanced the resistance by repressing the RBSDV replication ratio. ZmABCB15 might participate in the RBSDV resistance by affecting the homeostasis of active and inactive auxins in RBSDV infected seedlings. CONCLUSIONS: Polar auxin transport might participate in the RBSDV resistance by affecting the distribution of endogenous auxin among tissues. Our data showed the involvement of polar auxin transport in RBSDV resistance and provided novel mechanism underlying the auxin-mediated disease control technology.
PMID: 36217105
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
Mol Plant Microbe Interact , IF:4.171 , 2022 Oct , V35 (10) : P881-886 doi: 10.1094/MPMI-05-22-0113-TA
Berberine Bridge Enzyme-like Oligosaccharide Oxidases Act as Enzymatic Transducers Between Microbial Glycoside Hydrolases and Plant Peroxidases.
Department of Life, Health and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy.; Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy.
Oligogalacturonide (OG)-oxidase 1 (OGOX1) and cellodextrin (CD)-oxidase (CELLOX) are plant berberine bridge enzyme-like oligosaccharide oxidases that oxidize OGs and CDs, cell-wall fragments with the nature of damage-associated molecular patterns. The oxidation of OGs and CDs attenuates their elicitor activity and concomitantly releases H(2)O(2). By using a multiple enzyme-based assay, we demonstrate that the H(2)O(2) generated downstream of the combined action between a fungal polygalacturonase and OGOX1 or an endoglucanase and CELLOX can be directed by plant peroxidases (PODs) either towards a reaction possibly involved in plant defense, such as the oxidation of monolignol or a reaction possibly involved in a developmental event, such as the oxidation of auxin (indole-3-acetic acid), pointing to OGOX1 and CELLOX as enzymatic transducers between microbial glycoside hydrolases and plant PODs. [Formula: see text] Copyright (c) 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
PMID: 35704684
Microorganisms , IF:4.128 , 2022 Oct , V10 (10) doi: 10.3390/microorganisms10102047
A Plant Endophytic Bacterium Priestia megaterium StrainBP-R2 Isolated from the Halophyte Bolboschoenus planiculmis Enhances Plant Growth under Salt and Drought Stresses.
Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.; Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 402, Taiwan.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan.; Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan.
Global warming and climate change have contributed to the rise of weather extremes. Severe drought and soil salinization increase because of rising temperatures. Economically important crop production and plant growth and development are hindered when facing various abiotic stresses. Plant endophytic bacteria live inside host plants without causing visible harm and can be isolated from surface-sterilized plant tissues. Using plant endophytic bacteria to stimulate plant growth and increase environmental stress tolerance has become an alternative approach besides using the traditional breeding and genetically modifying approaches to select or create new crop types resistant to different environmental stresses. The plant endophytic bacterium, Priestia megaterium (previously known as Bacillus megaterium) strain BP-R2, was isolated from the surface-sterilized root tissues of the salt marsh halophyte Bolboschoenus planiculmis. The bacteria strain BP-R2 showed high tolerance to different sodium chloride (NaCl) concentrations and produced the auxin plant hormone, indole acetic acid (IAA), under various tested growth conditions. Inoculation of Arabidopsis and pak choi (Brassica rapa L. R. Chinensis Group) plants with the strain BP-R2 greatly enhanced different growth parameters of the host plants under normal and salt and drought stress conditions compared to that of the mock-inoculated plants. Furthermore, the hydrogen peroxide (H(2)O(2)) content, electrolyte leakage (EL), and malondialdehyde (MDA) concentration accumulated less in the BP-R2-inoculated plants than in the mock-inoculated control plants under salt and drought stresses. In summary, the plant endophytic bacterium strain BP-R2 increased host plant growth and stress tolerance to salt and drought conditions.
PMID: 36296323
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 (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
Genes (Basel) , IF:4.096 , 2022 Oct , V13 (10) doi: 10.3390/genes13101903
Comparative Biochemical and Transcriptomic Analyses Provide New Insights into Phytoplasma Infection Responses in Cucumber.
School of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225009, China.; Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
Flat stem and witches' broom phytoplasma-like symptoms in the cucumber inbred line C17 were observed in a greenhouse at Yangzhou University, China for three consecutive planting seasons; these symptoms resulted in a decreased yield. To better understand the cause of these symptoms, 16S rRNA PCR, plant hormones, mineral elements, and RNA-seq profiling were performed using symptomatic and normal stem samples. The results showed that the causal agent was classified as the Candidatus phytoplasma asteris strain, a plant pathogenic prokaryote that could not be cultured in vitro. Measurement of plant hormones showed that auxin, salicylic acid, and jasmonic acid contents were significantly increased, whereas that of ethylene's immediate biosynthetic precursor, 1-aminocyclopropane-1-carboxylic acid, was decreased in the phytoplasma-infected stems compared with the healthy stems. Furthermore, measurement of mineral element composition showed that magnesium, calcium, sodium, iron, and zinc concentrations significantly changed in the phytoplasma-infected cucumber stems compared with the uninfected stems. Comparative RNA-seq identified 253 differentially expressed genes, including 179 upregulated and 74 downregulated genes. Further analyses suggested that genes related to phenylpropanoid biosynthesis, phenylalanine metabolism, and plant hormone signal transduction contributed to phytoplasma infection. Taken together, this study presents the first in-depth assessment of disease symptoms and biochemical content of cucumber stems known to be infected with phytoplasma.
PMID: 36292788
Genes (Basel) , IF:4.096 , 2022 Oct , V13 (10) doi: 10.3390/genes13101803
Effects of Exogenous (K(+)) Potassium Application on Plant Hormones in the Roots of Tamarix ramosissima under NaCl Stress.
Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing 210037, China.; Department of Forest Resources Management, Faculty of Science, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Abiotic stresses such as salt stress seriously affect the growth and yield of plants. Tamarix ramosissima Lcdcb (T. ramosissima) is a widely cultivated halophyte in saline-alkali areas of the world. As an essential element for plant growth and development, K(+) plays an irreplaceable role in improving the tolerance of plants to salt stress. However, there are few reports on the mechanism of K(+) in promoting plant hormones to reduce the damage of NaCl stress to T. ramosissima. In this study, we sequenced the transcriptome of the roots of T. ramosissima which were treated with exogenous potassium (K(+)) for 0 h, 48 h and 168 h under NaCl stress, according to the changes in the expression levels of differentially expressed genes (DEGs) in T. ramosissima roots. Key candidate genes and metabolic pathways related to plant hormones were mined for analysis and further verified by quantitative real-time PCR (qRT-PCR). The results showed that under NaCl stress for 48 h and 168 h, there were a large number of DEGs in the roots of T. ramosissima, and the expression levels changed over time. In particular, we found that 56 plant hormone-related genes were annotated to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and with the increase of time, their expression levels were mainly up-regulated and involved in the related metabolic pathways to resist NaCl stress. It is worth noting that 7 DEGs related to abscisic acid (ABA), 28 DEGs related to auxin, 1 DEG related to ethylene (ET), and 1 DEG related to cytokinin (CK) were added within 168 h of exogenous potassium, and they were involved in alleviating the root damage of T. ramosissima under NaCl stress and played an important role. In addition, we found the plant hormone signal transduction pathway, which plays an important role in resistance to NaCl stress. As a result of this study, the molecular mechanism of plant hormones involved in applying exogenous potassium under NaCl stress is further understood, resulting in a better understanding of how exogenous potassium can alleviate the damage caused by NaCl under stress in T. ramosissima.
PMID: 36292689
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
Plant Mol Biol , IF:4.076 , 2022 Oct , V110 (3) : P253-268 doi: 10.1007/s11103-022-01298-1
SlBBX28 positively regulates plant growth and flower number in an auxin-mediated manner in tomato.
Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Escola Superior de Agricultura 'Luiz de Queiroz', Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil. mmrossi@usp.br.
SlBBX28 is a positive regulator of auxin metabolism and signaling, affecting plant growth and flower number in tomato B-box domain-containing proteins (BBXs) comprise a family of transcription factors that regulate several processes, such as photomorphogenesis, flowering, and stress responses. For this reason, attention is being directed toward the functional characterization of these proteins, although knowledge in species other than Arabidopsis thaliana remains scarce. Particularly in the tomato, Solanum lycopersicum, only three out of 31 SlBBX proteins have been functionally characterized to date. To deepen the understanding of the role of these proteins in tomato plant development and yield, SlBBX28, a light-responsive gene, was constitutively silenced, resulting in plants with smaller leaves and fewer flowers per inflorescence. Moreover, SlBBX28 knockdown reduced hypocotyl elongation in darkness-grown tomato. Analyses of auxin content and responsiveness revealed that SlBBX28 promotes auxin-mediated responses. Altogether, the data revealed that SlBBX28 promotes auxin production and signaling, ultimately leading to proper hypocotyl elongation, leaf expansion, and inflorescence development, which are crucial traits determining tomato yield.
PMID: 35798935
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
BMC Genomics , IF:3.969 , 2022 Oct , V23 (1) : P733 doi: 10.1186/s12864-022-08935-5
Full-length fruit transcriptomes of southern highbush (Vaccinium sp.) and rabbiteye (V. virgatum Ait.) blueberry.
Department of Horticulture, University of Georgia, 1111 Miller Plant Sciences Building, 120 Carlton Street, Athens, GA, 30602, USA.; Center for Applied Genetic Technologies, University of Georgia, 111 Riverbend Road, Athens, GA, 30602, USA.; Department of Horticulture, University of Georgia, 1111 Miller Plant Sciences Building, 120 Carlton Street, Athens, GA, 30602, USA. sunamb@uga.edu.
BACKGROUND: Blueberries (Vaccinium sp.) are native to North America and breeding efforts to improve blueberry fruit quality are focused on improving traits such as increased firmness, enhanced flavor and greater shelf-life. Such efforts require additional genomic resources, especially in southern highbush and rabbiteye blueberries. RESULTS: We generated the first full-length fruit transcriptome for the southern highbush and rabbiteye blueberry using the cultivars, Suziblue and Powderblue, respectively. The transcriptome was generated using the Pacific Biosciences single-molecule long-read isoform sequencing platform with cDNA pooled from seven stages during fruit development and postharvest storage. Raw reads were processed through the Isoseq pipeline and full-length transcripts were mapped to the 'Draper' genome with unmapped reads collapsed using Cogent. Finally, we identified 16,299 and 15,882 non-redundant transcripts in 'Suziblue' and 'Powderblue' respectively by combining the reads mapped to Northern Highbush blueberry 'Draper' genome and Cogent analysis. In both cultivars, > 80% of sequences were longer than 1,000 nt, with the median transcript length around 1,700 nt. Functionally annotated transcripts using Blast2GO were > 92% in both 'Suziblue' and 'Powderblue' with overall equal distribution of gene ontology (GO) terms in the two cultivars. Analyses of alternative splicing events indicated that around 40% non-redundant sequences exhibited more than one isoform. Additionally, long non-coding RNAs were predicted to represent 5.6% and 7% of the transcriptomes in 'Suziblue' and 'Powderblue', respectively. Fruit ripening is regulated by several hormone-related genes and transcription factors. Among transcripts associated with phytohormone metabolism/signaling, the highest number of transcripts were related to abscisic acid (ABA) and auxin metabolism followed by those for brassinosteroid, jasmonic acid and ethylene metabolism. Among transcription factor-associated transcripts, those belonging to ripening-related APETALA2/ethylene-responsive element-binding factor (AP2/ERF), NAC (NAM, ATAF1/2 and CUC2), leucine zipper (HB-zip), basic helix-loop-helix (bHLH), MYB (v-MYB, discovered in avian myeloblastosis virus genome) and MADS-Box gene families, were abundant. Further we measured three fruit ripening quality traits and indicators [ABA, and anthocyanin concentration, and texture] during fruit development and ripening. ABA concentration increased during the initial stages of fruit ripening and then declined at the Ripe stage, whereas anthocyanin content increased during the final stages of fruit ripening in both cultivars. Fruit firmness declined during ripening in 'Powderblue'. Genes associated with the above parameters were identified using the full-length transcriptome. Transcript abundance patterns of these genes were consistent with changes in the fruit ripening and quality-related characteristics. CONCLUSIONS: A full-length, well-annotated fruit transcriptome was generated for two blueberry species commonly cultivated in the southeastern United States. The robustness of the transcriptome was verified by the identification and expression analyses of multiple fruit ripening and quality-regulating genes. The full-length transcriptome is a valuable addition to the blueberry genomic resources and will aid in further improving the annotation. It will also provide a useful resource for the investigation of molecular aspects of ripening and postharvest processes.
PMID: 36309640
Pestic Biochem Physiol , IF:3.963 , 2022 Oct , V187 : P105211 doi: 10.1016/j.pestbp.2022.105211
Multiple resistance mechanisms to penoxsulam in Echinochloa crus-galli from China.
Department of Plant Protection, College of Plant Sciences & Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China.; General Station of Plant Protection, Hubei Province, Wuhan 430070, Hubei, PR China.; General Station of Plant Protection, Hubei Province, Wuhan 430070, Hubei, PR China. Electronic address: 897015023@qq.com.; Department of Plant Protection, College of Plant Sciences & Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China. Electronic address: mahongju@mail.hzau.edu.cn.
Penoxsulam is an important herbicide for the control of Echinochloa crus-galli (L.) P. Beauv. Two resistant populations 17GA (R1) and 16NXB (R2) showed 17- and 3-fold resistance to penoxsulam, respectively. A known resistance mutation of Trp-574-Leu in ALS gene and enhanced rates of penoxsulam metabolism likely involving GST contribute to penoxsulam resistance in R1 population. This population had resistance to the ALS-inhibitors pyribenzoxim and bispyribac‑sodium and the auxin herbicide quinclorac, but was susceptible to ACCase-inhibitors quizalofop-p-ethyl and cyhalofop-butyl. No known mutations in the ALS gene conferring target site resistance to ALS-inhibiting herbicides were presented in R2 population. However, penoxsulam metabolism in R2 plants was about 4-fold greater than in susceptible population 14YC (S0) plants. The enzyme inhibitors piperonyl butoxide, malathion and 4-chloro-7-nitrobenzoxadiazole reversed penoxsulam resistance in this population. GST and P450 enzyme activities and the genes of GST1-1, GST1-2, GST1-3, CYP81A18, CYP81A12, CYP81A21 were increased significantly in R2 population. These results indicate that multiple resistance mechanisms had occurred in E. crus-galli populations in central China and resistance needs to be managed effectively by diverse chemical and non-chemical methods.
PMID: 36127055
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
Plants (Basel) , IF:3.935 , 2022 Oct , V11 (21) doi: 10.3390/plants11212866
Photosynthesis, Phytohormone Signaling and Sugar Catabolism in the Culm Sheaths of Phyllostachys edulis.
Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, International Center for Bamboo and Rattan, State Forestry and Grassland Administration, Beijing 100102, China.
Culm sheaths play an important role in supporting and protecting bamboo shoots during the growth and development period. The physiological and molecular functions of bamboo sheaths during the growth of bamboo shoots remain unclear. In this study, we investigated the morphological anatomy of culm sheaths, photosynthesis in sheath blades, storage and distribution of sugars, and the transcriptome of the sheath. Respiration in the base of the culm sheath was higher than that in the sheath blades; chloroplasts matured with the development of the sheath blades, the fluorescence efficiency Fv/Fm value increased from 0.3 to 0.82; and sucrose and hexose accumulated in the sheath blade and the culm sheath. The sucrose, glucose, and fructose contents of the middle sheath blades were 10.66, 5.73, and 8.84 mg/g FW, respectively. Starches accumulated in parenchymal cells close to vascular bundles. Genes related to the plant hormone signaling pathway and sugar catabolism were highly expressed in the culm sheath base. These findings provide a research basis for further understanding the possible role of bamboo sheaths in the growth and development of bamboo shoots.
PMID: 36365317
Plants (Basel) , IF:3.935 , 2022 Oct , V11 (19) doi: 10.3390/plants11192640
The S-Gene YUC6 Pleiotropically Determines Male Mating Type and Pollen Size in Heterostylous Turnera (Passifloraceae): A Novel Neofunctionalization of the YUCCA Gene Family.
School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.; Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
In heterostylous, self-incompatible Turnera species, a member of the YUCCA gene family, YUC6, resides at the S-locus and has been hypothesized to determine the male mating type. YUCCA gene family members synthesize the auxin, indole-3-acetic acid, via a two-step process involving the TAA gene family. Consequently, it has been speculated that differences in auxin concentration in developing anthers are the biochemical basis underlying the male mating type. Here, we provide empirical evidence that supports this hypothesis. Using a transgenic knockdown approach, we show that YUC6 acts pleiotropically to control both the male physiological mating type and pollen size, but not the filament length dimorphism associated with heterostyly in Turnera. Using qPCR to assess YUC6 expression in different transgenic lines, we demonstrate that the level of YUC6 knockdown correlates with the degree of change observed in the male mating type. Further assessment of YUC6 expression through anther development, in the knockdown lines, suggests that the male mating type is irreversibly determined during a specific developmental window prior to microsporogenesis, which is consistent with the genetically sporophytic nature of this self-incompatibility system. These results represent the first gene controlling male mating type to be characterized in any species with heterostyly.
PMID: 36235506
Am J Bot , IF:3.844 , 2022 Nov 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 evolutionary independent way how a plant attains its architecture, alternative to axillary stem branching. RS plants are better adapted to disturbance than non-RS plants, and the vigour of RS is frequently boosted by biomass removal. Nevertheless, RS plants are rarer than plants that are not capable of RS - 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 what is behind the ability of RS: phytohormones or injury? METHODS: In a greenhouse experiment, growth parameters, root respiration and phytohormones were analysed in two closely related clonal herbs that differ in RS ability (spontaneously RS Inula britannica and rhizomatous non-RS I. salicina) either exposed to severe biomass removal or not. RESULTS: We confirmed RS ability in the previously reported RS species I. britannica; however, RS ability was not boosted by injury. While root respiration did not differ between the two species and decreased continuously with time irrespectively of injury, phytohormone profiles differed significantly. In RS species, the auxins-to-cytokinins ratio was low and injury further decreased it. CONCLUSIONS: Our study represents the first attempt to test drivers behind different plant growth forms and suggests that intrinsic phytohormone regulation, especially the auxins-to-cytokinins ratio, might be behind RS ability. Injury - causing phytohormonal imbalance - seems to be less important in spontaneously RS species than it has been expected for RS species in general. This article is protected by copyright. All rights reserved.
PMID: 36371783
Biosci Rep , IF:3.84 , 2022 Sep , V42 (9) doi: 10.1042/BSR20221504
Negative regulation of seed germination by maternal AFB1 and AFB5 in Arabidopsis.
Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, 301 Physical Sciences, Stillwater, OK 74078, U.S.A.
The plant hormone auxin suppresses seed germination, but how auxin does it remains poorly understood. While studying the functions of the AUXIN SIGNALING F-BOX (AFB) auxin co-receptors in Arabidopsis, we consistently isolated AFB1 and AFB5 in reproductive tissues in co-immunoprecipitation experiments using their interacting protein ASK1 as the bait. However, T2 seeds of the AFB1 or AFB5 transgenic lines generated for the co-immunoprecipitation experiments frequently failed to germinate, which led to the studies of seed germination in these plants and afb1 and afb5 mutants, and AFB1 and AFB5 expression in nearly mature fruit and imbibed seeds using AFB1:GUS and AFB5:GUS lines. We found that AFB1 and AFB5 acted in maternal tissues to suppress seed germination and their effects were positively correlated with the plants' sensitivity to indole acetic acid. Conversely, afb1 and afb5 single mutants exhibited faster seed germination than the wild type and the seeds of the afb1-5afb5-5 double mutant germinated even faster than those of the afb1-5 and afb5-5 single mutants. Seed germination of the afb1-5afb5-5 double mutant also exhibited higher sensitivity to gibberellic acid than that of the wild-type and the afb1-3, afb1-5 and afb5-5 single mutants. Both AFB1 and AFB5 were expressed in the funiculus during seed maturation, and AFB1 was also transiently expressed in a small chalazal region surrounding the hilum in the seed coat during seed imbibition. Therefore, AFB1 and AFB5 likely suppress seed germination in the funiculus and AFB1 also briefly suppresses seed germination in the chalaza during seed imbibition.
PMID: 36039862
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 Oct , V277 : P153792 doi: 10.1016/j.jplph.2022.153792
Regulation of pollen tube growth by cellular pH and ions.
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China. Electronic address: zhouzhg18@lzu.edu.cn.; College of Life Sciences, Northwest Normal University, Lanzhou, Gansu, 730070, China; Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, Qinghai, 810016, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China.; College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China; Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, Qinghai, 810016, China; College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China. Electronic address: qiuqsh@lzu.edu.cn.
Tip growth of the pollen tube is a model system for the study of cell polarity establishment in flowering plants. The tip growth of the pollen tube displays an oscillating pattern corresponding to cellular ion and pH dynamics. Therefore, cellular pH and ions play an important role in pollen growth and development. In this review, we summarized the current advances in understanding the function of cellular pH and ions in regulating pollen tube growth. We analyzed the physiological roles and underlying mechanisms of cellular pH and ions, including Ca(2+), K(+), and Cl(-), in regulating pollen tube growth. We further examined the function of Ca(2+) in regulating cytoskeletons, small G proteins, and cell wall development in relation to pollen tube growth. We also examined the regulatory roles of cellular pH in pollen tube growth as well as pH regulation of ion flow, cell wall development, auxin signaling, and cytoskeleton function in pollen. In addition, we assessed the regulation of pollen tube growth by proton pumps and the maintenance of pH homeostasis in the trans-Golgi network by ion transporters. The interplay of ion homeostasis and pH dynamics was also assessed. We discussed the unanswered questions regarding pollen tube growth that need to be addressed in the future.
PMID: 35973258
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
PLoS One , IF:3.24 , 2022 , V17 (10) : Pe0274740 doi: 10.1371/journal.pone.0274740
Transcriptome analysis of trembling aspen (Populus tremuloides) under nickel stress.
Biomolecular Sciences Program, Laurentian University, Sudbury, Ontario, Canada.; Department of Biology, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada.
Plants have evolved heavy metal tolerance mechanisms to adapt and cope with nickel (Ni) toxicity. Decrypting whole gene expression of Trembling Aspen (Pinus tremuloides) under nickel stress could elucidate the nickel resistance/tolerance mechanisms. The main objectives of the present research were to 1) characterize the P. tremuloides transcriptome, and 2) compare gene expression dynamics between nickel-resistant and nickel-susceptible P. tremuloides genotypes with Whole Transcriptome (WT) sequencing. Illumina Sequencing generated 27-45 million 2X150 paired-end reads of raw data per sample. The alignment performed with StringTie Software added two groups of transcripts to the draft genome annotation. One group contained 32,677 new isoforms that match to 17,254 genes. The second group contained 17,349 novel transcripts that represent 16,157 novel genes. Overall, 52,987 genes were identified from which 36,770 genes were selected as differently expressed. With the high stringency (two-fold change, FDR value /=1 (upregulated) or
PMID: 36227867
PLoS One , IF:3.24 , 2022 , V17 (10) : Pe0275588 doi: 10.1371/journal.pone.0275588
Ecotype-specific blockage of tasiARF production by two different RNA viruses in Arabidopsis.
Department of Plant Biotechnology, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Godollo, Hungary.; Doctoral School of Biology, Institute of Biology, ELTE Eotvos Lorand University, Budapest, Hungary.
Arabidopsis thaliana is one of the most studied model organisms of plant biology with hundreds of geographical variants called ecotypes. One might expect that this enormous genetic variety could result in differential response to pathogens. Indeed, we observed previously that the Bur ecotype develops much more severe symptoms (upward curling leaves and wavy leaf margins) upon infection with two positive-strand RNA viruses of different families (turnip vein-clearing virus, TVCV, and turnip mosaic virus, TuMV). To find the genes potentially responsible for the ecotype-specific response, we performed a differential expression analysis of the mRNA and sRNA pools of TVCV and TuMV-infected Bur and Col plants along with the corresponding mock controls. We focused on the genes and sRNAs that showed an induced or reduced expression selectively in the Bur virus samples in both virus series. We found that the two ecotypes respond to the viral infection differently, yet both viruses selectively block the production of the TAS3-derived small RNA specimen called tasiARF only in the virus-infected Bur plants. The tasiARF normally forms a gradient through the adaxial and abaxial parts of the leaf (being more abundant in the adaxial part) and post-transcriptionally regulates ARF4, a major leaf polarity determinant in plants. The lack of tasiARF-mediated silencing could lead to an ectopically expressed ARF4 in the adaxial part of the leaf where the misregulation of auxin-dependent signaling would result in an irregular growth of the leaf blade manifesting as upward curling leaf and wavy leaf margin. QTL mapping using Recombinant Inbred Lines (RILs) suggests that the observed symptoms are the result of a multigenic interaction that allows the symptoms to develop only in the Bur ecotype. The particular nature of genetic differences leading to the ecotype-specific symptoms remains obscure and needs further study.
PMID: 36197942
PLoS One , IF:3.24 , 2022 , V17 (10) : Pe0275566 doi: 10.1371/journal.pone.0275566
Identification and characterization of miRNAome and target genes in Pseudostellaria heterophylla.
Guizhou University of Traditional Chinese Medicine, Guiyang, China.
miRNAs play a crucial role in the development and growth of plants by inhibiting the function of targeted genes at the post-transcription level. However, no miRNAs in Pseudostellaria heterophylla have been reported and their function in the morphogenesis of organs is still unclear. In this study, a total of 159 conserved miRNAs (belonging to 64 families) and 303 level miRNAs were identified from P. heterophylla. Some of them showed specifically up or down-regulated expression in different tissues and numbers of unigenes involved in Plant-pathogen interaction and MAPK signaling pathway-plant were targeted. The significant negative correlation of expression profiles between 30 miRNAs and their target genes (37 unigenes) was observed, respectively. Further, a large number of genes involved with signal transduction of auxin, zeatin, abscisic acid and, jasmonic acid were targeted. Predicated targets of two miRNAs were validated by 5'RLM-RACE, respectively. A large number of mRNAs from four pathogens were targeted by miRNAs from P. heterophylla and some of them were targeted by miR414. In summary, we reported a population of miRNAs from four different vegetative tissues of P. heterophylla by high throughput sequencing, which was analyzed by combining with the constructed transcriptome. These results may help to explain the function of miRNAs in the morphogenesis of organs and defense of pathogens, and may provide theoretical basis for breeding and genetic improvement of P. heterophylla.
PMID: 36197881
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 the transcription of related genes.
College of Life Science, Northeast Agricultural University, Harbin, 150030, China.
Low temperature limits the geographical distribution and yield of plants. Hormones play an important role in coordinating the growth and development of plants and their tolerance to low temperature. 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 differential metabolites showed that the "plant hormone signal transduction" pathway was the most typical. Our study showed that extreme low temperature increased the levels of most auxin, cytokinin and salicylic acid, and decreased the levels of jasmonic acid and abscisic acid, and the levels of auxin, jasmonic acid and cytokinin in Dn1 were greater 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 seem to be different from the previous hormone regulation mechanisms obtained mostly at 4 degrees C. Our results provide a basis for further understanding the molecular mechanisms by which plant endogenous hormones regulate plant freeze stress tolerance.
PMID: 36385725
Plant Direct , IF:3.038 , 2022 Oct , V6 (10) : Pe456 doi: 10.1002/pld3.456
Phenotypic and transcriptomic analysis reveals early stress responses in transgenic rice expressing Arabidopsis DREB1a.
Department of Crop, Soil, and Environmental Sciences University of Arkansas System Division of Agriculture Fayetteville Arkansas USA.; Present address: Biological and Life Sciences Division, School of Arts and Sciences Ahmedabad University Central Campus Navrangpura Ahmedabad India.; Department of Agriculture Federal University of Lavras Lavras Minas Gerais Brazil.
Overexpression of Arabidopsis dehydration response element binding 1a (DREB1a) is a well-known approach for developing salinity, cold and/or drought stress tolerance. However, understanding of the genetic mechanisms associated with DREB1a expression in rice is generally limited. In this study, DREB1a-associated early responses were investigated in a transgenic rice line harboring cold-inducible DREB1a at a gene stacked locus. Although the function of other genes in the stacked locus was not relevant to stress tolerance, this study demonstrates DREB1a can be co-localized with other genes for multigenic trait enhancement. As expected, the transgenic lines displayed improved tolerance to salinity stress and water withholding as compared with non-transgenic controls. RNA sequencing and transcriptome analysis showed upregulation of complex transcriptional networks and metabolic reprogramming as DREB1a expression led to the upregulation of multiple transcription factor gene families, suppression of photosynthesis, and induction of secondary metabolism. In addition to the detection of previously described mechanisms such as production of protective molecules, potentially novel pathways were also revealed. These include jasmonate, auxin, and ethylene signaling, induction of JAZ and WRKY regulons, trehalose synthesis, and polyamine catabolism. These genes regulate various stress responses and ensure timely attenuation of the stress signal. Furthermore, genes associated with heat stress response were downregulated in DREB1a expressing lines, suggesting antagonism between heat and dehydration stress response pathways. In summary, through a complex transcriptional network, multiple stress signaling pathways are induced by DREB1a that presumably lead to early perception and prompt response toward stress tolerance as well as attenuation of the stress signal to prevent deleterious effects of the runoff response.
PMID: 36267847
PeerJ , IF:2.984 , 2022 , V10 : Pe14236 doi: 10.7717/peerj.14236
Identification and functional analysis of PIN family genes in Gossypium barbadense.
College of Agronomy, Xinjiang Agricultural University, Urumqi, Xinjiang, China.; Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan, China.; Postdoctoral Research Station, Xinjiang Agricultural University, Urumqi, Xinjiang, China.
BACKGROUND: PIN proteins are an important class of auxin polar transport proteins that play an important regulatory role in plant growth and development. However, their characteristics and functions have not been identified in Gossypium barbadense. METHODS: PIN family genes were identified in the cotton species G. barbadense, Gossypium hirsutum, Gossypium raimondii, and Gossypium arboreum, and detailed bioinformatics analyses were conducted to explore the roles of these genes in G. barbadense using transcriptome data and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) technology. Functional verification of the genes was performed using virus-induced gene silencing (VIGS) technology. RESULTS: A total of 138 PIN family genes were identified in the four cotton species; the genes were divided into seven subgroups. GbPIN gene family members were widely distributed on 20 different chromosomes, and most had repeated duplication events. Transcriptome analysis showed that some genes had differential expression patterns in different stages of fiber development. According to 'PimaS-7' and '5917' transcript component association analysis, the transcription of five genes was directly related to endogenous auxin content in cotton fibers. qRT-PCR analysis showed that the GbPIN7 gene was routinely expressed during fiber development, and there were significant differences among materials. Transient silencing of the GbPIN7 gene by VIGS led to significantly higher cotton plant growth rates and significantly lower endogenous auxin content in leaves and stems. This study provides comprehensive analyses of the roles of PIN family genes in G. barbadense and their expression during cotton fiber development. Our results will form a basis for further PIN auxin transporter research.
PMID: 36275460
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
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 Nov 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 C. 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 tissue. 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
3 Biotech , IF:2.406 , 2022 Oct , V12 (10) : P262 doi: 10.1007/s13205-022-03322-z
Phosphate solubilization and indole acetic acid production by rhizosphere yeast Torulaspora globosa: improvement of culture conditions for better performance in vitro.
Pos-Graduacao Em Producao Vegetal E Bioprocessos Associados, Universidade Federal de Sao Carlos, Rod Anhanguera km 174, Araras, Sao Paulo, Brazil. GRID: grid.411247.5. ISNI: 0000 0001 2163 588X; Departamento de Tecnologia Agroindustrial E Socio-Economia Rural, Universidade Federal de Sao Carlos, Rod. Anhanguera km 174, Araras, Sao Paulo, Brazil. GRID: grid.411247.5. ISNI: 0000 0001 2163 588X; Departamento de Recursos Naturais E Protecao Ambiental, Universidade Federal de Sao Carlos, Rod Anhanguera km 174, Araras, Sao Paulo, Brazil. GRID: grid.411247.5. ISNI: 0000 0001 2163 588X
The rhizosphere yeast Torulaspora globosa is known to produce indole acetic acid (IAA) and to solubilize minerals. Due to the prospective use of this yeast as a biostimulant for agricultural applications, this work aimed to optimize the cultural conditions for both IAA production and phosphate solubilization. For phosphate solubilization, the temperature (20, 25 and 30 degrees C), initial medium pH (3.0, 5.0, and 7.0), and shaker speed (without mixing, 100 rpm, 150 rpm, and 200 rpm) were considered using the one-factor-at-a-time (OFAT) design. Temperature of 25 degrees C, initial medium pH 7.0, and static cultures were the conditions of greatest phosphate solubilization, with 40% of the total phosphorus content solubilized from calcium phosphate (419.86 mg L(-1)) after 48 h. By using the response surface methodology, the maximum IAA production (217.73 microg mL(-1)) was obtained with the highest initial pH 7.0, the lowest nitrogen, and glucose concentrations (5 g L(-1) and 10 g L(-1), respectively) and the lowest agitator speed (100 rpm). Further tests indicated that nitrogen affected significantly IAA production and the absence of nitrogen in the medium promoted higher IAA production (457 microg mL(-1)). The results obtained here may contribute to the scaling up for industrial and agricultural applications of a yeast-based product with T. globosa.
PMID: 36091086
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
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) : 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
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
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
Bio Protoc , 2022 Oct , V12 (19) doi: 10.21769/BioProtoc.4524
Extraction and Quantification of Plant Hormones and RNA from Pea Axillary Buds.
ARC Centre of Excellence for Plant Success in Nature and Agriculture, School of Biological Sciences, The University of Queensland, St Lucia, 4072, Australia.; Graduate School of Agriculture, Ehime University, Matsuyama, Japan.
The quantification of plant hormones and related gene expression is essential to improve the understanding of the molecular regulation of plant growth and development. However, plant hormone quantification is still challenging due to extremely low endogenous levels and high chemical diversity. In this study, we present a convenient extraction protocol that enables the simultaneous extraction of both phytohormones and RNA from the same sample in a small quantity (approximately 10 mg). Using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS), this protocol provides a method to quantify 13 phytohormones and their derivatives from four classes (cytokinin, auxin, abscisic acid, and gibberellin) at the speed of 14 min per sample.
PMID: 36313201
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
Curr Protoc , 2022 Oct , V2 (10) : Pe562 doi: 10.1002/cpz1.562
Maize Seedling Growth and Hormone Response Assays Using the Rolled Towel Method.
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa.; Current address: Corteva Agriscience, 8325 NW 62nd Ave, Johnston, Iowa.
Root system architecture is a critical factor in maize health and stress resilience. Determining the genetic and environmental factors that shape maize root system architecture is an active research area. However, the ability to phenotype juvenile root systems is hindered by the use of field-grown and soil-based systems. An alternative to soil- and field-based growing conditions for maize seedlings is a controlled environment with a soil-free medium, which can facilitate root system phenotyping. Here, we describe how to grow maize under soil-free conditions for up to 12 days to facilitate root phenotyping. Maize seeds are sterilized and planted on specialized seed germination paper to minimize fungal contamination and ensure synchronized seedling growth, followed by imaging at the desired time point. The root images are then analyzed to quantify traits of interest, such as primary root length, lateral root density, seminal root length, and seminal root number. In addition, juvenile shoot traits can be quantified using manual annotation methods. We also outline the steps for performing rigorous hormone response assays for four classical phytohormones: auxin, brassinosteroid, cytokinin, and jasmonic acid. This protocol can be rapidly scaled up and is compatible with genetic screens and sample collection for downstream molecular analyses such as transcriptomics and proteomics. (c) 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Maize seedling rolled towel assay and phenotyping Basic Protocol 2: Maize seedling hormone response assays using the rolled towel assay.
PMID: 36194012