Nat Commun , IF:14.919 , 2022 Feb , V13 (1) : P815 doi: 10.1038/s41467-022-28507-1
Defining molecular glues with a dual-nanobody cannabidiol sensor.
Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.; Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA.; Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA. nzheng@uw.edu.
"Molecular glue" (MG) is a term coined to describe the mechanism of action of the plant hormone auxin and subsequently used to characterize synthetic small molecule protein degraders exemplified by immune-modulatory imide drugs (IMiDs). Prospective development of MGs, however, has been hampered by its elusive definition and thermodynamic characteristics. Here, we report the crystal structure of a dual-nanobody cannabidiol-sensing system, in which the ligand promotes protein-protein interaction in a manner analogous to auxin. Through quantitative analyses, we draw close parallels among the dual-nanobody cannabidiol sensor, the auxin perception complex, and the IMiDs-bound CRL4(CRBN) E3, which can bind and ubiquitinate "neo-substrates". All three systems, including the recruitment of IKZF1 and CK1alpha to CRBN, are characterized by the lack of ligand binding activity in at least one protein partner and an under-appreciated preexisting low micromolar affinity between the two proteinaceous subunits that is enhanced by the ligand to reach the nanomolar range. These two unifying features define MGs as a special class of proximity inducers distinct from bifunctional compounds and can be used as criteria to guide target selection for future rational discovery of MGs.
PMID: 35145136
Dev Cell , IF:12.27 , 2022 Feb , V57 (4) : P526-542.e7 doi: 10.1016/j.devcel.2021.12.019
Dynamic chromatin state profiling reveals regulatory roles of auxin and cytokinin in shoot regeneration.
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; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, P.R. 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), Shanghai 200032, China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, P.R. 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), Shanghai 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, 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), Shanghai 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China. Electronic address: jwwang@sippe.ac.cn.
Shoot regeneration is mediated by the sequential action of two phytohormones, auxin and cytokinin. However, the chromatin regulatory landscapes underlying this dynamic response have not yet been studied. In this study, we jointly profiled chromatin accessibility, histone modifications, and transcriptomes to demonstrate that a high auxin/cytokinin ratio environment primes Arabidopsis shoot regeneration by increasing the accessibility of the gene loci associated with pluripotency and shoot fate determination. Cytokinin signaling not only triggers the commitment of the shoot progenitor at later stages but also allows chromatin to maintain shoot identity genes at the priming stage. Our analysis of transcriptional regulatory dynamics further identifies a catalog of regeneration cis-elements dedicated to cell fate transitions and uncovers important roles of BES1, MYC, IDD, and PIF transcription factors in shoot regeneration. Our results, thus, provide a comprehensive resource for studying cell reprogramming in plants and provide potential targets for improving future shoot regeneration efficiency.
PMID: 35063083
New Phytol , IF:10.151 , 2022 Feb , V233 (4) : P1732-1749 doi: 10.1111/nph.17890
A plastidial retrograde signal potentiates biosynthesis of systemic stress response activators.
Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, CA, 92521, USA.; Laboratory of Allergy and Inflammation, Chengdu Third People's Hospital Branch of National Clinical Research Center for Respiratory Disease, Chengdu,, 610031, China.; Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA.
Plants employ an array of intricate and hierarchical signaling cascades to perceive and transduce informational cues to synchronize and tailor adaptive responses. Systemic stress response (SSR) is a recognized complex signaling and response network quintessential to plant's local and distal responses to environmental triggers; however, the identity of the initiating signals has remained fragmented. Here, we show that both biotic (aphids and viral pathogens) and abiotic (high light and wounding) stresses induce accumulation of the plastidial-retrograde-signaling metabolite methylerythritol cyclodiphosphate (MEcPP), leading to reduction of the phytohormone auxin and the subsequent decreased expression of the phosphatase PP2C.D1. This enables phosphorylation of mitogen-activated protein kinases 3/6 and the consequential induction of the downstream events ultimately, resulting in biosynthesis of the two SSR priming metabolites pipecolic acid and N-hydroxy-pipecolic acid. This work identifies plastids as a major initiation site, and the plastidial retrograde signal MEcPP as an initiator of a multicomponent signaling cascade potentiating the biosynthesis of SSR activators, in response to biotic and abiotic triggers.
PMID: 34859454
Cold Spring Harb Perspect Biol , IF:10.005 , 2022 Feb , V14 (2) doi: 10.1101/cshperspect.a039875
Auxin Transporters-A Biochemical View.
Plant Systems Biology, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany.; Department of Plant Science and Landscape Architecture.; Agriculture Biotechnology Center, University of Maryland, College Park, Maryland 20742, USA.
From embryogenesis to fruit formation, almost every aspect of plant development and differentiation is controlled by the cellular accumulation or depletion of auxin from cells and tissues. The respective auxin maxima and minima are generated by cell-to-cell auxin transport via transporter proteins. Differential auxin accumulation as a result of such transport processes dynamically regulates auxin distribution during differentiation. In this review, we introduce all auxin transporter (families) identified to date and discuss the knowledge on prominent family members, namely, the PIN-FORMED exporters, ATP-binding cassette B (ABCB)-type transporters, and AUX1/LAX importers. We then concentrate on the biochemical features of these transporters and their regulation by posttranslational modifications and interactors.
PMID: 34127449
Cold Spring Harb Perspect Biol , IF:10.005 , 2022 Feb , V14 (2) doi: 10.1101/cshperspect.a040089
Modeling Auxin Signaling in Roots: Auxin Computations.
Computational Developmental Biology Group, Utrecht University, Utrecht 3584 CH, The Netherlands.
Auxin signaling and patterning is an inherently complex process, involving polarized auxin transport, metabolism, and signaling, its effect on developmental zones, as well as growth rates, and the feedback between all these different aspects. This complexity has led to an important role for computational modeling in unraveling the multifactorial roles of auxin in plant developmental and adaptive processes. Here we discuss the basic ingredients of auxin signaling and patterning models for root development as well as a series of key modeling studies in this area. These modeling studies have helped elucidate how plants use auxin signaling to compute the size of their root meristem, the direction in which to grow, and when and where to form lateral roots. Importantly, these models highlight how auxin, through patterning of and collaborating with other factors, can fulfill all these roles simultaneously.
PMID: 34001532
Plant Biotechnol J , IF:9.803 , 2022 Feb , V20 (2) : P399-408 doi: 10.1111/pbi.13723
Strong and tunable anti-CRISPR/Cas activities in plants.
Instituto de Biologia Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Cientificas (CSIC), Universitat Politecnica de Valencia, Valencia, Spain.
CRISPR/Cas has revolutionized genome engineering in plants. However, the use of anti-CRISPR proteins as tools to prevent CRISPR/Cas-mediated gene editing and gene activation in plants has not been explored yet. This study describes the characterization of two anti-CRISPR proteins, AcrIIA4 and AcrVA1, in Nicotiana benthamiana. Our results demonstrate that AcrIIA4 prevents site-directed mutagenesis in leaves when transiently co-expressed with CRISPR/Cas9. In a similar way, AcrVA1 is able to prevent CRISPR/Cas12a-mediated gene editing. Moreover, using a N. benthamiana line constitutively expressing Cas9, we show that the viral delivery of AcrIIA4 using Tobacco etch virus is able to completely abolish the high editing levels obtained when the guide RNA is delivered with a virus, in this case Potato virus X. We also show that AcrIIA4 and AcrVA1 repress CRISPR/dCas-based transcriptional activation of reporter genes. In the case of AcrIIA4, this repression occurs in a highly efficient, dose-dependent manner. Furthermore, the fusion of an auxin degron to AcrIIA4 results in auxin-regulated activation of a downstream reporter gene. The strong anti-Cas activity of AcrIIA4 and AcrVA1 reported here opens new possibilities for customized control of gene editing and gene expression in plants.
PMID: 34632687
Crit Rev Biotechnol , IF:8.429 , 2022 Feb , V42 (1) : P106-124 doi: 10.1080/07388551.2021.1924113
Plant phospholipase D: novel structure, regulatory mechanism, and multifaceted functions with biotechnological application.
National Institute of Plant Genome Research, New Delhi, India.
Phospholipases D (PLDs) are important membrane lipid-modifying enzymes in eukaryotes. Phosphatidic acid, the product of PLD activity, is a vital signaling molecule. PLD-mediated lipid signaling has been the subject of extensive research leading to discovery of its crystal structure. PLDs are involved in the pathophysiology of several human diseases, therefore, viewed as promising targets for drug design. The availability of a eukaryotic PLD crystal structure will encourage PLD targeted drug designing. PLDs have been implicated in plants response to biotic and abiotic stresses. However, the molecular mechanism of response is not clear. Recently, several novel findings have shown that PLD mediated modulation of structural and developmental processes, such as: stomata movement, root growth and microtubule organization are crucial for plants adaptation to environmental stresses. Involvement of PLDs in regulating membrane remodeling, auxin mediated alteration of root system architecture and nutrient uptake to combat nitrogen and phosphorus deficiencies and magnesium toxicity is established. PLDs via vesicle trafficking modulate cytoskeleton and exocytosis to regulate self-incompatibility (SI) signaling in flowering plants, thereby contributes to plants hybrid vigor and diversity. In addition, the important role of PLDs has been recognized in biotechnologically important functions, including oil/TAG synthesis and maintenance of seed quality. In this review, we describe the crystal structure of a plant PLD and discuss the molecular mechanism of catalysis and activity regulation. Further, the role of PLDs in regulating plant development under biotic and abiotic stresses, nitrogen and phosphorus deficiency, magnesium ion toxicity, SI signaling and pollen tube growth and in important biotechnological applications has been discussed.
PMID: 34167393
Plant Physiol , IF:8.34 , 2022 Feb doi: 10.1093/plphys/kiac084
The BTB-TAZ protein MdBT2 recruits auxin signaling components to regulate adventitious root formation in apple.
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Tai-An, 271018, Shandong, China.; Institute of Grape Science and Engineering,College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China.
Ubiquitination is an important post-translational protein modification. Although BTB and TAZ domain protein 2 (BT2) is involved in many biological processes, its role in apple (Malus domestic) root formation remains unclear. Here, we revealed that MdBT2 inhibits adventitious root (AR) formation through interacting with AUXIN RESPONSE FACTOR8 (MdARF8) and INDOLE-3-ACETIC ACID INDUCIBLE3 (MdIAA3). MdBT2 facilitated MdARF8 ubiquitination and degradation through the 26S proteasome pathway and negatively regulated GRETCHEN HAGEN 3.1 (MdGH3.1) and MdGH3.6 expression. MdARF8 regulates AR formation through inducing transcription of MdGH3s (MdGH3.1, MdGH3.2, MdGH3.5, and MdGH3.6). In addition, MdBT2 facilitated MdIAA3 stability and slightly promoted its interaction with MdARF8. MdIAA3 inhibited AR formation by forming heterodimers with MdARF8 as well as other MdARFs (MdARF5, MdARF6, MdARF7, and MdARF19). Our findings reveal that MdBT2 acts as a negative regulator of AR formation in apple.
PMID: 35218363
Plant Physiol , IF:8.34 , 2022 Feb doi: 10.1093/plphys/kiac046
The CCCH Zinc Finger Protein C3H15 Negatively Regulates Cell Elongation by Inhibiting Brassinosteroid Signaling.
College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.; Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.; Academy of Dongying Efficient Agricultural Technology and Industry on Saline and Alkaline Land in Collaboration with Qingdao Agricultural University, Dongying 257000, China.; State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.; College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.; Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan 430062, China.; Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, China.; College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, China.
Plant CCCH proteins participate in the control of multiple developmental and adaptive processes, but the regulatory mechanisms underlying these processes are not well known. In this study, we showed that the Arabidopsis (Arabidopsis thaliana) CCCH protein C3H15 negatively regulates cell elongation by inhibiting brassinosteroid (BR) signaling. Genetic and biochemical evidence showed that C3H15 functions downstream of the receptor BR INSENSITIVE 1 (BRI1) as a negative regulator in the BR pathway. C3H15 is phosphorylated by the GLYCOGEN SYNTHASE KINASE 3 (GSK3)-like kinase BR-INSENSITIVE 2 (BIN2) at Ser111 in the cytoplasm in the absence of BRs. Upon BR perception, C3H15 transcription is enhanced, and the phosphorylation of C3H15 by BIN2 is reduced. The dephosphorylated C3H15 protein accumulates in the nucleus, where C3H15 regulates transcription via G-rich elements (typically GGGAGA). C3H15 and BRASSINAZOLE RESISTANT 1 (BZR1)/BRI1-EMS-SUPPRESSOR 1 (BES1), two central transcriptional regulators of BR signaling, directly suppress each other and share a number of BR-responsive target genes. Moreover, C3H15 antagonizes BZR1 and BES1 to regulate the expression of their shared cell elongation-associated target gene, SMALL AUXIN-UP RNA 15 (SAUR15). This study demonstrates that C3H15-mediated BR signaling may be parallel to, or even attenuate, the dominant BZR1 and BES1 signaling pathways to control cell elongation. This finding expands our understanding of the regulatory mechanisms underlying BR-induced cell elongation in plants.
PMID: 35139225
Plant Physiol , IF:8.34 , 2022 Feb doi: 10.1093/plphys/kiac041
Cotton long non-coding RNAs regulate cell wall defense genes and strengthen resistance to Verticillium wilt.
State Key Laboratory of Cotton Biology, Henan Key Laboratory of Plant Stress Biology, School of Life Sciences, School of Computer and Information Engineering, Henan University, Kaifeng, 475001, Henan, China.; Department of Life Science and Biotechnology, Nanyang Normal University, Nanyang 473000, Henan, China.; Chongqing University of Posts and Telecommunications, College of Bioinformation, Chongqing Key Laboratory of Big Data for Bio Intelligence, Chongqing, China.; Southern Plains Agricultural Research Center, Agricultural Research Service, USDA, College Station, TX 77845, USA.; Kaifeng Academy of Agriculture and Forestry, Kaifeng, China, 475000.; State Key Laboratory of Cotton Biology, Cotton Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Anyang, 455000, Henan, China.
In plants, long non-coding RNAs regulate disease resistance against fungi and other pathogens. However, the specific mechanism behind this regulation remains unclear. In this study, we identified disease resistance-related lncRNAs as well as their regulating genes and assessed their functions by infection of cotton (Gossypium) chromosome segment substitution lines with Verticillium dahliae. Our results demonstrated that lncRNA7 and its regulating gene Pectin methylesterase inhibitor 13 (GbPMEI13) positively regulated disease resistance via the silencing approach, while ectopic overexpression of GbPMEI13 in Arabidopsis (Arabidopsis thaliana) promoted growth and enhanced resistance to V. dahliae. In contrast, lncRNA2 and its regulating gene Polygalacturonase 12 (GbPG12) negatively regulated resistance to V. dahliae. We further found that fungal disease-related agents, including the pectin-derived oligogalacturonide (OG), could down-regulate the expression of lncRNA2 and GbPG12, leading to pectin accumulation. Conversely, OG up-regulated the expression of lncRNA7, which encodes a plant peptide phytosulfokine (PSK-alpha), which was confirmed by lncRNA7 overexpression and UPLC-MS experiments. We showed that PSK-alpha promoted IAA accumulation and activated GbPMEI13 expression through Auxin Response Factor 5 (ARF5). Since it is an inhibitor of pectin methylesterase (PME), GbPMEI13 promotes pectin methylation and therefore increases the resistance to V. dahliae. Consistently, we also demonstrated that GbPMEI13 inhibits the mycelial growth and spore germination of V. dahliae in vitro. In this study, we demonstrated that lncRNA7, lncRNA2, and their regulating genes modulate cell wall defense against V. dahliae via auxin-mediated signaling, providing a strategy for cotton breeding.
PMID: 35134243
Plant Physiol , IF:8.34 , 2022 Feb , V188 (2) : P738-748 doi: 10.1093/plphys/kiab568
Toward synthetic plant development.
Department of Bioengineering, Stanford University, Stanford, California 94305, USA.
The ability to engineer plant form will enable the production of novel agricultural products designed to tolerate extreme stresses, boost yield, reduce waste, and improve manufacturing practices. While historically, plants were altered through breeding to change their size or shape, advances in our understanding of plant development and our ability to genetically engineer complex eukaryotes are leading to the direct engineering of plant structure. In this review, I highlight the central role of auxin in plant development and the synthetic biology approaches that could be used to turn auxin-response regulators into powerful tools for modifying plant form. I hypothesize that recoded, gain-of-function auxin response proteins combined with synthetic regulation could be used to override endogenous auxin signaling and control plant structure. I also argue that auxin-response regulators are key to engineering development in nonmodel plants and that single-cell -omics techniques will be essential for characterizing and modifying auxin response in these plants. Collectively, advances in synthetic biology, single-cell -omics, and our understanding of the molecular mechanisms underpinning development have set the stage for a new era in the engineering of plant structure.
PMID: 34904660
Plant Physiol , IF:8.34 , 2022 Feb , V188 (2) : P1095-1110 doi: 10.1093/plphys/kiab558
Auxin biosynthesis maintains embryo identity and growth during BABY BOOM-induced somatic embryogenesis.
Bioscience, Wageningen University and Research, Wageningen, 6700 AA, Netherlands.; Laboratory of Molecular Biology, Wageningen University and Research, Wageningen, 6700 AP, Netherlands.; Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, 40-032, Poland.; Enza Zaden Research and Development B.V, Enkhuizen, 1602 DB, The Netherlands.
Somatic embryogenesis is a type of plant cell totipotency where embryos develop from nonreproductive (vegetative) cells without fertilization. Somatic embryogenesis can be induced in vitro by auxins, and by ectopic expression of embryo-expressed transcription factors like the BABY BOOM (BBM) AINTEGUMENTA-LIKE APETALA2/ETHYLENE RESPONSE FACTOR domain protein. These different pathways are thought to converge to promote auxin response and biosynthesis, but the specific roles of the endogenous auxin pathway in somatic embryogenesis induction have not been well-characterized. Here we show that BBM transcriptionally regulates the YUCCA3 (YUC3) and YUC8 auxin biosynthesis genes during BBM-mediated somatic embryogenesis in Arabidopsis (Arabidopsis thaliana) seedlings. BBM induced local and ectopic YUC3 and YUC8 expression in seedlings, which coincided with increased DR5 auxin response and indole-3-acetic acid (IAA) biosynthesis and with ectopic expression of the WOX2 embryo reporter. YUC-driven auxin biosynthesis was required for BBM-mediated somatic embryogenesis, as the number of embryogenic explants was reduced by ca. 50% in yuc3 yuc8 mutants and abolished after chemical inhibition of YUC enzyme activity. However, a detailed YUC inhibitor time-course study revealed that YUC-dependent IAA biosynthesis is not required for the re-initiation of totipotent cell identity in seedlings. Rather, YUC enzymes are required later in somatic embryo development for the maintenance of embryo identity and growth. This study resolves a long-standing question about the role of endogenous auxin biosynthesis in transcription factor-mediated somatic embryogenesis and also provides an experimental framework for understanding the role of endogenous auxin biosynthesis in other in planta and in vitro embryogenesis systems.
PMID: 34865162
Plant Physiol , IF:8.34 , 2022 Feb , V188 (2) : P931-933 doi: 10.1093/plphys/kiab520
TINY ROOT HAIR 1: uncoupling transporter function in auxin-mediated gravitropism and root hair growth.
University of Melbourne, School of BioSciences, Parkville 3010, Australia.
PMID: 34747493
Plant Physiol , IF:8.34 , 2022 Feb , V188 (2) : P1043-1060 doi: 10.1093/plphys/kiab472
Potassium transporter TRH1/KUP4 contributes to distinct auxin-mediated root system architecture responses.
Department of Biotechnology, Agricultural University of Athens, Athens 118 55, Greece.; Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala SE-756 61, Sweden.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, Umea SE-901 83, Sweden.; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion GR 70 013, Greece.; Department of Biology, University of Crete, Heraklion GR 71 500, Greece.
In plants, auxin transport and development are tightly coupled, just as hormone and growth responses are intimately linked in multicellular systems. Here we provide insights into uncoupling this tight control by specifically targeting the expression of TINY ROOT HAIR 1 (TRH1), a member of plant high-affinity potassium (K+)/K+ uptake/K+ transporter (HAK/KUP/KT) transporters that facilitate K+ uptake by co-transporting protons, in Arabidopsis root cell files. Use of this system pinpointed specific root developmental responses to acropetal versus basipetal auxin transport. Loss of TRH1 function shows TRHs and defective root gravitropism, associated with auxin imbalance in the root apex. Cell file-specific expression of TRH1 in the central cylinder rescued trh1 root agravitropism, whereas positional TRH1 expression in peripheral cell layers, including epidermis and cortex, restored trh1 defects. Applying a system-level approach, the role of RAP2.11 and ROOT HAIR DEFECTIVE-LIKE 5 transcription factors (TFs) in root hair development was verified. Furthermore, ERF53 and WRKY51 TFs were overrepresented upon restoration of root gravitropism supporting involvement in gravitropic control. Auxin has a central role in shaping root system architecture by regulating multiple developmental processes. We reveal that TRH1 jointly modulates intracellular ionic gradients and cell-to-cell polar auxin transport to drive root epidermal cell differentiation and gravitropic response. Our results indicate the developmental importance of HAK/KUP/KT proton-coupled K+ transporters.
PMID: 34633458
Sci Total Environ , IF:7.963 , 2022 Feb , V806 (Pt 2) : P150592 doi: 10.1016/j.scitotenv.2021.150592
Characterization of bacterial communities isolated from municipal waste compost and screening of their plant-interactive phenotypes.
Department of Biology, UniPD, Padova, Italy; Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), UniPD, Legnaro, PD, Italy.; Department of Biology, UniPD, Padova, Italy.; Societa Estense Servizi Ambientali S.E.S.A., Este, PD, Italy.; Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), UniPD, Legnaro, PD, Italy.; Department of Biology, UniPD, Padova, Italy; Botanical Garden, UniPD, Padova, Italy. Electronic address: barbara.baldan@unipd.it.
Four batches of commercial compost obtained from the organic fraction of municipal solid waste were analyzed from chemical and microbiological standpoints. The working hypothesis was that, being this type of compost derived partly from plant waste, it could contain plant-growth promoting bacterial endophytes, prone to be active again upon its usual delivery as fertilizer. Culturable bacteria were isolated at different temperatures, quantified by colony morphology, identified taxonomically by 16S sequencing and screened for plant-growth promoting phenotypes including auxin and siderophore production, phosphate solubilization and peptide mineralization to ammonia. In parallel, the total community was assessed by culture independent DNA metabarcoding. The capability of plants to select, uptake and internally multiply bacteria from these compost samples was analyzed using grapevine in-vitro rooting cuttings from which acquired bacteria were reisolated, quantified and their identities determined as above. Major differences in compost bacterial composition were observed as function of the season, with the winter sample being rather distinct from the summer ones. Bacillales and Actinomycetales dominated the culturable communities while Alteromonadales, Oceanospirillales and Flavobacteriales prevailed in the total community. In spite of the challenging composting cycle conditions, the plant nature of the main input substrates appeared determinant in guaranteeing that 82% of the culturable bacteria were found endowed with one or more of the plant growth-promoting phenotypes tested. Beside its fertilization role, compost proved to be also a potential inoculant carrier for the in-soil delivery of plant beneficial microorganisms. Furthermore, upon an in vitro passage through grapevine plants under axenic conditions, the subsequently recoverable endophyte community yielded also members of the Rhizobiales order which had not been detectable when culturing directly from compost. This observation further suggests that compost-borne plant-interacting taxa could be also rescued from non-culturable states and/or enriched above detectability levels by a contact with their potential host plants.
PMID: 34592304
Curr Opin Plant Biol , IF:7.834 , 2022 Feb , V65 : P102174 doi: 10.1016/j.pbi.2022.102174
Auxin canalization: From speculative models toward molecular players.
Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria; Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences and Faculty of Science of Palacky University, Olomouc, Czech Republic.; Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria.; Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria. Electronic address: jiri.friml@ist.ac.at.
Among the most fascinated properties of the plant hormone auxin is its ability to promote formation of its own directional transport routes. These gradually narrowing auxin channels form from the auxin source toward the sink and involve coordinated, collective polarization of individual cells. Once established, the channels provide positional information, along which new vascular strands form, for example, during organogenesis, regeneration, or leave venation. The main prerequisite of this still mysterious auxin canalization mechanism is a feedback between auxin signaling and its directional transport. This is manifested by auxin-induced re-arrangements of polar, subcellular localization of PIN-FORMED (PIN) auxin exporters. Immanent open questions relate to how position of auxin source and sink as well as tissue context are sensed and translated into tissue polarization and how cells communicate to polarize coordinately. Recently, identification of the first molecular players opens new avenues into molecular studies of this intriguing example of self-organizing plant development.
PMID: 35123880
Curr Opin Plant Biol , IF:7.834 , 2022 Feb , V65 : P102146 doi: 10.1016/j.pbi.2021.102146
Phosphorylation control of PIN auxin transporters.
Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany.; Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany. Electronic address: claus.schwechheimer@wzw.tum.de.
The directional transport of the phytohormone auxin is required for proper plant development and tropic growth. Auxin cell-to-cell transport gains directionality through the polar distribution of 'canonical' long PIN-FORMED (PIN) auxin efflux carriers. In recent years, AGC kinases, MAP kinases, Ca(2+)/CALMODULIN-DEPENDENT PROTEIN KINASE-RELATED KINASEs and receptor kinases have been implicated in the control of PIN activity, polarity and trafficking. In this review, we summarize the current knowledge in understanding the posttranslational regulation of PINs by these different protein kinase families. The proposed regulation of PINs by AGC kinases after salt stress and by the stress-activated MAP kinases suggest that abiotic and biotic stress factors may modulate auxin transport and thereby plant growth.
PMID: 34974229
Curr Opin Plant Biol , IF:7.834 , 2022 Feb , V65 : P102115 doi: 10.1016/j.pbi.2021.102115
Cellular and molecular bases of lateral root initiation and morphogenesis.
Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico (UNAM), Cuernavaca, 62210, Morelos, Mexico.; Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico (UNAM), Cuernavaca, 62210, Morelos, Mexico. Electronic address: joseph.dubrovsky@ibt.unam.mx.
Lateral root development is essential for the establishment of the plant root system. Lateral root initiation is a multistep process that impacts early primordium morphogenesis and is linked to the formation of a morphogenetic field of pericycle founder cells. Gradual recruitment of founder cells builds this morphogenetic field in an auxin-dependent manner. The complex process of lateral root primordium morphogenesis includes several subprocesses, which are presented in this review. The underlying cellular and molecular mechanisms of these subprocesses are examined.
PMID: 34742019
Curr Opin Plant Biol , IF:7.834 , 2022 Feb , V65 : P102117 doi: 10.1016/j.pbi.2021.102117
Integration of nutrient and water availabilities via auxin into the root developmental program.
Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466, Stadt Seeland, OT Gatersleben, Germany.; Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466, Stadt Seeland, OT Gatersleben, Germany. Electronic address: vonwiren@ipk-gatersleben.de.
In most soils, the spatial distribution of nutrients and water in the rooting zone of plants is heterogeneous and changes over time. To access localized resources more efficiently, plants induce foraging responses by modulating individual morphological root traits, such as the length of the primary root or the number and length of lateral roots. These adaptive responses require the integration of exogenous and endogenous nutrient- or water-related signals into the root developmental program. Recent studies corroborated a central role of auxin in shaping root architectural traits in response to fluctuating nutrient and water availabilities. In this review, we highlight current knowledge on nutrient- and water-related developmental processes that impact root foraging and involve auxin as a central player. A deeper understanding and exploitation of these auxin-related processes and mechanisms promises advances in crop breeding for higher resource efficiency.
PMID: 34624806
Curr Opin Plant Biol , IF:7.834 , 2022 Feb , V65 : P102111 doi: 10.1016/j.pbi.2021.102111
Hormonal control of cell identity and growth in the shoot apical meristem.
College of Agriculture, South China Agricultural University, 510642, Guangzhou, China; Guangdong Laboratory for Lingnan Modern Agriculture, 510642, Guangzhou, China; Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France.; Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France. Electronic address: teva.vernoux@ens-lyon.fr.
How cells acquire their identities and grow coordinately within a tissue is a fundamental question to understand plant development. In angiosperms, the shoot apical meristem (SAM) is a multicellular tissue containing a stem cell niche, which activity allows for a dynamic equilibrium between maintenance of stem cells and production of differentiated cells that are incorporated in new aerial tissues and lateral organs produced in the SAM. Plant hormones are small-molecule signals controlling many aspects of plant development and physiology. Several hormones are essential regulators of SAM activities. This review highlights current advances that are starting to decipher the complex mechanisms underlying the hormonal control of cell identity and growth in the SAM.
PMID: 34543915
Plant Cell Environ , IF:7.228 , 2022 Feb doi: 10.1111/pce.14290
Jasmonic acid coordinates with light, glucose and auxin signalling in regulating branching angle of Arabidopsis lateral roots.
National Institute of Plant Genome Research, New Delhi, India.
The role of jasmonates (JAs) in primary root growth and development and in plant response to external stimuli is already known. However, its role in lateral root (LR) development remains to be explored. Our work identified methyl jasmonate (MeJA) as a key phytohormone in determining the branching angle of Arabidopsis LRs. MeJA inclines the LRs to a more vertical orientation, which was dependent on the canonical JAR1-COI1-MYC2,3,4 signalling. Our work also highlights the dual roles of light in governing LR angle. Light signalling enhances JA biosynthesis, leading to erect root architecture; whereas, glucose (Glc) induces wider branching angles. Combining physiological and molecular assays, we revealed that Glc antagonises the MeJA response via TARGET OF RAPAMYCIN (TOR) signalling. Moreover, physiological assays using auxin mutants, MYC2-mediated transcriptional activation of LAZY2, LAZY4 and auxin biosynthetic gene CYP79B2, and asymmetric distribution of DR5::GFP and PIN2::GFP pinpointed the role of an intact auxin machinery required by MeJA for vertical growth of LRs. We also demonstrated that light perception and signalling are indispensable for inducing vertical angles by MeJA. Thus, our investigation highlights antagonism between light and Glc signalling and how they interact with JA-auxin signals to optimise the branching angle of LRs.
PMID: 35147228
Plant Cell Environ , IF:7.228 , 2022 Feb , V45 (2) : P572-590 doi: 10.1111/pce.14229
Insights into ROS-dependent signalling underlying transcriptomic plant responses to the herbicide 2,4-D.
Departamento de Bioquimica, Biologia Celular y Molecular de Plantas, EEZ, CSIC, Granada, Spain.; Bioinformatics Unit, IPBLN, CSIC, Granada, Spain.; Plataforma Andaluza de Bioinformatica-SCBI, Universidad de Malaga, Malaga, Spain.; Department Ciencies Agraries i del Medi Natural, Universitat Jaume I, Castello de la Plana, Spain.; Departamento de Biologia Molecular y Bioquimica, Ciencias, Univ. de Malaga, Malaga, Spain.; Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM-UMA-CSIC), Malaga, Spain.; Instituto de Biologia Molecular y Celular de Plantas (CSIC-Univ. Valencia), CPI Edificio 8E, Valencia, Spain.
The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) functions as an agronomic weed control herbicide. High concentrations of 2,4-D induce plant growth defects, particularly leaf epinasty and stem curvature. Although the 2,4-D triggered reactive oxygen species (ROS) production, little is known about its signalling. In this study, by using a null mutant in peroxisomal acyl CoA oxidase 1 (acx1-2), we identified acyl-coenzyme A oxidase 1 (ACX1) as one of the main sources of ROS production and, in part, also causing the epinastic phenotype following 2,4-D application. Transcriptomic analyses of wild type (WT) plants after treatment with 2,4-D revealed a ROS-related peroxisomal footprint in early plant responses, while other organelles, such as mitochondria and chloroplasts, are involved in later responses. Interestingly, a group of 2,4-D-responsive ACX1-dependent transcripts previously associated with epinasty is related to auxin biosynthesis, metabolism, and signalling. We found that the auxin receptor auxin signalling F-box 3 (AFB3), a component of Skp, Cullin, F-box containing complex (SCF) (ASK-cullin-F-box) E3 ubiquitin ligase complexes, which mediates auxin/indole acetic acid (AUX/IAA) degradation by the 26S proteasome, acts downstream of ACX1 and is involved in the epinastic phenotype induced by 2,4-D. We also found that protein degradation associated with ubiquitin E3-RING and E3-SCF-FBOX in ACX1-dependent signalling in plant responses to 2,4-D is significantly regulated over longer treatment periods.
PMID: 34800292
Plant Cell Environ , IF:7.228 , 2022 Feb , V45 (2) : P496-511 doi: 10.1111/pce.14216
(+)-Catechin, epicatechin and epigallocatechin gallate are important inducible defensive compounds against Ectropis grisescens in tea plants.
National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Hangzhou, China.
The tea plant, Camellia sinensis (L.) O. Kuntze, is an economically important, perennial woody plant rich in catechins. Although catechins have been reported to play an important role in plant defences against microbes, their roles in the defence of tea plants against herbivores remain unknown. In this study, we allowed the larvae of Ectropis grisescens, a leaf-feeding pest, to feed on the plants, and alternatively, we wounded the plants and then treated them with E. grisescens oral secretions (WOS). Both approaches triggered jasmonic acid-, ethylene- and auxin-mediated signalling pathways; as a result, plants accumulated three catechin compounds: (+)-catechin, epicatechin and epigallocatechin. Not only was the mass of E. grisescens larvae fed on plants previously infested with E. grisescens or treated with WOS significantly lower than that of larvae fed on controls, but also artificial diet supplemented with epicatechin, (+)-catechin or epigallocatechin gallate reduced larval growth rates. In addition, the exogenous application of jasmonic acid, ethylene or auxin induced the biosynthesis of the three catechins, which, in turn, enhanced the resistance of tea plants to E. grisescens, leading to the coordination of the three signalling pathways. Our results suggest that the three catechins play an important role in the defences of tea plants against E. grisescens.
PMID: 34719788
Microbiol Spectr , IF:7.171 , 2022 Feb , V10 (1) : Pe0034521 doi: 10.1128/spectrum.00345-21
Functional Genetic Diversity and Plant Growth Promoting Potential of Polyphosphate Accumulating Bacteria in Soil.
Division of Microbial Technology, CSIR-National Botanical Research Institute, Lucknow, India.; Academy of Scientific and Innovative Research, AcSIR, Ghaziabad, India.; Department of Botany, Kumaun University, Nainital, India.; Computational Biology Laboratory, Genetics and Biotechnology Division, CSIR-National Botanical Research Institute, Lucknow, India.
Polyphosphate (polyP) accumulation is an important trait of microorganisms. Implication of polyP accumulating bacteria (PAB) in enhanced biological phosphate removal, heavy metal sequestration, and dissolution of dental enamel is well studied. Phosphorous (P) accumulated within microbial biomass also regulates labile P in soil; however, abundance and diversity of the PAB in soil is still unexplored. Present study investigated the genetic and functional diversity of PAB in rhizosphere soil. Here, we report the abundance of Pseudomonas spp. as high PAB in soil, suggesting their contribution to global P cycling. Additional subset analysis of functional genes i.e., polyphosphate kinase (ppk) and exopolyphosphatase (ppx) in all PAB, indicates their significance in bacterial growth and metabolism. Distribution of functional genes in phylogenetic tree represent a more biologically realistic discrimination for the two genes. Distribution of ppx gene disclosed its phylogenetic conservation at species level, however, clustering of ppk gene of similar species in different clades illustrated its environmental condition mediated modifications. Selected PAB showed tolerance to abiotic stress and strong correlation with plant growth promotary (PGP) traits viz. phosphate solubilization, auxin and siderophore production. Interaction of PAB with A. thaliana enhanced the growth and phosphate status of the plant under salinity stress, suggestive of their importance in P cycling and stress alleviation. IMPORTANCE Study discovered the abundance of Pseudomonas genera as a high phosphate accumulator in soil. The presence of functional genes (polyphosphate kinase [ppk] and exopolyphosphatase [ppx]) in all PAB depicts their importance in polyphosphate metabolism in bacteria. Genetic and functional diversity reveals conservation of the ppx gene at species level. Furthermore, we found a positive correlation between PAB and plant growth promotary traits, stress tolerance, and salinity stress alleviation in A. thaliana.
PMID: 35196785
Chemosphere , IF:7.086 , 2022 Feb : P134044 doi: 10.1016/j.chemosphere.2022.134044
Increasing atmospheric CO2 differentially supports arsenite stress mitigating impact of arbuscular mycorrhizal fungi in wheat and soybean plants.
Laboratory for Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, Antwerp, Belgium; Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, 62521, Beni-Suef, Egypt.; Department of Agricultural Microbiology, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt.; Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia.; Department of Biological Sciences, College of Science, King Faisal University, Al-Ahsa, 31982, Saudi Arabia; Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza, 12613, Egypt.; Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia.; Department of Biological Sciences, College of Science, King Faisal University, Al-Ahsa, 31982, Saudi Arabia.; Laboratory for Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, Antwerp, Belgium.; Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt. Electronic address: salahco_2010@mans.edu.eg.
Arbuscular mycorrhizal fungi (AMF) are beneficial for the plant growth under heavy metal stress. Such beneficial effect is improved by elevated CO2 (eCO2). However, the mechanisms by which eCO2 improves AMF symbiotic associations under arsenite (As(III)) toxicity are hardly studied. Herein, we compared these regulatory mechanisms in species from two agronomical important plant families - grasses (wheat) and legumes (soybean). As(III) decreased plant growth (i.e., 53.75 and 60.29% of wheat and soybean, respectively) and photosynthesis. It also increased photorespiration and oxidative injury in both species, but soybean was more sensitive to oxidative stress as indicated by higher H2O2 accumulation and oxidation of protein and lipid. eCO2 significantly improved AMF colonization by increasing auxin levels, which induced high carotenoid cleavage dioxygenase (CCDs) activity, particularly in soybean roots. The improved sugar metabolism in plant shoots by co-application of eCO2 and As(III) allocated more sugars to roots sequentially. Sugar accumulation in plant roots is further induced by AMF, resulting in more C skeletons to produce organic acids, which are effectively exudated into the soil to reduce As(III) uptake. Exposure to eCO2 reduced oxidative damage and this mitigation was stronger in soybean. This could be attributed to a greater reduction in photorespiration as well as a stronger antioxidant and detoxification defence systems. The grass/legume-specificity was supported by principal component analysis, which revealed that soybean was more affected by As(III) stress and more responsive to AMF and eCO2. This study provided a mechanistic understanding of the impact of AMF, eCO2 and their interaction on As-stressed grass and legume plants, allowing better practical strategies to mitigate As(III) phytotoxicity.
PMID: 35202662
J Integr Plant Biol , IF:7.061 , 2022 Feb doi: 10.1111/jipb.13237
Symplastic communication in the root cap directs auxin distribution to modulate root development.
College of Life Sciences, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; The Department of Plant Systems Physiology, Radboud University, Netherlands.
Root cap not only protects root meristem, but also detects and transduces the signals of environmental changes to affect root development. The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments. However, it is unclear how the symplastic communication between root cap cells affects root growth. Here we exploit an inducible system to specifically block the symplastic communication in the root cap. Transient blockage of plasmodesmata (PD) in differentiated collumella cells severely impairs the root development in Arabidopsis, in particular in the stem cell niche and the proximal meristem. The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution. In the later stage, the cell division in proximal meristem is inhibited, presumably due to the reduced auxin level in the root cap. Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development. This article is protected by copyright. All rights reserved.
PMID: 35199475
J Integr Plant Biol , IF:7.061 , 2022 Feb , V64 (2) : P371-392 doi: 10.1111/jipb.13225
Auxin signaling: Research advances over the past 30 years.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China.; Institute of Science and Technology (IST), Klosterneuburg, 3400, Austria.
Auxin, one of the first identified and most widely studied phytohormones, has been and will remain a hot topic in plant biology. After more than a century of passionate exploration, the mysteries of its synthesis, transport, signaling, and metabolism have largely been unlocked. Due to the rapid development of new technologies, new methods, and new genetic materials, the study of auxin has entered the fast lane over the past 30 years. Here, we highlight advances in understanding auxin signaling, including auxin perception, rapid auxin responses, TRANSPORT INHIBITOR RESPONSE 1 and AUXIN SIGNALING F-boxes (TIR1/AFBs)-mediated transcriptional and non-transcriptional branches, and the epigenetic regulation of auxin signaling. We also focus on feedback inhibition mechanisms that prevent the over-amplification of auxin signals. In addition, we cover the TRANSMEMBRANE KINASE-mediated non-canonical signaling, which converges with TIR1/AFBs-mediated transcriptional regulation to coordinate plant growth and development. The identification of additional auxin signaling components and their regulation will continue to open new avenues of research in this field, leading to an increasingly deeper, more comprehensive understanding of how auxin signals are interpreted at the cellular level to regulate plant growth and development.
PMID: 35018726
J Exp Bot , IF:6.992 , 2022 Feb doi: 10.1093/jxb/erac074
Serratia marcescens PLR enhances lateral root formation through supplying PLR-derived auxin and enhancing auxin biosynthesis in Arabidopsis.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China.; Peking University Institute of Advanced Agricultural Sciences, Weifang, China.; Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China.; State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
Plant-growth-promoting rhizobacteria (PGPR) refer to bacteria that colonize the rhizosphere and contribute to plant growth or stress tolerance. To further understand the molecular mechanism of symbiosis of plants-PGPRs, we performed a high-throughput single colony screening from rhizosphere, and uncovered a bacterium (named promoting lateral root, PLR) that significantly promotes Arabidopsis lateral root formation. By 16S rDNA sequencing, PLR was identified as a novel sub-species of Serratia marcescens. RNA-seq analysis of Arabidopsis integrated with phenotypic verification of auxin signaling mutants demonstrated that the promotion effect of PLR on lateral root formation is dependent on auxin signaling. Furthermore, PLR enhanced the tryptophan-dependent IAA synthesis by inducing multiple auxin synthesis genes in Arabidopsis. Genome-wide sequencing of PLR integrated with the identification of IAA and its precursors in PLR exudates showed that tryptophan treatment significantly enhanced the ability of PLR to produce IAA and its precursors IPA and IAM. Interestingly, PLR induced multiple nutrient (N, P, K, S) transporter genes in an auxin-independent manner. In summary, this study provides evidence to show how PLR enhances plant growth through finely tuning auxin biosynthesis and signaling in Arabidopsis, implying a potential application of PLR in crop yield improvement through accelerating root development.
PMID: 35196372
J Exp Bot , IF:6.992 , 2022 Feb doi: 10.1093/jxb/erac059
Ammonium transporters cooperatively regulate rice crown root formation responding to ammonium nitrogen.
MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China.
Crown roots (CRs) are major components of rice root system and develop at the basal node of the shoot, and CR development is largely influenced by environmental factors. Ammonium nitrogen is known to impact plant root development through ammonium transporter AMTs, but it remains unclear whether ammonium and AMTs play roles in rice CR formation. In this study, we revealed a significant role of ammonium, rather than nitrate, in regulating rice CR development. High ammonium supply increases CR formation but inhibits CR elongation. Genetic evidence showed that the regulation of ammonium in CR development relies on ammonium uptake mediated jointly by OsAMT1;1, OsAMT1;2; OsAMT1;3, and OsAMT2;1, but not on root acidification in which ammonium uptake resulted. OsAMTs are also needed for glutamine-induced CR formation. Furthermore, we showed that auxin efflux carriers PINs-dependent polar auxin transport acts downstream of ammonium uptake and assimilation to activate local auxin signaling at CR primordium, in turn promoting CR formation. Taken together, our results highlight a critical role of OsAMTs in cooperatively regulating CR formation through regulating auxin transport under N-rich condition.
PMID: 35176162
J Exp Bot , IF:6.992 , 2022 Feb doi: 10.1093/jxb/erac050
ORESARA 15, a PLATZ transcription factor, controls root meristem size through auxin and cytokinin signaling-related pathways.
Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea.; Center for Plant Aging Research, Institute for Basic Science, Daegu 42988, Republic of Korea.; Department of Biological Sciences, Chungnam National University, Daejeon 34134, Republic of Korea.; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea.; New Biology Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea.
An optimal size of postembryonic root apical meristem (RAM) is achieved by a balance between cell division and differentiation. Despite extensive research, molecular mechanisms underlying the coordination of cell division and differentiation are still fragmentary. Here, we report that ORESARA 15 (ORE15), an Arabidopsis PLATZ transcription factor preferentially expressed in the RAM, determines RAM size. The primary root length, RAM size, cell division rate, and stem cell niche activity were reduced in an ore15 loss-of-function mutant but enhanced in an activation-tagged line overexpressing ORE15 compared with the wild type. ORE15 forms mutually positive and negative feedback loops with auxin and cytokinin signaling, respectively. Collectively, our findings imply that ORE15 controls the RAM size by mediating the antagonistic interaction between auxin and cytokinin signaling-related pathways.
PMID: 35139177
J Exp Bot , IF:6.992 , 2022 Feb doi: 10.1093/jxb/erac036
FRAGILE CULM 18 encodes a UDP-glucuronic acid decarboxylase required for xylan biosynthesis and plant growth in rice.
Rice Research Institute, Shenyang Agricultural University, Shenyang, China.; Jinzhou Academy of Science and Technology, Jinzhou, China.
Although UDP-glucuronic acid decarboxylases (UXSs) have been well studied to catalyze the conversion of UDP-glucuronic acid into UDP-xylose, their biological roles in grasses remains largely unknown. The rice (Oryza sativa) genome contains six UXSs, but none of them has been genetically characterized. Here, we reported on the characterization of a novel rice fragile culm mutant, fc18, which exhibited brittleness with altered cell wall and pleiotropic defects in growth. Map-based cloning and transgenic analyses revealed that the FC18 encodes a cytosol-localized OsUXS3 and is widely expressed with higher levels in xylan-rich tissues. Monosaccharide analysis showed that the xylose level decreased in fc18, and cell wall fractions determinations confirmed that the xylan content in fc18 declined, suggesting that UDP-xylose from FC18 participates in xylan biosynthesis. Moreover, the fc18 mutant displayed defective cellulose properties, which led to an enhancement in biomass saccharification. Furthermore, genes involved in sugar metabolism and phytohormone signal transduction were largely altered in fc18. Consistently, the fc18 mutant exhibited significantly reduced free auxin (indole-3-acetic acid, IAA) content and lower expression levels of PIN family genes compared to wild-type. Our work underpins the physiological roles of FC18/UXS3 in xylan biosynthesis, cellulose deposition, and plant growth in rice.
PMID: 35104839
Hortic Res , IF:6.793 , 2022 Feb doi: 10.1093/hr/uhac032
Physiological, biochemical, and molecular aspects of grafting in fruit trees.
Horticultural Sciences Department, University of Florida, Gainesville, FL 32607 USA.
Grafting is a widely used practice for asexual propagation of fruit trees. Many physiological, biochemical, and molecular changes occur upon grafting that can influence important horticultural traits. This technology has many advantages, including avoidance of juvenility, modifying the scion architecture, improving productivity, adapting scion cultivars to unfavourable environmental conditions, and developing traits in resistance to insect pests, bacterial and fungal diseases. A limitation of grafting is scion-rootstock incompatibility. It may be caused by many factors, including insufficient genetic proximity, physiological or biochemical factors, lignification at the graft union, poor graft architecture, insufficient cell recognition between union tissues, and metabolic differences in the scion and the rootstock. Plant hormones, like auxin, ethylene (ET), cytokinin (CK), gibberellin (GA), abscisic acid (ABA), and jasmonic acid (JA) orchestrate several crucial physiological and biochemical processes happening at the site of the graft union. Additionally, epigenetic changes at the union affect chromatin architecture by DNA methylation, histone modification, and the action of small RNA molecules. The mechanism triggering these effects likely is affected by hormonal crosstalk, protein and small molecules movement, nutrients uptake, and transport in the grafted trees. This review provides an overview of the basis of physiological, biochemical, and molecular aspects of fruit tree grafting between scion and rootstock.
PMID: 35184166
Plant J , IF:6.417 , 2022 Feb doi: 10.1111/tpj.15710
NS encodes an auxin transporter that regulates the 'numerous spines' trait in cucumber (Cucumis sativus) fruit.
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Fruit spine is an important agronomic trait in cucumber and the "numerous spines (ns)" cucumber varieties are popular in Europe and West Asia. Although the classical genetic locus of ns was reported more than two decades ago, the NS gene has not been cloned yet. In this study, nine genetic loci for the different densities of fruit spines were identified by a genome-wide association study. Among the nine loci, fsdG2.1 was closely associated with the classical genetic locus ns, which harbors a candidate gene Csa2G264590. Overexpression of Csa2G264590 resulted in lower fruit spine density, and the knockout mutant generated by CRISPR/Cas9 displayed an increased spine density, demonstrating that the Csa2G264590 gene is NS. NS is specifically expressed in the fruit peel and spine. Genetic analysis showed that NS regulates fruit spine development independently of the tuberculate gene, Tu, which regulates spine development on tubercules; the cucumber glabrous mutants csgl1 and csgl3 are epistatic to ns. Furthermore, we found that auxin levels in the fruit peel and spine were significantly lower in the knockout mutant ns-cr. Moreover, RNA-sequencing showed that the plant hormone signal transduction pathway was enriched. Notably, most of the auxin responsive Aux/IAA family genes were downregulated in ns-cr. Haplotype analysis showed that the non-functional haplotype of NS exists exclusively in the Eurasian cucumber backgrounds. Taken together, the cloning of NS gene provides new insights into the regulatory network of fruit spine development.
PMID: 35181968
Plant J , IF:6.417 , 2022 Feb , V109 (4) : P980-991 doi: 10.1111/tpj.15609
Genetic variations in ZmSAUR15 contribute to the formation of immature embryo-derived embryonic calluses in maize.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China.
The ability of immature maize (Zea mays) embryos to form embryonic calluses (ECs) is highly genotype dependent, which limits transgenic breeding development in maize. Here, we report the association map-based cloning of ZmSAUR15 using an association panel (AP) consisting of 309 inbred lines with diverse formation abilities for ECs. We demonstrated that ZmSAUR15, which encodes a small auxin-upregulated RNA, acts as a negative effector in maize EC induction. Polymorphisms in the ZmSAUR15 promoter that influence the expression of ZmSAUR15 transcripts modulate the EC induction capacity in maize. ZmSAUR15 is involved in indole-3-acetic acid biosynthesis and cell division in immature embryo-derived callus. The ability of immature embryos to induce EC formation can be improved by the knockout of ZmSAUR15, which consequently increases the callus regeneration efficiency. Our study provides new insights into overcoming the genotypic limitations associated with EC formation and improving genetic transformation in maize.
PMID: 34822726
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (5) doi: 10.3390/ijms23052696
Thidiazuron Promotes Leaf Abscission by Regulating the Crosstalk Complexities between Ethylene, Auxin, and Cytokinin in Cotton.
Engineering Research Center of Plant Growth Regulator, Ministry of Education/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.; Institute of Agricultural Information, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; High Latitude Crops Institute, Shanxi Agriculture University, Datong 037008, China.
Thidiazuron (TDZ) is widely used as a defoliant to induce leaf abscission in cotton. However, the underlying molecular mechanism is still unclear. In this study, RNA-seq and enzyme-linked immunosorbent assays (ELISA) were performed to reveal the dynamic transcriptome profiling and the change of endogenous phytohormones upon TDZ treatment in leaf, petiole, and abscission zone (AZ). We found that TDZ induced the gene expression of ethylene biosynthesis and signal, and promoted ethylene accumulation earlier in leaf than that in AZ. While TDZ down-regulated indole-3-acetic acid (IAA) biosynthesis genes mainly in leaf and IAA signal and transport genes. Furthermore, the IAA content reduced more sharply in the leaf than that in AZ to change the auxin gradient for abscission. TDZ suppressed CTK biosynthesis genes and induced CTK metabolic genes to reduce the IPA accumulation for the reduction of ethylene sensitivity. Furthermore, TDZ regulated the gene expression of abscisic acid (ABA) biosynthesis and signal and induced ABA accumulation between 12-48 h, which could up-regulate ABA response factor genes and inhibit IAA transporter genes. Our data suggest that TDZ orchestrates metabolism and signal of ethylene, auxin, and cytokinin, and also the transport of auxin in leaf, petiole, and AZ, to control leaf abscission.
PMID: 35269837
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (5) doi: 10.3390/ijms23052472
Combined BSA-Seq Based Mapping and RNA-Seq Profiling Reveal Candidate Genes Associated with Plant Architecture in Brassica napus.
National Center of Rapeseed Improvement in Wuhan, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Plant architecture involves important agronomic traits affecting crop yield, resistance to lodging, and fitness for mechanical harvesting in Brassica napus. Breeding high-yield varieties with plant architecture suitable for mechanical harvesting is the main goal of rapeseed breeders. Here, we report an accession of B. napus (4942C-5), which has a dwarf and compact plant architecture in contrast to cultivated varieties. A BC8 population was constructed by crossing a normal plant architecture line, 8008, with the recurrent parent 4942C-5. To investigate the molecular mechanisms underlying plant architecture, we performed phytohormone profiling, bulk segregant analysis sequencing (BSA-Seq), and RNA sequencing (RNA-Seq) in BC8 plants with contrasting plant architecture. Genetic analysis indicated the plant architecture traits of 4942C-5 were recessive traits controlled by multiple genes. The content of auxin (IAA), gibberellin (GA), and abscisic acid (ABA) differed significantly between plants with contrasting plant architecture in the BC8 population. Based on BSA-Seq analysis, we identified five candidate intervals on chromosome A01, namely those of 0 to 6.33 Mb, 6.45 to 6.48 Mb, 6.51 to 6.53 Mb, 6.77 to 6.79 Mb, and 7 to 7.01 Mb regions. The RNA-Seq analysis revealed a total of 4378 differentially expressed genes (DEGs), of which 2801 were up-regulated and 1577 were down-regulated. There, further analysis showed that genes involved in plant hormone biosynthesis and signal transduction, cell structure, and the phenylpropanoid pathway might play a pivotal role in the morphogenesis of plant architecture. Association analysis of BSA-Seq and RNA-Seq suggested that seven DEGs involved in plant hormone signal transduction and a WUSCHEL-related homeobox (WOX) gene (BnaA01g01910D) might be candidate genes responsible for the dwarf and compact phenotype in 4942C-5. These findings provide a foundation for elucidating the mechanisms underlying rapeseed plant architecture and should contribute to breed new varieties suitable for mechanization.
PMID: 35269615
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23042361
Maize Transcription Factor ZmARF4 Confers Phosphorus Tolerance by Promoting Root Morphological Development.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Wenjiang 611130, China.; Maize Research Institute, Sichuan Agricultural University, Wenjiang 611130, China.; Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Wenjiang 611130, China.; Triticeae Research Institute and Key Lab for Major Crop Diseases, Sichuan Agricultural University, Wenjiang 611130, China.
Plant growth and development are closely related to phosphate (Pi) and auxin. However, data regarding auxin response factors (ARFs) and their response to phosphate in maize are limited. Here, we isolated ZmARF4 in maize and dissected its biological function response to Pi stress. Overexpression of ZmARF4 in Arabidopsis confers tolerance of Pi deficiency with better root morphology than wild-type. Overexpressed ZmARF4 can partially restore the absence of lateral roots in mutant arf7 arf19. The ZmARF4 overexpression promoted Pi remobilization and up-regulated AtRNS1, under Pi limitation while it down-regulated the expression of the anthocyanin biosynthesis genes AtDFR and AtANS. A continuous detection revealed higher activity of promoter in the Pi-tolerant maize P178 line than in the sensitive 9782 line under low-Pi conditions. Meanwhile, GUS activity was specifically detected in new leaves and the stele of roots in transgenic offspring. ZmARF4 was localized to the nucleus and cytoplasm of the mesophyll protoplast and interacted with ZmILL4 and ZmChc5, which mediate lateral root initiation and defense response, respectively. ZmARF4 overexpression also conferred salinity and osmotic stress tolerance in Arabidopsis. Overall, our findings suggest that ZmARF4, a pleiotropic gene, modulates multiple stress signaling pathways, and thus, could be a candidate gene for engineering plants with multiple stress adaptation.
PMID: 35216479
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23042228
Salicylic Acid in Root Growth and Development.
Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia.; Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia.
In plants, salicylic acid (SA) is a hormone that mediates a plant's defense against pathogens. SA also takes an active role in a plant's response to various abiotic stresses, including chilling, drought, salinity, and heavy metals. In addition, in recent years, numerous studies have confirmed the important role of SA in plant morphogenesis. In this review, we summarize data on changes in root morphology following SA treatments under both normal and stress conditions. Finally, we provide evidence for the role of SA in maintaining the balance between stress responses and morphogenesis in plant development, and also for the presence of SA crosstalk with other plant hormones during this process.
PMID: 35216343
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23042210
BnERF114.A1, a Rapeseed Gene Encoding APETALA2/ETHYLENE RESPONSE FACTOR, Regulates Plant Architecture through Auxin Accumulation in the Apex in Arabidopsis.
State Key Laboratory of Stress Biology for Arid Areas, Northwest A&F University, Xianyang 712100, China.; 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 430062, China.
Plant architecture is crucial for rapeseed breeding. Here, we demonstrate the involvement of BnERF114.A1, a transcription factor for ETHYLENE RESPONSE FACTOR (ERF), in the regulation of plant architecture in Brassica napus. BnERF114.A1 is a member of the ERF family group X-a, encoding a putative 252-amino acid (aa) protein, which harbours the AP2/ERF domain and the conserved CMX-1 motif. BnERF114.A1 is localised to the nucleus and presents transcriptional activity, with the functional region located at 142-252 aa of the C-terminus. GUS staining revealed high BnERF114.A1 expression in leaf primordia, shoot apical meristem, leaf marginal meristem, and reproductive organs. Ectopic BnERF114.A1 expression in Arabidopsis reduced plant height, increased branch and silique number per plant, and improved seed yield per plant. Furthermore, in Arabidopsis, BnERF114.A1 overexpression inhibited indole-3-acetic acid (IAA) efflux, thus promoting auxin accumulation in the apex and arresting apical dominance. Therefore, BnERF114.A1 probably plays an important role in auxin-dependent plant architecture regulation.
PMID: 35216327
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23042091
Global N(6)-Methyladenosine Profiling Revealed the Tissue-Specific Epitranscriptomic Regulation of Rice Responses to Salt Stress.
Institute of Crop Sciences, National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; College of Agronomy, Anhui Agricultural University, Hefei 230036, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China.
N(6)-methyladenosine (m(6)A) methylation represents a new layer of the epitranscriptomic regulation of plant development and growth. However, the effects of m(6)A on rice responses to environmental stimuli remain unclear. In this study, we performed a methylated-RNA immunoprecipitation sequencing analysis and compared the changes in m(6)A methylation and gene expression in rice under salt stress conditions. Salt stress significantly increased the m(6)A methylation in the shoots (p value < 0.05). Additionally, 2537 and 2304 differential m(6)A sites within 2134 and 1997 genes were identified in the shoots and roots, respectively, under salt stress and control conditions. These differential m(6)A sites were largely regulated in a tissue-specific manner. A unique set of genes encoding transcription factors, antioxidants, and auxin-responsive proteins had increased or decreased m(6)A methylation levels only in the shoots or roots under salt stress, implying m(6)A may mediate salt tolerance by regulating transcription, ROS homeostasis, and auxin signaling in a tissue-specific manner. Integrating analyses of m(6)A modifications and gene expression changes revealed that m(6)A changes regulate the expression of genes controlling plant growth, stress responses, and ion transport under saline conditions. These findings may help clarify the regulatory effects of m(6)A modifications on rice salt tolerance.
PMID: 35216209
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23042073
Transcriptomic Analysis Suggests Auxin Regulation in Dorsal-Ventral Petal Asymmetry of Wild Progenitor Sinningia speciosa.
Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan.; Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei 10617, Taiwan.; Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan.
The establishment of dorsal-ventral (DV) petal asymmetry is accompanied by differential growth of DV petal size, shape, and color differences, which enhance ornamental values. Genes involved in flower symmetry in Sinningia speciosa have been identified as CYCLOIDEA (SsCYC), but which gene regulatory network (GRN) is associated with SsCYC to establish DV petal asymmetry is still unknown. To uncover the GRN of DV petal asymmetry, we identified 630 DV differentially expressed genes (DV-DEGs) from the RNA-Seq of dorsal and ventral petals in the wild progenitor, S. speciosa 'ES'. Validated by qRT-PCR, genes in the auxin signaling transduction pathway, SsCYC, and a major regulator of anthocyanin biosynthesis were upregulated in dorsal petals. These genes correlated with a higher endogenous auxin level in dorsal petals, with longer tube length growth through cell expansion and a purple dorsal color. Over-expression of SsCYC in Nicotiana reduced petal size by regulating cell growth, suggesting that SsCYC also controls cell expansion. This suggests that auxin and SsCYC both regulate DV petal asymmetry. Transiently over-expressed SsCYC, however, could not activate most major auxin signaling genes, suggesting that SsCYC may not trigger auxin regulation. Whether auxin can activate SsCYC or whether they act independently to regulate DV petal asymmetry remains to be explored in the future.
PMID: 35216188
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (4) doi: 10.3390/ijms23041933
Auxin/Cytokinin Antagonistic Control of the Shoot/Root Growth Ratio and Its Relevance for Adaptation to Drought and Nutrient Deficiency Stresses.
Plant Physiology, Biochemistry, Molecular Biology Program, Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
The hormones auxin and cytokinin regulate numerous aspects of plant development and often act as an antagonistic hormone pair. One of the more striking examples of the auxin/cytokinin antagonism involves regulation of the shoot/root growth ratio in which cytokinin promotes shoot and inhibits root growth, whereas auxin does the opposite. Control of the shoot/root growth ratio is essential for the survival of terrestrial plants because it allows growth adaptations to water and mineral nutrient availability in the soil. Because a decrease in shoot growth combined with an increase in root growth leads to survival under drought stress and nutrient limiting conditions, it was not surprising to find that auxin promotes, while cytokinin reduces, drought stress tolerance and nutrient uptake. Recent data show that drought stress and nutrient availability also alter the cytokinin and auxin signaling and biosynthesis pathways and that this stress-induced regulation affects cytokinin and auxin in the opposite manner. These antagonistic effects of cytokinin and auxin suggested that each hormone directly and negatively regulates biosynthesis or signaling of the other. However, a growing body of evidence supports unidirectional regulation, with auxin emerging as the primary regulatory component. This master regulatory role of auxin may not come as a surprise when viewed from an evolutionary perspective.
PMID: 35216049
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (3) doi: 10.3390/ijms23031915
Screening of Differentially Expressed Genes and Localization Analysis of Female Gametophyte at the Free Nuclear Mitosis Stage in Pinus tabuliformis Carr.
College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.; College of Horticulture, Jilin Agriculture University, Changchun 130118, China.
Female sterility is a common phenomenon in the plant world, and systematic research has not been carried out in gymnosperms. In this study, the ovules of No. 28 sterile line and No. 15 fertile line Pinus tabuliformis were used as materials, and a total of 18 cDNA libraries were sequenced by the HiSeqTM 4000 platform to analyze the differentially expressed genes (DEGs) and simple sequence repeats (SSRs) between the two lines. In addition, this study further analyzed the DEGs involved in the signal transduction of plant hormones, revealing that the signal pathways related to auxin, cytokinin, and gibberellin were blocked in the sterile ovule. Additionally, real-time fluorescent quantitative PCR verified that the expression trend of DEGs related to plant hormones was consistent with the results of high-throughput sequencing. Frozen sections and fluorescence in situ hybridization (FISH) were used to study the temporal and spatial expression patterns of PtRab in the ovules of P. tabuliformis. It was found that PtRab was significantly expressed in female gametophytes and rarely expressed in the surrounding diploid tissues. This study further explained the molecular regulation mechanism of female sterility in P. tabuliformis, preliminarily mining the key factors of ovule abortion in gymnosperms at the transcriptional level.
PMID: 35163836
Int J Mol Sci , IF:5.923 , 2022 Feb , V23 (3) doi: 10.3390/ijms23031810
Phytoplasma Infection Blocks Starch Breakdown and Triggers Chloroplast Degradation, Leading to Premature Leaf Senescence, Sucrose Reallocation, and Spatiotemporal Redistribution of Phytohormones.
Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA.; Electron and Confocal Microscopy Unit, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA.
Witches'-broom (WB, excessive initiation, and outgrowth of axillary buds) is one of the remarkable symptoms in plants caused by phytoplasmas, minute wall-less intracellular bacteria. In healthy plants, axillary bud initiation and outgrowth are regulated by an intricate interplay of nutrients (such as sugars), hormones, and environmental factors. However, how these factors are involved in the induction of WB by phytoplasma is poorly understood. We postulated that the WB symptom is a manifestation of the pathologically induced redistribution of sugar and phytohormones. Employing potato purple top phytoplasma and its alternative host tomato (Solanum lycopersicum), sugar metabolism and transportation, and the spatiotemporal distribution of phytohormones were investigated. A transmission electron microscopy (TEM) analysis revealed that starch breakdown was inhibited, resulting in the degradation of damaged chloroplasts, and in turn, premature leaf senescence. In the infected source leaves, two marker genes encoding asparagine synthetase (Sl-ASN) and trehalose-6-phosphate synthase (Sl-TPS) that induce early leaf senescence were significantly up-regulated. However, the key gibberellin biosynthesis gene that encodes ent-kaurene synthase (Sl-KS) was suppressed. The assessment of sugar content in various infected tissues (mature leaves, stems, roots, and leaf axils) indicated that sucrose transportation through phloem was impeded, leading to sucrose reallocation into the leaf axils. Excessive callose deposition and the resulting reduction in sieve pore size revealed by aniline blue staining and TEM provided additional evidence to support impaired sugar transport. In addition, a spatiotemporal distribution study of cytokinin and auxin using reporter lines detected a cytokinin signal in leaf axils where the axillary buds initiated. However, the auxin responsive signal was rarely present in such leaf axils, but at the tips of the newly elongated buds. These results suggested that redistributed sucrose as well as cytokinin in leaf axils triggered the axillary bud initiation, and auxin played a role in the bud elongation. The expression profiles of genes encoding squamosa promoter-binding proteins (Sl-SBP1), and BRANCHED1 (Sl-BRC1a and Sl-BRC1b) that control axillary bud release, as determined by quantitative reverse transcription (qRT)-PCR, indicated their roles in WB induction. However, their interactions with sugars and cytokinins require further study. Our findings provide a comprehensive insight into the mechanisms by which phytoplasmas induce WB along with leaf chlorosis, little leaf, and stunted growth.
PMID: 35163732
Plant Methods , IF:4.993 , 2022 Feb , V18 (1) : P17 doi: 10.1186/s13007-022-00850-w
Optimized synthesis of layered double hydroxide lactate nanosheets and their biological effects on Arabidopsis seedlings.
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Crops, Hainan University, Haikou, 570228, Hainan, China.; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.; Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China.; College of Environment, Beijing Forestry University, Beijing, 100083, China.; Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Crops, Hainan University, Haikou, 570228, Hainan, China. ylwan@hainanu.edu.cn.; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China. ylwan@hainanu.edu.cn.
BACKGROUND: Layered double hydroxide lactate nanosheets (LDH-lactate-NS) are powerful carriers for delivering macro-molecules into intact plant cells. In the past few years, some studies have been carried out on DNA/RNA transformation and plant disease resistance, but little attention has been paid to these factors during LDH-lactate-NS synthesis and delamination, nor has their relationship to the DNA adsorption capacity or transformation efficiency of plant cells been considered. RESULTS: Since the temperature during delamination alters particle sizes and zeta potentials of LDH-lactate-NS products, we compared the LDH-lactate-NS stability, DNA adsorption rate and delivery efficiency of fluorescein isothiocyanate isomer I (FITC) of them, found that the LDH-lactate-NS obtained at 25 degrees C has the best characters for delivering biomolecules into plant cell. To understand the potential side effects and cytotoxicity of LDH-lactate-NS to plants, we compared the root growth rate between the Arabidopsis thaliana seedlings grown in the culture medium with 1-300 mug/mL LDH-lactate-NS and equivalent raw material, Mg(lactate)2 and Al (lactate)3. Phenotypic analysis showed LDH in a range of 1-300 mug/mL can enhance the root elongation, whereas the same concentration of raw materials dramatically inhibited root elongation, suggesting the nanocrystallization has a dramatical de-toxic effect to Mg(lactate)2 and Al (lactate)3. Since enhancing of root elongation by LDH is an unexpected phenomenon, we further designed experiments to investigate influence of LDH to Arabidopsis seedlings. We further used the gravitropic bending test, qRT-PCR analysis of auxin transport proteins, non-invasive micro-test technology and liquid chromatography-mass spectrometry to investigate the auxin transport and distribution in Arabidopsis root. Results indicated that LDH-lactate-NS affect root growth by increasing the polar auxin transport. CONCLUSIONS: Optimal synthesized LDH-lactate-NS can delivery biomolecules into intact plant cells with high efficiency and low cytotoxity. The working solution of LDH-lactate-NS can promote root elongation via increase the polar auxin transport in Arabidopsis roots.
PMID: 35144635
Plant Cell Physiol , IF:4.927 , 2022 Feb , V63 (2) : P265-278 doi: 10.1093/pcp/pcab169
NARROW AND DWARF LEAF 1, the Ortholog of Arabidopsis ENHANCER OF SHOOT REGENERATION1/DORNROSCHEN, Mediates Leaf Development and Maintenance of the Shoot Apical Meristem in Oryza sativa L.
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657 Japan.; Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540 Japan.; Graduate School of Agricultural Regional Vitalization, Kibi International University, Minamiawaji, Hyogo, 656-0484 Japan.; Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, 980-8577 Japan.; Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, 060-0810 Japan.
The molecular basis for leaf development, a major focus in developmental biology, remains unclear in the monocotyledonous grass, rice (Oryza sativa). Here, we performed a mutant screen in rice and identified an AP2-type transcription factor family protein, NARROW AND DWARF LEAF1 (NDL1). NDL1 is the ortholog of Arabidopsis thaliana (subsequently called Arabidopsis) ENHANCER OF SHOOT REGENERATION1 (ESR1)/DORNROSCHEN (DRN) and mediates leaf development and maintenance of the shoot apical meristem (SAM). Loss of function of NDL1 results in bladeless leaves and SAMs that are flat, rather than dome-shaped, and lack cell proliferation activity. This loss of function also causes reduced auxin signaling. Moreover, as is the case with Arabidopsis ESR1/DRN, NDL1 plays crucial roles in shoot regeneration. Importantly, we found that NDL1 is not expressed in the SAM but is expressed in leaf primordia. We propose that NDL1 cell autonomously regulates leaf development, but non-cell autonomously regulates SAM maintenance in rice.
PMID: 35166362
Plant Cell Physiol , IF:4.927 , 2022 Feb doi: 10.1093/pcp/pcac017
Warm Temperature Promotes Shoot Regeneration in Arabidopsis thaliana.
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.; Department of Biological Sciences, Faculty of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.; Institut de Biologie Moleculaire des Plantes, 12 rue du General Zimmer, Strasbourg 67084, France.; Department of Biology, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181, Japan.; College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan.; UMR5004 Biochimie et Physiologie Moleculaire des Plantes, Universite de Montpellier, CNRS, INRAE, Institut Agro, 2 place Pierre Viala, Montpellier 34060, France.; Leibniz-Institut fur Gemuse- und Zierpflanzenbau (IGZ) e.V., Theodor-Echtermeyer-Weg 1, Grossbeeren 14979, Germany.
Many plants are able to regenerate upon cutting, and this process can be enhanced in vitro by incubating explants on hormone-supplemented media. While such protocols have been used for decades, little is known about the molecular details of how incubation conditions influence their efficiency. In this study, we find that warm temperature promotes both callus formation and shoot regeneration in Arabidopsis thaliana. We show that such an increase in shoot regenerative capacity at higher temperatures correlates with the enhanced expression of several regeneration-associated genes, such as CUP-SHAPED COTYLEDON 1 (CUC1) encoding a transcription factor involved in shoot meristem formation and YUCCAs (YUCs) encoding auxin biosynthesis enzymes. ChIP-sequencing analyses further reveal that the histone variant H2A.Z is enriched on these loci at 17 degrees C, while its occupancy is reduced by an increase in ambient temperature to 27 degrees C. Moreover, we provide genetic evidence to demonstrate that H2A.Z acts as a repressor of de novo shoot organogenesis, since H2A.Z-depleted mutants display enhanced shoot regeneration. This study thus uncovers a new chromatin-based mechanism that influences hormone-induced regeneration and additionally highlights incubation temperature as a key parameter for optimizing in vitro tissue culture.
PMID: 35157760
Plant Physiol Biochem , IF:4.27 , 2022 Feb , V175 : P1-11 doi: 10.1016/j.plaphy.2022.02.002
Loss-of-function mutations in the ERF96 gene enhance iron-deficient tolerance in Arabidopsis.
School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.; State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, 230036, China.; School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China. Electronic address: jiangli@ustc.edu.cn.
Iron is an essential micronutrient for plant growth and development. Here we provide evidence for a role of ERF96 in iron-deficiency response in Arabidopsis thaliana. The ERF96-loss-of-function mutants were found to be more tolerant to iron-deficiency stress than wild type (WT) and to have higher iron and chlorophyll content. Further studies showed that the transcriptional levels of iron-uptake related genes IRT1, FRO2, AHA2, FIT and bHLH38 in mutants were significantly higher than in WT under iron deficiency. Comparative transcriptome analysis suggested that the differentially expressed genes (DEGs) between ERF96-loss-of-function mutant and WT under iron deficiency were mainly enriched in iron uptake and chlorophyll degradation. According to the specific analysis of these two kinds of DEGs, the expression of iron uptake and transport related genes in ERF96-loss-of-function mutant was higher and the expression of chlorophyll degradation related genes was lower under iron deficiency. Furthermore, loss-of-function of ERF96 influenced the plant hormone, especially auxin and ethylene signal transduction. Altogether, our results demonstrate that loss-of-function of ERF96 increased Fe uptake and chlorophyll level through ethylene and auxin signal pathway in the regulation of iron-deficiency response in Arabidopsis.
PMID: 35158317
Environ Sci Pollut Res Int , IF:4.223 , 2022 Feb , V29 (6) : P9232-9247 doi: 10.1007/s11356-021-16246-7
Amelioration of sodium and arsenic toxicity in Salvinia natans L. with 2,4-D priming through physiological responses.
Plant Physiology, Biochemistry and Plant Molecular Biology Research Unit, Department of Botany, University of Kalyani, Kalyani, 74 1235, Nadia, W.B., India.; Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, 1207, Bangladesh. mhzsauag@yahoo.com.; Plant Physiology, Biochemistry and Plant Molecular Biology Research Unit, Department of Botany, University of Kalyani, Kalyani, 74 1235, Nadia, W.B., India. mkadak09@gmail.com.
Sodium (Na) and arsenic (As) toxicity were monitored by hyperaccumulation of metals in Salvinia natans L. with 2,4-dichlorophenoxyacetic acid (2,4-D) induction. Salvinia was recorded with significant bioaccumulation of those metals with de-folding of cellular attributes in sustenance under toxic environment. 2,4-D priming has revised the growth components like net assimilation rate and relative water content to register initial plants' survival against Na and As. Proline biosynthesis supported in the maintenance of osmotic adjustment and plants sustained better activity through subdued electrolytic leakage. Oxidative stress due to both Na and As exposure is responsible for induction under significant moderation of lipid peroxidation and protein carbonization by 2,4-D application was evident to release the stress from metal and metalloids. Reactive oxygen species (ROS) like superoxide and hydrogen peroxide accumulation were monitored with activity of NADP(H)-oxidase. However, it was downregulated by 2,4-D to check the oxidative damages. Superoxide dismutase and peroxidases were significantly moderated to reduce the oxidative degradation for both metals with 2,4-D induction. Glutathione metabolism and recycling of ascorbate with monodehydroascorbate activity were other features to maintain the redox homeostasis for metal toxicity. At the molecular level, polymorphic variations of concern genes in redox cascades demarked significantly for those two metals and established the biomarker for those metals, respectively. As a whole, the biocompatibility of auxin herbicide in Salvinia may raise the possibility for auxin metabolism and thereby, the bioaccumulation to Na and As vis-a-vis tolerance for ecological safety is established.
PMID: 34495473
Tree Physiol , IF:4.196 , 2022 Feb , V42 (2) : P317-324 doi: 10.1093/treephys/tpab110
Auxin concentration and xylem production of Pinus massoniana in a subtropical forest in south China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe, Guangzhou 510650, China.; Center for Plant Ecology, Core Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe, Guangzhou 510650, China.; University of Chinese Academy of Sciences, 19(A) Yuquan Road, Shijingshan, Beijing 100049, China.; Departement des Sciences Fondamentales, Universite du Quebec a Chicoutimi, 555 boulevard de l'Universite Chicoutimi, QC G7H 2B1, Canada.; Key Laboratory of Geospatial Technology for Middle and Lower Yellow River Regions, Henan University, 1 Jinming Road, Kaifeng Henan 475004, China.
Auxin is involved in various developmental processes of plants, including cell division in cambium and xylem differentiation. However, most studies linking auxin and xylem cell production are performed in environments with a strong seasonality (i.e., temperate and boreal climates). The temporal dynamics of auxin and cambial activity of subtropical trees remain basically unknown. In this study, we sampled four microcores weekly in three individuals of Chinese red pine (Pinus massoniana Lamb.) from February to December 2015-16 to compare xylem formation with auxin concentration in subtropical China. During the entire period of sampling, the number of cambial cells varied from 2 to 7, while the number of cells in the enlarging zone ranged from 1 to 4 and from 1 to 5 in the wall-thickening zone. In 2015, the average auxin concentration was 3.46 ng g-1, with 33 xylem cells being produced at the end of the year. In 2016, a lower auxin concentration (2.59 ng g-1) corresponded to a reduced annual xylem production (13.7 cells). No significant relationship between auxin concentration and number of xylem cells in differentiation was found at the weekly scale. Unlike in boreal and temperate forests, the lack of wood formation seasonality in subtropical forests makes it more difficult to reveal the relationship between auxin concentration and number of xylem cells in differentiation at the intra-annual scale. The frequent and repeated samplings might have reduced auxin concentration in the developing cambium and xylem, resulting in a lower xylem cell production.
PMID: 34505152
Tree Physiol , IF:4.196 , 2022 Feb , V42 (2) : P391-410 doi: 10.1093/treephys/tpab102
The meristem-associated endosymbiont Methylorubrum extorquens DSM13060 reprograms development and stress responses of pine seedlings.
Ecology and Genetics Research Unit, University of Oulu, Paavo Havaksentie J1, FI-90014 Oulu, Finland.; Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Haartmaninkatu 8, FI-00014 Helsinki, Finland.; Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany.; Institute of Molecular Biology and Genetics of NASU, Acad. Zabolotnoho str., 150 03680 Kyiv, Ukraine.; Weiden am See, Burgenland 7121, Austria.; Production Systems, Tree Breeding, Natural Resources Institute Finland LUKE, FI-57200 Savonlinna, Finland.
Microbes living in plant tissues-endophytes-are mainly studied in crop plants where they typically colonize the root apoplast. Trees-a large carbon source with a high capacity for photosynthesis-provide a variety of niches for endophytic colonization. We have earlier identified a new type of plant-endophyte interaction in buds of adult Scots pine, where Methylorubrum species live inside the meristematic cells. The endosymbiont Methylorubrum extorquens DSM13060 significantly increases needle and root growth of pine seedlings without producing plant hormones, but by aggregating around host nuclei. Here, we studied gene expression and metabolites of the pine host induced by M. extorquens DSM13060 infection. Malic acid was produced by pine to potentially boost M. extorquens colonization and interaction. Based on gene expression, the endosymbiont activated the auxin- and ethylene (ET)-associated hormonal pathways through induction of CUL1 and HYL1, and suppressed salicylic and abscisic acid signaling of pine. Infection by the endosymbiont had an effect on pine meristem and leaf development through activation of GLP1-7 and ALE2, and suppressed flowering, root hair and lateral root formation by downregulation of AGL8, plantacyanin, GASA7, COW1 and RALFL34. Despite of systemic infection of pine seedlings by the endosymbiont, the pine genes CUL1, ETR2, ERF3, HYL, GLP1-7 and CYP71 were highly expressed in the shoot apical meristem, rarely in needles and not in stem or root tissues. Low expression of MERI5, CLH2, EULS3 and high quantities of ononitol suggest that endosymbiont promotes viability and protects pine seedlings against abiotic stress. Our results indicate that the endosymbiont positively affects host development and stress tolerance through mechanisms previously unknown for endophytic bacteria, manipulation of plant hormone signaling pathways, downregulation of senescence and cell death-associated genes and induction of ononitol biosynthesis.
PMID: 34328183
Microorganisms , IF:4.128 , 2022 Feb , V10 (2) doi: 10.3390/microorganisms10020365
Control of Fungal Diseases and Fruit Yield Improvement of Strawberry Using Bacillus velezensis CE 100.
Department of Chemical Engineering, University of California, Davis, CA 95616, USA.; Department of Plant Sciences, University of California, Davis, CA 95616, USA.; Department of Forest Resources, Chonnam National University, Gwangju 61186, Korea.; Division of Agricultural and Biological Chemistry, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju 61186, Korea.
Due to the increasing health and environmental risks associated with the use of fungicides in agriculture, alternatives-such as using plant growth-promoting bacteria (PGPB) to suppress phytopathogens-that simultaneously improve plant yield, are important. This study evaluated the biocontrol efficiency of Bacillus velezensis CE100 against Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae, the respective causal agents for charcoal rot and fusarium wilt diseases in strawberry, and its potential to enhance strawberry growth and fruit production. B. velezensis CE 100 produced fungal cell wall-degrading enzymes, chitinases, and beta-1,3-glucanases; and inhibited the mycelial growth of M. phaseolina and F. oxysporum f. sp. fragariae by 64.7% and 55.2%, respectively. The mycelia of both phytopathogenic fungi showed severe swelling and rupturing of the hyphae compared to the smooth, normal growth in the control group. Moreover, B. velezensis CE100 produced up to 2.8 units/mL of indole-3-acetic acid (IAA) during incubation and enhanced root biomass in strawberries. Consequently, B. velezensis CE 100 not only increased the fruit yield of strawberries by controlling the fungal diseases but also through enhancing plant growth. The findings of this study indicate that B. velezensis CE100 could be a safe, ecofriendly biocontrol alternative to chemical fungicides in strawberry production.
PMID: 35208819
Genes (Basel) , IF:4.096 , 2022 Feb , V13 (3) doi: 10.3390/genes13030441
Transcriptome Profiling Reveals Role of MicroRNAs and Their Targeted Genes during Adventitious Root Formation in Dark-Pretreated Micro-Shoot Cuttings of Tetraploid Robinia pseudoacacia L.
National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design (BAICFTBMD), Engineering Technology Research Center of Black Locust of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.; School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.; School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.; Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing 100083, China.
Tetraploid Robinia pseudoacacia L. is a difficult-to-root species, and is vegetatively propagated through stem cuttings. Limited information is available regarding the adventitious root (AR) formation of dark-pretreated micro-shoot cuttings. Moreover, the role of specific miRNAs and their targeted genes during dark-pretreated AR formation under in vitro conditions has never been revealed. The dark pretreatment has successfully promoted and stimulated adventitious rooting signaling-related genes in tissue-cultured stem cuttings with the application of auxin (0.2 mg L(-1) IBA). Histological analysis was performed for AR formation at 0, 12, 36, 48, and 72 h after excision (HAE) of the cuttings. The first histological events were observed at 36 HAE in the dark-pretreated cuttings; however, no cellular activities were observed in the control cuttings. In addition, the present study aimed to uncover the role of differentially expressed (DE) microRNAs (miRNAs) and their targeted genes during adventitious root formation using the lower portion (1-1.5 cm) of tetraploid R. pseudoacacia L. micro-shoot cuttings. The samples were analyzed using Illumina high-throughput sequencing technology for the identification of miRNAs at the mentioned time points. Seven DE miRNA libraries were constructed and sequenced. The DE number of 81, 162, 153, 154, 41, 9, and 77 miRNAs were upregulated, whereas 67, 98, 84, 116, 19, 16, and 93 miRNAs were downregulated in the following comparisons of the libraries: 0-vs-12, 0-vs-36, 0-vs-48, 0-vs-72, 12-vs-36, 36-vs-48, and 48-vs-72, respectively. Furthermore, we depicted an association between ten miRNAs (novel-m0778-3p, miR6135e.2-5p, miR477-3p, miR4416c-5p, miR946d, miR398b, miR389a-3p, novel m0068-5p, novel-m0650-3p, and novel-m0560-3p) and important target genes (auxin response factor-3, gretchen hagen-9, scarecrow-like-1, squamosa promoter-binding protein-like-12, small auxin upregulated RNA-70, binding protein-9, vacuolar invertase-1, starch synthase-3, sucrose synthase-3, probable starch synthase-3, cell wall invertase-4, and trehalose phosphatase synthase-5), all of which play a role in plant hormone signaling and starch and sucrose metabolism pathways. The quantitative polymerase chain reaction (qRT-PCR) was used to validate the relative expression of these miRNAs and their targeted genes. These results provide novel insights and a foundation for further studies to elucidate the molecular factors and processes controlling AR formation in woody plants.
PMID: 35327995
Plant Mol Biol , IF:4.076 , 2022 Feb , V108 (3) : P257-275 doi: 10.1007/s11103-021-01238-5
CIN-like TCP13 is essential for plant growth regulation under dehydration stress.
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science (CSRS), 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan. kaoru.urano@riken.jp.; Institute of Agrobiological Sciences, NARO 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan. kaoru.urano@riken.jp.; Plant Biotechnology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki, 305-8686, Japan.; Bioorganic Research Institute, Suntory Foundation for Life Sciences, Seikacho, Kyoto, 619-0284, Japan.; INRAE, Universite de Bordeaux, UMR1332 Biologie du Fruit Et Pathologie, 33882, Villenave d'Ornon Cedex, France.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium.; VIB Center for Plant Systems Biology, 9052, Ghent, Belgium.; Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.; Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science (CSRS), 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan. kazuo.shinozaki@riken.jp.
KEY MESSAGE: A dehydration-inducible Arabidopsis CIN-like TCP gene, TCP13, acts as a key regulator of plant growth in leaves and roots under dehydration stress conditions. Plants modulate their shape and growth in response to environmental stress. However, regulatory mechanisms underlying the changes in shape and growth under environmental stress remain elusive. The CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family of transcription factors (TFs) are key regulators for limiting the growth of leaves through negative effect of auxin response. Here, we report that stress-inducible CIN-like TCP13 plays a key role in inducing morphological changes in leaves and growth regulation in leaves and roots that confer dehydration stress tolerance in Arabidopsis thaliana. Transgenic Arabidopsis plants overexpressing TCP13 (35Spro::TCP13OX) exhibited leaf rolling, and reduced leaf growth under osmotic stress. The 35Spro::TCP13OX transgenic leaves showed decreased water loss from leaves, and enhanced dehydration tolerance compared with their control counterparts. Plants overexpressing a chimeric repressor domain SRDX-fused TCP13 (TCP13pro::TCP13SRDX) showed severely serrated leaves and enhanced root growth. Transcriptome analysis of TCP13pro::TCP13SRDX transgenic plants revealed that TCP13 affects the expression of dehydration- and abscisic acid (ABA)-regulated genes. TCP13 is also required for the expression of dehydration-inducible auxin-regulated genes, INDOLE-3-ACETIC ACID5 (IAA5) and LATERAL ORGAN BOUNDARIES (LOB) DOMAIN 1 (LBD1). Furthermore, tcp13 knockout mutant plants showed ABA-insensitive root growth and reduced dehydration-inducible gene expression. Our findings provide new insight into the molecular mechanism of CIN-like TCP that is involved in both auxin and ABA response under dehydration stress.
PMID: 35050466
Phytochemistry , IF:4.072 , 2022 Feb , V194 : P113039 doi: 10.1016/j.phytochem.2021.113039
The GH3 amidosynthetases family and their role in metabolic crosstalk modulation of plant signaling compounds.
Department of Biochemistry, Nicolaus Copernicus University in Torun, Lwowska 1, 87-100, Torun, Poland.; Department of Biochemistry, Nicolaus Copernicus University in Torun, Lwowska 1, 87-100, Torun, Poland. Electronic address: maciejost@umk.pl.
The Gretchen Hagen 3 (GH3) genes encoding proteins belonging to the ANL superfamily are widespread in the plant kingdom. The ANL superfamily consists of three groups of adenylating enzymes: aryl- and acyl-CoA synthetases, firefly luciferase, and amino acid-activating adenylation domains of the nonribosomal peptide synthetases (NRPS). GH3s are cytosolic, acidic amidosynthetases of the firefly luciferase group that conjugate auxins, jasmonates, and benzoate derivatives to a wide group of amino acids. In contrast to auxins, which amide conjugates mainly serve as a storage pool of inactive phytohormone or are involved in the hormone degradation process, conjugation of jasmonic acid (JA) results in biologically active phytohormone jasmonyl-isoleucine (JA-Ile). Moreover, GH3s modulate salicylic acid (SA) concentration by conjugation of its precursor, isochorismate. GH3s, as regulators of the phytohormone level, are crucial for normal plant development as well as plant defense response to different abiotic and biotic stress factors. Surprisingly, recent studies indicate that FIN219/JAR1/GH3.11, one of the GH3 proteins, may act not only as an enzyme but is also able to interact with tau-class glutathione S-transferase (GSTU) and constitutive photomorphogenic 1 (COP1) proteins and regulate light and stress signaling pathways. The aim of this work is to summarize our current knowledge of the GH3 family.
PMID: 34861536
BMC Genomics , IF:3.969 , 2022 Feb , V23 (1) : P109 doi: 10.1186/s12864-022-08341-x
Combined transcriptomic and metabolomic analysis reveals the potential mechanism of seed germination and young seedling growth in Tamarix hispida.
College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.; Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin, Xinjiang Production and Construction Corps, College of Life Sciences, Tarim University, Alar, 843300, China.; Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, Hubei, China.; Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, Hubei, China. qinrui@scuec.edu.cn.; Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, Hubei, China. liuhong@scuec.edu.cn.; College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China. yaojlmy@mail.hzau.edu.cn.
BACKGROUND: Seed germination is a series of ordered physiological and morphogenetic processes and a critical stage in plant life cycle. Tamarix hispida is one of the most salt-tolerant plant species; however, its seed germination has not been analysed using combined transcriptomics and metabolomics. RESULTS: Transcriptomic sequencing and widely targeted metabolomics were used to detect the transcriptional metabolic profiles of T. hispida at different stages of seed germination and young seedling growth. Transcriptomics showed that 46,538 genes were significantly altered throughout the studied development period. Enrichment study revealed that plant hormones, such as auxin, ABA, JA and SA played differential roles at varying stages of seed germination and post-germination. Metabolomics detected 1022 metabolites, with flavonoids accounting for the highest proportion of differential metabolites. Combined analysis indicated that flavonoid biosynthesis in young seedling growth, such as rhoifolin and quercetin, may improve the plant's adaptative ability to extreme desert environments. CONCLUSIONS: The differential regulation of plant hormones and the accumulation of flavonoids may be important for the seed germination survival of T. hispida in response to salt or arid deserts. This study enhanced the understanding of the overall mechanism in seed germination and post-germination. The results provide guidance for the ecological value and young seedling growth of T. hispida.
PMID: 35135479
BMC Genomics , IF:3.969 , 2022 Feb , V23 (1) : P95 doi: 10.1186/s12864-021-08251-4
Dissection of canopy layer-specific genetic control of leaf angle in Sorghum bicolor by RNA sequencing.
Department of Agronomy, Iowa State University, Ames, IA, 50011, USA.; Present address: Bayer Crop Science, Chesterfield, MO, USA.; Corn Insects and Crop Genetics Research, USDA-ARS, Ames, IA, 50011, USA.; Department of Statistics, Iowa State University, Ames, IA, 50011, USA.; Department of Agronomy, Iowa State University, Ames, IA, 50011, USA. mgsalas@iastate.edu.
BACKGROUND: Leaf angle is an important plant architecture trait, affecting plant density, light interception efficiency, photosynthetic rate, and yield. The "smart canopy" model proposes more vertical leaves in the top plant layers and more horizontal leaves in the lower canopy, maximizing conversion efficiency and photosynthesis. Sorghum leaf arrangement is opposite to that proposed in the "smart canopy" model, indicating the need for improvement. Although leaf angle quantitative trait loci (QTL) have been previously reported, only the Dwarf3 (Dw3) auxin transporter gene, colocalizing with a major-effect QTL on chromosome 7, has been validated. Additionally, the genetic architecture of leaf angle across canopy layers remains to be elucidated. RESULTS: This study characterized the canopy-layer specific transcriptome of five sorghum genotypes using RNA sequencing. A set of 284 differentially expressed genes for at least one layer comparison (FDR < 0.05) co-localized with 69 leaf angle QTL and were consistently identified across genotypes. These genes are involved in transmembrane transport, hormone regulation, oxidation-reduction process, response to stimuli, lipid metabolism, and photosynthesis. The most relevant eleven candidate genes for layer-specific angle modification include those homologous to genes controlling leaf angle in rice and maize or genes associated with cell size/expansion, shape, and cell number. CONCLUSIONS: Considering the predicted functions of candidate genes, their potential undesirable pleiotropic effects should be further investigated across tissues and developmental stages. Future validation of proposed candidates and exploitation through genetic engineering or gene editing strategies targeted to collar cells will bring researchers closer to the realization of a "smart canopy" sorghum.
PMID: 35114939
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (5) doi: 10.3390/plants11050664
In Silico Genome-Wide Characterisation of the Lipid Transfer Protein Multigenic Family in Sunflower (H. annuus L.).
Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
The sunflower (Helianthus annuus L.) is among the most widely cultivated crops in the world due to the oilseed production. Lipid transfer proteins (LTPs) are low molecular mass proteins encoded by a broad multigenic family in higher plants, showing a vast range of functions; these proteins have not been characterised in sunflower at the genomic level. In this work, we exploited the reliable genome sequence of sunflower to identify and characterise the LTP multigenic family in H. annuus. Overall, 101 sunflower putative LTP genes were identified using a homology search and the HMM algorithm. The selected sequences were characterised through phylogenetic analysis, exon-intron organisation, and protein structural motifs. Sunflower LTPs were subdivided into four clades, reflecting their genomic and structural organisation. This gene family was further investigated by analysing the possible duplication origin of genes, which showed the prevalence of tandem and whole genome duplication events, a result that is in line with polyploidisation events that occurred during sunflower genome evolution. Furthermore, LTP gene expression was evaluated on cDNA libraries constructed on six sunflower tissues (leaf, root, ligule, seed, stamen, and pistil) and from roots treated with stimuli mimicking biotic and abiotic stress. Genes encoding LTPs belonging to three out of four clades responded specifically to external stimuli, especially to abscisic acid, auxin, and the saline environment. Interestingly, genes encoding proteins belonging to one clade were expressed exclusively in sunflower seeds. This work is a first attempt of genome-wide identification and characterisation of the LTP multigenic family in a plant species.
PMID: 35270134
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (5) doi: 10.3390/plants11050650
Throttling Growth Speed: Evaluation of aux1-7 Root Growth Profile by Combining D-Root system and Root Penetration Assay.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, 165 02 Prague, Czech Republic.; Department of Experimental Plant Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic.; Department of Functional and Evolutionary Ecology, Molecular Systems Biology (MoSys), Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, 1030 Wien, Austria.; Vienna Metabolomics Center (VIME), University of Vienna, Djerassiplatz 1, 1030 Wien, Austria.
Directional root growth control is crucial for plant fitness. The degree of root growth deviation depends on several factors, whereby exogenous growth conditions have a profound impact. The perception of mechanical impedance by wild-type roots results in the modulation of root growth traits, and it is known that gravitropic stimulus influences distinct root movement patterns in concert with mechanoadaptation. Mutants with reduced shootward auxin transport are described as being numb towards mechanostimulus and gravistimulus, whereby different growth conditions on agar-supplemented medium have a profound effect on how much directional root growth and root movement patterns differ between wild types and mutants. To reduce the impact of unilateral mechanostimulus on roots grown along agar-supplemented medium, we compared the root movement of Col-0 and auxin resistant 1-7 in a root penetration assay to test how both lines adjust the growth patterns of evenly mechanostimulated roots. We combined the assay with the D-root system to reduce light-induced growth deviation. Moreover, the impact of sucrose supplementation in the growth medium was investigated because exogenous sugar enhances root growth deviation in the vertical direction. Overall, we observed a more regular growth pattern for Col-0 but evaluated a higher level of skewing of aux1-7 compared to the wild type than known from published data. Finally, the tracking of the growth rate of the gravistimulated roots revealed that Col-0 has a throttling elongation rate during the bending process, but aux1-7 does not.
PMID: 35270119
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (5) doi: 10.3390/plants11050618
The Effects of Exogenous Salicylic Acid on Endogenous Phytohormone Status in Hordeum vulgare L. under Salt Stress.
Faculty of Agriculture, Duzce University, 81620 Duzce, Turkey.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, CZ-78371 Olomouc, Czech Republic.; Faculty of Science, Karadeniz Technical University, 61080 Trabzon, Turkey.
Acclimation to salt stress in plants is regulated by complex signaling pathways involving endogenous phytohormones. The signaling role of salicylic acid (SA) in regulating crosstalk between endogenous plant growth regulators' levels was investigated in barley (Hordeum vulgare L. 'Ince'; 2n = 14) leaves and roots under salt stress. Salinity (150 and 300 mM NaCl) markedly reduced leaf relative water content (RWC), growth parameters, and leaf water potential (LWP), but increased proline levels in both vegetative organs. Exogenous SA treatment did not significantly affect salt-induced negative effects on RWC, LWP, and growth parameters but increased the leaf proline content of plants under 150 mM salt stress by 23.1%, suggesting that SA enhances the accumulation of proline, which acts as a compatible solute that helps preserve the leaf's water status under salt stress. Changes in endogenous phytohormone levels were also investigated to identify agents that may be involved in responses to increased salinity and exogenous SA. Salt stress strongly affected endogenous cytokinin (CK) levels in both vegetative organs, increasing the concentrations of CK free bases, ribosides, and nucleotides. Indole-3-acetic acid (IAA, auxin) levels were largely unaffected by salinity alone, especially in barley leaves, but SA strongly increased IAA levels in leaves at high salt concentration and suppressed salinity-induced reductions in IAA levels in roots. Salt stress also significantly increased abscisic acid (ABA) and ethylene levels; the magnitude of this increase was reduced by treatment with exogenous SA. Both salinity and SA treatment reduced jasmonic acid (JA) levels at 300 mM NaCl but had little effect at 150 mM NaCl, especially in leaves. These results indicate that under high salinity, SA has antagonistic effects on levels of ABA, JA, ethylene, and most CKs, as well as basic morphological and physiological parameters, but has a synergistic effect on IAA, which was well exhibited by principal component analysis (PCA).
PMID: 35270088
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (5) doi: 10.3390/plants11050580
Comparisons of Anatomical Characteristics and Transcriptomic Differences between Heterografts and Homografts in Pyrus L.
Qingdao Key Laboratory of Genetic Improvement and Breeding in Horticultural Plants, Engineering Laboratory of Genetic Improvement of Horticultural Crops of Shandong Province, College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China.; Haidu College, Qingdao Agricultural University, Laiyang 265200, China.
Pear (Pyrus L.) is an important temperate fruit worldwide, and grafting is widely used in pear vegetative propagation. However, the mechanisms of graft healing or incompatibility remain poorly understood in Pyrus. To study the differences in graft healing in Pyrus, the homograft "Qingzhen D1/Qingzhen D1" and the heterograft "QAUP-1/Qingzhen D1" as compatibility and incompatibility combinations were compared. Anatomical differences indicated the healing process was faster in homografts than in heterografts. During the healing process, four critical stages in graft union formation were identified in the two types of grafts. The expression of the genes associated with hormone signaling (auxin and cytokinins), and lignin biosynthesis was delayed in the healing process of heterografts. In addition, the PbBglu13 gene, encoded beta-glucosidase, was more highly up-regulated in heterografts than in homografts to promote healing. Meanwhile, the most of DEGs related starch and sucrose metabolism were found to be up-regulated in heterografts; those results indicated that cellulose and sugar signals were also involved in graft healing. The results of this study improved the understanding of the differences in the mechanisms of graft healing between homografts and heterografts.
PMID: 35270050
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (4) doi: 10.3390/plants11040561
Electrophysiological, Morphologic, and Transcriptomic Profiling of the Ogura-CMS, DGMS and Maintainer Broccoli Lines.
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, #12 Zhong Guan Cun Nandajie Street, Beijing 100081, China.; China Vegetable Biotechnology (Shouguang) Co., Ltd., Shouguang 262700, China.; Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
To better serve breeding of broccoli, the electrophysiological, morphological and transcriptomic profiling of the isogenic Ogura-CMS, DGMS and their maintainer fertile lines, were carried out by scanning electron microscopy, investigation of agronomic traits and RNA-sequencing analysis. The agronomic traits of plant height, length of the largest leaf, plant spread angle, single head weight, head width and stem diameter showed stronger performance in Ogura-CMS broccoli than in DGMS line or maintainer fertile line. However, the Ogura-CMS broccoli was poorer in the seed yield and seed germination than in the DGMS line and maintainer fertile line. Additionally, the DGMS broccoli had longer maturation and flowering periods than the Ogura-CMS and maintainer fertile lines. There were obvious differences in the honey gland, happening in the male sterility and fertile lines of broccoli. Additionally, the mechanism regulating Ogura-CMS and DGMS in broccoli was investigated using florets transcriptome analyses of the Ogura-CMS, DGMS and maintainer fertile lines. As a result, a total of 2670 differentially expressed genes (DEGs) were detected, including 1054 up- and 1616 downregulated genes in the Ogura-CMS and DGMS lines compared to the maintainer fertile line. A number of functionally known genes involved in plant hormones (auxin, salicylic acid and brassinosteroid), five Mitochondrial Oxidative Phosphorylation (OXPHOS) genes of atp8, LOC106319879, LOC106324734, LOC106314622 and LOC106298585, and three upregulated genes (Lhcb1, Lhcb3 and Lhcb5) associated with the photosynthesis-antenna protein pathway, were obviously detected to be highly associated with reproductive development including flowering time, maturity and reproductive period in the Ogura-CMS and DGMS broccoli comparing to their maintainer fertile line. Our research would provide a comprehensive foundation for understanding the differences of electrophysiological, morphological and transcriptomic profiles in the Ogura-CMS, DGMS and maintainer broccoli, and as well as being beneficial to exploring the mechanism of male sterility in Brassica crops.
PMID: 35214894
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (4) doi: 10.3390/plants11040538
Identification of One Major QTL and a Novel Gene OsIAA17q5 Associated with Tiller Number in Rice Using QTL Analysis.
Division of Plant Biosciences, School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu 41566, Korea.; Crop Breeding Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea.; Coastal Agriculture Research Institute, Kyungpook National University, Daegu 41566, Korea.; Biosafety Division, National Institute of Agricultural Science, Jeonju 54874, Korea.; School of Electronics Engineering, College of IT Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Korea.
Rice tillers are one of the most important traits for the yield and development of rice, although little is known about its mode of inheritance. Tiller numbers were recorded every 7 days a total of nine times, starting 30 days after transplantation. Quantitative trait locus (QTL) based analysis on a set of double haploid population derivatives of a cross between the Cheongcheong and Nagdong varieties identified a major effect of locus RM18130-RM3381 on chromosome 5, which was expressed in eight different growth stages. Within the target region RM18130-RM3381 (physical distance: 2.08 Mb), 61 candidate genes were screened by annotation. Among the candidate genes, Os05g0230700 (named OsIAA17q5), which belongs to the family of auxin-responsive genes, was selected as a target. Auxin promotes cell division and meristem maintenance and is an effective plant regulator which influences plant growth and development by altering the expression of various genes. OsIAA17q5 is expected to control the number of tillers. The present study provides further understanding of the basic genetic mechanisms that selectively express the control of tiller numbers in different growth stages, as well as provides valuable information for future research aimed at cloning the target gene. These results may contribute to developing a comprehensive understanding of the basic genetic processes regulating the developmental behavior of tiller numbers in rice.
PMID: 35214873
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (4) doi: 10.3390/plants11040498
Interaction between Growth Regulators Controls In Vitro Shoot Multiplication in Paulownia and Selection of NaCl-Tolerant Variants.
Central Laboratory of Genetic Engineering, Botany and Microbiology Department, Faculty of Science, Sohag University, Sohag 82524, Egypt.; Biology Department, Faculty of Science, Jazan University, Jazan 82817, Saudi Arabia.; Plant Pathology Research Institute, Agricultural Research Center, Giza 12619, Egypt.; Botany and Microbiology Department, Faculty of Science, South Valley University, Qena 83523, Egypt.
The interaction between cytokinin, auxin and GA controlled in vitro shoot multiplication in paulownia was influenced by a medium water potential (Psi) modulation, where it was modulated using different textures or strengths of MS medium, media of different types (MS, WPM, SH and B5) or NaCl incorporation. The interaction between 2 mg/L BAP and 0.1 mg/L NAA expressed the highest shoot number on each media type, but it was better with media of lower water potential (MS and WPM), and MS medium was the best. Psi of full-strength semisolid MS medium expressed the highest shoot multiplication. The opposite was detected when Psi of MS medium was changed using half- or double-strength MS. Psi of full-strength MS medium in semisolid form resulted in a valuable interaction between 2 mg/L BAP, 0.1 mg/L NAA and 0.1 mg/L GA, leading to efficient shoot formation, and it was associated with an increase in internode length and decrease in stem diameter, which facilitated obtaining synseeds with a high ability to convert. High genetic variation was recorded under long-term culture (14 subcultures). Polymorphism using the ISSR technique was higher than that of RAPD. A further increase in polymorphism was detected when NaCl was used, where five salt-tolerant lines were selected. Some salt-tolerant-selected lines showed one or more amplification products of a specific molecular weight that did not appear in the control. For example, with OPA-07 and OPG-02 RAPD primers, all the salt-tolerant-selected lines showed the appearance of amplification fragments (610 bp and 300 bp, respectively) that were not detected in control.
PMID: 35214831
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (4) doi: 10.3390/plants11040472
Identification of Peanut Aux/IAA Genes and Functional Prediction during Seed Development and Maturation.
State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China.; College of Agronomy, Shandong Agricultural University, Tai'an 271018, China.; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
Auxin-responsive genes AUX/IAA are important during plant growth and development, but there are few relevant reports in peanut. In this study, 44 AhIAA genes were identified from cultivated peanut, of which 31 genes were expressed in seed at varying degrees. AhIAA-3A, AhIAA-16A and AhIAA-15B were up-regulated, while AhIAA-11A, AhIAA-5B and AhIAA-14B were down-regulated with seed development and maturation. The expression patterns of seven genes, AhIAA-1A, AhIAA-4A, AhIAA-10A, AhIAA-20A, AhIAA-1B, AhIAA-4B and AhIAA-19B, were consistent with the change trend of auxin, and expression in late-maturing variety LM was significantly higher than that in early-maturing EM. Furthermore, allelic polymorphism analysis of AhIAA-1A and AhIAA-1B, which were specifically expressed in seeds, showed that three SNP loci in 3'UTR of AhIAA-1A could effectively distinguish the EM- and LM- type germplasm, providing a basis for breeding markers development. Our results offered a comprehensive understanding of Aux/IAA genes in peanut and provided valuable clues for further investigation of the auxin signal transduction pathway and auxin regulation mechanism in peanut.
PMID: 35214804
Plants (Basel) , IF:3.935 , 2022 Feb , V11 (3) doi: 10.3390/plants11030454
Functional Antagonism of WRI1 and TCP20 Modulates GH3.3 Expression to Maintain Auxin Homeostasis in Roots.
School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.; Kentucky Tobacco Research and Development Center, Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
Auxin is a well-studied phytohormone, vital for diverse plant developmental processes. The GH3 genes are one of the major auxin responsive genes, whose expression changes lead to modulation of plant development and auxin homeostasis. However, the transcriptional regulation of these GH3 genes remains largely unknown. WRI1 is an essential transcriptional regulator governing plant fatty acid biosynthesis. Recently, we identified that the expression of GH3.3 is increased in the roots of wri1-1 mutant. Nevertheless, in this study we found that AtWRI1 did not activate or repress the promoter of GH3.3 (proGH3.3) despite of its binding to proGH3.3. Cross-family transcription factor interactions play pivotal roles in plant gene regulatory networks. To explore the molecular mechanism by which WRI1 controls GH3.3 expression, we screened an Arabidopsis transcription factor library and identified TCP20 as a novel AtWRI1-interacting regulator. The interaction between AtWRI1 and TCP20 was further verified by several approaches. Importantly, we found that TCP20 directly regulates GH3.3 expression via binding to TCP binding element. Furthermore, AtWRI1 repressed the TCP20-mediated transactivation of proGH3.3. EMSAs demonstrated that AtWRI1 antagonized TCP20 from binding to proGH3.3. Collectively, we provide new insights that WRI1 attenuates GH3.3 expression through interaction with TCP20, highlighting a new mechanism that contributes to fine-tuning auxin homeostasis.
PMID: 35161435
J Plant Physiol , IF:3.549 , 2022 Feb , V269 : P153594 doi: 10.1016/j.jplph.2021.153594
Auxin transport in developing protophloem: A case study in canalization.
Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland.; Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland. Electronic address: christian.hardtke@unil.ch.
Spatiotemporal cues orchestrate the development of organs and cellular differentiation in multicellular organisms. For instance, in the root apical meristem an auxin gradient patterns the transition from stem cell maintenance to transit amplification and eventual differentiation. Among the proximal tissues generated by this growth apex, the early, so-called protophloem, is the first tissue to differentiate. This observation has been linked to increased auxin activity in the developing protophloem sieve element cell files as compared to the neighboring tissues. Here we review recent progress in the characterization of the unique mechanism by which auxin canalizes its activity in the developing protophloem and fine-tunes its own transport to guide proper timing of protophloem sieve element differentiation.
PMID: 34953411
AoB Plants , IF:3.276 , 2022 Feb , V14 (1) : Pplab075 doi: 10.1093/aobpla/plab075
AtANN1 and AtANN2 are involved in phototropism of etiolated hypocotyls of Arabidopsis by regulating auxin distribution.
Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.; Department of Agricultural and Animal Engineering, Cangzhou Vocation College of Technology, Cangzhou 061001, China.
Phototropism is an essential response in some plant organs and features several signalling molecules involved in either photo-sensing or post-sensing responses. Annexins are involved in regulating plant growth and its responses to various stimuli. Here, we provide novel data showing that two members of the Annexin family in Arabidopsis thaliana, AtANN1 and AtANN2, may be involved in the phototropism of etiolated hypocotyls. In wild type, unilateral blue light (BL) induced a strong phototropic response, while red light (RL) only induced a weak response. The responses of single- or double-null mutants of the two annexins, including atann1, atann2 and atann1/atann2, were significantly weaker than those observed in wild type, indicating the involvement of AtANN1 and AtANN2 in BL-induced phototropism. Unilateral BL induced asymmetric distribution of DR5-GFP and PIN3-GFP fluorescence in hypocotyls; notably, fluorescent intensity on the shaded side was markedly stronger than that on the illuminated side. In etiolated atann1, atann2 or atann1/atann2 hypocotyls, unilateral BL-induced asymmetric distributions of DR5-GFP and PIN3-GFP were weakened or impaired. Herein, we suggest that during hypocotyls phototropic response, AtANN1 and AtANN2 may be involved in BL-stimulated signalling by regulating PIN3-charged auxin transport.
PMID: 35079328
Funct Plant Biol , IF:3.101 , 2022 Feb , V49 (3) : P245-258 doi: 10.1071/FP21288
Nitric oxide is involved in hydrogen sulfide-induced adventitious rooting in tomato (Solanum lycopersicum).
College of Horticulture, Gansu Agricultural University, 1 Yinmen Village, Anning District, Lanzhou 730070, China.
Nitric oxide (NO) and hydrogen sulfide (H2 S) are signalling molecules that regulate adventitious rooting in plants. However, little is known about the cross-talk between NO and H2 S during adventitious rooting. Tomato (Solanum lycopersicum L.) explants were used to investigate the roles of and relationships between NO and H2 S during rooting. Effects of the NO donor sodium nitroprusside (SNP) and the H2 S donor sodium hydrosulfide (NaHS) on adventitious rooting were dose-dependent, and the greatest biological responses were observed under 25muM SNP and 50muM NaHS. The positive effect of NaHS was reversed by the NO scavenger 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), indicating that the H2 S-induced response was partially NO-dependent. Peroxidase (POD), polyphenol oxidase (PPO), and superoxide dismutase (SOD) activities significantly increased by SNP and NaHS treatment, and indoleacetic acid oxidase (IAAO) activity and the O2 - and H2 O2 content significantly decreased by SNP and NaHS treatment. SNP and NaHS treatment also increased the content of soluble sugar and protein and indole-3-acetic acid (IAA). cPTIO significantly mitigated the increases in POD, PPO and SOD activity and soluble sugar, protein and IAA content induced by NaHS. SNP and NaHS upregulated the expression of auxin-related genes (ARF4 and ARF16 ), cell cycle-related genes (CYCD3 , CYCA3 and CDKA1 ), and antioxidant-related genes (TPX2 , SOD and POD ); whereas cPTIO significantly inhibited the increase in the expression of these genes induced by NaHS. Overall, these results show that NO may be involved in H2 S-induced adventitious rooting by regulating the activity of rooting-related enzymes, the expression of related genes, and the content of various nutrients.
PMID: 34991782
Arch Microbiol , IF:2.552 , 2022 Feb , V204 (3) : P181 doi: 10.1007/s00203-022-02768-2
A new endophytic fungus CJAN1179 isolated from the Cholistan desert promotes lateral root growth in Arabidopsis and produces IAA through tryptophan-dependent pathway.
Chemistry Department, The Islamia University of Bahawalpur, Bahawalpur, 63000, Pakistan.; INRES, Molecular Phytomedicine, Rheinische Friedrich-Wilhelms-University Bonn, Karlrobert-Kreiten-Str. 13, 53115, Bonn, Germany.; Institute of Biochemistry, Biotechnology and Bioinformatics, The Islamia University of Bahawalpur, Baghdad Ul Jadeed Campus, Bahawalpur, 63000, Pakistan.; Department of Botany, The Islamia University of Bahawalpur, Bahawalpur, 63000, Pakistan.; INRES, Molecular Phytomedicine, Rheinische Friedrich-Wilhelms-University Bonn, Karlrobert-Kreiten-Str. 13, 53115, Bonn, Germany. sylvia.schleker@uni-bonn.de.
Fungi, important for growth of plants in arid lands, are expected to be involved in novel biochemical activities during fungal-plant interactions. We isolated 150 fungi associated with rhizosphere and root endosphere of two perennial grasses, Cymbopogon jwarancusa and Panicum antidotale, from Cholistan desert. The isolates were screened for their impact on plant growth and development using Arabidopsis thaliana (Col-0) as a model system. A root-endophytic fungus CJAN1179 from C. jwarancusa showed the highest plant growth-promoting effects. The most remarkable was enhanced number of lateral roots (3.1-fold). CJAN1179 produced indole-3-acetic acid (IAA) particularly in the presence of tryptophan. ITS sequence and phylogenetic analysis characterisation suggested the fungus to be a new species within Sordariomycetidae. CJAN1179 appears to promote plant growth by secreting IAA using tryptophan as a precursor. This fungus can be further explored for its suitability to promote growth of commercially important crops, particularly in arid regions.
PMID: 35175443
Virus Genes , IF:2.332 , 2022 Feb , V58 (1) : P1-14 doi: 10.1007/s11262-021-01881-6
The interplay of plant hormonal pathways and geminiviral proteins: partners in disease development.
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, -110021, India.; Department of Botany, Bhagat Singh Government P.G. College, Jaora, Ratlam, Madhya Pradesh, 457226, India.; Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, -110021, India. indasgup@south.du.ac.in.
Viruses belonging to the family Geminiviridae infect plants and are responsible for a number of diseases of crops in the tropical and sub-tropical regions of the World. The innate immune response of the plant assists in its defense against such viral pathogens by the recognition of pathogen/microbe-associated molecular patterns through pattern-recognition receptors. Phytohormone signalling pathways play a vital role in plant defense responses against these devastating viruses. Geminiviruses, however, have developed counter-defense strategies that prevail over the above defense pathways. The proteins encoded by geminiviruses act as suppressors of plant immunity by interacting with the signalling components of several hormones. In this review we focus on the molecular interplay of phytohormone pathways and geminiviral infection and try to find interesting parallels with similar mechanisms known in other plant-infecting viruses and strengthen the argument that this interplay is necessary for disease development.
PMID: 35034268
Plant Signal Behav , IF:2.247 , 2022 Feb doi: 10.1080/15592324.2022.2031784
The epigenetic regulator ULTRAPETALA1 suppresses de novo root regeneration from Arabidopsis leaf explants.
Key Laboratory of Saline-Alkali Vegetation Ecology Restoration Ministry of Education, Northeast Forestry University, Harbin, China.; College of Life Science, Institute of Genetics, Northeast Forestry University, Harbin, China.; Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, China.
Plants have the potency to regenerate adventitious roots from aerial organs after detachment. In Arabidopsis thaliana, de novo root regeneration (DNRR) from leaf explants is triggered by wounding signaling that rapidly induces the expression of the ETHYLENE RESPONSE FACTOR (ERF) transcription factors ERF109 and ABR1 (ERF111). In turn, the ERFs promote the expression of ASA1, an essential enzyme of auxin biosynthesis, which contributes to rooting by providing high levels of auxin near the wounding side of the leaf. Here, we show that the loss of the epigenetic regulator ULTRAPETALA1 (ULT1), which interacts with Polycomb and Trithorax Group proteins, accelerates and reinforces adventitious root formation. Expression of ERF109 and ASA1 was increased in ult1 mutants, whereas ABR1 was not significantly changed. Cultivation of explants on media with exogenous auxin equates adventitious root formation in wild-type with ult1 mutants, suggesting that ULT1 negatively regulates DNRR by suppressing auxin biosynthesis. Based on these findings, we propose that ULT1 is involved in a novel mechanism that prevents overproliferation of adventitious roots during DNRR.
PMID: 35164655
J Environ Sci Health B , IF:1.99 , 2022 Feb : P1-10 doi: 10.1080/03601234.2022.2028528
Searching for biomarkers of early detection of 2,4-D effects in a native tree species from the Brazilian Cerrado biome.
Ciencia e Tecnologia - Campus Rio Verde, Instituto Federal Goiano de Educacao, Rio Verde, Goias, Brazil.; Laboratorio de Estudo de Plantas sob Estresse, Universidade de Sao Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Piracicaba, Sao Paulo, Brazil.; Ciencia e Tecnologia Goiano - Campus Morrinhos, Instituto Federal de Educacao, Morrinhos, Goias, Brazil.; Nucleo de Pesquisa em Ecologia, Instituto de Botanica, Sao Paulo, Sao Paulo, Brazil.
Biodiversity in the Brazilian Cerrado biome has been declining sharply with the continued expansion of agriculture and the excessive use of herbicides. Thus, the aim of this study was to evaluate the morphophysiological and biochemical responses in Dipteryx alata plants to various doses of the herbicide 2,4-D. Specific biomarkers that characterize the phytoindicator potential of this species were determined. Gas exchange, chlorophyll a fluorescence, photosynthetic pigments, and the activities of antioxidant enzymes and cellulase were performed after 24, 96 and/or 396 hours after 2,4-D application (HAA). The herbicide caused higher antioxidant enzymatic activity 24 HAA and damage to the photosynthetic machinery after 96 HAA. Reduction in gas exchange, chlorophyll content, and photochemical traits were observed. Increased respiratory rates, non-photochemical quenching, and carotenoid concentrations in 2,4-D-treated plants were important mechanisms in the defense against the excess energy absorbed. Furthermore, the absence of leaf symptoms suggested tolerance of D. alata to 2,4-D. Nevertheless, changes in the photosynthetic and biochemical metabolism of D. alata are useful as early indicators of herbicide contamination, especially in the absence of visual symptoms. These results are important for early monitoring of plants in conserved areas and for preventing damage to sensitive species.
PMID: 35114885
Biochem Genet , IF:1.89 , 2022 Feb , V60 (1) : P127-152 doi: 10.1007/s10528-021-10093-4
Identification and Expression Analysis of miR160 and Their Target Genes in Cucumber.
School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang, 453003, China.; Henan Province Engineering Research Center of Horticultural Plant Resource Utilization and Germplasm Enhancement, Xinxiang, 453003, China.; School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang, 453003, China. sunyd2001@163.com.; Henan Province Engineering Research Center of Horticultural Plant Resource Utilization and Germplasm Enhancement, Xinxiang, 453003, China. sunyd2001@163.com.; Institute of Horticulture, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.
miR160 plays a crucial role in various biological processes by regulating their target gene auxin response factor (ARF) in plants. However, little is known about miR160 and ARF in cucumber fruit expansion. Here, 4 Csa-MIR160 family members and 17 CsARFs were identified through a genome-wide search. Csa-miR160 showed a closer relationship with those in melon. Phylogenetic analysis revealed that CsARFs were divided into four classes and most of CsARFs presented a closer evolutionary relationship with those from tomato. Putative cis-elements analysis predicted that Csa-MIR160 and CsARFs were involved in light, phytohormone and stress response, which proved that they might take part in light, phytohormone and stress signaling pathway by the miR160-ARF module. In addition, CsARF5, CsARF11, CsARF13 and CsARF14 were predicted as the target genes of Csa-miR160. qRT-PCR revealed that Csa-miR160 and their target gene CsARFs were differentially expressed in differential cucumber tissues and developmental stages. Csa-miR160d was only expressed in the expanded cucumber fruit. CsARF5, CsARF11 and CsARF13 exhibited the lower expression in the expanded fruit than those in the ovary, while, CsARF14 showed the reverse trend. Our results suggested that Csa-miR160d might play a crucial role in cucumber fruit expansion by negatively targeting CsARF5, CsARF11 and CsARF13. This is the first genome-wide analysis of miR160 in cucumber. These findings provide useful information and resources for further studying the role of miR160 and ARF in cucumber fruit expansion.
PMID: 34117971