Nat Rev Mol Cell Biol , IF:94.444 , 2022 May doi: 10.1038/s41580-022-00479-6
Plant hormone regulation of abiotic stress responses.
Institute of Technology, University of Tartu, Tartu, Estonia.; Institut fur Biologie und Biotechnologie der Pflanzen, Westfalische Wilhelms-Universitat Munster, Munster, Germany.; Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.; Graduate School of Environmental and Life Science, Okayama University, Tsushima-Naka, Okayama, Japan.; Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA. jischroeder@ucsd.edu.
Plant hormones are signalling compounds that regulate crucial aspects of growth, development and environmental stress responses. Abiotic stresses, such as drought, salinity, heat, cold and flooding, have profound effects on plant growth and survival. Adaptation and tolerance to such stresses require sophisticated sensing, signalling and stress response mechanisms. In this Review, we discuss recent advances in understanding how diverse plant hormones control abiotic stress responses in plants and highlight points of hormonal crosstalk during abiotic stress signalling. Control mechanisms and stress responses mediated by plant hormones including abscisic acid, auxin, brassinosteroids, cytokinins, ethylene and gibberellins are discussed. We discuss new insights into osmotic stress sensing and signalling mechanisms, hormonal control of gene regulation and plant development during stress, hormone-regulated submergence tolerance and stomatal movements. We further explore how innovative imaging approaches are providing insights into single-cell and tissue hormone dynamics. Understanding stress tolerance mechanisms opens new opportunities for agricultural applications.
PMID: 35513717
Trends Plant Sci , IF:18.313 , 2022 May , V27 (5) : P440-449 doi: 10.1016/j.tplants.2021.11.006
Bending to auxin: fast acid growth for tropisms.
Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.; Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria. Electronic address: jiri.friml@ist.ac.at.
The phytohormone auxin is the major growth regulator governing tropic responses including gravitropism. Auxin build-up at the lower side of stimulated shoots promotes cell expansion, whereas in roots it inhibits growth, leading to upward shoot bending and downward root bending, respectively. Yet it remains an enigma how the same signal can trigger such opposite cellular responses. In this review, we discuss several recent unexpected insights into the mechanisms underlying auxin regulation of growth, challenging several existing models. We focus on the divergent mechanisms of apoplastic pH regulation in shoots and roots revisiting the classical Acid Growth Theory and discuss coordinated involvement of multiple auxin signaling pathways. From this emerges a more comprehensive, updated picture how auxin regulates growth.
PMID: 34848141
Nat Plants , IF:15.793 , 2022 Apr , V8 (4) : P373-388 doi: 10.1038/s41477-022-01127-9
Genomes of leafy and leafless Platanthera orchids illuminate the evolution of mycoheterotrophy.
Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China.; Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China.; Tsinghua-Berkeley Shenzhen Institute (TBSI), Center for Biotechnology and Biomedicine, Shenzhen Key Laboratory of Gene and Antibody Therapy, State Key Laboratory of Chemical Oncogenomics, State Key Laboratory of Health Sciences and Technology, Institute of Biopharmaceutical and Health Engineering (iBHE), Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB Center for Plant Systems Biology, Ghent, Belgium.; Institute of Tropical Plant Sciences, National Cheng Kung University, Tainan, Taiwan.; Zijin Baixi Provincial Nature Reserve of Guangdong, Heyuan, China.; Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.; Orchid Research and Development Center, National Cheng Kung University, Tainan, Taiwan.; Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan.; Department of Applied Chemistry, National Pingtung University, Pingtung, Taiwan.; PubBio-Tech, Wuhan, China.; State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.; Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China. lkzx@fafu.edu.cn.; Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China. lkzx@fafu.edu.cn.; Orchid Research and Development Center, National Cheng Kung University, Tainan, Taiwan. tsaiwc@mail.ncku.edu.tw.; Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan. tsaiwc@mail.ncku.edu.tw.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. yves.vandepeer@psb.vib-ugent.be.; VIB Center for Plant Systems Biology, Ghent, Belgium. yves.vandepeer@psb.vib-ugent.be.; Center for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa. yves.vandepeer@psb.vib-ugent.be.; College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, China. yves.vandepeer@psb.vib-ugent.be.; Key Laboratory of Orchid Conservation and Utilization of National Forestry and Grassland Administration at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China. zjliu@fafu.edu.cn.; Fujian Colleges and Universities Engineering Research Institute of Conservation and Utilization of Natural Bioresources, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China. zjliu@fafu.edu.cn.; Henry Fok College of Biology and Agriculture, Shaoguan University, Shaoguan, China. zjliu@fafu.edu.cn.
To improve our understanding of the origin and evolution of mycoheterotrophic plants, we here present the chromosome-scale genome assemblies of two sibling orchid species: partially mycoheterotrophic Platanthera zijinensis and holomycoheterotrophic Platanthera guangdongensis. Comparative analysis shows that mycoheterotrophy is associated with increased substitution rates and gene loss, and the deletion of most photoreceptor genes and auxin transporter genes might be linked to the unique phenotypes of fully mycoheterotrophic orchids. Conversely, trehalase genes that catalyse the conversion of trehalose into glucose have expanded in most sequenced orchids, in line with the fact that the germination of orchid non-endosperm seeds needs carbohydrates from fungi during the protocorm stage. We further show that the mature plant of P. guangdongensis, different from photosynthetic orchids, keeps expressing trehalase genes to hijack trehalose from fungi. Therefore, we propose that mycoheterotrophy in mature orchids is a continuation of the protocorm stage by sustaining the expression of trehalase genes. Our results shed light on the molecular mechanism underlying initial, partial and full mycoheterotrophy.
PMID: 35449401
Nat Plants , IF:15.793 , 2022 Apr , V8 (4) : P419-433 doi: 10.1038/s41477-022-01121-1
The auxin-responsive transcription factor SlDOF9 regulates inflorescence and flower development in tomato.
Universite de Toulouse, INRAe/INP Toulouse, Genomique et Biotechnologie des Fruits-UMR990, Castanet-Tolosan, France.; Laboratoire de Recherche en Sciences Vegetales-UMR5546, Universite de Toulouse, CNRS, UPS, Toulouse-INP, Toulouse, France.; Biologie du Fruit et Pathologie-UMR 1332, Universite Bordeaux, INRAE, Villenave d'Ornon, France.; Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing, China.; Universite de Toulouse, INRAe/INP Toulouse, Genomique et Biotechnologie des Fruits-UMR990, Castanet-Tolosan, France. bouzayen@ensat.fr.; Laboratoire de Recherche en Sciences Vegetales-UMR5546, Universite de Toulouse, CNRS, UPS, Toulouse-INP, Toulouse, France. bouzayen@ensat.fr.; Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing, China. bouzayen@ensat.fr.
Understanding the mechanisms underlying differentiation of inflorescence and flower meristems is essential towards enlarging our knowledge of reproductive organ formation and to open new prospects for improving yield traits. Here, we show that SlDOF9 is a new modulator of floral differentiation in tomato. CRISPR/Cas9 knockout strategy uncovered the role of SlDOF9 in controlling inflorescence meristem and floral meristem differentiation via the regulation of cell division genes and inflorescence architecture regulator LIN. Tomato dof9-KO lines have more flowers in both determinate and indeterminate cultivars and produce more fruit upon vibration-assisted fertilization. SlDOF9 regulates inflorescence development through an auxin-dependent ARF5-DOF9 module that seems to operate, at least in part, differently in Arabidopsis and tomato. Our findings add a new actor to the complex mechanisms underlying reproductive organ differentiation in flowering plants and provide leads towards addressing the diversity of factors controlling the transition to reproductive organs.
PMID: 35422080
Mol Plant , IF:13.164 , 2022 Apr doi: 10.1016/j.molp.2022.04.009
Coordination of plant growth and abiotic stress responses by tryptophan synthase beta subunit 1 through modulation of tryptophan and ABA homeostasis in Arabidopsis.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China.; State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China.; State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China. Electronic address: yingtlu@whu.edu.cn.
To adapt to changing environments, plants have evolved elaborate regulatory mechanisms balancing their growth with stress responses. It is currently unclear whether and how the tryptophan (Trp), the growth-related hormone auxin, and the stress hormone abscisic acid (ABA) are coordinated in this trade-off. Here, we show that tryptophan synthase beta subunit 1 (TSB1) is involved in the coordination of Trp and ABA, thereby affecting plant growth and abiotic stress responses. Plants experiencing high salinity or drought display reduced TSB1 expression, resulting in decreased Trp and auxin accumulation and thus reduced growth. In comparison with the wild type, amiR-TSB1 lines and TSB1 mutants exhibited repressed growth under non-stress conditions but had enhanced ABA accumulation and stress tolerance when subjected to salt or drought stress. Furthermore, we found that TSB1 interacts with and inhibits beta-glucosidase 1 (BG1), which hydrolyses glucose-conjugated ABA into active ABA. Mutation of BG1 in the amiR-TSB1 lines compromised their increased ABA accumulation and enhanced stress tolerance. Moreover, stress-induced H2O2 disrupted the interaction between TSB1 and BG1 by sulfenylating cysteine-308 of TSB1, relieving the TSB1-mediated inhibition of BG1 activity. Taken together, we revealed that TSB1 serves as a key coordinator of plant growth and stress responses by balancing Trp and ABA homeostasis.
PMID: 35488429
Dev Cell , IF:12.27 , 2022 May , V57 (9) : P1177-1192.e6 doi: 10.1016/j.devcel.2022.04.013
Gene regulatory networks shape developmental plasticity of root cell types under water extremes in rice.
Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA; IBBM, FCE-UNLP CONICET, La Plata 1900, Argentina.; Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA.; Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA; Department of Biology, University of Padova, Padova, Italy.; Department of Biology, Emory University, Atlanta, GA 30322, USA.; Department of Plant Biology, University of California, Davis, Davis, CA 95616, USA.; Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA 95616, USA.; Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA; Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 Utrecht, the Netherlands. Electronic address: serres@ucr.edu.
Understanding how roots modulate development under varied irrigation or rainfall is crucial for development of climate-resilient crops. We established a toolbox of tagged rice lines to profile translating mRNAs and chromatin accessibility within specific cell populations. We used these to study roots in a range of environments: plates in the lab, controlled greenhouse stress and recovery conditions, and outdoors in a paddy. Integration of chromatin and mRNA data resolves regulatory networks of the following: cycle genes in proliferating cells that attenuate DNA synthesis under submergence; genes involved in auxin signaling, the circadian clock, and small RNA regulation in ground tissue; and suberin biosynthesis, iron transporters, and nitrogen assimilation in endodermal/exodermal cells modulated with water availability. By applying a systems approach, we identify known and candidate driver transcription factors of water-deficit responses and xylem development plasticity. Collectively, this resource will facilitate genetic improvements in root systems for optimal climate resilience.
PMID: 35504287
Plant Cell , IF:11.277 , 2022 May doi: 10.1093/plcell/koac146
A molecular framework of ethylene-mediated fruit growth and ripening processes in tomato.
Institute of Plant and Food Science, Department of Biology, Southern University of Science and Technology (SUSTech), 518055 Shenzhen, Guangdong, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology (SUSTech), 518055 Shenzhen, Guangdong, China.; Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331 Chongqing, China.; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology (SUSTech), 518055 Shenzhen, Guangdong, China.
Although the role of ethylene in tomato (Solanum lycopersicum) fruit ripening has been intensively studied, its role in tomato fruit growth remains poorly understood. In addition, the relationship between ethylene and the developmental factors NON-RIPENING (NOR) and RIPENING INHIBITOR (RIN) during ripening is under debate. Here, we carried out comprehensive genetic analyses of genome-edited mutants of tomato ETHYLENE INSENSITIVE 2 (SlEIN2), four EIN3-like genes (SlEIL1-4), and three EIN3 BINDING F-box protein genes (SlEBF1-3). Both slein2-1 and the high-order sleil mutant (sleil1 sleil2 sleil3/SlEIL3 sleil4) showed reduced fruit size, mainly due to decreased auxin biosynthesis. During fruit maturation, slein2 mutants displayed the complete cessation of ripening, which was partially rescued by slebf1 but not slebf2 or slebf3. We also discovered that ethylene directly activates the expression of the developmental genes NOR, RIN, and FRUITFULL1 (FUL1) via SlEIL proteins. Indeed, overexpressing these genes partially rescued the ripening defects of slein2-1. Finally, the signal intensity of the ethylene burst during fruit maturation was intimately connected with the progression of full ripeness. Collectively, our work uncovers a critical role of ethylene in fruit growth and supports a molecular framework of ripening control in which the developmental factors NOR, RIN, and FUL1 act downstream of ethylene signaling.
PMID: 35604102
Plant Cell , IF:11.277 , 2022 Apr doi: 10.1093/plcell/koac107
AUXIN RESPONSE FACTOR7 integrates gibberellin and auxin signaling via interactions between DELLA and AUX/IAA proteins to regulate cambial activity in poplar.
Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing 400715, China.; School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia.; Department of Land, Air and Water Resources, University of California at Davis, Davis, CA 95616, USA.; Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
Cambial development in the stems of perennial woody species is rigorously regulated by phytohormones. Auxin and gibberellin (GA) play crucial roles in stimulating cambial activity in poplar (Populus spp.). In this study, we show that the DELLA protein REPRESSOR of ga1-3 Like 1 (RGL1), AUXIN RESPONSE FACTOR 7 (ARF7), and Aux/INDOLE-3-ACETIC ACID 9 (IAA9) form a ternary complex that mediates crosstalk between the auxin and GA signaling pathways in poplar stems during cambial development. Biochemical analysis revealed that ARF7 physically interacts with RGL1 and IAA9 through distinct domains. The arf7 loss-of-function mutant showed markedly attenuated responses to auxin and GA, whereas transgenic poplar plants overexpressing ARF7 displayed strongly improved cambial activity. ARF7 directly binds to the promoter region of the cambial stem cell regulator WOX4 to modulate its expression, thus integrating auxin and GA signaling to regulate cambial activity. Furthermore, the direct activation of PIN-FORMED 1 (PIN1) expression by ARF7 in the RGL1-ARF7-IAA9 module increased GA-dependent cambial activity via polar auxin transport. Collectively, these findings reveal that the crosstalk between auxin and GA signaling mediated by the RGL1-ARF7-IAA9 module is crucial for the precise regulation of cambial development in poplar.
PMID: 35435234
Plant Cell , IF:11.277 , 2022 May , V34 (6) : P2114-2115 doi: 10.1093/plcell/koac087
The sum is greater than the parts: Co-dependent auxin efflux is mediated by ABCBs and PINs.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Biology, Duke University, Durham, North Carolina, USA.
PMID: 35394537
Plant Cell , IF:11.277 , 2022 May , V34 (6) : P2309-2327 doi: 10.1093/plcell/koac086
Systems approaches reveal that ABCB and PIN proteins mediate co-dependent auxin efflux.
Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.; Department of Biology, University of Fribourg, Fribourg CH-1700, Switzerland.; Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
Members of the B family of membrane-bound ATP-binding cassette (ABC) transporters represent key components of the auxin efflux machinery in plants. Over the last two decades, experimental studies have shown that modifying ATP-binding cassette sub-family B (ABCB) expression affects auxin distribution and plant phenotypes. However, precisely how ABCB proteins transport auxin in conjunction with the more widely studied family of PIN-formed (PIN) auxin efflux transporters is unclear, and studies using heterologous systems have produced conflicting results. Here, we integrate ABCB localization data into a multicellular model of auxin transport in the Arabidopsis thaliana root tip to predict how ABCB-mediated auxin transport impacts organ-scale auxin distribution. We use our model to test five potential ABCB-PIN regulatory interactions, simulating the auxin dynamics for each interaction and quantitatively comparing the predictions with experimental images of the DII-VENUS auxin reporter in wild-type and abcb single and double loss-of-function mutants. Only specific ABCB-PIN regulatory interactions result in predictions that recreate the experimentally observed DII-VENUS distributions and long-distance auxin transport. Our results suggest that ABCBs enable auxin efflux independently of PINs; however, PIN-mediated auxin efflux is predominantly through a co-dependent efflux where co-localized with ABCBs.
PMID: 35302640
Curr Biol , IF:10.834 , 2022 Apr , V32 (8) : PR370-R372 doi: 10.1016/j.cub.2022.03.008
Plant biology: Local auxin synthesis drives pollen maturation in barley.
Section of Cell and Developmental Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA.; Section of Cell and Developmental Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA. Electronic address: yundezhao@ucsd.edu.
Pollen grains stock up on starch to power germination and pollen tube growth upon pollination. New findings in barley show that localized auxin biosynthesis by a YUC flavin monooxygenase leads to reprogramming energy metabolism during pollen maturation.
PMID: 35472426
Curr Biol , IF:10.834 , 2022 May , V32 (9) : P1974-1985.e3 doi: 10.1016/j.cub.2022.03.019
Cytokinin promotes growth cessation in the Arabidopsis root.
Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany.; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany; Physics Department, Technical University Munich, James-Franck-Str. 1/I, 85748 Garching b. Munich, Germany.; Dipartimento di Biologia e Biotecnologie, Laboratory of Functional Genomics and Proteomics of Model Systems, Universita di Roma, Sapienza, via dei Sardi, 70, 00185 Rome, Italy.; Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany.; Institute for Cell and Interaction Biology, Heinrich-Heine Universitat Dusseldorf, Universitatsstrasse 1, 40225 Dusseldorf, Germany.; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany; Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK.; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829 Cologne, Germany. Electronic address: tsiantis@mpipz.mpg.de.
The Arabidopsis root offers good opportunities to investigate how regulated cellular growth shapes different tissues and organs, a key question in developmental biology. Along the root's longitudinal axis, cells sequentially occupy different developmental states. Proliferative meristematic cells give rise to differentiating cells, which rapidly elongate in the elongation zone, then mature and stop growing in the differentiation zone. The phytohormone cytokinin contributes to this zonation by positioning the boundary between the meristem and the elongation zone, called the transition zone. However, the cellular growth profile underlying root zonation is not well understood, and the cellular mechanisms that mediate growth cessation remain unclear. By using time-lapse imaging, genetics, and computational analysis, we analyze the effect of cytokinin on root zonation and cellular growth. We found that cytokinin promotes growth cessation in the distal (shootward) elongation zone in conjunction with accelerating the transition from elongation to differentiation. We estimated cell-wall stiffness by using osmotic treatment experiments and found that cytokinin-mediated growth cessation is associated with cell-wall stiffening and requires the action of an auxin influx carrier, AUX1. Our measurement of growth and cell-wall mechanical properties at a cellular resolution reveal mechanisms via which cytokinin influences cell behavior to shape tissue patterns.
PMID: 35354067
Curr Biol , IF:10.834 , 2022 May , V32 (9) : P1883-1894.e7 doi: 10.1016/j.cub.2022.02.069
Cell-wall damage activates DOF transcription factors to promote wound healing and tissue regeneration in Arabidopsis thaliana.
Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas alle 5, 756 51, Uppsala, Sweden.; Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Japan.; Independent Junior Research Group - Designer Glycans, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.; The Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Independent Junior Research Group - Designer Glycans, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany; Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA.; Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Japan; Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Japan.; Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas alle 5, 756 51, Uppsala, Sweden. Electronic address: charles.melnyk@slu.se.
Wound healing is a fundamental property of plants and animals that requires recognition of cellular damage to initiate regeneration. In plants, wounding activates a defense response via the production of jasmonic acid and a regeneration response via the hormone auxin and several ethylene response factor (ERF) and NAC domain-containing protein (ANAC) transcription factors. To better understand how plants recognize damage and initiate healing, we searched for factors upregulated during the horticulturally relevant process of plant grafting and found four related DNA binding with one finger (DOF) transcription factors, HIGH CAMBIAL ACTIVITY2 (HCA2), TARGET OF MONOPTEROS6 (TMO6), DOF2.1, and DOF6, whose expression rapidly activated at the Arabidopsis graft junction. Grafting or wounding a quadruple hca2, tmo6, dof2.1, dof6 mutant inhibited vascular and cell-wall-related gene expression. Furthermore, the quadruple dof mutant reduced callus formation, tissue attachment, vascular regeneration, and pectin methylesterification in response to wounding. We also found that activation of DOF gene expression after wounding required auxin, but hormone treatment alone was insufficient for their induction. However, modifying cell walls by enzymatic digestion of cellulose or pectin greatly enhanced TMO6 and HCA2 expression, whereas genetic modifications to the pectin or cellulose matrix using the PECTIN METHYLESTERASE INHIBITOR5 overexpression line or korrigan1 mutant altered TMO6 and HCA2 expression. Changes to the cellulose or pectin matrix were also sufficient to activate the wound-associated ERF115 and ANAC096 transcription factors, suggesting that cell-wall damage represents a common mechanism for wound perception and the promotion of tissue regeneration.
PMID: 35320706
Curr Biol , IF:10.834 , 2022 Apr , V32 (8) : P1798-1811.e8 doi: 10.1016/j.cub.2022.02.073
Auxin boosts energy generation pathways to fuel pollen maturation in barley.
Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umea, Sweden.; Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany; Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria.; Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854, USA.; Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854, USA; Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.; Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany. Electronic address: acosta@mpipz.mpg.de.
Pollen grains become increasingly independent of the mother plant as they reach maturity through poorly understood developmental programs. We report that the hormone auxin is essential during barley pollen maturation to boost the expression of genes encoding almost every step of heterotrophic energy production pathways. Accordingly, auxin is necessary for the flux of sucrose and hexoses into glycolysis and to increase the levels of pyruvate and two tricarboxylic (TCA) cycle metabolites (citrate and succinate). Moreover, bioactive auxin is synthesized by the pollen-localized enzyme HvYUCCA4, supporting that pollen grains autonomously produce auxin to stimulate a specific cellular output, energy generation, that fuels maturation processes such as starch accumulation. Our results demonstrate that auxin can shift central carbon metabolism to drive plant cell development, which suggests a direct mechanism for auxin's ability to promote growth and differentiation.
PMID: 35316655
New Phytol , IF:10.151 , 2022 May doi: 10.1111/nph.18200
Broad-range metalloprotease profiling in plants uncovers immunity provided by defence-related metalloenzyme.
The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK.; Department of Chemistry and the Ineos Oxford Institute for Antimcrobial Research, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.; The Plant Chemetics Laboratory, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany.; Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.; Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
Plants encode > 100 metalloproteases representing > 19 different protein families. Tools to study this large and diverse class of proteases have not yet been introduced into plant research. We describe the use of hydroxamate-based photoaffinity probes to explore plant proteomes for metalloproteases. We detected labelling of 23 metalloproteases in leaf extracts of the model plant Arabidopsis thaliana that belong to nine different metalloprotease families and localize to different subcellular compartments. The probes identified several chloroplastic FtsH proteases, vacuolar aspartyl aminopeptidase DAP1, peroxisomal metalloprotease PMX16, extracellular matrix metalloproteases and many cytosolic metalloproteases. We also identified nonproteolytic metallohydrolases involved in the release of auxin and in the urea cycle. Studies on tobacco plants (Nicotiana benthamiana) infected with the bacterial plant pathogen Pseudomonas syringae uncovered the induced labelling of PRp27, a secreted protein with implicated metalloprotease activity. PRp27 overexpression increases resistance, and PRp27 mutants lacking metal binding site are no longer labelled, but still show increased immunity. Collectively, these studies reveal the power of broad-range metalloprotease profiling in plants using hydroxamate-based probes.
PMID: 35510806
New Phytol , IF:10.151 , 2022 May doi: 10.1111/nph.18196
A novel chemical inhibitor of polar auxin transport promotes shoot regeneration by local enhancement of HD-ZIP III transcription.
Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.; Plant Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.; Biotechnology of Horticultural Crops, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
De novo shoot organogenesis is a prerequisite for numerous applications in plant research and breeding but is often a limiting factor, for example, in genome editing approaches. HD-ZIP III transcription factors have been characterized as crucial regulators of shoot specification, however up-stream components controlling their activity during shoot regeneration are only partially identified. In a chemical genetic screen, we isolated ZIC2, a novel activator of HD-ZIP III activity. Using molecular, physiological and hormone transport analyses in Arabidopsis and sunflower (Helianthus annuus), we examined the molecular mechanism by which the drug promotes HD-ZIP III expression. ZIC2-dependent upregulation of HD-ZIP III transcription promotes shoot regeneration in Arabidopsis and is accompanied by the induction of shoot specifying factors WUS and RAP2.6L and a subset of cytokinin biosynthesis enzymes. ZIC2's effect on HD-ZIP III expression and regeneration is based on its ability to limit polar auxin transport. We further provide evidence that chemical modulation of auxin efflux can enhance de novo shoot formation in the regeneration recalcitrant species sunflower. Activation of HD-ZIP III transcription during shoot regeneration depends on the local distribution of auxin and chemical modulation of auxin transport can be used to overcome poor shoot organogenesis in tissue culture.
PMID: 35491431
New Phytol , IF:10.151 , 2022 Apr doi: 10.1111/nph.18159
Auxin response factors are keys to the many auxin doors.
Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 38000, Grenoble, France.; Laboratoire de Reproduction et Developpement des Plantes, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Univ. Lyon, Lyon, France.
In plants, most developmental programs depend on the action of auxin. The best described model of the auxin signaling pathway, which explains most, but not all, of the auxin transcriptional responses, relies on a de-repression mechanism. The auxin/indole-3-acetic acid repressors (Aux/IAAs) interact with the auxin response factors (ARFs), the transcription factors of the auxin signaling pathway, leading to repression of the ARF-controlled genes. Auxin induces Aux/IAA degradation, releases ARFs and activates transcription. However, this elegant model is not suitable for all ARFs. Indeed, in Arabidopsis, which has 22 ARFs, only five of them fit into the model since they are the ones able to interact with Aux/IAAs. The remaining 17 have a limited capacity to interact with the repressors, and their mechanisms of action are still unclear. The differential interactions between ARF and Aux/IAA proteins constitute one of many examples of the biochemical and structural diversification of ARFs that affect their action and therefore affect auxin transcriptional responses. A deeper understanding of the structural properties of ARFs is fundamental to obtaining a better explanation of the action of auxin in plants.
PMID: 35434800
New Phytol , IF:10.151 , 2022 May , V234 (3) : P783-803 doi: 10.1111/nph.17955
Developmental regulation of leaf venation patterns: monocot versus eudicots and the role of auxin.
Department of Plant Sciences, University of Oxford, South Parks Rd, Oxford, OX1 3RB, UK.
Organisation and patterning of the vascular network in land plants varies in different taxonomic, developmental and environmental contexts. In leaves, the degree of vascular strand connectivity influences both light and CO2 harvesting capabilities as well as hydraulic capacity. As such, developmental mechanisms that regulate leaf venation patterning have a direct impact on physiological performance. Development of the leaf venation network requires the specification of procambial cells within the ground meristem of the primordium and subsequent proliferation and differentiation of the procambial lineage to form vascular strands. An understanding of how diverse venation patterns are manifest therefore requires mechanistic insight into how procambium is dynamically specified in a growing leaf. A role for auxin in this process was identified many years ago, but questions remain. In this review we first provide an overview of the diverse venation patterns that exist in land plants, providing an evolutionary perspective. We then focus on the developmental regulation of leaf venation patterns in angiosperms, comparing patterning in eudicots and monocots, and the role of auxin in each case. Although common themes emerge, we conclude that the developmental mechanisms elucidated in eudicots are unlikely to fully explain how parallel venation patterns in monocot leaves are elaborated.
PMID: 35020214
Cold Spring Harb Perspect Biol , IF:10.005 , 2022 May , V14 (5) doi: 10.1101/cshperspect.a039859
Fourteen Stations of Auxin.
Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.
Auxin has always been at the forefront of research in plant physiology and development. Since the earliest contemplations by Julius von Sachs and Charles Darwin, more than a century-long struggle has been waged to understand its function. This largely reflects the failures, successes, and inevitable progress in the entire field of plant signaling and development. Here I present 14 stations on our long and sometimes mystical journey to understand auxin. These highlights were selected to give a flavor of the field and to show the scope and limits of our current knowledge. A special focus is put on features that make auxin unique among phytohormones, such as its dynamic, directional transport network, which integrates external and internal signals, including self-organizing feedback. Accented are persistent mysteries and controversies. The unexpected discoveries related to rapid auxin responses and growth regulation recently disturbed our contentment regarding understanding of the auxin signaling mechanism. These new revelations, along with advances in technology, usher us into a new, exciting era in auxin research.
PMID: 34400554
Cold Spring Harb Perspect Biol , IF:10.005 , 2022 May , V14 (4) doi: 10.1101/cshperspect.a039933
Auxin in Root Development.
Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom.
Root system architecture is an important determinant of below-ground resource capture and hence overall plant fitness. The plant hormone auxin plays a central role in almost every facet of root development from the cellular to the whole-root-system level. Here, using Arabidopsis as a model, we review the multiple gene signaling networks regulated by auxin biosynthesis, conjugation, and transport that underpin primary and lateral root development. We describe the role of auxin in establishing the root apical meristem and discuss how the tight spatiotemporal regulation of auxin distribution controls transitions between cell division, cell growth, and differentiation. This includes the localized reestablishment of mitotic activity required to elaborate the root system via the production of lateral roots. We also summarize recent discoveries on the effects of auxin and auxin signaling and transport on the control of lateral root gravitropic setpoint angle (GSA), a critical determinant of the overall shape of the root system. Finally, we discuss how environmental conditions influence root developmental plasticity by modulation of auxin biosynthesis, transport, and the canonical auxin signaling pathway.
PMID: 34312248
Plant Biotechnol J , IF:9.803 , 2022 May , V20 (5) : P862-875 doi: 10.1111/pbi.13765
TaMOR is essential for root initiation and improvement of root system architecture in wheat.
National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Optimal root system architecture is beneficial for water-fertilizer use efficiency, stress tolerance and yield improvement of crops. However, because of the complexity of root traits and difficulty in phenotyping deep roots, the study on mechanisms of root development is rarely reported in wheat (Triticum aestivum L.). In this study, we identified that the LBD (LATERAL ORGAN BOUNDARIES DOMAIN) gene TaMOR (MORE ROOT in wheat) determines wheat crown root initiation. The mor mutants exhibited less or even no crown root, dwarfism, less grain number and lodging caused by few roots. The observation of cross sections showed that crown root initiation is inhibited in the mor mutants. Molecular assays revealed that TaMOR interacts with the auxin response factor ARF5 to directly induce the expression of the auxin transporter gene PIN2 (PIN-FORMED 2) in the root base to regulate crown root initiation. In addition, a 159-bp MITE (miniature inverted-repeat transposable element) insertion causing DNA methylation and lower expression of TaMOR-B was identified in TaMOR-B promoter, which is associated with lower root dry weight and shorter plant height. The results bring new light into regulation mechanisms of crown root initiation and offer a new target for the improvement of root system architecture in wheat.
PMID: 34890129
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac239
Mycorrhizal symbiosis reprograms ion fluxes and fatty acid metabolism in wild jujube during salt stress.
Key Laboratory of National Forestry and Grassland Administration on Silviculture in Loess Plateau, College of Forestry, Northwest A&F University, Yangling, 712100, China.; Farmland Irrigation Research Institute of Chinese Academy of Agricultural Sciences, China.; Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
Chinese jujube (Ziziphus jujuba) is an important fruit tree in China, and soil salinity is the main constraint affecting jujube production. It is unclear how arbuscular mycorrhizal (AM) symbiosis supports jujube adaptation to salt stress. Herein, we performed comparative physiological, ion flux, fatty acid (FA) metabolomic, and transcriptomic analyses to examine the mechanism of AM jujube responding to salt stress. AM seedlings showed better performance during salt stress. AM symbiosis altered phytohormonal levels: IAA and ABA contents were significantly increased in AM roots and reduced by salt stress. Mycorrhizal colonization enhanced root H+ efflux and K+ influx, while inducing expression of plasma membrane-type ATPase 7 (ZjAHA7) and high-affinity K+ transporter 2 (ZjHAK2) in roots. High K+/Na+ homeostasis was maintained throughout salt exposure. FA content was elevated in AM leaves as well as roots, especially for palmitic acid, oleic acid, trans oleic acid, and linoleic acid, and similar effects were also observed in AM poplar (P. alba x P. glandulosa cv. 84K) and Medicago truncatula, indicating AM symbiosis elevating FA levels could be a conserved physiological effect. Gene co-expression network analyses uncovered a core gene set including 267 genes in roots associated with AM symbiosis and conserved transcriptional responses, e.g., FA metabolism, phytohormone signal transduction, SNARE interaction in vesicular transport, and biotin metabolism. In contrast to widely up-regulated genes related to FA metabolism in AM roots, limited genes were affected in leaves. We propose a model of AM symbiosis-linked reprogramming of FA metabolism and provide a comprehensive insight into AM symbiosis with a woody species adaptation to salt stress.
PMID: 35604107
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac220
MEDIATOR SUBUNIT17 integrates jasmonate and auxin signaling pathways to regulate thermomorphogenesis.
Plant Mediator Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.; Signalling Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.; Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology,Masaryk University, Brno, Czech Republic.; Plant Transcription Regulation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
Plant adjustment to environmental changes involves complex crosstalk between extrinsic and intrinsic cues. In the past two decades, extensive research has elucidated the key roles of PHYTOCHROME INTERACTING FACTOR4 (PIF4) and the phytohormone auxin in thermomorphogenesis. In this study, we identified a previously unexplored role of jasmonate (JA) signaling components, the Mediator complex, and their integration with auxin signaling during thermomorphogenesis in Arabidopsis (Arabidopsis thaliana). Warm temperature induces expression of JA signaling genes including MYC2, but, surprisingly, this transcriptional activation is not JA dependent. Warm temperature also promotes accumulation of the JA-signaling receptor CORONATINE INSENSITIVE1 (COI1) and degradation of the JA-signaling repressor JASMONATE-ZIM-DOMAIN PROTEIN9 (JAZ9), which probably leads to de-repression of MYC2, enabling it to contribute to the expression of MEDIATOR SUBUNIT17 (MED17). In response to warm temperature, MED17 occupies the promoters of thermosensory genes including PIF4, YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE19 (IAA19), and IAA29. Moreover, MED17 facilitates enrichment of H3K4me3 on the promoters of PIF4, YUC8, IAA19, and IAA29 genes. Interestingly, both occupancy of MED17 and enrichment of H3K4me3 on these thermomorphogenesis-related promoters are dependent on PIF4 (or PIFs). Altered accumulation of COI1 under warm temperature in the med17 mutant suggests the possibility of a feedback mechanism. Overall, this study reveals the role of the Mediator complex as an integrator of JA and auxin signaling pathways during thermomorphogenesis.
PMID: 35567489
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac215
A PLETHORA/PIN-FORMED/auxin network mediates prehaustorium formation in the parasitic plant Striga hermonthica.
BESE Division, Plant Cell and Developmental Biology, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.; BESE Division, The BioActives Lab, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.; Institute of Cytology and Genetics, Lavrentyeva Avenue 10, Novosibirsk, 630090, Russian Federation.; Novosibirsk State University, 2 Pirogova Street, Novosibirsk, 630090, Russian Federation.; Plant Systems Physiology, Radboud University, Heyendaalseweg 135, 6500 AJ Nijmegen, NL.
The parasitic plant Striga (Striga hermonthica) invades the host root through the formation of a haustorium and has detrimental impacts on cereal crops. The haustorium results from the prehaustorium, which is derived directly from the differentiation of the Striga radicle. The molecular mechanisms leading to radicle differentiation shortly after germination remain unclear. In this study, we determined the developmental programs that regulate terminal prehaustorium formation in S. hermonthica at cellular resolution. We showed that shortly after germination, cells in the root meristem undergo multiplanar divisions. During growth, the meristematic activity declines and associates with reduced expression of the stem cell regulator PLETHORA1 and the cell cycle genes CYCLINB1 and HISTONE H4. We also observed a basal localization of the PIN-FORMED (PIN) proteins and a decrease in auxin levels in the meristem. Using the structural layout of the root meristem and the polarity of outer-membrane PIN proteins, we constructed a mathematical model of auxin transport that explains the auxin distribution patterns observed during S. hermonthica root growth. Our results reveal a fundamental molecular and cellular framework governing the switch of S. hermonthica roots to form the invasive prehaustoria.
PMID: 35543497
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac212
The HD-Zip transcription factor SlHB15A regulates abscission by modulating jasmonoyl-isoleucine biosynthesis.
College of Horticulture, Shenyang Agricultural University, Shenyang, Liaoning 110866, People's Republic of China.; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, Liaoning Province, China.; Department of Plant Sciences, University of California at Davis, CA 95616, USA.; Crops Pathology and Genetic Research Unit, USDA-ARS, Davis, CA 95616, USA.
Plant organ abscission, a process that is important for development and reproductive success, is inhibited by the phytohormone auxin and promoted by another phytohormone, jasmonic acid (JA). However, the molecular mechanisms underlying the antagonistic effects of auxin and JA in organ abscission are unknown. We identified a tomato (Solanum lycopersicum) class III homeodomain-leucine zipper transcription factor, HOMEOBOX15A (SlHB15A), which was highly expressed in the flower pedicel abscission zone and induced by auxin. Knocking out SlHB15A using clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 technology significantly accelerated abscission. In contrast, overexpression of microRNA166-resistant SlHB15A (mSlHB15A) delayed abscission. RNA sequencing and reverse transcription quantitative PCR analyses showed that knocking out SlHB15A altered the expression of genes related to JA biosynthesis and signaling. Furthermore, functional analysis indicated that SlHB15A regulates abscission by depressing JA-isoleucine (JA-Ile) levels through inhabiting the expression of JASMONATE-RESISTANT1 (SlJAR1), a gene involved in JA-Ile biosynthesis, which could induce abscission-dependent and -independent ethylene signaling. SlHB15A bound directly to the SlJAR1 promoter to silence SlJAR1, thus delaying abscission. We also found that flower removal enhanced JA-Ile content and that application of JA-Ile severely impaired the inhibitory effects of auxin on abscission. These results indicated that SlHB15A mediates the antagonistic effect of auxin and JA-Ile during tomato pedicel abscission, while auxin inhibits abscission through the SlHB15A-SlJAR1 module.
PMID: 35522030
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac213
High temperature induces male sterility via MYB66-MYB4-Casein kinase I signaling in cotton.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, Hubei, China.; College of Life Sciences, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, Guangdong, China.
High temperature (HT) causes male sterility and decreases crop yields. Our previous works have demonstrated that sugar and auxin signaling pathways, Gossypium hirsutum Casein kinase I (GhCKI), and DNA methylation are all involved in HT-induced male sterility in cotton. However, the signaling mechanisms leading to distinct GhCKI expression patterns induced by HT between HT-tolerant and HT-sensitive cotton anthers remain largely unknown. Here, we identified a GhCKI promoter (ProGhCKI) region that functions in response to HT in anthers and found the transcription factor GhMYB4 binds to this region to act as an upstream positive regulator of GhCKI. In the tapetum of early-stage cotton anthers, upregulated expression of GhMYB4 under HT and overexpressed GhMYB4 under normal temperature both led to severe male sterility phenotypes, coupled with enhanced expression of GhCKI. We also found that GhMYB4 interacts with GhMYB66 to form a heterodimer to enhance its binding to ProGhCKI. However, GhMYB66 showed an expression pattern similar to GhMYB4 under HT but did not directly bind to ProGhCKI. Furthermore, HT reduced siRNA-mediated CHH DNA methylations in the GhMYB4 promoter, which enhanced the expression of GhMYB4 in tetrad stage anthers and promoted the formation of the GhMYB4/GhMYB66 heterodimer, which in turn elevated the transcription of GhCKI in the tapetum, leading to male sterility. Overall, we shed light on the GhMYB66-GhMYB4-GhCKI regulatory pathway in response to HT in cotton anthers.
PMID: 35522025
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac194
SAUR15 interaction with BRI1 activates plasma membrane H+-ATPase to promote organ development of Arabidopsis.
State Key Laboratory of Grassland Agro-ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, People's Republic of China.; Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, Ontario, K1S 5B6, Canada.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China.; School of Life Sciences, Guangzhou University, Guangzhou 510006, People's Republic of China.
Brassinosteroids (BRs) are an important group of plant steroid hormones that regulate growth and development. Several members of the SMALL AUXIN UP RNA (SAUR) family have roles in BR-regulated hypocotyl elongation and root growth. However, the mechanisms are unclear. Here, we show in Arabidopsis (Arabidopsis thaliana) that SAUR15 interacts with cell surface receptor-like kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) in BR-treated plants, resulting in enhanced BRI1 phosphorylation status and recruitment of the co-receptor BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1). Genetic and phenotypic assays indicated that the SAUR15 effect on BRI1 can be uncoupled from BRASSINOSTEROID INSENSITIVE 2 (BIN2) activity. Instead, we show that SAUR15 promotes BRI1 direct activation of plasma membrane H+-ATPase (PM H+-ATPase) via phosphorylation. Consequently, SAUR15-BRI1-PM H+-ATPase acts as a direct, PM-based mode of BR signaling that drives cell expansion to promote the growth and development of various organs. These data define an alternate mode of BR signaling in plants.
PMID: 35511168
Plant Physiol , IF:8.34 , 2022 Apr doi: 10.1093/plphys/kiac158
SPATULA and ALCATRAZ confer female sterility and fruit cavity via mediating pistil development in cucumber.
State Key Laboratories of Agrobiotechnology, Joint International Research Laboratory of Crop Molecular Breeding, Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Sciences, China Agricultural University, Beijing 100193, China.; College of Horticulture Science and Technology, Hebei Normal University of Science & Technology, Qinhuangdao, China.
Fruits and seeds play essential roles in plant sexual reproduction and the human diet. Successful fertilization involves delivery of sperm in the pollen tube to the egg cell within the ovary along the transmitting tract (TT). Fruit cavity is an undesirable trait directly affecting cucumber (Cucumis sativus) commercial value. However, the regulatory genes underlying fruit cavity formation and female fertility determination remain unknown in crops. Here, we characterized a bHLH gene Cucumis sativus SPATULA (CsSPT) and its redundant and divergent function with ALCATRAZ (CsALC) in cucumber. CsSPT transcripts were enriched in reproductive organs. Mutation of CsSPT resulted in 60% reduction in female fertility, with seed produced only in the upper portion of fruits. Csspt Csalc mutants displayed complete loss of female fertility and fruit cavity due to carpel separation. Further examination showed that stigmas in the double mutant turned outward with defective papillae identity, and extracellular matrix contents in the abnormal TT were dramatically reduced, which resulted in no path for pollen tube extension and no ovules fertilized. Biochemical and transcriptome analysis showed that CsSPT and CsALC act in homodimers and heterodimers to confer fruit cavity and female sterility by mediating genes involved in TT development, auxin-mediated signaling, and cell wall organization in cucumber.
PMID: 35389464
Plant Physiol , IF:8.34 , 2022 Apr doi: 10.1093/plphys/kiac157
The interplay of auxin and brassinosteroid signaling tunes root growth under low and different nitrogen forms.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India, 110067.
The coordinated signaling activity of auxin and brassinosteroids (BRs) is critical for optimal plant growth and development. Nutrient-derived signals regulate root growth by modulating the levels and spatial distribution of growth hormones to optimize nutrient uptake and assimilation. However, the effect of the interaction of these two hormones and their signaling on root plasticity during low and differential availability of nitrogen (N) forms (NH4+/NO3-) remains elusive. We demonstrate that root elongation under low nitrogen (LN) is an outcome of the interdependent activity of auxin and BR signaling pathways in Arabidopsis (Arabidopsis thaliana). LN promotes root elongation by increasing BR-induced auxin transport activity in the roots. Increased nuclear auxin signaling and its transport efficiency have a distinct impact on root elongation under LN conditions. High auxin levels reversibly inhibit BR signaling via BRI1 KINASE INHIBITOR1 (BKI1). Using the tissue-specific approach, we show that BR signaling from root vasculature (stele) tissues is sufficient to promote cell elongation and, hence, root growth under LN condition. Further, we show that N form-defined root growth attenuation or enhancement depends on the fine balance of BR and auxin signaling activity. NH4+ as a sole N source represses BR signaling and response, which in turn inhibits auxin response and transport, whereas NO3- promotes root elongation in a BR signaling-dependent manner. In this study, we demonstrate the interplay of auxin and BR-derived signals, which are critical for root growth in a heterogeneous N environment and appear essential for root N foraging response and adaptation.
PMID: 35377445
Plant Physiol , IF:8.34 , 2022 May , V189 (1) : P285-300 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 -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 May , V189 (1) : P264-284 doi: 10.1093/plphys/kiac041
lncRNA7 and lncRNA2 modulate cell wall defense genes to regulate cotton 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, China.; College of life science and agricultural engineering, Nanyang Normal University, Nanyang 473000, China.; Chongqing Key Laboratory of Big Data for Bio Intelligence, College of Bioinformation, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.; Southern Plains Agricultural Research Center, Agricultural Research Service, USDA, College Station, Texas 77845, USA.; Kaifeng Academy of Agriculture and Forestry, Kaifeng 475000, China.; State Key Laboratory of Cotton Biology, Key Laboratory of Biological and Genetic Breeding of Cotton, The Ministry of Agriculture, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China.
In plants, long noncoding RNAs (lncRNAs) 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 downregulate the expression of lncRNA2 and GbPG12, leading to pectin accumulation. Conversely, OG upregulated the expression of lncRNA7, which encodes a plant peptide phytosulfokine (PSK-alpha), which was confirmed by lncRNA7 overexpression and Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS) experiments. We showed that PSK-alpha promoted 3-Indoleacetic acid (IAA) accumulation and activated GbPMEI13 expression through Auxin Response Factor 5. 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 May , V189 (1) : P248-263 doi: 10.1093/plphys/kiab589
TARGET OF RAPAMYCIN is essential for asexual vegetative reproduction in Kalanchoe.
School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, M13 9PT, UK.
The unique mechanism by which leaf margin cells regain potency and then form a plantlet in Kalanchoe spp. remains elusive but involves organogenesis and embryogenesis in response to age, day length, nutrient availability, and drought stress. In light of this, we investigated whether TARGET OF RAPAMYCIN (TOR), a conserved protein kinase in eukaryotes that controls cell growth and metabolism in response to nutrient and energy availability, may regulate plantlet formation. Kalanchoe daigremontiana TOR (KdTOR) was expressed in the leaf margin at the site of plantlet initiation, in the early plantlet cotyledons, and in the root tip of the developed plantlet. Both chemical and genetic inhibition of TOR Kinase activity in Kalanchoe daigremontiana leaves disrupted plantlet formation. Furthermore, downregulation of KdTOR in transgenic plants led to wide-ranging transcriptional changes, including decreased K. daigremontiana SHOOTMERISTEMLESS and K. daigremontiana LEAFYCOTYLEDON1 expression, whereas auxin treatments induced KdTOR expression in the plantlet roots. These results suggest that the KdTOR pathway controls plantlet development in cooperation with auxin, organogenesis, and embryogenesis pathways. The ancient and highly conserved TOR Kinase therefore controls diverse and unique developmental pathways, such as asexual reproduction within the land plant lineage.
PMID: 34935983
Environ Pollut , IF:8.071 , 2022 Apr , V306 : P119375 doi: 10.1016/j.envpol.2022.119375
Physiological and Transcriptomic Analysis provide Molecular Insight into 24-Epibrassinolide mediated Cr(VI)-Toxicity Tolerance in Pepper Plants.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China; Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China.; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China.; College of Ecology and Environment, Hainan University, Haikou, 570100, China.; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China; Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China. Electronic address: wangzhiwei@hainanu.edu.cn.
The ever-increasing industrial activities over the decades have generated high toxic metals such as chromium (Cr) that hampers plant growth and development. To counter Cr-toxicity, plants have evolved complex defensive systems including hormonal crosstalk with various signaling pathways. 24-epibrassinolide (24-EBR) lowers oxidative stress and alleviates Cr(VI)-toxicity in plants. In this study, the concealed BR-mediated influences on Cr(VI)-stress tolerance were explored by transcriptome analysis in the Capsicum annuum. Results revealed a linkage between plant development under Cr(VI)-stress and the mitigating effect of 24-epibrassinolide and brassinazole. Growth inhibition, chlorophyll degradation, and a significant rise of malondialdehyde (MDA) were observed after 40 mg/L Cr(VI) treatment in Brz supplemented seedlings, whereas 24-EBR supplemented seedlings exhibited commendatory effect. Comparative transcriptome analysis showed that the expression levels of 6687 genes changed (3846 up-regulated and 2841 downregulated) under Cr(VI)-stress with Brz supplementation. Whereas the expression levels of only 1872 genes changed under Cr(VI)-stress with 24-EBR supplementation (1223 up-regulated and 649 downregulated). The functional categories of the differentially expressed genes (DEGs) by gene ontology (GO) revealed that drug transport, defense responses, and drug catabolic process were the considerable enrichments between 24-EBR and Brz supplemented seedlings under Cr(VI)-stress. Furthermore, auxin signaling, glutathione metabolism, ABC transporters, MAPK pathway, and 36 heavy metal-related genes were significantly differentially expressed components between Cr(VI)-stress, 24-EBR, and Brz supplemented seedlings. Overall, our data demonstrate that employing 24-EBR can commendably act as a growth stimulant in plants subjected to Cr(VI)-stress by modulating the physiological and defense regulatory system.
PMID: 35500717
Plant Cell Environ , IF:7.228 , 2022 May doi: 10.1111/pce.14366
The co-chaperone HOP participates in TIR1 stabilization and in auxin response in plants.
Centro de Biotecnologia y Genomica de Plantas. Universidad Politecnica de Madrid (UPM) - Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA). Campus Montegancedo UPM. 28223-Pozuelo de Alarcon, Madrid, Spain.; Departamento de Botanica, Ecologia y Fisiologia Vegetal. Campus de Rabanales. Edificio Severo Ochoa, Universidad de Cordoba, 14071, Cordoba, Spain.; Fundacion Instituto Leloir and Instituto de Investigaciones Bioquimicas de Buenos Aires (IIBA, CONICET). Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina.
HOP (HSP90-HSP70 organizing protein) is a conserved family of co-chaperones well known in mammals for its role in the folding of signaling proteins associated to development. In plants, HOP proteins have been involved in the response to multiple stresses, but their role in plant development remains elusive. Herein, we describe that the members of the HOP family participate in different aspects of plant development as well as in the response to warm temperatures through the regulation of auxin signaling. Our data demonstrate that Arabidopsis hop1 hop2 hop3 triple mutant shows different auxin-related phenotypes and a reduced auxin sensitivity. HOP interacts with TIR1 auxin co-receptor in vivo. Furthermore, TIR1 accumulation and auxin transcriptional response are reduced in the hop1 hop2 hop3 triple mutant, suggesting that HOP s function in auxin signaling is related, at least, to TIR1 interaction and stabilization. Interestingly, HOP proteins form part of the same complexes as SGT1b (a different HSP90 co-chaperone) and these co-chaperones synergistically cooperate in auxin signaling. This study provides relevant data about the role of HOP in auxin regulation in plants and uncover that both co-chaperones, SGT1b and HOP, cooperate in the stabilization of common targets involved in plant development. This article is protected by copyright. All rights reserved.
PMID: 35610185
Plant Cell Environ , IF:7.228 , 2022 May , V45 (5) : P1554-1572 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
Chemosphere , IF:7.086 , 2022 May , V295 : P133790 doi: 10.1016/j.chemosphere.2022.133790
Remediation for trace metals in polluted soils by turfgrass assisted with chemical reagents.
College of Environment, Zhejiang University of Technology, Deqing, 313200, Zhejiang, PR China.; Zhejiang Zhengjie Environmental Science & Technology Co.,Ltd. Hangzhou, 311222, Zhejiang, PR China.; College of Environment, Zhejiang University of Technology, Deqing, 313200, Zhejiang, PR China. Electronic address: Jdwang@zjut.edu.cn.
Trace metal pollution in soils is one of the universal environmental problems in the world. Phytoremediation is a green, safe, ecological, and economic method to achieve continuous reduction of soil pollutants. Turfgrass is a plant with great landscape value and has considerable biomass when used for remediation of trace metal contaminated soil. However, its remediation ability needs to be improved in future application. The combined application of turfgrass, citric acid (CA) and auxin (gibberellin, GA3) were applied in the phytoremediation of an artificial nutritive soil derived from sludge, and a field scale orthogonal experiment (L9) was conducted to understand the interaction effect and obtain the optimum phytoremediation. Experimental results showed that the types and cultural patterns of turfgrass mainly determined plant height, root length and trace metal concentration in turfgrass, however CA treatment was prone to increase the aboveground biomass and the concentrations of most trace metals in turfgrasses, especially the concentration of Ni in turfgrass. GA3 spraying significantly increased the concentration of Cd in turfgrass. The culture patterns of turfgrass played 42.4% influence on acid-extractable Cd, while CA applying had 53.8% influence on the acid-extractable Ni. The annual phytoextraction amount of trace metals based on five mowing a year were proposed to assess the remediation ability of treatments, which of the combination treatment (T3, intercropping Zoysia matrella and Lolium perenne, and applying 400 mg kg(-1) CA and 30 mg kg(-1) GA3) were 1.6-2.1 times higher CK group. This research provides technical reference for intercropping turfgrass for remediation of trace metals in sludge-derived nutritive soil.
PMID: 35104547
J Integr Plant Biol , IF:7.061 , 2022 Apr doi: 10.1111/jipb.13269
GmPIN1-mediated auxin asymmetry regulates leaf petiole angle and plant architecture in soybean.
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Center, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Department of Horticulture, Beijing Vocational College of Agriculture, Beijing, 102442, China.; College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
Crop breeding during the Green Revolution resulted in high yields largely due to the creation of plants with semi-dwarf architectures that could tolerate high-density planting. Although semi-dwarf varieties have been developed in rice, wheat and maize, none was reported in soybean (Glycine max), and few genes controlling plant architecture have been characterized in soybean. Here, we demonstrate that the auxin efflux transporter PINFORMED1 (GmPIN1), which determines polar auxin transport, regulates the leaf petiole angle in soybean. CRISPR-Cas9-induced Gmpin1abc and Gmpin1bc multiple mutants displayed a compact architecture with a smaller petiole angle than wild-type plants. GmPIN1 transcripts and auxin were distributed asymmetrically in the petiole base, with high levels of GmPIN1a/c transcript and auxin in the lower cells, which resulted in asymmetric cell expansion. By contrast, the (iso)flavonoid content was greater in the upper petiole cells than in the lower cells. Our results suggest that (iso)flavonoids inhibit GmPIN1a/c expression to regulate the petiole angle. Overall, our study demonstrates that a signal cascade that integrates (iso)flavonoid biosynthesis, GmPIN1a/c expression, auxin accumulation, and cell expansion in an asymmetric manner creates a desirable petiole curvature in soybean. This study provides a genetic resource for improving soybean plant architecture. This article is protected by copyright. All rights reserved.
PMID: 35485227
J Integr Plant Biol , IF:7.061 , 2022 Apr doi: 10.1111/jipb.13268
A feedback regulation between ARF7-mediated auxin signaling and auxin homeostasis involving MES17 affects plant gravitropism.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, College of Life Sciences, Shandong University, Qingdao, 266237, China.; Horticulture Biology and Metabolomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Gravitropism is an essential adaptive response of land plants. Asymmetric auxin gradients across plant organs, interpreted by multiple auxin signaling components including AUXIN RESPONSE FACTOR7 (ARF7), trigger differential growth and bending response. However, how this fundamental process is strictly maintained in nature remains unclear. Here, we report that gravity stimulates the transcription of METHYL ESTERASE17 (MES17) along the lower side of the hypocotyl via ARF7-dependent auxin signaling. The asymmetric distribution of MES17, a methyltransferase that converts auxin from its inactive form methyl indole-3-acetic acid ester (MeIAA) to its biologically active form free-IAA, enhanced the gradient of active auxin across the hypocotyl, which in turn reversely amplified the asymmetric auxin responses and differential growth that shape gravitropic bending. Taken together, our findings reveal the novel role of MES17-mediated auxin homeostasis in gravitropic responses and identify an ARF7-triggered feedback mechanism that reinforces the asymmetric distribution of active auxin and strictly controls gravitropism in plants. This article is protected by copyright. All rights reserved.
PMID: 35475598
J Integr Plant Biol , IF:7.061 , 2022 May , V64 (5) : P965-978 doi: 10.1111/jipb.13243
BYPASS1-LIKE regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis.
Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.; College of Life Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.; School of Forestry, Beijing Forestry University, Beijing, 100083, China.
Auxin and auxin-mediated signaling pathways are known to regulate lateral root development. Although exocytic vesicle trafficking plays an important role in recycling the PIN-FORMED (PIN) auxin efflux carriers and in polar auxin transport during lateral root formation, the mechanistic details of these processes are not well understood. Here, we demonstrate that BYPASS1-LIKE (B1L) regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis thaliana. b1l mutants contained significantly more lateral roots than the wild type, primarily due to increased lateral root primordium initiation. Furthermore, the auxin signal was stronger in stage I lateral root primordia of b1l than in those of the wild type. Treatment with exogenous auxin and an auxin transport inhibitor indicated that the lateral root phenotype of b1l could be attributed to higher auxin levels and that B1L regulates auxin efflux. Indeed, compared to the wild type, C-terminally green fluorescent protein-tagged PIN1 and PIN3 accumulated at higher levels in b1l lateral root primordia. B1L interacted with the exocyst, and b1l showed defective PIN exocytosis. These observations indicate that B1L interacts with the exocyst to regulate PIN-mediated polar auxin transport and lateral root initiation in Arabidopsis.
PMID: 35249253
J Exp Bot , IF:6.992 , 2022 May doi: 10.1093/jxb/erac228
In vitro functional characterization predicts the impact of bacterial root endophytes on plant growth.
Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette IN.
Utilizing beneficial microbes for crop improvement is one strategy to achieve sustainable agriculture. However, identifying microbial isolates that promote crop growth is challenging, in part because using bacterial taxonomy to predict an isolate's effect on plant growth may not be reliable. The overall aim of this work was to determine whether in vitro functional traits of bacteria were predictive of their in planta impact. We isolated 183 bacterial endophytes from field-grown roots of two tomato species, Solanum lycopersicum and S. pimpinellifolium. Sixty isolates were screened for six in vitro functional traits: auxin production, siderophore production, phosphate solubilization, antagonism to a soilborne pathogen, and the presence of two antimicrobial metabolite synthesis genes. Hierarchical clustering of the isolates based on the in vitro functional traits identified several groups of isolates sharing similar traits. We called these groups 'functional groups'. To understand how in vitro functional traits of bacteria relate to their impact on plants, we inoculated three isolates from each of the functional groups on tomato seedlings. Isolates within the same functional group promoted plant growth at similar levels, regardless of their host origin or taxonomy. Together, our results demonstrate the importance of examining root endophyte functions for improving crop production.
PMID: 35596672
J Exp Bot , IF:6.992 , 2022 May doi: 10.1093/jxb/erac188
ROOT PENETRATION INDEX 3, a major quantitative trait locus (QTL) associated with root system penetrability in Arabidopsis.
Unidad de Genomica Avanzada/LANGEBIO, Centro de Investigacion y de Estudios Avanzados, Irapuato, Mexico.; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, USA.; Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
Soil mechanical impedance precludes root penetration, confining root system development to shallow soil horizons where mobile nutrients are scarce. Using a two-phase-agar system, we characterized Arabidopsis thaliana responses to low and high mechanical impedance at three root penetration stages. We found that seedlings whose roots fail to penetrate agar barriers show a significant reduction in leaf area, root length and elongation zone and an increment in root diameter, while those capable of penetrating show only minor morphological effects. Analyses using different auxin-responsive reporter lines, exogenous auxins and inhibitor treatments suggest that auxin responsiveness and PIN-mediated auxin distribution play an important role in regulating root responses to mechanical impedance. The assessment of 21 Arabidopsis accessions revealed that primary root penetrability (PRP) varies widely among accessions. To search for quantitative trait loci (QTLs) associated to root system penetrability, we evaluated a recombinant inbred population (RIL) derived from Landsberg erecta (Ler-0, with a high PRP) and Shahdara (Sha, with a low PRP) accessions. QTL analysis revealed a major-effect QTL localized in chromosome 3 (q-RPI3), which accounted for 29.98% (LOD = 8.82) of the total phenotypic variation. Employing an introgression line (IL-321), with a homozygous q-RPI3 region from Sha in the Ler-0 genetic background, we demonstrated that q-RPI3 plays a crucial role in root penetrability. This multiscale study revels new insights into root plasticity during the penetration process in hard agar layers, natural variation and genetic architecture behind primary root penetrability in Arabidopsis.
PMID: 35512438
J Exp Bot , IF:6.992 , 2022 Apr doi: 10.1093/jxb/erac152
auxin receptorS as integrators of Developmental and hormonal signals during reproductive development In pea.
Plant BioSystems, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Auxins regulate many aspects of plant growth and development. In pea, three of the five TIR1/AFB members (PsTIR1a, PsTIR1b, PsAFB2) have been implicated in auxin-related responses during fruit/seed development; however, the roles of PsAFB4 and PsAFB6 in these processes are unknown. Using yeast two-hybrid assays, we found that all five pea TIR1/AFB receptor proteins interacted with pea AUX/IAAs PsIAA6 and/or PsIAA7 in an auxin-dependent manner, a requirement for functional auxin receptors. All five auxin receptors are expressed in young ovaries (pericarps) and rapidly developing seeds with overlapping and unique developmental and hormone-regulated gene expression patterns. Pericarp PsAFB6 expression was suppressed by seeds and increased in response to deseeding, and exogenous hormone treatments suggest that seed-derived auxin and deseeding-induced ethylene are involved in these responses, respectively. Ethylene-induced elevation of pericarp PsAFB6 expression was associated with 4-Cl-IAA-specific reduction in ethylene responsiveness. In developing seeds, expression of PsTAR2 and PsYUC10 auxin biosynthesis genes was associated with high auxin levels in seed coat and cotyledon tissues, and PsAFB2 dominated the seed tissue transcript pool. Overall, auxin receptors had overlapping and unique developmental and hormone-regulated gene expression patterns during fruit/seed development suggesting mediation of diverse responses to auxin, with PsAFB6 linking auxin and ethylene signaling.
PMID: 35395070
J Exp Bot , IF:6.992 , 2022 Apr doi: 10.1093/jxb/erac143
Reduced auxin signalling through the cyclophilin DIAGEOTROPICA impacts tomato fruit development and metabolism during ripening.
Departamento de Biologia Vegetal, Universidade Federal de Vicosa, 36570-900, Vicosa, Minas Gerais, Brazil.; Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.; Departmento de Ciencias Biologicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de Sao Paulo, Piracicaba 13418-900, Brazil.
Auxin is an important hormone playing crucial roles during fruit growth and ripening, however, the metabolic impact of changes in auxin signalling during tomato (Solanum lycopersicum L.) ripening remains unclear. Here, we investigated the significance of changes in auxin signalling during different stages of fruit development by analysing changes in tomato fruit quality and primary metabolism using mutants with either lower or higher auxin sensitivity [diageotropica (dgt) and entire mutants, respectively]. Altered auxin sensitivity modifies metabolism, through direct impacts on fruit respiration and fruit growth. We verified that the dgt mutant plants exhibit reductions in fruit set, total fruit dry weight, fruit size, number of seeds per fruit, and fresh weight loss during post-harvest. Sugar accumulation was associated with delayed fruit ripening in dgt, likely connected with reduced ethylene levels and respiration, coupled with a lower rate of starch degradation. By contrast, despite exhibiting parthenocarpy, increased auxin perception (entire) did not alter fruit ripening, leading to only minor changes in primary metabolism. By performing a comprehensive analysis our results connect auxin signalling and metabolic changes during tomato fruit development, indicating that reduced auxin signalling led to extensive changes in sugar content and starch metabolism during tomato fruit ripening.
PMID: 35383842
J Exp Bot , IF:6.992 , 2022 Apr , V73 (8) : P2511-2524 doi: 10.1093/jxb/erac050
ORESARA 15, a PLATZ transcription factor, controls root meristem size through auxin and cytokinin signalling-related pathways.
Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.; Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea.; Department of Biological Sciences, Chungnam National University, Daejeon, Republic of Korea.; School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.; New Biology Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.
An optimal size of post-embryonic 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 PLANT A/T-RICH SEQUENCE-AND ZINC-BINDING PROTEIN (PLATZ) transcription factor preferentially expressed in the RAM, determines RAM size. 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 wild type. ORE15 forms mutually positive and negative feedback loops with auxin and cytokinin signalling, respectively. Collectively, our findings imply that ORE15 controls RAM size by mediating the antagonistic interaction between auxin and cytokinin signalling-related pathways.
PMID: 35139177
J Exp Bot , IF:6.992 , 2022 Apr , V73 (8) : P2469-2486 doi: 10.1093/jxb/erac040
Overexpression of SHORT-ROOT2 transcription factor enhances the outgrowth of mature axillary buds in poplar trees.
School of Environmental Science and Engineering, Tianjin University, Tianjin, China.
SHORT-ROOT (SHR) transcription factors play important roles in asymmetric cell division and radial patterning of Arabidopsis roots. In hybrid poplar (P. tremula x P. alba clone INRA 717-1B4), PtaSHR2 was preferentially expressed in axillary buds (AXBs) and transcriptionally up-regulated during AXB maturation and activation. Overexpression of SHR2 (PtSHR2OE) induced an enhanced outgrowth of AXBs below the bud maturation point, with a simultaneous transition of an active shoot apex into an arrested terminal bud. The larger and more mature AXBs of PtSHR2OE trees revealed altered expression of genes involved in axillary meristem initiation and bud activation, as well as a higher ratio of cytokinin to auxin. To elucidate the underlying mechanism of PtSHR2OE-induced high branching, subsequent molecular and biochemical studies showed that compared with wild-type trees, decapitation induced a quicker bud outburst in PtSHR2OE trees, which could be fully inhibited by exogenous application of auxin or cytokinin biosynthesis inhibitor, but not by N-1-naphthylphthalamic acid. Our results indicated that overexpression of PtSHR2B disturbed the internal hormonal balance in AXBs by interfering with the basipetal transport of auxin, rather than causing auxin biosynthesis deficiency or auxin insensitivity, thereby releasing mature AXBs from apical dominance and promoting their outgrowth.
PMID: 35107566
J Exp Bot , IF:6.992 , 2022 Apr , V73 (8) : P2320-2335 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 with regard to catalysing the conversion of UDP-glucuronic acid into UDP-xylose, their biological roles in grasses remain 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 gene encodes a cytosol-localized OsUXS3 and is widely expressed with higher expression in xylan-rich tissues. Monosaccharide analysis showed that the xylose level was decreased in fc18, and cell wall fraction determinations confirmed that the xylan content in fc18 was lower, 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, expression of genes involved in sugar metabolism and phytohormone signal transduction was largely altered in fc18. Consistent with this, the fc18 mutant exhibited significantly reduced free auxin (indole-3-acetic acid) content and lower expression levels of PIN family genes compared with wild type. Our work reveals the physiological roles of FC18/UXS3 in xylan biosynthesis, cellulose deposition, and plant growth in rice.
PMID: 35104839
J Exp Bot , IF:6.992 , 2022 Apr , V73 (8) : P2308-2319 doi: 10.1093/jxb/erac019
Auxin analog-induced Ca2+ signaling is independent of inhibition of endosomal aggregation in Arabidopsis roots.
Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium.; Department of Biosciences, University of Milan, 20133 Milan, Italy.; Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, 69120 Heidelberg, Germany.; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada.; Department of Plants and Crops, Ghent University, 9000 Ghent, Belgium.; Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria.; Institute of Biophysics, National Research Council of Italy (CNR), 20133 Milan, Italy.; Lab of Plant Growth Analysis, Ghent University Global Campus, Incheon 21985, Republic of Korea.
Much of what we know about the role of auxin in plant development derives from exogenous manipulations of auxin distribution and signaling, using inhibitors, auxins, and auxin analogs. In this context, synthetic auxin analogs, such as 1-naphthalene acetic acid (1-NAA), are often favored over the endogenous auxin, indole-3-acetic acid (IAA), in part due to their higher stability. While such auxin analogs have proven instrumental in revealing the various faces of auxin, they display in some cases bioactivities distinct from IAA. Here, we focused on the effect of auxin analogs on the accumulation of PIN proteins in brefeldin A-sensitive endosomal aggregations (BFA bodies), and correlation with the ability to elicit Ca2+ responses. For a set of commonly used auxin analogs, we evaluated if auxin analog-induced Ca2+ signaling inhibits PIN accumulation. Not all auxin analogs elicited a Ca2+ response, and their differential ability to elicit Ca2+ responses correlated partially with their ability to inhibit BFA-body formation. However, in tir1/afb and cngc14, 1-NAA-induced Ca2+ signaling was strongly impaired, yet 1-NAA still could inhibit PIN accumulation in BFA bodies. This demonstrates that TIR1/AFB-CNGC14-dependent Ca2+ signaling does not inhibit BFA body formation in Arabidopsis roots.
PMID: 35085386
J Exp Bot , IF:6.992 , 2022 Apr , V73 (7) : P2021-2034 doi: 10.1093/jxb/erab556
The role of AUX1 during lateral root development in the domestication of the model C4 grass Setaria italica.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Institute of Biology II, University of Freiburg, Schanzlestrasse 1, D-79104 Freiburg, Germany.; Academy of Agricultural Sciences/Key Laboratory of Regional Ecological Protection & Agricultural and Animal Husbandry Development, Chifeng University, Chifeng, 024000, Inner Mongolia, China.; Department of Computational Biology, Center for Advanced Studies, St. Petersburg State Polytechnic University, St. Petersburg, 195259, Russia.; Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran.; Institute of Biology III, University of Freiburg, Schanzlestrasse 1, D-79104 Freiburg, Germany.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; Centre of Biological Systems Analysis and BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104 Freiburg, Germany.
C4 photosynthesis increases the efficiency of carbon fixation by spatially separating high concentrations of molecular oxygen from Rubisco. The specialized leaf anatomy required for this separation evolved independently many times. The morphology of C4 root systems is also distinctive and adapted to support high rates of photosynthesis; however, little is known about the molecular mechanisms that have driven the evolution of C4 root system architecture. Using a mutant screen in the C4 model plant Setaria italica, we identify Siaux1-1 and Siaux1-2 as root system architecture mutants. Unlike in S. viridis, AUX1 promotes lateral root development in S. italica. A cell by cell analysis of the Siaux1-1 root apical meristem revealed changes in the distribution of cell volumes in all cell layers and a dependence of the frequency of protophloem and protoxylem strands on SiAUX1. We explore the molecular basis of the role of SiAUX1 in seedling development using an RNAseq analysis of wild-type and Siaux1-1 plants and present novel targets for SiAUX1-dependent gene regulation. Using a selection sweep and haplotype analysis of SiAUX1, we show that Hap-2412TT in the promoter region of SiAUX1 is an allele which is associated with lateral root number and has been strongly selected for during Setaria domestication.
PMID: 34940828
J Exp Bot , IF:6.992 , 2022 Apr , V73 (7) : P1963-1977 doi: 10.1093/jxb/erab542
INTERMEDIUM-C mediates the shade-induced bud growth arrest in barley.
Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466 Stadt Seeland, Germany.; Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466 Stadt Seeland, Germany.; International Rice Research Institute (IRRI), Grain Quality and Nutrition Center, Metro Manila, Philippines.
Tiller formation is a key agronomic determinant for grain yield in cereal crops. The modulation of this trait is controlled by transcriptional regulators and plant hormones, tightly regulated by external environmental conditions. While endogenous (genetic) and exogenous (environmental factors) triggers for tiller formation have mostly been investigated separately, it has remained elusive how they are integrated into the developmental program of this trait. The transcription factor gene INTERMEDIUM-C (INT-C), which is the barley ortholog of the maize domestication gene TEOSINTE BRANCHED1 (TB1), has a prominent role in regulating tiller bud outgrowth. Here we show that INT-C is expressed in tiller buds, required for bud growth arrest in response to shade. In contrast to wild-type plants, int-c mutant plants are impaired in their shade response and do not stop tiller production after shading. Gene expression levels of INT-C are up-regulated under light-limiting growth conditions, and down-regulated after decapitation. Transcriptome analysis of wild-type and int-c buds under control and shading conditions identified target genes of INT-C that belong to auxin and gibberellin biosynthesis and signaling pathways. Our study identifies INT-C as an integrator of the shade response into tiller formation, which is prerequisite for implementing shading responses in the breeding of cereal crops.
PMID: 34894212
Int J Biol Macromol , IF:6.953 , 2022 May , V208 : P844-857 doi: 10.1016/j.ijbiomac.2022.03.179
Genomic & structural diversity and functional role of potassium (K(+)) transport proteins in plants.
National Institute of Plant Genome Research, New Delhi 110067, India.; National Institute of Plant Genome Research, New Delhi 110067, India. Electronic address: amarjeet.singh@nipgr.ac.in.
Potassium (K(+)) is an essential macronutrient for plant growth and productivity. It is the most abundant cation in plants and is involved in various cellular processes. Variable K(+) availability is sensed by plant roots, consequently K(+) transport proteins are activated to optimize K(+) uptake. In addition to K(+) uptake and translocation these proteins are involved in other important physiological processes like transmembrane voltage regulation, polar auxin transport, maintenance of Na(+)/K(+) ratio and stomata movement during abiotic stress responses. K(+) transport proteins display tremendous genomic and structural diversity in plants. Their key structural features, such as transmembrane domains, N-terminal domains, C-terminal domains and loops determine their ability of K(+) uptake and transport and thus, provide functional diversity. Most K(+) transporters are regulated at transcriptional and post-translational levels. Genetic manipulation of key K(+) transporters/channels could be a prominent strategy for improving K(+) utilization efficiency (KUE) in plants. This review discusses the genomic and structural diversity of various K(+) transport proteins in plants. Also, an update on the function of K(+) transport proteins and their regulatory mechanism in response to variable K(+) availability, in improving KUE, biotic and abiotic stresses is provided.
PMID: 35367275
Development , IF:6.868 , 2022 May , V149 (10) doi: 10.1242/dev.200362
Phytochrome-interacting factors orchestrate hypocotyl adventitious root initiation in Arabidopsis.
National Key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; School of Life Science, Henan University, Kaifeng 457000, China.; Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Adventitious roots (ARs) are an important type of plant root and display high phenotypic plasticity in response to different environmental stimuli. It is known that photoreceptors inhibit darkness-induced hypocotyl adventitious root (HAR) formation by directly stabilizing Aux/IAA proteins. In this study, we further report that phytochrome-interacting factors (PIFs) plays a central role in HAR initiation by simultaneously inducing the expression of genes involved in auxin biosynthesis, auxin transport and the transcriptional control of root primordium initiation. We found that, on the basis of their activity downstream of phytochrome, PIFs are required for darkness-induced HAR formation. Specifically, PIFs directly bind to the promoters of some genes involved in root formation, including auxin biosynthesis genes YUCCA2 (YUC2) and YUC6, the auxin influx carrier genes AUX1 and LAX3, and the transcription factors WOX5/7 and LBD16/29, to activate their expression. These findings reveal a previously uncharacterized transcriptional regulatory network underlying HAR formation.
PMID: 35502748
Development , IF:6.868 , 2022 May , V149 (9) doi: 10.1242/dev.200381
Species-specific function of conserved regulators in orchestrating rice root architecture.
Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Uttarakhand 247667, India.; School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India.; School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram 695001, Kerala, India.; School of Biology, Indian Institute of Science Education and Research, Pune 411007, Maharashtra, India.; Laboratory of Plant-Microbe Interactions, Regional Center for Biotechnology, Faridabad, Haryana 110076, India.
Shoot-borne adventitious/crown roots form a highly derived fibrous root system in grasses. The molecular mechanisms controlling their development remain largely unknown. Here, we provide a genome-wide landscape of transcriptional signatures - tightly regulated auxin response and in-depth spatio-temporal expression patterns of potential epigenetic modifiers - and transcription factors during priming and outgrowth of rice (Oryza sativa) crown root primordia. Functional analyses of rice transcription factors from WUSCHEL-RELATED HOMEOBOX and PLETHORA gene families reveal their non-redundant and species-specific roles in determining the root architecture. WOX10 and PLT1 regulate both shoot-borne crown roots and root-borne lateral roots, but PLT2 specifically controls lateral root development. PLT1 activates local auxin biosynthesis genes to promote crown root development. Interestingly, O. sativa PLT genes rescue lateral root primordia outgrowth defects of Arabidopsis plt mutants, demonstrating their conserved role in root primordia outgrowth irrespective of their developmental origin. Together, our findings unveil a molecular framework of tissue transdifferentiation during root primordia establishment, leading to the culmination of robust fibrous root architecture. This also suggests that conserved factors have evolved their transcription regulation to acquire species-specific function.
PMID: 35394032
Cells , IF:6.6 , 2022 Apr , V11 (9) doi: 10.3390/cells11091420
Transcriptomic, Hormonomic and Metabolomic Analyses Highlighted the Common Modules Related to Photosynthesis, Sugar Metabolism and Cell Division in Parthenocarpic Tomato Fruits during Early Fruit Set.
Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan.; Tsukuba-Plant Innovation Research Center (T-PIRC), University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan.; RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan.; Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto 606-8522, Japan.; Graduate School of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan.; Graduate School and Faculty of Bioresources, Mie University, Tsu 514-8507, Japan.; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.; Rijk Zwaan Breeding Japan K.K., Chiba 289-1608, Japan.; Research Institute, Kagome Co., Ltd., 17 Nishitomiyama, Nasushiobara 329-2762, Japan.
Parthenocarpy, the pollination-independent fruit set, can raise the productivity of the fruit set even under adverse factors during the reproductive phase. The application of plant hormones stimulates parthenocarpy, but artificial hormones incur extra financial and labour costs to farmers and can induce the formation of deformed fruit. This study examines the performance of parthenocarpic mutants having no transcription factors of SlIAA9 and SlTAP3 and sldella that do not have the protein-coding gene, SlDELLA, in tomato (cv. Micro-Tom). At 0 day after the flowering (DAF) stage and DAFs after pollination, the sliaa9 mutant demonstrated increased pistil development compared to the other two mutants and wild type (WT). In contrast to WT and the other mutants, the sliaa9 mutant with pollination efficiently stimulated the build-up of auxin and GAs after flowering. Alterations in both transcript and metabolite profiles existed for WT with and without pollination, while the three mutants without pollination demonstrated the comparable metabolomic status of pollinated WT. Network analysis showed key modules linked to photosynthesis, sugar metabolism and cell proliferation. Equivalent modules were noticed in the famous parthenocarpic cultivars 'Severianin', particularly for emasculated samples. Our discovery indicates that controlling the genes and metabolites proffers future breeding policies for tomatoes.
PMID: 35563726
mSystems , IF:6.496 , 2022 Apr , V7 (2) : Pe0009122 doi: 10.1128/msystems.00091-22
Transcriptional Profiles of a Foliar Fungal Endophyte (Pestalotiopsis, Ascomycota) and Its Bacterial Symbiont (Luteibacter, Gammaproteobacteria) Reveal Sulfur Exchange and Growth Regulation during Early Phases of Symbiotic Interaction.
School of Plant Sciences, The University of Arizonagrid.134563.6, Tucson, Arizona, USA.; Department of Pediatrics, School of Medicine, University of California, La Jolla, California, USA.; Hexagon Bio, Menlo Park, California, USA.; Department of Plant Pathology and Environmental Microbiology, Pennsylvania State Universitygrid.29857.31, Pennsylvania, USA.; Department of Ecology and Evolutionary Biology, The University of Arizonagrid.134563.6, Tucson, Arizona, USA.
Symbiosis with bacteria is widespread among eukaryotes, including fungi. Bacteria that live within fungal mycelia (endohyphal bacteria) occur in many plant-associated fungi, including diverse Mucoromycota and Dikarya. Pestalotiopsis sp. strain 9143 is a filamentous ascomycete isolated originally as a foliar endophyte of Platycladus orientalis (Cupressaceae). It is infected naturally with the endohyphal bacterium Luteibacter sp. strain 9143, which influences auxin and enzyme production by its fungal host. Previous studies have used transcriptomics to examine similar symbioses between endohyphal bacteria and root-associated fungi such as arbuscular mycorrhizal fungi and plant pathogens. However, currently there are no gene expression studies of endohyphal bacteria of Ascomycota, the most species-rich fungal phylum. To begin to understand such symbioses, we developed methods for assessing gene expression by Pestalotiopsis sp. and Luteibacter sp. when grown in coculture and when each was grown axenically. Our assays showed that the density of Luteibacter sp. in coculture was greater than in axenic culture, but the opposite was true for Pestalotiopsis sp. Dual-transcriptome sequencing (RNA-seq) data demonstrate that growing in coculture modulates developmental and metabolic processes in both the fungus and bacterium, potentially through changes in the balance of organic sulfur via methionine acquisition. Our analyses also suggest an unexpected, potential role of the bacterial type VI secretion system in symbiosis establishment, expanding current understanding of the scope and dynamics of fungal-bacterial symbioses. IMPORTANCE Interactions between microbes and their hosts have important outcomes for host and environmental health. Foliar fungal endophytes that infect healthy plants can harbor facultative endosymbionts called endohyphal bacteria, which can influence the outcome of plant-fungus interactions. These bacterial-fungal interactions can be influential but are poorly understood, particularly from a transcriptome perspective. Here, we report on a comparative, dual-RNA-seq study examining the gene expression patterns of a foliar fungal endophyte and a facultative endohyphal bacterium when cultured together versus separately. Our findings support a role for the fungus in providing organic sulfur to the bacterium, potentially through methionine acquisition, and the potential involvement of a bacterial type VI secretion system in symbiosis establishment. This work adds to the growing body of literature characterizing endohyphal bacterial-fungal interactions, with a focus on a model facultative bacterial-fungal symbiosis in two species-rich lineages, the Ascomycota and Proteobacteria.
PMID: 35293790
Plant J , IF:6.417 , 2022 Apr doi: 10.1111/tpj.15766
Control of OsARF3a by OsKANADI1 contributes to lemma development in rice.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.; University of Chinese Academy of Sciences, Beijing, 100039, China.; Southern University of Science and Technology, Shenzhen, 518055, China.; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Beijing, 100101, China.; Innovative Academy of Seed Design (INASEED), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
In rice (Oryza sativa), the lemma and palea protect the internal organs of the floretprovide nutrients for seed development, and determine grain size. We previously revealed that a trans-acting small interfering RNA targeting AUXIN RESPONSE FACTORS (tasiR-ARF), regulates lemma polarity establishment via post-transcriptional repression of AUXIN RESPONSE FACTORS (ARFs) in rice. TasiR-ARF formation requires RNA-DEPENDENT RNA POLYMERASE 6 (RDR6). However, the underlying molecular mechanism of the tasiR-ARF-ARF regulon in lemma development remains unclear. Here, by genetic screening for suppressors of the thermosensitive mutant osrdr6-1, we identified three suppressors, huifu1 (hf1), hf9, and hf17. Mapping-by-sequencing revealed that HF1 encodes a MYB transcription factor belonging to the KANADI1 family. The hf1 mutation partially rescued the osrdr6-1 lemma defect but not the defect in tasiR-ARF levels. DNA affinity purification sequencing (DAP-seq) identified 17,725 OsKANADI1-associated sites, most of which contain the SPBP-box binding motif (RGAATAWW) and are located in the promoter, protein coding, intron, and intergenic regions. Moreover, we found that OsKANADI1 could directly bind to the intron of OsARF3a in vitro and in vivo, and promote OsARF3a expression at the transcriptional level. In addition, hf9 and hf17 are intragenic suppressors containing mutations in OsRDR6 that partially rescue tasiR-ARF levels by restoring OsRDR6 protein levels. Collectively, our results demonstrate that OsKANADI1 and tasiR-ARFs synergistically maintain the proper expression of OsARF3a and thus contribute to rice lemma development.
PMID: 35403315
Plant J , IF:6.417 , 2022 Apr doi: 10.1111/tpj.15759
The GATA factor HANABA TARANU promotes runner formation by regulating axillary bud initiation and outgrowth in cultivated strawberry.
Department of Fruit Science, College of Horticulture, China Agricultural University, Beijing, 100193, China.; Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Latokartanonkaari 7, 00790, Helsinki, Finland.; Key Laboratory of Landscaping Agriculture, Ministry of Agriculture and Rural Affairs, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; NIAB EMR, Kent, ME19 6BJ, UK.
A runner, as an elongated branch, develops from the axillary bud (AXB) in the leaf axil and is crucial for the clonal propagation of cultivated strawberry (Fragaria x ananassa Duch.). Runner formation occurs in at least two steps: AXB initiation and AXB outgrowth. HANABA TARANU (HAN ) encodes a GATA transcription factor that affects AXB initiation in Arabidopsis and promotes branching in grass species, but the underlying mechanism is largely unknown. Here, the function of a strawberry HAN homolog FaHAN in runner formation was characterized. FaHAN transcripts can be detected in the leaf axils. Overexpression (OE) of FaHAN increased the number of runners, mainly by enhancing AXB outgrowth, in strawberry. The expression of the strawberry homolog of BRANCHED1 , a key inhibitor of AXB outgrowth in many plant species, was significantly downregulated in the AXBs of FaHAN -OE lines, whereas the expression of the strawberry homolog of SHOOT MERISTEMLESS, a marker gene for AXB initiation in Arabidopsis, was upregulated. Moreover, several genes of gibberellin biosynthesis and cytokinin signaling pathways were activated, whereas the auxin response pathway genes were repressed. Further assays indicated that FaHAN could be directly activated by FaNAC2, the overexpression of which in strawberry also increased the number of runners. The silencing of FaNAC2 or FaHAN inhibited AXB initiation and led to a higher proportion of dormant AXBs, confirming their roles in the control of runner formation. Taken together, our results revealed a FaNAC2-FaHAN pathway in the control of runner formation and have provided a means to enhance the vegetative propagation of cultivated strawberry.
PMID: 35384101
Plant J , IF:6.417 , 2022 Apr doi: 10.1111/tpj.15748
Gypsy retrotransposon-derived maize lncRNA GARR2 modulates gibberellin response.
Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, 225009, China.; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China.
Long non-coding RNAs (lncRNAs) mediate diverse biological events mainly through the modulation of transcriptional hierarchy. The phytohormone gibberellin (GA) is essential for various aspects of plant growth and development. However, the roles of lncRNAs in the regulation of the GA response remain largely unknown. Through sequencing multiple strand-specific and ribosomal-depleted RNA libraries, we delineated the landscape of lncRNAs in maize (Zea mays). Out of identified lncRNAs, 445 GIBBERELLIN-RESPONSIVE lncRNAs (GARRs) were differentially expressed upon GA application. By the intersection of GARRs from normal-height and dwarf plants from an advanced backcross population, four shared GARRs (GARR1 to GARR4) were identified. Out of these four shared GARRs, GARR2 was derived from a Gypsy LTR retrotransposon. GA-responsive element P-boxes were identified upstream of GARR2. GARR2-edited lines exhibited a GA-induced phenotype. Editing of GARR2 resulted in changes in the transcriptional abundance of GA pathway components and endogenous GA contents. Besides GA, GARR2 affected the primary auxin response. An RNA pull-down assay revealed the HECT ubiquitin-protein ligase family member ZmUPL1 as a potential interaction target of GARR2. GARR2 influenced the abundance of ZmUPL1 in the GA response. Our study uncovers lncRNA players involved in the modulation of the GA response and guides the development of plant height ideotype driven by knowledge of the phytohormone GA.
PMID: 35368126
Int J Mol Sci , IF:5.923 , 2022 May , V23 (10) doi: 10.3390/ijms23105309
Genome-Wide Identification of Auxin Response Factors in Peanut (Arachis hypogaea L.) and Functional Analysis in Root Morphology.
Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.; State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an 271018, China.; State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an 271018, China.
Auxin response factors (ARFs) play important roles in plant growth and development; however, research in peanut (Arachis hypogaea L.) is still lacking. Here, 63, 30, and 30 AhARF genes were identified from an allotetraploid peanut cultivar and two diploid ancestors (A. duranensis and A. ipaensis). Phylogenetic tree and gene structure analysis showed that most AhARFs were highly similar to those in the ancestors. By scanning the whole-genome for ARF-recognized cis-elements, we obtained a potential target gene pool of AhARFs, and the further cluster analysis and comparative analysis showed that numerous members were closely related to root development. Furthermore, we comprehensively analyzed the relationship between the root morphology and the expression levels of AhARFs in 11 peanut varieties. The results showed that the expression levels of AhARF14/26/45 were positively correlated with root length, root surface area, and root tip number, suggesting an important regulatory role of these genes in root architecture and potential application values in peanut breeding.
PMID: 35628135
Int J Mol Sci , IF:5.923 , 2022 May , V23 (10) doi: 10.3390/ijms23105301
Genetic Dissection of Light-Regulated Adventitious Root Induction in Arabidopsis thaliana Hypocotyls.
Department Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.; Biotechnology Research and Development Institute, Can Tho University, Can Tho City 900000, Vietnam.; Department of Plant Biotechnology and Bioinformatics, Faculty of Sciences, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.; VIB Center for Plant SystemsBiology, VIB, Technologiepark 71, 9052 Ghent, Belgium.; Lab of Plant Growth Analysis, Ghent University Global Campus, Incheon 21985, Korea.
Photomorphogenic responses of etiolated seedlings include the inhibition of hypocotyl elongation and opening of the apical hook. In addition, dark-grown seedlings respond to light by the formation of adventitious roots (AR) on the hypocotyl. How light signaling controls adventitious rooting is less well understood. Hereto, we analyzed adventitious rooting under different light conditions in wild type and photomorphogenesis mutants in Arabidopsis thaliana. Etiolation was not essential for AR formation but raised the competence to form AR under white and blue light. The blue light receptors CRY1 and PHOT1/PHOT2 are key elements contributing to the induction of AR formation in response to light. Furthermore, etiolation-controlled competence for AR formation depended on the COP9 signalosome, E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC (COP1), the COP1 interacting SUPPRESSOR OF PHYA-105 (SPA) kinase family members (SPA1,2 and 3) and Phytochrome-Interacting Factors (PIF). In contrast, ELONGATED HYPOCOTYL5 (HY5), suppressed AR formation. These findings provide a genetic framework that explains the high and low AR competence of Arabidopsis thaliana hypocotyls that were treated with dark, and light, respectively. We propose that light-induced auxin signal dissipation generates a transient auxin maximum that explains AR induction by a dark to light switch.
PMID: 35628112
Int J Mol Sci , IF:5.923 , 2022 May , V23 (9) doi: 10.3390/ijms23095284
Beyond Photoprotection: The Multifarious Roles of Flavonoids in Plant Terrestrialization.
Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, 50019 Sesto Fiorentino, Florence, Italy.; Institute for Sustainable Plant Protection (IPSP), National Research Council of Italy, 50019 Sesto Fiorentino, Florence, Italy.
Plants evolved an impressive arsenal of multifunctional specialized metabolites to cope with the novel environmental pressures imposed by the terrestrial habitat when moving from water. Here we examine the multifarious roles of flavonoids in plant terrestrialization. We reason on the environmental drivers, other than the increase in UV-B radiation, that were mostly responsible for the rise of flavonoid metabolism and how flavonoids helped plants in land conquest. We are reasonably based on a nutrient-deficiency hypothesis for the replacement of mycosporine-like amino acids, typical of streptophytic algae, with the flavonoid metabolism during the water-to-land transition. We suggest that flavonoids modulated auxin transport and signaling and promoted the symbiosis between plants and fungi (e.g., arbuscular mycorrhizal, AM), a central event for the conquest of land by plants. AM improved the ability of early plants to take up nutrients and water from highly impoverished soils. We offer evidence that flavonoids equipped early land plants with highly versatile "defense compounds", essential for the new set of abiotic and biotic stressors imposed by the terrestrial environment. We conclude that flavonoids have been multifunctional since the appearance of plants on land, not only acting as UV filters but especially improving both nutrient acquisition and biotic stress defense.
PMID: 35563675
Int J Mol Sci , IF:5.923 , 2022 May , V23 (9) doi: 10.3390/ijms23095192
Identification of a Major QTL and Validation of Related Genes for Tiller Angle in Rice Based on QTL Analysis.
Department of Applied Biosciences, Graduate School, Kyungpook National University, Daegu 41566, Korea.; Crop Breeding Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea.; Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju 54874, Korea.; Coastal Agriculture Research Institute, Kyungpook National University, Daegu 41566, Korea.
An ideal plant architecture is an important condition to achieve high crop yields. The tiller angle is an important and complex polygenic trait of rice (Oryza sativa L.) plant architecture. Therefore, the discovery and identification of tiller angle-related genes can aid in the improvement of crop architecture and yield. In the present study, 222 SSR markers were used to establish a high-density genetic map of rice doubled haploid population, and a total of 8 quantitative trait loci (QTLs) were detected based on the phenotypic data of the tiller angle and tiller crown width over 2 years. Among them, four QTLs (qTA9, qCW9, qTA9-1, and qCW9-1) were overlapped at marker interval RM6235-RM24288 on chromosome 9 with a large effect value regarded as a stable major QTL. The selected promising related genes were further identified by relative gene expression analysis, which gives us a basis for the future cloning of these genes. Finally, OsSAURq9, which belongs to the SMALL AUXIN UP RNA (SAUR), an auxin-responsive protein family, was selected as a target gene. Overall, this work will help broaden our knowledge of the genetic control of tiller angle and tiller crown width, and this study provides both a good theoretical basis and a new genetic resource for the breeding of ideal-type rice.
PMID: 35563584
Int J Mol Sci , IF:5.923 , 2022 May , V23 (9) doi: 10.3390/ijms23095068
Overexpression of EgrIAA20 from Eucalyptus grandis, a Non-Canonical Aux/IAA Gene, Specifically Decouples Lignification of the Different Cell-Types in Arabidopsis Secondary Xylem.
Laboratoire de Recherche en Sciences Vegetales, Universite de Toulouse, CNRS, UPS, Toulouse INP, 31320 Auzeville-Tolosane, France.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China.; Arrhenius Laboratories, Department of Ecology, Environment and Plant Sciences (DEEP), Stockholm University, Svante Arrhenius vag 20A, 106 91 Stockholm, Sweden.
Wood (secondary xylem) formation is regulated by auxin, which plays a pivotal role as an integrator of developmental and environmental cues. However, our current knowledge of auxin-signaling during wood formation is incomplete. Our previous genome-wide analysis of Aux/IAAs in Eucalyptus grandis showed the presence of the non-canonical paralog member EgrIAA20 that is preferentially expressed in cambium. We analyzed its cellular localization using a GFP fusion protein and its transcriptional activity using transactivation assays, and demonstrated its nuclear localization and strong auxin response repressor activity. In addition, we functionally tested the role of EgrIAA20 by constitutive overexpression in Arabidopsis to investigate for phenotypic changes in secondary xylem formation. Transgenic Arabidopsis plants overexpressing EgrIAA20 were smaller and displayed impaired development of secondary fibers, but not of other wood cell types. The inhibition in fiber development specifically affected their cell wall lignification. We performed yeast-two-hybrid assays to identify EgrIAA20 protein partners during wood formation in Eucalyptus, and identified EgrIAA9A, whose ortholog PtoIAA9 in poplar is also known to be involved in wood formation. Altogether, we showed that EgrIAA20 is an important auxin signaling component specifically involved in controlling the lignification of wood fibers.
PMID: 35563457
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (9) doi: 10.3390/ijms23094886
Mutant lpa1 Analysis of ZmLPA1 Gene Regulates Maize Leaf-Angle Development through the Auxin Pathway.
College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China.; Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China.; Gansu Key Laboratory of Crop Improvement & Germplasm Enhancement, Lanzhou 730070, China.
Maize plant type is one of the main factors determining maize yield, and leaf angle is an important aspect of plant type. The rice Loose Plant Architecture1 (LPA1) gene and Arabidopsis AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene are related to their leaf angle. However, the homologous ZmLPA1 in maize has not been studied. In this study, the changing of leaf angle, as well as gene expression in leaves in maize mutant lpa1 and wild-type 'B73' under different IAA concentrations were investigated. The regulation effect of IAA on the leaf angle of lpa1 was significantly stronger than that of the wild type. Transcriptome analysis showed that different exogenous IAA treatments had a common enrichment pathway-the indole alkaloid biosynthesis pathway-and among the differentially expressed genes, four genes-AUX1, AUX/IAA, ARF and SAUR-were significantly upregulated. This study revealed the regulation mechanism of ZmLPA1 gene on maize leaf angle and provided a promising gene resource for maize breeding.
PMID: 35563277
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (9) doi: 10.3390/ijms23094852
Identification of Zinc Efficiency-Associated Loci (ZEALs) and Candidate Genes for Zn Deficiency Tolerance of Two Recombination Inbred Line Populations in Maize.
Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.; State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.; Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Maize Research Center, Beijing Academy of Agriculture & Forestry Science (BAAFS), Beijing 100097, China.
Zinc (Zn) deficiency is one of the most common micronutrient disorders in cereal plants, greatly impairing crop productivity and nutritional quality. Identifying the genes associated with Zn deficiency tolerance is the basis for understanding the genetic mechanism conferring tolerance. In this study, the K22xBY815 and DAN340xK22 recombination inbred line (RIL) populations, which were derived from Zn-inefficient and Zn-efficient inbred lines, were utilized to detect the quantitative trait loci (QTLs) associated with Zn deficiency tolerance and to further identify candidate genes within these loci. The BLUP (Best Linear Unbiased Prediction) values under Zn-deficient condition (-Zn) and the ratios of the BLUP values under Zn deficient condition to the BLUP values under Zn-sufficient condition (-Zn/CK) were used to perform linkage mapping. In QTL analysis, 21 QTLs and 33 QTLs controlling the Zn score, plant height, shoot and root dry weight, and root-to-shoot ratio were detected in the K22xBY815 population and the DAN340xK22 population, explaining 5.5-16.6% and 4.2-23.3% of phenotypic variation, respectively. In addition, seventeen candidate genes associated with the mechanisms underlying Zn deficiency tolerance were identified in QTL colocalizations or the single loci, including the genes involved in the uptake, transport, and redistribution of Zn (ZmIRT1, ZmHMAs, ZmNRAMP6, ZmVIT, ZmNAS3, ZmDMAS1, ZmTOM3), and the genes participating in the auxin and ethylene signal pathways (ZmAFBs, ZmIAA17, ZmETR, ZmEIN2, ZmEIN3, ZmCTR3, ZmEBF1). Our findings will broaden the understanding of the genetic structure of the tolerance to Zn deficiency in maize.
PMID: 35563244
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (9) doi: 10.3390/ijms23094618
The Phytotoxin Myrigalone A Triggers a Phased Detoxification Programme and Inhibits Lepidium sativum Seed Germination via Multiple Mechanisms including Interference with Auxin Homeostasis.
Department of Biological Sciences, Royal Holloway University of London, Egham TW20 0EX, UK.; Syngenta Jealott's Hill International Research Centre, Bracknell RG42 6EY, UK.; Syngenta Crop Protection, LLC, Research Triangle Park, NC 27709, USA.; National Center for Genome Resources, 2935 Rodeo Park Dr E, Santa Fe, NM 87505, USA.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacky University Olomouc, CZ-78371 Olomouc, Czech Republic.
Molecular responses of plants to natural phytotoxins comprise more general and compound-specific mechanisms. How phytotoxic chalcones and other flavonoids inhibit seedling growth was widely studied, but how they interfere with seed germination is largely unknown. The dihydrochalcone and putative allelochemical myrigalone A (MyA) inhibits seed germination and seedling growth. Transcriptome (RNAseq) and hormone analyses of Lepidium sativum seed responses to MyA were compared to other bioactive and inactive compounds. MyA treatment of imbibed seeds triggered the phased induction of a detoxification programme, altered gibberellin, cis-(+)-12-oxophytodienoic acid and jasmonate metabolism, and affected the expression of hormone transporter genes. The MyA-mediated inhibition involved interference with the antioxidant system, oxidative signalling, aquaporins and water uptake, but not uncoupling of oxidative phosphorylation or p-hydroxyphenylpyruvate dioxygenase expression/activity. MyA specifically affected the expression of auxin-related signalling genes, and various transporter genes, including for auxin transport (PIN7, ABCG37, ABCG4, WAT1). Responses to auxin-specific inhibitors further supported the conclusion that MyA interferes with auxin homeostasis during seed germination. Comparative analysis of MyA and other phytotoxins revealed differences in the specific regulatory mechanisms and auxin transporter genes targeted to interfere with auxin homestasis. We conclude that MyA exerts its phytotoxic activity by multiple auxin-dependent and independent molecular mechanisms.
PMID: 35563008
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (8) doi: 10.3390/ijms23084439
Multidimensional Gene Regulatory Landscape of Motor Organ Pulvinus in the Model Legume Medicago truncatula.
CAS Key Laboratory of Topical Plant Resources and Sustainable Use, CAS Center for Excellence in Molecular Plant Sciences, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefu Road, Kunming 650223, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China.; School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.; Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK 73401, USA.; Basic Forestry and Proteomics Research Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Nyctinastic leaf movement of Fabaceae is driven by the tiny motor organ pulvinus located at the base of the leaf or leaflet. Despite the increased understanding of the essential role of ELONGATED PETIOLULE1 (ELP1)/PETIOLE LIKE PULVINUS (PLP) orthologs in determining pulvinus identity in legumes, key regulatory components and molecular mechanisms underlying this movement remain largely unclear. Here, we used WT pulvinus and the equivalent tissue in the elp1 mutant to carry out transcriptome and proteome experiments. The omics data indicated that there are multiple cell biological processes altered at the gene expression and protein abundance level during the pulvinus development. In addition, comparative analysis of different leaf tissues provided clues to illuminate the possible common primordium between pulvinus and petiole, as well as the function of ELP1. Furthermore, the auxin pathway, cell wall composition and chloroplast distribution were altered in elp1 mutants, verifying their important roles in pulvinus development. This study provides a comprehensive insight into the motor organ of the model legume Medicago truncatula and further supplies a rich dataset to facilitate the identification of novel players involved in nyctinastic movement.
PMID: 35457256
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (8) doi: 10.3390/ijms23084272
The Interplay between Hydrogen Sulfide and Phytohormone Signaling Pathways under Challenging Environments.
International Genome Center, Jiangsu University, Zhenjiang 212013, China.; Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education of China, Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.; State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
Hydrogen sulfide (H2S) serves as an important gaseous signaling molecule that is involved in intra- and intercellular signal transduction in plant-environment interactions. In plants, H2S is formed in sulfate/cysteine reduction pathways. The activation of endogenous H2S and its exogenous application has been found to be highly effective in ameliorating a wide variety of stress conditions in plants. The H2S interferes with the cellular redox regulatory network and prevents the degradation of proteins from oxidative stress via post-translational modifications (PTMs). H2S-mediated persulfidation allows the rapid response of proteins in signaling networks to environmental stimuli. In addition, regulatory crosstalk of H2S with other gaseous signals and plant growth regulators enable the activation of multiple signaling cascades that drive cellular adaptation. In this review, we summarize and discuss the current understanding of the molecular mechanisms of H2S-induced cellular adjustments and the interactions between H2S and various signaling pathways in plants, emphasizing the recent progress in our understanding of the effects of H2S on the PTMs of proteins. We also discuss future directions that would advance our understanding of H2S interactions to ultimately mitigate the impacts of environmental stresses in the plants.
PMID: 35457090
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (8) doi: 10.3390/ijms23084223
The Combination of Conventional QTL Analysis, Bulked-Segregant Analysis, and RNA-Sequencing Provide New Genetic Insights into Maize Mesocotyl Elongation under Multiple Deep-Seeding Environments.
State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China.
Mesocotyl length (MES) is an important trait that affects the emergence of maize seedlings after deep-seeding and is closely associated with abiotic stress. The elucidation of constitutive-QTLs (cQTLs) and candidate genes for MES and tightly molecular markers are thus of great importance in marker-assisted selection (MAS) breeding. Therefore, the objective of this study was to perform detailed genetic analysis of maize MES across 346 F2:3 families, 30/30 extreme bulks of an F2 population, and two parents by conventional QTL analysis, bulked-segregation analysis (BSA), and RNA-sequencing when maize was sown at the depths of 3, 15, and 20 cm, respectively. QTL analysis identified four major QTLs in Bin 1.09, Bin 3.04, Bin 4.06-4.07, and Bin 6.01 under two or more environments, which explained 2.89-13.97% of the phenotypic variance within a single environment. BSA results revealed the presence of seven significantly linked SNP/InDel regions on chromosomes 1 and 4, and six SNP/InDel regions and the major QTL of qMES4-1 overlapped and formed a cQTL, cQMES4, within the 160.98-176.22 Mb region. In total, 18,001 differentially expressed genes (DEGs) were identified across two parents by RNA-sequencing, and 24 of these genes were conserved core DEGs. Finally, we validated 15 candidate genes in cQMES4 to involve in cell wall structure, lignin biosyntheis, phytohormones (auxin, abscisic acid, brassinosteroid) signal transduction, circadian clock, and plant organ formation and development. Our findings provide a basis for MAS breeding and enhance our understanding of the deep-seeding tolerance of maize.
PMID: 35457037
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (8) doi: 10.3390/ijms23084219
TaKLU Plays as a Time Regulator of Leaf Growth via Auxin Signaling.
College of Life Sciences, Northwest A&F University, Yangling 712100, China.; College of Landscape Architecture and Art, Northwest A&F University, Yangling 712100, China.; State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, China.; College of Plant Protection, Northwest A&F University, Yangling 712100, China.
The growth of leaves is subject to strict time regulation. Several genes influencing leaf growth have been identified, but little is known about how genes regulate the orderly initiation and growth of leaves. Here, we demonstrate that TaKLU/TaCYP78A5 contributes to a time regulation mechanism in leaves from initiation to expansion. TaKLU encodes the cytochrome P450 CYP78A5, and its homolog AtKLU has been described whose deletion is detrimental to organ growth. Our results show that TaKLU overexpression increases leaf size and biomass by altering the time of leaf initiation and expansion. TaKLU-overexpressing plants have larger leaves with more cells. Further dynamic observations indicate that enlarged wheat leaves have experienced a longer expansion time. Different from AtKLU inactivation increases leaf number and initiation rates, TaKLU overexpression only smooths the fluctuations of leaf initiation rates by adjusting the initiation time of local leaves, without affecting the overall leaf number and initiation rates. In addition, complementary analyses suggest TaKLU is functionally conserved with AtKLU in controlling the leaf initiation and size and may involve auxin accumulation. Our results provide a new insight into the time regulation mechanisms of leaf growth in wheat.
PMID: 35457033
Front Plant Sci , IF:5.753 , 2022 , V13 : P888425 doi: 10.3389/fpls.2022.888425
Molecular Determinants of in vitro Plant Regeneration: Prospects for Enhanced Manipulation of Lettuce (Lactuca sativa L.).
The Genome Center, University of California, Davis, Davis, CA, United States.; Graduate Group in Horticulture and Agronomy, University of California, Davis, Davis, CA, United States.; Department of Plant Sciences, University of California, Davis, Davis, CA, United States.
In vitro plant regeneration involves dedifferentiation and molecular reprogramming of cells in order to regenerate whole organs. Plant regeneration can occur via two pathways, de novo organogenesis and somatic embryogenesis. Both pathways involve intricate molecular mechanisms and crosstalk between auxin and cytokinin signaling. Molecular determinants of both pathways have been studied in detail in model species, but little is known about the molecular mechanisms controlling de novo shoot organogenesis in lettuce. This review provides a synopsis of our current knowledge on molecular determinants of de novo organogenesis and somatic embryogenesis with an emphasis on the former as well as provides insights into applying this information for enhanced in vitro regeneration in non-model species such as lettuce (Lactuca sativa L.).
PMID: 35615120
Front Plant Sci , IF:5.753 , 2022 , V13 : P855243 doi: 10.3389/fpls.2022.855243
Transcriptomic and Metabolomic Response to High Light in the Charophyte Alga Klebsormidium nitens.
Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla - Consejo Superior de Investigaciones Cientificas, Seville, Spain.; Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain.
The characterization of the molecular mechanisms, such as high light irradiance resistance, that allowed plant terrestralization is a cornerstone in evolutionary studies since the conquest of land by plants played a pivotal role in life evolution on Earth. Viridiplantae or the green lineage is divided into two clades, Chlorophyta and Streptophyta, that in turn splits into Embryophyta or land plants and Charophyta. Charophyta are used in evolutionary studies on plant terrestralization since they are generally accepted as the extant algal species most closely related to current land plants. In this study, we have chosen the facultative terrestrial early charophyte alga Klebsormidium nitens to perform an integrative transcriptomic and metabolomic analysis under high light in order to unveil key mechanisms involved in the early steps of plants terrestralization. We found a fast chloroplast retrograde signaling possibly mediated by reactive oxygen species and the inositol polyphosphate 1-phosphatase (SAL1) and 3'-phosphoadenosine-5'-phosphate (PAP) pathways inducing gene expression and accumulation of specific metabolites. Systems used by both Chlorophyta and Embryophyta were activated such as the xanthophyll cycle with an accumulation of zeaxanthin and protein folding and repair mechanisms constituted by NADPH-dependent thioredoxin reductases, thioredoxin-disulfide reductases, and peroxiredoxins. Similarly, cyclic electron flow, specifically the pathway dependent on proton gradient regulation 5, was strongly activated under high light. We detected a simultaneous co-activation of the non-photochemical quenching mechanisms based on LHC-like stress related (LHCSR) protein and the photosystem II subunit S that are specific to Chlorophyta and Embryophyta, respectively. Exclusive Embryophyta systems for the synthesis, sensing, and response to the phytohormone auxin were also activated under high light in K. nitens leading to an increase in auxin content with the concomitant accumulation of amino acids such as tryptophan, histidine, and phenylalanine.
PMID: 35599877
Front Plant Sci , IF:5.753 , 2022 , V13 : P888703 doi: 10.3389/fpls.2022.888703
Cotton miR393-TIR1 Module Regulates Plant Defense Against Verticillium dahliae via Auxin Perception and Signaling.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China.; The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Plant auxin is essential in plant growth and development. However, the molecular mechanisms of auxin involvement in plant immunity are unclear. Here, we addressed the function of the cotton (Gossypium hirsutum) miR393-TIR1 module in plant defense against Verticillium dahliae infection via auxin perception and signaling. GhTIR1 was directedly cleaved by ghr-miR393 according to mRNA degradome data, 5'-RACE analysis, and a GUS reporter assay. Ghr-miR393 knockdown significantly increased plant susceptibility to V. dahliae compared to the control, while ghr-miR393 overexpression and GhTIR1 knockdown significantly increased plant resistance. External indole-3-acetic acid (IAA) application significantly enhanced susceptibility to V. dahliae in ghr-miR393 knockdown and control plants compared to mock treatment, and only slightly increased susceptibility in overexpressing ghr-miR393 and GhTIR1-silenced plants. Application of external PEO-IAA (an auxin antagonist) had a contrary trend with IAA application. Based on yeast two-hybrid and bimolecular fluorescence complementation assays, GhTIR1 interacted with GhIAA14 in the nucleus, and GhIAA14 knockdown reduced plant resistance to V. dahliae infection. The results suggested that the ghr-miR393-GhTIR1 module regulates plant defense via auxin perception and signaling. Additionally, simultaneous knockdown of GhTIR1 and GhICS1 significantly increased plant susceptibility to V. dahliae compared to the control, indicating that salicylic acid (SA) accumulation is vital for the ghr-miR393-GhTIR1 module to regulates plant resistance. Transcriptome data also demonstrated that GhTIR1 knockdown significantly downregulated expression of auxin-related genes and upregulated expression of SA-related genes. Overall, the ghr-miR393-GhTIR1 module participates in plant response to V. dahliae infection via IAA perception and signaling partially depending on the SA defense pathway.
PMID: 35592575
Front Plant Sci , IF:5.753 , 2022 , V13 : P858686 doi: 10.3389/fpls.2022.858686
New Insights Into the Local Auxin Biosynthesis and Its Effects on the Rapid Growth of Moso Bamboo (Phyllostachys edulis).
Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo & Rattan Science and Technology, International Center for Bamboo and Rattan, Beijing, China.
Auxin plays a crucial regulatory role in higher plants, but systematic studies on the location of auxin local biosynthesis are rare in bamboo and other graminaceous plants. We studied moso bamboo (Phyllostachys edulis), which can grow up to 1 m/day and serves as a reference species for bamboo and other fast-growing species. We selected young tissues such as root tips, shoot tips, young culm sheaths, sheath blades, and internode divisions for local auxin biosynthesis site analysis. IAA immunofluorescence localization revealed that auxin was similarly distributed in different stages of 50-cm and 300-cm bamboo shoots. Shoot tips had the highest auxin content, and it may be the main site of auxin biosynthesis in the early stage of rapid growth. A total of 22 key genes in the YUCCA family for auxin biosynthesis were identified by genome-wide identification, and these had obvious tissue-specific and spatio-temporal expression patterns. In situ hybridization analysis revealed that the localization of YUCCA genes was highly consistent with the distribution of auxin. Six major auxin synthesis genes, PheYUC3-1, PheYUC6-1, PheYUC6-3, PheYUC9-1, PheYUC9-2, and PheYUC7-3, were obtained that may have regulatory roles in auxin accumulation during moso bamboo growth. Culm sheaths were found to serve as the main local sites of auxin biosynthesis and the auxin required for internode elongation may be achieved mainly by auxin transport.
PMID: 35592571
Front Plant Sci , IF:5.753 , 2022 , V13 : P862171 doi: 10.3389/fpls.2022.862171
The Root Hair Development of Pectin Polygalacturonase PGX2 Activation Tagging Line in Response to Phosphate Deficiency.
Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.
Pectin, cellulose, and hemicellulose constitute the primary cell wall in eudicots and function in multiple developmental processes in plants. Root hairs are outgrowths of specialized epidermal cells that absorb water and nutrients from the soil. Cell wall architecture influences root hair development, but how cell wall remodeling might enable enhanced root hair formation in response to phosphate (P) deficiency remains relatively unclear. Here, we found that POLYGALACTURONASE INVOLVED IN EXPANSION 2 (PGX2) functions in conditional root hair development. Under low P conditions, a PGX2 activation tagged line (PGX2(AT) ) displays bubble-like root hairs and abnormal callose deposition and superoxide accumulation in roots. We found that the polar localization and trafficking of PIN2 are altered in PGX2(AT) roots in response to P deficiency. We also found that actin filaments were less compact but more stable in PGX2(AT) root hair cells and that actin filament skewness in PGX2(AT) root hairs was recovered by treatment with 1-N-naphthylphthalamic acid (NPA), an auxin transport inhibitor. These results demonstrate that activation tagging of PGX2 affects cell wall remodeling, auxin signaling, and actin microfilament orientation, which may cooperatively regulate root hair development in response to P starvation.
PMID: 35586221
Front Plant Sci , IF:5.753 , 2022 , V13 : P863283 doi: 10.3389/fpls.2022.863283
CBL-Interacting Protein Kinase OsCIPK18 Regulates the Response of Ammonium Toxicity in Rice Roots.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.; Department of Chemistry, University of Kentucky, Lexington, KY, United States.; College of Life Sciences, Nanchang University, Nanchang, China.
Ammonium ( NH 4 + ) is one of the major nitrogen sources for plants. However, excessive ammonium can cause serious harm to the growth and development of plants, i.e., ammonium toxicity. The primary regulatory mechanisms behind ammonium toxicity are still poorly characterized. In this study, we showed that OsCIPK18, a CBL-interacting protein kinase, plays an important role in response to ammonium toxicity by comparative analysis of the physiological and whole transcriptome of the T-DNA insertion mutant (cipk18) and the wild-type (WT). Root biomass and length of cipk18 are less inhibited by excess NH 4 + compared with WT, indicating increased resistance to ammonium toxicity. Transcriptome analysis reveals that OsCIPK18 affects the NH 4 + uptake by regulating the expression of OsAMT1;2 and other NH 4 + transporters, but does not affect ammonium assimilation. Differentially expressed genes induced by excess NH 4 + in WT and cipk18 were associated with functions, such as ion transport, metabolism, cell wall formation, and phytohormones signaling, suggesting a fundamental role for OsCIPK18 in ammonium toxicity. We further identified a transcriptional regulatory network downstream of OsCIPK18 under NH 4 + stress that is centered on several core transcription factors. Moreover, OsCIPK18 might function as a transmitter in the auxin and abscisic acid (ABA) signaling pathways affected by excess ammonium. These data allowed us to define an OsCIPK18-regulated/dependent transcriptomic network for the response of ammonium toxicity and provide new insights into the mechanisms underlying ammonium toxicity.
PMID: 35574117
Front Plant Sci , IF:5.753 , 2022 , V13 : P815131 doi: 10.3389/fpls.2022.815131
Characterization of a Novel Creeping Tartary Buckwheat (Fagopyrum tataricum) Mutant lazy1.
Research Center of Buckwheat Industry Technology, School of Life Sciences, Guizhou Normal University, Guiyang, China.; Guizhou Biotechnology Institute, Guizhou Academy of Agricultural Sciences, Guiyang, China.; Guizhou Key Laboratory of Agricultural Biotechnology, Guiyang, China.
Gravity is known as an important environmental factor involved in the regulation of plant architecture. To identify genes related to the gravitropism of Tartary buckwheat, a creeping line was obtained and designated as lazy1 from the mutant bank by (60)Co-gamma ray radiation. Genetic analysis indicated that the creeping phenotype of lazy1 was attributed to a single recessive locus. As revealed by the horizontal and inverted suspension tests, lazy1 was completely lacking in shoot negative gravitropism. The creeping growth of lazy1 occurred at the early seedling stage, which could not be recovered by exogenous heteroauxin, hormodin, alpha-rhodofix, or gibberellin. Different from the well-organized and equivalent cell elongation of wild type (WT), lazy1 exhibited dilated, distorted, and abnormally arranged cells in the bending stem. However, no statistical difference of indole-3-acetic acid (IAA) levels was found between the far- and near-ground bending sides in lazy1, which suggests that the asymmetric cell elongation of lazy1 was not induced by auxin gradient. Whereas, lazy1 showed up-expressed gibberellin-regulated genes by quantitative real-time PCR (qRT-PCR) as well as significantly higher levels of gibberellin, suggesting that gibberellin might be partly involved in the regulation of creeping growth in lazy1. RNA sequencing (RNA-seq) identified a number of differentially expressed genes (DEGs) related to gravitropism at stages I (before bending), II (bending), and III (after bending) between WT and lazy1. Venn diagram indicated that only Pectate lyase 5 was down-expressed at stages I [Log2 fold change (Log2FC): -3.20], II (Log2FC: -4.97), and III (Log2FC: -1.23) in lazy1, compared with WT. Gene sequencing revealed that a fragment deletion occurred in the coding region of Pectate lyase 5, which induced the destruction of a pbH domain in Pectate lyase 5 of lazy1. qRT-PCR indicated that Pectate lyase 5 was extremely down-expressed in lazy1 at stage II (0.02-fold of WT). Meanwhile, lazy1 showed the affected expression of lignin- and cellulose-related genes and cumulatively abnormal levels of pectin, lignin, and cellulose. These results demonstrate the possibility that Pectate lyase 5 functions as the key gene that could mediate primary cell wall metabolism and get involved in the asymmetric cell elongation regulation of lazy1.
PMID: 35574111
Front Plant Sci , IF:5.753 , 2022 , V13 : P883363 doi: 10.3389/fpls.2022.883363
Cytoplasmic Linker Protein-Associating Protein at the Nexus of Hormone Signaling, Microtubule Organization, and the Transition From Division to Differentiation in Primary Roots.
Department of Botany, University of British Columbia, Vancouver, BC, Canada.
The transition from cell division to differentiation in primary roots is dependent on precise gradients of phytohormones, including auxin, cytokinins and brassinosteroids. The reorganization of microtubules also plays a key role in determining whether a cell will enter another round of mitosis or begin to rapidly elongate as the first step in terminal differentiation. In the last few years, progress has been made to establish connections between signaling pathways at distinct locations within the root. This review focuses on the different factors that influence whether a root cell remains in the division zone or transitions to elongation and differentiation using Arabidopsis thaliana as a model system. We highlight the role of the microtubule-associated protein CLASP as an intermediary between sustaining hormone signaling and controlling microtubule organization. We discuss new, innovative tools and methods, such as hormone sensors and computer modeling, that are allowing researchers to more accurately visualize the belowground growth dynamics of plants.
PMID: 35574108
Front Plant Sci , IF:5.753 , 2022 , V13 : P850829 doi: 10.3389/fpls.2022.850829
Transcriptomic and Metabolomic Analyses Reveal a Potential Mechanism to Improve Soybean Resistance to Anthracnose.
Zhejiang Key Laboratory of Digital Dry Land Crops, Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Anthracnose, caused by Colletotrichum truncatum, leads to large-scale reduction in quality and yield in soybean production. Limited information is available regarding the molecular mechanisms of resistance to anthracnose in soybean. We conducted a transcriptomic and targeted metabolomic analysis of pods from two soybean lines, "Zhechun No. 3" (ZC3) and ZC-2, in response to C. truncatum infection. Factors contributing to the enhanced resistance of ZC-2 to anthracnose compared with that of ZC3, included signal transduction (jasmonic acid, auxin, mitogen-activated protein kinase, and Ca(2+) signaling), transcription factors (WRKY and bHLH), resistance genes (PTI1, RPP13, RGA2, RPS6, and ULP2B), pathogenesis-related genes (chitinase and lipid transfer protein), and terpenoid metabolism. Targeted metabolomic analysis revealed that terpenoid metabolism responded more promptly and more intensely to C. truncatum infection in ZC-2 than in ZC3. In vitro antifungal activity and resistance induction test confirmed that jasmonic acid, auxin signaling and terpenoids played important roles in soybean resistance to anthracnose. This research is the first study to explore the molecular mechanisms of soybean resistance to anthracnose. The findings are important for in-depth analysis of molecular resistance mechanisms, discovery of resistance genes, and to expedite the breeding of anthracnose-resistant soybean cultivars.
PMID: 35574068
Front Plant Sci , IF:5.753 , 2022 , V13 : P850956 doi: 10.3389/fpls.2022.850956
Characterization of Transcription Regulatory Domains of OsMADS29: Identification of Proximal Auxin-Responsive Domains and a Strong Distal Negative Element.
Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India.; Centre for Plant Molecular Biology, Osmania University, Hyderabad, India.; University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi, India.
OsMADS29 (M29) is a seed-specific MADS-box transcription factor involved in programmed cell death of nucellar tissue and maintaining auxin:cytokinin homeostasis. It affects embryo and endosperm development and starch filling during seed development in rice. Its expression seems to be tightly regulated by developmental, spatial, and temporal cues; however, cis- and trans-regulatory factors that affect its expression are largely unknown. In silico analysis of the 1.7 kb upstream regulatory region (URR) consisting of 1,290 bp promoter and 425 bp 5'-UTR regions revealed several auxin-responsive and seed-specific cis-regulatory elements distributed across the URR. In this study, the analysis of four URR deletions fused to a downstream beta-glucuronidase (GUS) reporter in transgenic rice has revealed the presence of several proximal positive elements and a strong distal negative element (NE). The promoter regions containing auxin-responsive elements responded positively to the exogenous application of auxins to transgenic seedlings. The proximal positive elements are capable of driving reporter expression in both vegetative and reproductive tissues. In contrast, the NE strongly suppresses reporter gene expression in both vegetative and reproductive tissues. In a transient onion peel assay system, the NE could reduce the efficacy of a 2x CaMV 35S promoter by approximately 90%. Our results indicate the existence of a complex array of positive and negative regulatory regions along with auxin-responsive elements guiding the development-dependent and spatial expression of M29.
PMID: 35557721
Front Plant Sci , IF:5.753 , 2022 , V13 : P836592 doi: 10.3389/fpls.2022.836592
Auxin-Cytokinin Balance Shapes Maize Root Architecture by Controlling Primary Root Elongation and Lateral Root Development.
Departamento de Biologia Vegetal, Ecologia y Ciencias de la Tierra, Universidad de Extremadura, Badajoz, Spain.; Departamento de Hortofruticultura, Instituto de Investigaciones Agrarias "La Orden-Valdesequera", Centro de Investigaciones Cientificas y Tecnologicas de Extremadura (CICYTEX), Junta de Extremadura, Badajoz, Spain.
The root system is responsible for water and nutrients uptake from the soil, and therefore, its extension is basic for an efficient acquisition. The maize root system is formed by different types of roots, and the lateral root branching substantially increases the surface for nutrient uptake. Therefore, the regulation of lateral root formation is fundamental in the development of root functions. Root architecture is basically controlled by auxin and cytokinins, which antagonize in the formation of lateral roots (LR) along the primary root axis, with auxin, a stimulator, and cytokinins inhibitors of LR development. This interaction has been analyzed in several zones along the primary root where LRs in different developmental stages were located. The root has been divided into several zones, such as meristem, elongation zone, and mature zone, according to the developmental processes occurring in each one. As Arabidopsis root elongated more slowly than maize root, these zones are shorter, and its delimitation is more difficult. However, these zones have previously been delimitated clearly in maize, and therefore, they analyze the effect of exogenous hormones in several LR developmental stages. The inhibitory effect of cytokinin on lateral root formation was observed in already elongated primary root zones in which initial events to form new lateral roots are taking place. Contrarily, auxin increased LR formation in the primary root segments elongated in the presence of the hormone. The inhibitory effect of cytokinin was reversed by auxin in a concentration-dependent manner when both hormones were combined. However, auxin is unable to recover LR development in primary root zones that have been previously elongated only in the presence of cytokinin. This antagonistic auxin-cytokinin effect on LR development depended on the balance between both hormones, which controls the root system architecture and determines the formation of LR during the process of initiation.
PMID: 35548278
Front Plant Sci , IF:5.753 , 2022 , V13 : P840260 doi: 10.3389/fpls.2022.840260
Loss of Multiple ABCB Auxin Transporters Recapitulates the Major twisted dwarf 1 Phenotypes in Arabidopsis thaliana.
Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, United States.; School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.
FK506-BINDING PROTEIN 42/TWISTED DWARF 1 (FKBP42/TWD1) directly regulates cellular trafficking and activation of multiple ATP-BINDING CASSETTE (ABC) transporters from the ABCB and ABCC subfamilies. abcb1 abcb19 double mutants exhibit remarkable phenotypic overlap with twd1 including severe dwarfism, stamen elongation defects, and compact circinate leaves; however, twd1 mutants exhibit greater loss of polar auxin transport and additional helical twisting of roots, inflorescences, and siliques. As abcc1 abcc2 mutants do not exhibit any visible phenotypes and TWD1 does not interact with PIN or AUX1/LAX auxin transporters, loss of function of other ABCB auxin transporters is hypothesized to underly the remaining morphological phenotypes. Here, gene expression, mutant analyses, pharmacological inhibitor studies, auxin transport assays, and direct auxin quantitations were used to determine the relative contributions of loss of other reported ABCB auxin transporters (4, 6, 11, 14, 20, and 21) to twd1 phenotypes. From these analyses, the additional reduction in plant height and the twisted inflorescence, root, and silique phenotypes observed in twd1 compared to abcb1 abcb19 result from loss of ABCB6 and ABCB20 function. Additionally, abcb6 abcb20 root twisting exhibited the same sensitivity to the auxin transport inhibitor 1-napthalthalamic acid as twd1 suggesting they are the primary contributors to these auxin-dependent organ twisting phenotypes. The lack of obvious phenotypes in higher order abcb4 and abcb21 mutants suggests that the functional loss of these transporters does not contribute to twd1 root or shoot twisting. Analyses of ABCB11 and ABCB14 function revealed capacity for auxin transport; however, their activities are readily outcompeted by other substrates, suggesting alternate functions in planta, consistent with a spectrum of relative substrate affinities among ABCB transporters. Overall, the results presented here suggest that the ABCB1/19 and ABCB6/20 pairs represent the primary long-distance ABCB auxin transporters in Arabidopsis and account for all reported twd1 morphological phenotypes. Other ABCB transporters appear to participate in highly localized auxin streams or mobilize alternate transport substrates.
PMID: 35528937
Front Plant Sci , IF:5.753 , 2022 , V13 : P844292 doi: 10.3389/fpls.2022.844292
Long-Term High-Temperature Stress Impacts on Embryo and Seed Development in Brassica napus.
National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia.; Hormonal Crosstalk in Plant Development, Mendel Center for Plant Genomics and Proteomics, CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, Czechia.; Plant Sciences Core Facility, Mendel Center for Plant Genomics and Proteomics, CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, Czechia.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Olomouc, Czechia.; Research Institute of Oilseed Crops, Opava, Czechia.
Brassica napus (rapeseed) is the second most important oilseed crop worldwide. Global rise in average ambient temperature and extreme weather severely impact rapeseed seed yield. However, fewer research explained the phenotype changes caused by moderate-to-high temperatures in rapeseed. To investigate these events, we determined the long-term response of three spring cultivars to different temperature regimes (21/18 degrees C, 28/18 degrees C, and 34/18 degrees C) mimicking natural temperature variations. The analysis focused on the plant appearance, seed yield, quality and viability, and embryo development. Our microscopic observations suggest that embryonic development is accelerated and defective in high temperatures. Reduced viable seed yield at warm ambient temperature is due to a reduced fertilization rate, increased abortion rate, defective embryonic development, and pre-harvest sprouting. Reduced auxin levels in young seeds and low ABA and auxin levels in mature seeds may cause embryo pattern defects and reduced seed dormancy, respectively. Glucosinolates and oil composition measurements suggest reduced seed quality. These identified cues help understand seed thermomorphogenesis and pave the way to developing thermoresilient rapeseed.
PMID: 35528932
Front Plant Sci , IF:5.753 , 2022 , V13 : P891361 doi: 10.3389/fpls.2022.891361
Integrated Analysis of Coding and Non-coding RNAs Reveals the Molecular Mechanism Underlying Salt Stress Response in Medicago truncatula.
School of Grassland Science, Beijing Forestry University, Beijing, China.
Salt stress is among the most severe abiotic stresses in plants worldwide. Medicago truncatula is a model plant for legumes and analysis of its response to salt stress is helpful for providing valuable insights into breeding. However, few studies have focused on illustrating the whole-transcriptome molecular mechanism underlying salt stress response in Medicago truncatula. Herein, we sampled the leaves of Medicago truncatula treated with water or NaCl and analyzed the characteristics of its coding and non-coding RNAs. We identified a total of 4,693 differentially expressed mRNAs (DEmRNAs), 505 DElncRNAs, 21 DEcircRNAs, and 55 DEmiRNAs. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed that their functions were mostly associated with metabolic processes. We classified the lncRNAs and circRNAs into different types and analyzed their genomic distributions. Furthermore, we predicted the interactions between different RNAs based on the competing endogenous RNA (ceRNA) theory and identified multiple correlation networks, including 27 DEmiRNAs, 43 DEmRNAs, 19 lncRNAs, and 5 DEcircRNAs. In addition, we comprehensively analyzed the candidate DEmRNAs and ceRNAs and found that they were involved in Ca(+) signaling, starch and sucrose biosynthesis, phenylpropanoid and lignin metabolism, auxin and jasmonate biosynthesis, and transduction pathways. Our integrated analyses in salt stress response in Medicago truncatula revealed multiple differentially expressed coding and non-coding RNAs, including mRNAs, lncRNAs, circRNAs, and miRNAs, and identified multiple DEmRNA and ceRNA interaction pairs that function in many pathways, providing insights into salt stress response in leguminous plants.
PMID: 35519807
Front Plant Sci , IF:5.753 , 2022 , V13 : P827147 doi: 10.3389/fpls.2022.827147
High-Throughput 3D Phenotyping of Plant Shoot Apical Meristems From Tissue-Resolution Data.
Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.; Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom.; Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, Beijing, China.; Computational Biology and Biological Physics, Lund University, Lund, Sweden.
Confocal imaging is a well-established method for investigating plant phenotypes on the tissue and organ level. However, many differences are difficult to assess by visual inspection and researchers rely extensively on ad hoc manual quantification techniques and qualitative assessment. Here we present a method for quantitatively phenotyping large samples of plant tissue morphologies using triangulated isosurfaces. We successfully demonstrate the applicability of the approach using confocal imaging of aerial organs in Arabidopsis thaliana. Automatic identification of flower primordia using the surface curvature as an indication of outgrowth allows for high-throughput quantification of divergence angles and further analysis of individual flowers. We demonstrate the throughput of our method by quantifying geometric features of 1065 flower primordia from 172 plants, comparing auxin transport mutants to wild type. Additionally, we find that a paraboloid provides a simple geometric parameterisation of the shoot inflorescence domain with few parameters. We utilise parameterisation methods to provide a computational comparison of the shoot apex defined by a fluorescent reporter of the central zone marker gene CLAVATA3 with the apex defined by the paraboloid. Finally, we analyse the impact of mutations which alter mechanical properties on inflorescence dome curvature and compare the results with auxin transport mutants. Our results suggest that region-specific expression domains of genes regulating cell wall biosynthesis and local auxin transport can be important in maintaining the wildtype tissue shape. Altogether, our results indicate a general approach to parameterise and quantify plant development in 3D, which is applicable also in cases where data resolution is limited, and cell segmentation not possible. This enables researchers to address fundamental questions of plant development by quantitative phenotyping with high throughput, consistency and reproducibility.
PMID: 35519801
Front Plant Sci , IF:5.753 , 2022 , V13 : P834378 doi: 10.3389/fpls.2022.834378
Auxin Distribution in Lateral Root Primordium Development Affects the Size and Lateral Root Diameter of Rice.
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.; School of Agriculture and Environment, The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia.; International Center for Research and Education in Agriculture, Nagoya University, Nagoya, Japan.; Department of Crop Botany, Bangladesh Agricultural University, Mymensingh, Bangladesh.; Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan.
Lateral roots (LRs) occupy a large part of the root system and play a central role in plant water and nutrient uptake. Monocot plants, such as rice, produce two types of LRs: the S-type (short and thin) and the L-type (long, thick, and capable of further branching). Because of the ability to produce higher-order branches, the L-type LR formation contributes to efficient root system expansion. Auxin plays a major role in regulating the root system development, but its involvement in developing different types of LRs is largely unknown. Here, we show that auxin distribution is involved in regulating LR diameter. Dynamin-related protein (DRP) genes were isolated as causative genes of the mutants with increased L-type LR number and diameter than wild-type (WT). In the drp mutants, reduced endocytic activity was detected in rice protoplast and LRs with a decreased OsPIN1b-GFP endocytosis in the protoplast. Analysis of auxin distribution using auxin-responsive promoter DR5 revealed the upregulated auxin signaling in L-type LR primordia (LRP) of the WT and the mutants. The application of polar auxin transport inhibitors enhanced the effect of exogenous auxin to increase LR diameter with upregulated auxin signaling in the basal part of LRP. Inducible repression of auxin signaling in the mOsIAA3-GR system suppressed the increase in LR diameter after root tip excision, suggesting a positive role of auxin signaling in LR diameter increase. A positive regulator of LR diameter, OsWOX10, was auxin-inducible and upregulated in the drp mutants more than the WT, and revealed as a potential target of ARF transcriptional activator. Therefore, auxin signaling upregulation in LRP, especially at the basal part, induces OsWOX10 expression, increasing LR diameter.
PMID: 35498720
Front Plant Sci , IF:5.753 , 2022 , V13 : P820348 doi: 10.3389/fpls.2022.820348
High-Resolution Translatome Analysis Reveals Cortical Cell Programs During Early Soybean Nodulation.
Divisions of Plant Sciences and Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, United States.; Department of Electrical Engineering and Computer Science, C.S. Bond Life Science Center, University of Missouri, Columbia, MO, United States.
Nodule organogenesis in legumes is regulated temporally and spatially through gene networks. Genome-wide transcriptome, proteomic, and metabolomic analyses have been used previously to define the functional role of various plant genes in the nodulation process. However, while significant progress has been made, most of these studies have suffered from tissue dilution since only a few cells/root regions respond to rhizobial infection, with much of the root non-responsive. To partially overcome this issue, we adopted translating ribosome affinity purification (TRAP) to specifically monitor the response of the root cortex to rhizobial inoculation using a cortex-specific promoter. While previous studies have largely focused on the plant response within the root epidermis (e.g., root hairs) or within developing nodules, much less is known about the early responses within the root cortex, such as in relation to the development of the nodule primordium or growth of the infection thread. We focused on identifying genes specifically regulated during early nodule organogenesis using roots inoculated with Bradyrhizobium japonicum. A number of novel nodulation gene candidates were discovered, as well as soybean orthologs of nodulation genes previously reported in other legumes. The differential cortex expression of several genes was confirmed using a promoter-GUS analysis, and RNAi was used to investigate gene function. Notably, a number of differentially regulated genes involved in phytohormone signaling, including auxin, cytokinin, and gibberellic acid (GA), were also discovered, providing deep insight into phytohormone signaling during early nodule development.
PMID: 35498680
Front Plant Sci , IF:5.753 , 2022 , V13 : P865928 doi: 10.3389/fpls.2022.865928
OsbZIP47 Is an Integrator for Meristem Regulators During Rice Plant Growth and Development.
Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.
Stem cell homeostasis by the WUSCHEL-CLAVATA (WUS-CLV) feedback loop is generally conserved across species; however, its links with other meristem regulators can be species-specific, rice being an example. We characterized the role of rice OsbZIP47 in vegetative and reproductive development. The knockdown (KD) transgenics showed meristem size abnormality and defects in developmental progression. The size of the shoot apical meristem (SAM) in 25-day OsbZIP47KD plants was increased as compared to the wild-type (WT). Inflorescence of KD plants showed reduced rachis length, number of primary branches, and spikelets. Florets had defects in the second and third whorl organs and increased organ number. OsbZIP47KD SAM and panicles had abnormal expression for CLAVATA peptide-like signaling genes, such as FON2-LIKE CLE PROTEIN1 (FCP1), FLORAL ORGAN NUMBER 2 (FON2), and hormone pathway genes, such as cytokinin (CK) ISOPENTEYLTRANSFERASE1 (OsIPT1), ISOPENTEYLTRANSFERASE 8 (OsIPT8), auxin biosynthesis OsYUCCA6, OsYUCCA7 and gibberellic acid (GA) biosynthesis genes, such as GRAIN NUMBER PER PANICLE1 (GNP1/OsGA20OX1) and SHORTENED BASAL INTERNODE (SBI/OsGA2ox4). The effects on ABBERANT PANICLE ORGANIZATION1 (APO1), OsMADS16, and DROOPING LEAF (DL) relate to the second and third whorl floret phenotypes in OsbZIP47KD. Protein interaction assays showed OsbZIP47 partnerships with RICE HOMEOBOX1 (OSH1), RICE FLORICULA/LEAFY (RFL), and OsMADS1 transcription factors. The meta-analysis of KD panicle transcriptomes in OsbZIP47KD, OsMADS1KD, and RFLKD transgenics, combined with global OSH1 binding sites divulge potential targets coregulated by OsbZIP47, OsMADS1, OSH1, and RFL. Further, we demonstrate that OsbZIP47 redox status affects its DNA binding affinity to a cis element in FCP1, a target locus. Taken together, we provide insights on OsbZIP47 roles in SAM development, inflorescence branching, and floret development.
PMID: 35498659
Front Plant Sci , IF:5.753 , 2022 , V13 : P853435 doi: 10.3389/fpls.2022.853435
Dual Roles of OsGH3.2 in Modulating Rice Root Morphology and Affecting Arbuscular Mycorrhizal Symbiosis.
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
Several angiosperm GRETCHEN HAGEN 3 (GH3) genes, including tomato SlGH3.4 and rice OsGH3.2 are induced during arbuscular mycorrhizal (AM) symbiosis, but their functions remain largely unclear. Recently, tomato SlGH3.4 was suggested to negatively regulate arbuscule incidence via decreasing auxin levels in colonized cells. In this study, by acquiring rice OsGH3.2pro:beta-glucuronidase (GUS) transgenic plants and generating Osgh3.2 mutants via CRISPR/Cas9 technique, the roles of OsGH3.2 in modulating rice root morphology and affecting AM symbiosis were investigated through time course experiments. Unlike SlGH3.4, OsGH3.2 showed asymbiotic expression in rice young lateral roots, and its mutation resulted in a "shallow" root architecture. Such root morphological change was also observed under symbiotic condition and it likely promoted AM fungal colonization, as the mutants exhibited higher colonization levels and arbuscule incidence than wild-type at early stages. Similar to SlGH3.4, OsGH3.2 showed symbiotic expression in cortical cells that have formed mature arbuscules. At late stages of symbiosis, Osgh3.2 mutants showed elongated cortical cells and larger arbuscules than wild-type, indicating elevated auxin level in the colonized cells. Together, these results revealed both asymbiotic and symbiotic roles of OsGH3.2 in modulating rice root architecture and controlling auxin levels in arbusculated cells, which further affected colonization rate and arbuscule phenotype.
PMID: 35481141
Front Plant Sci , IF:5.753 , 2022 , V13 : P851939 doi: 10.3389/fpls.2022.851939
The Viral Threat in Cotton: How New and Emerging Technologies Accelerate Virus Identification and Virus Resistance Breeding.
Plant Molecular Virology Laboratory, Department of Virology, Microbiology Institute, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.; Programa de Pos-graduacao em Biotecnologia e Bioprocessos da UFRJ, Rio de Janeiro, Brazil.
Cotton (Gossypium spp. L., Malvaceae) is the world's largest source of natural fibers. Virus outbreaks are fast and economically devasting regarding cotton. Identifying new viruses is challenging as virus symptoms usually mimic nutrient deficiency, insect damage, and auxin herbicide injury. Traditional viral identification methods are costly and time-consuming. Developing new resistant cotton lines to face viral threats has been slow until the recent use of molecular virology, genomics, new breeding techniques (NBT), remote sensing, and artificial intelligence (AI). This perspective article demonstrates rapid, sensitive, and cheap technologies to identify viral diseases and propose their use for virus resistance breeding.
PMID: 35449884
Front Plant Sci , IF:5.753 , 2022 , V13 : P865778 doi: 10.3389/fpls.2022.865778
Uniconazole Augments Abscisic Acid in Promoting Somatic Embryogenesis in Cotton (Gossypium hirsutum L.).
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.; College of Plant Science and Technology of Huazhong Agricultural University, Wuhan, China.
During somatic embryogenesis (SE), somatic cells initiate embryogenic development under appropriate conditions. Uniconazole, a plant growth regulator, was found to inhibit the proliferation of callus but promoted the conversion of callus into an embryogenic callus (EC) in cotton. The supplementation of uniconazole in the culture medium significantly suppressed the endogenous auxin [indole acetic acid (IAA)] level in callus tissues in both the callus initiation and proliferation stage but enhanced the abscisic acid (ABA) level only in the callus proliferation stage. Exogenous ABA and uniconazole showed cooperative effects on promoting the differentiation rate of callus into EC. These findings were verified by RNA-seq analysis, which elucidated that the genes involved in the IAA biosynthesis, metabolism, and signaling, and ABA metabolism pathways were regulated by uniconazole during the callus development and SE. Overall, the results suggest that uniconazole could modulate callus proliferation and callus differentiation rate by regulating the endogenous levels of IAA and ABA.
PMID: 35444669
Genomics , IF:5.736 , 2022 Apr , V114 (3) : P110374 doi: 10.1016/j.ygeno.2022.110374
Transcriptome mining of genes in Zanthoxylum armatum revealed ZaMYB86 as a negative regulator of prickly development.
College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, Hubei, China.; School of Horticulture and Landscape, Wuhan University of Bioengineering, Wuhan, China.; College of Landscape Architecture and Life Science, Chongqing University of Arts and Sciences, Chongqing 402160, China; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing 400000, China.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, Hubei, China; Spice Crops Research Institute, Yangtze University, Jingzhou 434025, Hubei, China. Electronic address: wwzhangchn@163.com.; School of Modern Industry for Selenium Science and Engineering, National R&D Center for Se-rich Agricultural Products Processing Technology, Wuhan Polytechnic University, Wuhan 430023, Hubei, China.; School of Modern Industry for Selenium Science and Engineering, National R&D Center for Se-rich Agricultural Products Processing Technology, Wuhan Polytechnic University, Wuhan 430023, Hubei, China; National Selenium Rich Product Quality Supervision and Inspection Center, Enshi 445000, Hubei, China.; Sichuan Academy of Forestry, Chengdu 610081, Sichuan, China.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, Hubei, China. Electronic address: xufeng198@126.com.
Zanthoxylum armatum DC. is an important economic tree species. Prickle is a type of trichome with special morphology, and there are a lot of prickles on the leaves of Z. armatum, which seriously restricts the development of Z. armatum industry. In this study, the leaves of Z. armatum cv. Zhuye (ZY) and its budding variety 'Rongchangwuci' (WC) (A less prickly mutant variety) at different developmental stages were used as materials, and the transcriptome sequencing data were analyzed. A total of 96,931 differentially expressed genes (DEGs) were identified among the samples, among which 1560 were candidate DEGs that might be involved in hormone metabolism. The contents of JA, auxin and CK phytohormones in ZY leaves were significantly higher than those in WC leaves. Combined with weighted gene co-expression network analysis, eight genes (MYC, IAA, ARF, CRE/AHK, PP2C, ARR-A, AOS and LOX) were identified, including 25 transcripts, which might affect the metabolism of the three hormones and indirectly participate in the formation of prickles. Combining with the proteins successfully reported in other plants to regulate trichome formation, ZaMYB86, a transcription factor of R2R3 MYB family, was identified through local Blast and phylogenetic tree analysis, which might regulate prickle formation of Z. armatum. Overexpression of ZaMYB86 in mutant A. thaliana resulted in the reduction of trichomes in A. thaliana leaves, which further verified that ZaMYB86 was involved in the formation of pickles. Yeast two-hybrid results showed that ZaMYB86 interacted with ZaMYB5. Furthermore, ZaMYB5 was highly homologous to AtMYB5, a transcription factor that regulated trichomes development, in MYB DNA binding domain. Taken together, these results indicated that ZaMYB86 and ZaMYB5 act together to regulate the formation of prickles in Z. armatum. Our findings provided a new perspective for revealing the molecular mechanism of prickly formation.
PMID: 35489616
iScience , IF:5.458 , 2022 May , V25 (5) : P104298 doi: 10.1016/j.isci.2022.104298
MNSs-mediated N-glycan processing is essential for auxin homeostasis in Arabidopsis roots during alkaline response.
Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop and College of Resource and Environment, Fujian Agriculture and Forestry University, Jinshan, Fuzhou 350002, China.; Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
Early steps in the endoplasmic reticulum (ER) lumen and cis-Golgi comprise trimming of N-glycans by class I alpha-mannosidases (MNSs) play crucial roles in root growth and stress response. Herein, we found that the root growth inhibition in the mns1 mns2 mns3 mutant was partially rescued under alkaline condition, and inhibitor treatment to disrupt auxin transport counteracted this alkaline-maintained root growth. Further study showed that indole-3-acetic acid (IAA) levels were undetectable in mns1 mns2 mns3 at normal condition and recovered at alkaline condition, which corroborate our N-glycopeptide profiling, from which N-glycopeptides related with IAA biosynthesis, amino acid conjugates hydrolysis, and response showed differential abundance between normal and alkaline conditions in mns1 mns2 mns3. Overall, our results linked the need for MNSs-mediated N-glycan processing in the ER and cis-Golgi with maintenance of auxin homeostasis and transport in Arabidopsis roots during the response to alkaline stress.
PMID: 35602943
iScience , IF:5.458 , 2022 May , V25 (5) : P104238 doi: 10.1016/j.isci.2022.104238
Plasma membrane H(+)-ATPases promote TORC1 activation in plant suspension cells.
Molecular Physiology of the Cell, Universite Libre de Bruxelles (ULB), Biopark, B-6041 Gosselies, Belgium.; Louvain Institute of Biomolecular Science and Technology, UCLouvain, B-1348 Louvain-la-Neuve, Belgium.
The TORC1 (Target of Rapamycin Complex 1) kinase complex plays a pivotal role in controlling cell growth in probably all eukaryotic species. The signals and mechanisms regulating TORC1 have been intensely studied in mammals but those of fungi and plants are much less known. We have previously reported that the yeast plasma membrane H(+)-ATPase Pma1 promotes TORC1 activation when stimulated by cytosolic acidification or nutrient-uptake-coupled H(+) influx. Furthermore, a homologous plant H(+)-ATPase can substitute for yeast Pma1 to promote this H(+)-elicited TORC1 activation. We here report that TORC1 activity in Nicotiana tabacum BY-2 cells is also strongly influenced by the activity of plasma membrane H(+)-ATPases. In particular, stimulation of H(+)-ATPases by fusicoccin activates TORC1, and this response is also observed in cells transferred to a nutrient-free and auxin-free medium. Our results suggest that plant H(+)-ATPases, known to be regulated by practically all factors controlling cell growth, contribute to TOR signaling.
PMID: 35494253
Microbiol Res , IF:5.415 , 2022 May , V258 : P126976 doi: 10.1016/j.micres.2022.126976
Pythium oligandrum in plant protection and growth promotion: Secretion of hydrolytic enzymes, elicitors and tryptamine as auxin precursor.
Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic. Electronic address: katerina.belonoznikova@natur.cuni.cz.; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic. Electronic address: veronika.hyskova@natur.cuni.cz.; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic. Electronic address: josef.chmelik@natur.cuni.cz.; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic. Electronic address: daniel.kavan@natur.cuni.cz.; Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 313, 165 00 Praha 6, Czech Republic. Electronic address: cerovska@ueb.cas.cz.; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic. Electronic address: helena.ryslava@natur.cuni.cz.
Pythium is a genus of parasitic oomycetes which target plants and both nonvertebrate and vertebrate animals, including fish and mammalian species. However, several Pythium spp., such as P. oligandrum, function as mycoparasites of pathogenic fungi, bacteria, and oomycetes in soil and thus as advantageous biocontrol agents. This review primarily focuses on biochemical processes underlying their positive effects. For example, P. oligandrum degrades host cell wall polysaccharides using chitinases, cellulases, endo-beta-1,3-glucanases, and various exoglycosidases. Proteases from various classes also participate in the cell wall hydrolysis. All these processes can modify cell surface structures and help Pythium spp. compete for space and nutrition. Accordingly, enzyme secretion most likely plays a key role in plant root colonisation. Plant-P. oligandrum interactions, nevertheless, do not involve tissue injury but instead activate plant defence mechanisms, thereby strengthening future plant responses to pathogen attacks. Priming induces the phenylpropanoid and terpenoid pathways and thus synthesis of secondary metabolites, including lignin, for cell wall fortification and other metabolic adjustments. Such metabolic changes are mediated by elicitins, cell wall glycoproteins and oligandrins produced by P. oligandrum. As homologous proteins of beta-cinnamomin from Phytophthora cinnamomi with similar essential amino acids for sterol binding, oligandrins stand out for their structure, which they share with cell wall glycoproteins, albeit without the Ser-Thr-rich O-glycosylated domain for cell wall attachment. P. oligandrum also provides plant with tryptamine used for auxin synthesis, promoting plant growth. Overall, in addition to discussing plant metabolic and phytohormonal changes after P. oligandrum inoculation, we review data on P. oligandrum applications as researchers increasingly search for effective and environmentally friendly ways to protect crops. In this context, P. oligandrum emerges as a highly suitable biotechnological solution.
PMID: 35158298
Nanomaterials (Basel) , IF:5.076 , 2022 Apr , V12 (8) doi: 10.3390/nano12081341
Triiron Tetrairon Phosphate (Fe7(PO4)6) Nanomaterials Enhanced Flavonoid Accumulation in Tomato Fruits.
School of Environment and Civil Engineering, Institute of Environmental Processes and Pollution Control, Jiangnan University, Wuxi 214122, China.; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Wuxi 214122, China.; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA.
Flavonoids contribute to fruit sensorial and nutritional quality. They are also highly beneficial for human health and can effectively prevent several chronic diseases. There is increasing interest in developing alternative food sources rich in flavonoids, and nano-enabled agriculture provides the prospect for solving this action. In this study, triiron tetrairon phosphate (Fe7(PO4)6) nanomaterials (NMs) were synthesized and amended in soils to enhance flavonoids accumulation in tomato fruits. 50 mg kg(-1) of Fe7(PO4)6 NMs was the optimal dose based on its outstanding performance on promoting tomato fruit flavonoids accumulation. After entering tomato roots, Fe7(PO4)6 NMs promoted auxin (IAA) level by 70.75 and 164.21% over Fe-EDTA and control, and then up-regulated the expression of genes related to PM H(+) ATPase, leading to root proton ef-flux at 5.87 pmol cm(-2) s(-1) and rhizosphere acidification. More Mg, Fe, and Mn were thus taken up into plants. Subsequently, photosynthate was synthesized, and transported into fruits more rapidly to increase flavonoid synthesis potential. The metabolomic and transcriptomic profile in fruits further revealed that Fe7(PO4)6 NMs regulated sucrose metabolism, shi-kimic acid pathway, phenylalanine synthesis, and finally enhanced flavonoid biosynthesis. This study implies the potential of NMs to improve fruit quality by enhancing flavonoids synthesis and accumulation.
PMID: 35458049
Plant Cell Physiol , IF:4.927 , 2022 May doi: 10.1093/pcp/pcac069
Seed Dormancy and Longevity: A Mutual Dependence or a Trade-Off?
School of Environment and Ecology, Northwestern Polytechnical University, Xi'an 710129, China.; Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, 518057, China.
Seed dormancy is an important agronomic trait in cereals and leguminous crops as low levels of seed dormancy during harvest season, coupled with high humidity, can cause pre-harvest sprouting. Seed longevity is another critical trait for commercial crop propagation and production, directly influencing seed germination and early seedling establishment. Both traits are precisely regulated by the integration of genetic and environmental cues. Despite the significance of these two traits in crop production, the relationship between them at the molecular level is still elusive, even with contradictory conclusions being reported. Some studies have proposed a positive correlation between seed dormancy and longevity in association with differences in seed coat permeability or seed reserve accumulation, whereas an increasing number of studies have highlighted a negative relationship, largely with respect to phytohormone-dependent pathways. In this review paper, we try to provide some insights into the interactions between regulatory mechanisms of genetic and environmental cues which result in positive or negative relationships between seed dormancy and longevity. Finally, we conclude that further dissection of the molecular mechanism responsible for this apparently contradictory relationship between them is needed.
PMID: 35594901
Plant Cell Physiol , IF:4.927 , 2022 Apr doi: 10.1093/pcp/pcac055
SMAX1 Integrates Karrikin and Light Signals into GA-Mediated Hypocotyl Growth during Seedling Establishment.
Department of Chemistry, Seoul National University, Seoul 08826, Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.; Lead Contact.
Morphogenic adaptation of young seedlings to light environments is a critical developmental process that ensures plant survival and propagation, as they emerge from the soil. Photomorphogenic responses are facilitated by a network of light and growth hormonal signals, such as auxin and gibberellic acid (GA). Karrikins (KARs), a group of butenolide compounds that is produced from burning plant materials in wildfires, are known to stimulate seed germination in fire-prone plant species. Notably, recent studies support that they also regulate seedling growth, while underlying molecular mechanisms have been unexplored yet. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), a negative regulator of KAR signaling, integrates light and KAR signals into GA-DELLA pathways that regulate hypocotyl growth during seedling establishment. We found that SMAX1 facilitates degradation of DELLA proteins in the hypocotyls. Interestingly, light induces accumulation of SMAX1 proteins, and SMAX1-mediated degradation of DELLA is elevated in seedling establishment during the dark-to-light transition. Our observations indicate that SMAX1-mediated integration of light and KAR signals into GA pathways elaborately modulates seedling establishment.
PMID: 35477800
Plant Cell Physiol , IF:4.927 , 2022 May , V63 (5) : P618-634 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, Universite de Strasbourg, 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 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 Sci , IF:4.729 , 2022 May , V318 : P111238 doi: 10.1016/j.plantsci.2022.111238
Glutamate: A multifunctional amino acid in plants.
Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan. Electronic address: ming@gate.sinica.edu.tw.
Glutamate (Glu) is a versatile metabolite and a signaling molecule in plants. Glu biosynthesis is associated with the primary nitrogen assimilation pathway. The conversion between Glu and 2-oxoglutarate connects Glu metabolism to the tricarboxylic acid cycle, carbon metabolism, and energy production. Glu is the predominant amino donor for transamination reactions in the cell. In addition to protein synthesis, Glu is a building block for tetrapyrroles, glutathione, and folate. Glu is the precursor of gamma-aminobutyric acid that plays an important role in balancing carbon/nitrogen metabolism and various cellular processes. Glu can conjugate to the major auxin indole 3-acetic acid (IAA), and IAA-Glu is destined for oxidative degradation. Glu also conjugates with isochorismate for the production of salicylic acid. Accumulating evidence indicates that Glu functions as a signaling molecule to regulate plant growth, development, and defense responses. The ligand-gated Glu receptor-like proteins (GLRs) mediate some of these responses. However, many of the Glu signaling events are GLR-independent. The receptor perceiving extracellular Glu as a danger signal is still unknown. In addition to GLRs, Glu may act on receptor-like kinases or receptor-like proteins to trigger immune responses. Glu metabolism and Glu signaling may entwine to regulate growth, development, and defense responses in plants.
PMID: 35351313
Plant Sci , IF:4.729 , 2022 May , V318 : P111221 doi: 10.1016/j.plantsci.2022.111221
Maize GSK3-like kinase ZmSK2 is involved in embryonic development.
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, 100193, Beijing, China.; State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, 100193, Beijing, China. Electronic address: zhaoqian@cau.edu.cn.
Grain size and weight are closely related to the yield of cereal crops. Abnormal development of the embryo, an important part of the grain, not only affects crop yield but also impacts next-generation survival. Here, we found that maize GSK3-like kinase ZmSK2, a homolog of BIN2 in Arabidopsis, is involved in embryonic development. ZmSK2 overexpression resulted in severe BR defective phenotypes and arrested embryonic development at the transition stage, while the zmsk2 knockout lines showed enlarged embryos. ZmSK2 interacts with Aux/IAA-transcription factor 28 (ZmIAA28), a negative regulator of auxin signaling, and the interaction region is the auxin degron "GWPPV" motif of ZmIAA28 domain II. Coexpression of ZmSK2 with ZmIAA28 increased the accumulation of ZmIAA28 in maize protoplasts, which may have been due to phosphorylation by ZmSK2. In conclusion, this study reveals the function of ZmSK2 in maize embryonic development and proposes that ZmSK2-ZmIAA28 may be another link in the signaling pathway that integrates BR and auxin.
PMID: 35351312
Plant Sci , IF:4.729 , 2022 May , V318 : P111220 doi: 10.1016/j.plantsci.2022.111220
Transcriptome analysis reveals that cytokinins inhibit adventitious root formation through the MdRR12-MdCRF8 module in apple rootstock.
College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: keli505@163.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 2826267803@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 2987827737@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 3361604145@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 835734450@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 794700190@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: 2654669505@qq.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: mjp588@163.com.; College of Horticulture, Yangling Sub-Center of National Center for Apple Improvement, Northwest A&F University, Yangling 712100, Shannxi, P.R. China. Electronic address: afant@nwsuaf.edu.cn.
Adventitious root (AR) formation is great significance for apple rootstock breeding. Transcriptome analyses were performed with cytokinins (CTKs) signal treatments to analyze the mechanism of AR formation. The results showed that 6-benzyadenine (6-BA) treatment inhibited AR formation. Histological analysis also observed that AR primordium cell formation was significantly suppressed by 6-BA treatment; the ratio of auxin/cytokinins exhibited the lowest values at 1 and 3 day (d) in the 6-BA treatment group. Furthermore, the differentially expressed genes were divided into five categories, including auxin, cytokinins, other hormones, cell cycle, and carbohydrate metabolism pathways. Due to the study of cytokinins signal treatment, it is important to understand the particular module mediated by the cytokinins pathway. The expression level of MdRR12 (a family member of B-type cytokinins-responsive factors) was significantly upregulated at 3 d by 6-BA treatment. Compared to the wild type, the 35S::MdRR12 transgenic tobaccos suppressed AR formation. The promoter sequence of MdCRF8 contains AGATT motif elements that respond to MdRR12. RNA-seq and RT-qPCR assays predicted cytokinins response factor (MdCRF8) to be a downstream gene regulated by MdRR12. The activity of the pro-MdCRF8-GUS promoter was obviously induced by 6-BA treatment and inhibited by lovastatin (Lov) treatment. Yeast one-hybrid, dual-luciferase reporter, and GUS coexpression assays revealed that MdRR12 could directly bind to the MdCRF8 promoter. Additionally, 35S::MdCRF8 transgenic tobaccos also blocked AR growth. Compared to the wild type, 35S::MdRR12 and 35S::MdCRF8 transgenic tobaccos enhanced sensitivity to cytokinins. Thus, we describe that MdRR12 and MdCRF8 function as integrators of cytokinins signals that affect cell cycle- and carbohydrate metabolism-related genes to regulate cell fate transition during AR formation. On the basis of these results, we concluded that the MdRR12-MdCRF8 module is involved in the negative regulation of AR formation in apple rootstock and can potentially be applied in agriculture using genetic approaches.
PMID: 35351311
Plant Sci , IF:4.729 , 2022 May , V318 : P111219 doi: 10.1016/j.plantsci.2022.111219
Hydrogen sulfide inhibits the abscission of tomato pedicel through reconstruction of a basipetal auxin gradient.
School of Life Science, Shanxi University, Taiyuan 030006, China; Shanxi Key Laboratory for Research and Development of Regional Plants, Taiyuan 030006, China.; School of Life Science, Shanxi University, Taiyuan 030006, China; Shanxi Key Laboratory for Research and Development of Regional Plants, Taiyuan 030006, China. Electronic address: peiyanxi@sxu.edu.cn.
Abscission is an important developmental process and an essential agricultural trait. Auxin and ethylene are two phytohormones with important roles in the complex, but still elusive signaling network of abscission. Here, we found that hydrogen sulfide (H2S), a newly identified gasotransmitter, inhibits the initiation of tomato pedicel abscission. The underlying mechanism was explored through transcriptome profile analysis in various pedicel tissues with or without H2S treatment in the early abscission stage. The data suggested that H2S strongly influences the global transcription of pedicel tissues, exerts differential expression regulation along the pedicel, and markedly influences both the auxin and ethylene signaling pathways. Computational analysis revealed that H2S reconstructs a basipetal auxin gradient along the pedicel at 4 h after treatment; this finding was further substantiated by the GUS-staining results of DR5::GUS pedicels. The inhibitory effect of H2S to the ethylene signaling pathway might be an indirect action. Moreover, the subtilisin-like proteinase family members involved in the release of peptide signal molecules are critical components of the abscission signaling network downstream of auxin and ethylene.
PMID: 35351302
Plant Cell Rep , IF:4.57 , 2022 May , V41 (5) : P1197-1208 doi: 10.1007/s00299-022-02849-y
MusaATAF2-like protein regulates shoot development and multiplication by inducing cytokinin hypersensitivity and flavonoid accumulation in banana plants.
Plant Cell Culture Technology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India.; Homi Bhabha National Institute, Mumbai, India.; Department of Biotechnology, University of Mumbai, Mumbai, India.; Plant Biotechnology and Secondary Metabolites Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India.; Plant Cell Culture Technology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India. trgana@barc.gov.in.; Homi Bhabha National Institute, Mumbai, India. trgana@barc.gov.in.
KEY MESSAGE: Senescence-associated transcription factor ATAF2 regulates cytokinin signalling and in vitro shoot multiplication in banana plants. MusaATAF2-like protein is a stress-related NAC transcription factor of banana. It regulates senescence in rooted banana plants. During the early stages of plant development under in vitro conditions, the presence of 6-benzylaminopurine leads to vigorous shoot multiplication. The major contributor to plant shoot multiplication is auxin to cytokinin ratio and their signalling components. The LC-MS analysis of transgenic banana plants overexpressing MusaATAF2 indicated significantly higher cytokinin content and remarkably lower auxin content. Auxin transport has been reported to be inhibited by flavonoids. Their significantly higher abundance in the shoot tissues in transgenic lines suggested potential negative regulation of auxin signalling in transgenic plants. Enhanced shoot multiplication in transgenic lines was further corroborated by reduced transcript abundance of type-A Arabidopsis response regulator-like genes (inhibitors of cytokinin signalling pathway) and higher expression of Arabidopsis histidine kinase-like genes and type-B Arabidopsis response regulator-like genes (positive regulators of cytokinin signalling pathway) in transgenic lines. Altogether, the data concludes that MusaATAF2 induces cytokinin hypersensitivity in banana shoots by modulating/regulating the cytokinin signalling components and flavonoids content.
PMID: 35244754
Plant Cell Rep , IF:4.57 , 2022 May , V41 (5) : P1171-1180 doi: 10.1007/s00299-021-02807-0
Molecular mechanisms of maize endosperm transfer cell development.
School of Life Sciences, Anqing Normal University, Anqing, 246133, Anhui, China. zhengyankun1985@163.com.
Endosperm transfer cells function as the nutrient transporter, antimicrobic barrier, and signal mediator between filial and maternal tissues. Sugar supply of maternal tissues, sugar demand of filial tissues, and requirement for defence against pathogens are three elemental factors inducing differentiation of endosperm transfer cells. Epigenetic factors, especially MEG1, moderate the key genetic factor ZmMRP-1 to activate endosperm transfer cell-specific genes that control the flange wall ingrowth formation and defensin-like protein secretion in maize. Auxin and cytokinin are primary hormones involved in development of maize endosperm transfer cells. Crosstalk between glucose and hormone signaling regulates endosperm transfer cell development via modifying ZmMRP-1 expression. This review summarizes the current knowledge on maize endosperm transfer cell development, and discusses its potential molecular mechanisms. It is expected to strengthen the theoretical basis for structural and functional optimization of endosperm transfer cells, and yield improvement of kernels in maize.
PMID: 34689216
Physiol Plant , IF:4.5 , 2022 May : Pe13714 doi: 10.1111/ppl.13714
Auxin response factors in plant adaptation to drought and salinity stress.
College of Horticulture and Forestry Thunag, Dr. Y. S. Parmar University of Horticulture and Forestry Nauni-173 230, Solan, India.; University Institute of Biotechnology, Chandigarh University, Mohali, India.; School of Life Sciences, Jaipur National University, Jaipur, Rajasthan, India.; Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Salinity and drought stresses affect plant growth worldwide and limit crop production. Auxin is crucial in regulating plants' salinity and drought stress adaptative response. As a chemical messenger, auxin influences gene expression through a family of functionally distinct transcription factors, the DNA-binding AUXIN RESPONSE FACTORS (ARFs). Various studies have revealed the important roles of ARFs in regulating drought and salinity stress responses in plants. Different ARFs regulate soluble sugar content, promote root development and maintain chlorophyll content under drought and saline stress conditions to help plants adapt to these stresses. The functional characterization of ARFs pertaining to the regulation of drought and salinity stress responses is still in its infancy. Interestingly, the small RNA-mediated post-transcriptional regulation of ARF expression has been shown to influence plant responses to both stresses. The current knowledge on the diverse roles of ARFs in conferring specificity to auxin-mediated drought and salinity stress responses has not been reviewed to date. In this review, we summarize the recent research concerning the role of ARFs in response to drought and salinity stresses: gene expression patterns, functional characterization and post-transcriptional regulation under drought and salinity stresses. We have also reviewed the modulation of ARF expression by other molecular regulators in the context of drought and salt stress signalling.
PMID: 35560231
Sci Rep , IF:4.379 , 2022 May , V12 (1) : P7951 doi: 10.1038/s41598-022-12026-6
Bacillus velezensis strain B26 modulates the inflorescence and root architecture of Brachypodium distachyon via hormone homeostasis.
Department of Plant Science, Macdonald Campus of McGill University, 21,111 Lakeshore Rd., Ste-Anne de Bellevue, QC, H9X 3V9, Canada.; Department of Plant Science, Macdonald Campus of McGill University, 21,111 Lakeshore Rd., Ste-Anne de Bellevue, QC, H9X 3V9, Canada. suha.jabaji@mcgill.ca.
Plant growth-promoting rhizobacteria (PGPR) influence plant health. However, the genotypic variations in host organisms affect their response to PGPR. To understand the genotypic effect, we screened four diverse B. distachyon genotypes at varying growth stages for their ability to be colonized by B. velezensis strain B26. We reasoned that B26 may have an impact on the phenological growth stages of B. distachyon genotypes. Phenotypic data suggested the role of B26 in increasing the number of awns and root weight in wild type genotypes and overexpressing transgenic lines. Thus, we characterized the expression patterns of flowering pathway genes in inoculated plants and found that strain B26 modulates the transcript abundance of flowering genes. An increased root volume of inoculated plants was estimated by CT-scanning which suggests the role of B26 in altering the root architecture. B26 also modulated plant hormone homeostasis. A differential response was observed in the transcript abundance of auxin and gibberellins biosynthesis genes in inoculated roots. Our results reveal that B. distachyon plant genotype is an essential determinant of whether a PGPR provides benefit or harm to the host and shed new insight into the involvement of B. velezensis in the expression of flowering genes.
PMID: 35562386
Sci Rep , IF:4.379 , 2022 May , V12 (1) : P7609 doi: 10.1038/s41598-022-11801-9
Integrated transcriptome and endogenous hormone analysis provides new insights into callus proliferation in Osmanthus fragrans.
Key Laboratory of Landscape Architecture, Nanjing Forestry University, Nanjing, Jiangsu, China.; College of Landscape Architecture, Nanjing Forestry University, Nanjing, China.; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.; Key Laboratory of Landscape Architecture, Nanjing Forestry University, Nanjing, Jiangsu, China. yueyuanzheng@njfu.edu.cn.; College of Landscape Architecture, Nanjing Forestry University, Nanjing, China. yueyuanzheng@njfu.edu.cn.; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China. yueyuanzheng@njfu.edu.cn.; Key Laboratory of Landscape Architecture, Nanjing Forestry University, Nanjing, Jiangsu, China. wlg@njfu.com.cn.; College of Landscape Architecture, Nanjing Forestry University, Nanjing, China. wlg@njfu.com.cn.; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China. wlg@njfu.com.cn.
Osmanthus fragrans is an important evergreen species with both medicinal and ornamental value in China. Given the low efficiency of callus proliferation and the difficulty of adventitious bud differentiation, tissue culture and regeneration systems have not been successfully established for this species. To understand the mechanism of callus proliferation, transcriptome sequencing and endogenous hormone content determination were performed from the initial growth stages to the early stages of senescence on O. fragrans calli. In total, 47,340 genes were identified by transcriptome sequencing, including 1798 previously unidentified genes specifically involved in callus development. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of differentially expressed genes (DEGs) was significantly enriched in plant hormone signal transduction pathways. Furthermore, our results from the orthogonal projections to latent structures discrimination analysis (OPLS-DA) of six typical hormones in five development stages of O. fragrans calli showed jasmonic acid (JA) could play important role in the initial stages of calli growth, whereas JA and auxin (IAA) were dominant in the early stages of calli senescence. Based on the weighted gene co-expression network analysis, OfSRC2, OfPP2CD5 and OfARR1, OfPYL3, OfEIL3b were selected as hub genes from the modules with the significant relevance to JA and IAA respectively. The gene regulation network and quantitative real-time PCR implied that during the initial stages of callus growth, the transcription factors (TFs) OfERF4 and OfMYC2a could down-regulate the expression of hub genes OfSRC2 and OfPP2CD5, resulting in decreased JA content and rapid callus growth; during the late stage of callus growth, the TFs OfERF4, OfMYC2a and OfTGA21c, OfHSFA1 could positively regulate the expression of hub genes OfSRC2, OfPP2CD5 and OfARR1, OfPYL3, OfEIL3b, respectively, leading to increased JA and IAA contents and inducing the senescence of O. fragrans calli. Hopefully, our results could provide new insights into the molecular mechanism of the proliferation of O. fragrans calli.
PMID: 35534621
Sci Rep , IF:4.379 , 2022 May , V12 (1) : P7481 doi: 10.1038/s41598-022-11689-5
Bioinformatic approach for the discovery of cis-eQTL signals during fruit ripening of a woody species as grape (Vitis vinifera L.).
Department of Plant Breeding, Centro de Edafologia y Biologia Aplicada del Segura (CEBAS), CSIC, P.O. Box 164, 30100, Espinardo, Spain. pjmartinez@cebas.csic.es.; Department of Plant Breeding, Centro de Edafologia y Biologia Aplicada del Segura (CEBAS), CSIC, P.O. Box 164, 30100, Espinardo, Spain.; Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA.; Department of Neurodegenerative Disease, University College London, London, WC1N 3BG, UK.; Departamento de Ingenieria de la Informacion y las Comunicaciones, Universidad de Murcia, 30100, Murcia, Spain.
Expression quantitative trait loci (eQTLs) are associations between genetic variants, such as Single Nucleotide Polymorphisms (SNPs), and gene expression. eQTLs are an important tool to understand the genetic variance of gene expression of complex phenotypes. eQTLs analyses are common in biomedical models but are scarce in woody crop species such as fruit trees or grapes. In this study, a comprehensive bioinformatic analysis was conducted leveraging with expression data from two different growth stages, around ripening onset, of 10 genotypes of grape (Vitis vinifera L.). A total of 2170 cis-eQTL were identified in 212 gene modulated at ripening onset. The 48% of these DEGs have a known function. Among the annotated protein-coding genes, terpene synthase, auxin-regulatory factors, GRFS, ANK_REP_REGION domain-containing protein, Kinesin motor domain-containing protein and flavonol synthase were noted. This new inventory of cis-eQTLs influencing gene expression during fruit ripening will be an important resource to examine variation for this trait and will help to elucidate the complex genetic architecture underlying this process in grape.
PMID: 35523985
Sci Rep , IF:4.379 , 2022 Apr , V12 (1) : P6947 doi: 10.1038/s41598-022-10458-8
An Arabidopsis mutant deficient in phosphatidylinositol-4-phosphate kinases ss1 and ss2 displays altered auxin-related responses in roots.
Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic.; University of Chemistry and Technology, Technicka 5, 16628, Prague, Czech Republic.; Sorbonne Universite, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), 75005, Paris, France.; Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. kalachova@ueb.cas.cz.; Universite de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France.; Universite Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France.; Universite de Technologie de Compiegne, Enzyme and Cell Engineering Laboratory, CNRS, 60203, Compiegne, France.
Phosphatidylinositol 4-kinases (PI4Ks) are the first enzymes that commit phosphatidylinositol into the phosphoinositide pathway. Here, we show that Arabidopsis thaliana seedlings deficient in PI4Kbeta1 and beta2 have several developmental defects including shorter roots and unfinished cytokinesis. The pi4kbeta1beta2 double mutant was insensitive to exogenous auxin concerning inhibition of root length and cell elongation; it also responded more slowly to gravistimulation. The pi4kss1ss2 root transcriptome displayed some similarities to a wild type plant response to auxin. Yet, not all the genes displayed such a constitutive auxin-like response. Besides, most assessed genes did not respond to exogenous auxin. This is consistent with data with the transcriptional reporter DR5-GUS. The content of bioactive auxin in the pi4kss1ss2 roots was similar to that in wild-type ones. Yet, an enhanced auxin-conjugating activity was detected and the auxin level reporter DII-VENUS did not respond to exogenous auxin in pi4kss1ss2 mutant. The mutant exhibited altered subcellular trafficking behavior including the trapping of PIN-FORMED 2 protein in rapidly moving vesicles. Bigger and less fragmented vacuoles were observed in pi4kss1ss2 roots when compared to the wild type. Furthermore, the actin filament web of the pi4kss1ss2 double mutant was less dense than in wild-type seedling roots, and less prone to rebuilding after treatment with latrunculin B. A mechanistic model is proposed in which an altered PI4K activity leads to actin filament disorganization, changes in vesicle trafficking, and altered auxin homeostasis and response resulting in a pleiotropic root phenotypes.
PMID: 35484296
Plant Physiol Biochem , IF:4.27 , 2022 May , V183 : P46-55 doi: 10.1016/j.plaphy.2022.05.003
Probing into the unique relationship between a soil bacterium, Pseudomonas putida AKMP7 and Arabidopsis thaliana: A case of "conditional pathogenesis".
Department of Biological Sciences, Birla Institute of Technology and Science (Pilani), Hyderabad Campus, India.; Department of Biological Sciences, Birla Institute of Technology and Science (Pilani), Hyderabad Campus, India. Electronic address: sridev.mohapatra@hyderabad.bits-pilani.ac.in.
Plant growth-promoting rhizobacteria (PGPR) are beneficial soil bacteria that colonise the rhizosphere and help plants in growth, development, and stress tolerance. While there is a significant body of research elucidating their benefits to plants, studies on the "abnormal" or "unexpected" behavior of these bacteria are almost non-existent. One such study from our laboratory has previously reported a unique situation in which a certain strain of drought and thermo-tolerant PGPR, namely, Pseudomonas putida AKMP7, becomes pathogenic towards Arabidopsis thaliana under drought conditions, but not under normal (well-watered) conditions. In this study, we have probed deeper into this phenomenon of "conditional pathogenesis". We found that, AKMP7 imparts an enhancement in plant growth under well-watered conditions, while, causing a deterioration in plant health under drought conditions. In an attempt to understand the underlying reasons for this phenomenon, we analysed the phytohormones released by Pseudomonas putida AKMP7 using LC-ESI-MS/MS technique. We identified that AKMP7 releases zeatin (a cytokinin), the auxin derivative -indole acetamide and amino acid-conjugates of auxin (indole-3-acetyl-L-alanine, indole-3-acetyl-L-phenylalanine and indole-3-acetyl-L-aspartate) in the growth medium. By treating the plants with commercially obtained forms of these phytohormones, individually or in combination with AKMP7, we identified that zeatin and auxin derivative indole acetamide can play a crucial role in the conditional pathogenesis exhibited by this bacterium on A. thaliana under drought conditions. Our work lays a foundation for further understanding the precise molecular mechanisms involved in this unique phenomenon of conditional/opportunistic pathogenesis.
PMID: 35567874
Plant Physiol Biochem , IF:4.27 , 2022 May , V179 : P179-190 doi: 10.1016/j.plaphy.2022.03.027
Identification of genes and metabolic pathways involved in wounding-induced kiwifruit ripening.
Laboratory of Pomology, Department of Horticulture, Aristotle University of Thessaloniki, Thessaloniki-Thermi, 57001, Greece.; Department of Biology, National and Kapodistrian University of Athens, GR-15784, Athens, Greece.; Institute of Plant Breeding and Genetic Resources, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece; Joint Laboratory of Horticulture, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece.; Joint Laboratory of Horticulture, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece; Institute of Soil and Water Resources, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece.; Institute of Plant Breeding and Genetic Resources, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece; Joint Laboratory of Horticulture, ELGO-DIMITRA, Thessaloniki-Thermi, 57001, Greece; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829, Cologne, Germany.; Laboratory of Pomology, Department of Horticulture, Aristotle University of Thessaloniki, Thessaloniki-Thermi, 57001, Greece. Electronic address: amolasio@agro.auth.gr.
Fruit is constantly challenged by wounding events, inducing accelerated ripening and irreversible metabolic changes. However, cognate mechanisms that regulate this process are little known. To expand our knowledge of ripening metabolism induced by wounding, an artificial-wound global transcriptome investigation combined with metabolite profiling study was conducted in postharvest kiwifruit (Actinidia chinensis var. deliciosa (A. Chev.) A. Chev. 'Hayward'). Wounding treatment promoted fruit ripening, as demonstrated by changes in fruit firmness, ethylene production and respiration activity determined periodically during a ripening period of 8 d at room temperature. Calcium imaging using fluorescent probe Fluo-3 AM revealed spatial dynamics of Ca(2+) signaling in the wounding area following 8d ripening. Several sugars including fructose, glucose, and sucrose as well as organic acids such as citric, succinic and galacturonic acid were increased by wounding. Changes of various amino acids in wounded-treated fruit, especially 5-oxoproline and valine along with alternations of soluble alcohols, like myo-inositol were detected. Gene expression analysis of the wounded fruit showed increased expression of genes that are mainly involved in defense response (e.g., AdTLP.1-3, AdPP2C.1-2, AdMALD1), calcium ion binding (e.g., AdCbEFh, AdCLR, AdANX), TCA cycle (e.g., AdMDH.1, AdMDH.2, AdCS), sugars (e.g., AdSUSA.1, AdSPS4, AdABFr), secondary metabolism (e.g., AdPAL.1-3, AdCCR, AdHCT.1-2), lipid processing (e.g., AdGELP.1-4, AdGELP) and pectin degradation (e.g., AdPE.1-2, AdPAE.1-2, AdPG.1-2) as well as in ethylene (AdERF7, AdERF1B, AdACO.1-4) and auxin (AdICE, AdAEFc, AdASII) synthesis and perception. Moreover, genes related to aquaporins, such as AdAQP2, AdAQP4 and AdAQP7 were down-regulated in fruit exposed to wounding. These results demonstrate multiple metabolic points of wounding regulatory control during kiwifruit ripening and provide insights into the molecular basis of wounding-mediated ripening.
PMID: 35358868
Plant Physiol Biochem , IF:4.27 , 2022 May , V179 : P78-89 doi: 10.1016/j.plaphy.2022.03.022
Ultrastructural and hormonal changes related to harmaline-induced treatment in Arabidopsis thaliana (L.) Heynh. root meristem.
Departamento de Bioloxia Vexetal e Ciencias do Solo, Facultade de Bioloxia, Universidade de Vigo, Campus Lagoas-Marcosende s/n, 36310, Vigo, Spain.; Dipartimento di Scienze Agrarie e Ambientali - Produzione, Territorio, Agroenergia, Universita Statale di Milano, Via Celoria n masculine2, 20133, Milano, Italy.; Departamento de Bioloxia Vexetal e Ciencias do Solo, Facultade de Bioloxia, Universidade de Vigo, Campus Lagoas-Marcosende s/n, 36310, Vigo, Spain. Electronic address: adela@uvigo.es.
Harmaline is an indole alkaloid with demonstrated phytotoxicity and recognized pharmacological applications. However, no information is available concerning its mode of action on plant metabolism. Therefore, the present work evaluated bioherbicide mode of action of harmaline on plant metabolism of Arabidopsis thaliana (L.) Heynh. Harmaline induced a strong inhibitory activity on root growth of treated seedlings, reaching IC50 and IC80 values of 14 and 29 muM, respectively. Treated roots were shorter and thicker than control and were characterized by a shorter root meristem size and an increase of root hairs production. Harmaline induced ultrastructural changes such as increment of cell wall thickness, higher density and condensation of mitochondria and vacuolization, appearance of cell wall deposits, increment of Golgi secretory activity and higher percentage of aberrant nuclei. The ethylene inhibitor AgNO3 reversed high root hair appearance and increment of root thickness, and pTCSn::GFP transgenic line showed fluorescence cytokinin signal in stele zone after harmaline treatment that was absent in control, whereas the auxin signal in the transgenic line DR5 was significantly reduced by the treatment. All these results suggest that the mode of action of harmaline could be involving auxin, ethylene and cytokinin synergic/antagonistic action.
PMID: 35325658
BMC Plant Biol , IF:4.215 , 2022 May , V22 (1) : P250 doi: 10.1186/s12870-022-03594-w
Combined use of specific length amplified fragment sequencing (SLAF-seq) and bulked segregant analysis (BSA) for rapid identification of genes influencing fiber content of hemp (Cannabis sativa L.).
Daqing Branch of Heilongjiang Academy of Sciences, Heilongjiang, China.; Daqing Branch of Heilongjiang Academy of Agricultural Sciences, Heilongjiang, China.; Daqing Branch of Heilongjiang Academy of Sciences, Heilongjiang, China. wxn_fern@163.com.
Hemp (Cannabis sativa L.), an ancient crop, is a significant source of high-quality fiber that primarily caters to the textile industry worldwide. Fiber content is a crucial quantitative trait for evaluating fiber yield in hemp. Understanding the genetic mechanisms involved in hemp breeding is essential for improving yield. In this study, we developed 660 F1 plants from a cross between Jindao-15 (high fiber content fiber-use variety) and Fire No.1 (low fiber content fiber-use variety), and thirty plants each with high and low fiber content were selected from 305 monoecious plants of this population according to 5%-10% of population size for quantitative traits. The DNA from these plants was extracted to establish two bulk DNA pools and then subjected to the restriction digestion by the enzymes RsaI and HaeIII to obtain 314-364 bp digestion fragments and subjected to sequencing using specific length amplified fragment sequencing (SLAF-seq). Finally, we successfully developed 368,404 SLAF tags, which led to the detection of 25,133 high-quality SNPs. Combing with the resequencing results of parents, the SNPs of mixed pools were then subjected to the SNP-Index correlation algorithm, which revealed four candidate regions related to fiber content traits on Chromosome 1, with a length of 8.68 Mb and containing 389 annotated genes. The annotation information and the comparison results identified 15 genes that were highly likely to modulate the fiber content of hemp. Further, qPCR validation identified six genes (LOC115705530, LOC115705875, LOC115704794, LOC115705371, LOC115705688 and LOC115707511) that were highly positively correlated with influencing the hemp fiber content. These genes were involved in the transcription regulation, auxin and water transportion, one carbon and sugar metabolism. And non-synnoumous mutation SNPs which may play vital role in influencing the fiber content were detected in LOC115705875, LOC115704794, LOC115705688 and LOC115707511. Thus, our study highlights the importance of the combined use of SLAF-Seq and Bulked Segregant analysis (BSA) to locate genes related to hemp fiber content rapidly. Hence, our study provides novel mechanistic inputs for the fast identification of genes related to important agronomic traits of hemp and other crops catering to the textile industry.
PMID: 35596150
BMC Plant Biol , IF:4.215 , 2022 Apr , V22 (1) : P208 doi: 10.1186/s12870-022-03591-z
Transcriptome analysis of the growth-promoting effect of volatile organic compounds produced by Microbacterium aurantiacum GX14001 on tobacco (Nicotiana benthamiana).
Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, 530008, China.; Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, 530008, China. mzxyjiang@163.com.
BACKGROUND: Plant growth-promoting rhizobacteria (PGPR) release volatile organic compounds (VOCs), which promote plant growth. RESULTS: A potential PGPR strain GX14001 was isolated from marine samples, and the VOCs produced by GX14001 significantly promoted tobacco (Nicotiana benthamiana) growth in a plate experiment. Based on 16S rRNA sequence alignment and physiological and biochemical characterization, GX14001 was identified as Microbacterium aurantiacum. Comparative transcriptome analysis was conducted between GX14001 VOCs-treated tobacco and the control; it was found that 1286 genes were upregulated and 1088 genes were downregulated. Gene ontology (GO) analysis showed that upregulated genes were involved in three biological processes: polysaccharide metabolic, polysaccharide catabolic and carbohydrate metabolic. The downregulated genes were involved in six biological processes, namely cell redox homeostasis, cellular homeostasis, carbohydrate metabolic process, homeostatic process, obsolete electron transport, and regulation of biological quality. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that 190 upregulated differentially expressed genes were mainly involved in plant hormone signal transduction, phenylpropyl biosynthesis, plant-pathogen interaction, and flavonoid biosynthesis. The 148 downregulated differentially expressed genes were mainly involved in plant hormone signal transduction and the metabolism of ascorbic, aldehyde, and pyruvate acids. Further analysis revealed that many genes were differentially expressed in the metabolic pathways of plant hormone signals, which were speculated to be the main reason why GX14001 VOCs promoted tobacco growth. To further study its regulatory mechanism, we found that GX14001 promoted plant growth through auxin, salicylic acid, and gibberellin in Arabidopsis mutant experiments. CONCLUSION: The VOCs produced by Microbacterium aurantiacum GX14001 may promote the growth of tobacco through the auxin, salicylic acid and gibberellin pathways.
PMID: 35448945
BMC Plant Biol , IF:4.215 , 2022 Apr , V22 (1) : P200 doi: 10.1186/s12870-022-03568-y
Exogenously applied spermidine alleviates hypoxia stress in Phyllostachys praecox seedlings via changes in endogenous hormones and gene expression.
State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. syzhuang@issas.ac.cn.
BACKGROUND: Hypoxia stress is thought to be one of the major abiotic stresses that inhibits the growth and development of higher plants. Phyllostachys pracecox is sensitive to oxygen and suffers soil hypoxia during cultivation; however, the corresponding solutions to mitigate this stress are still limited in practice. In this study, Spermidine (Spd) was tested for regulating the growth of P. praecox seedlings under the hypoxia stress with flooding. RESULTS: A batch experiment was carried out in seedlings treated with 1 mM and 2 mM Spd under flooding for eight days. Application of 1 mM and 2 mM Spd could alleviate plant growth inhibition and reduce oxidative damage from hypoxia stress. Exogenous Spd significantly (P < 0.05) increased proline, soluble protein content, catalase (CAT), superoxide dismutase (SOD), and S-adenosylmethionine decarboxylase (SAMDC) activity, enhanced abscisic acid (ABA) and indole-3-acetic acid (IAA) content, and reduced ethylene emission, hydrogen peroxide (H2O2), superoxide radical (O2(.-)) production rate, ACC oxidase (ACO) and ACC synthase (ACS) to protect membranes from lipid peroxidation under flooding. Moreover, exogenous Spd up-regulated the expression of auxin-related genes auxin responsive factor1 (ARF1), auxin1 protein (AUX1), auxin2 protein (AUX2), auxin3 protein (AUX3) and auxin4 protein (AUX4), and down-regulated the expression of ethylene-related ACO and ACS genes during flooding. CONCLUSION: The results indicated that exogenous Spd altered hormone concentrations and the expression of hormone-related genes, thereby protecting the bamboo growth under flooding. Our data suggest that Spd can be used to reduce hypoxia-induced cell damage and improve the adaptability of P. praecox to flooding stress.
PMID: 35439921
BMC Plant Biol , IF:4.215 , 2022 Apr , V22 (1) : P178 doi: 10.1186/s12870-022-03564-2
Genome-wide identification and expression of SAUR gene family in peanut (Arachis hypogaea L.) and functional identification of AhSAUR3 in drought tolerance.
Key Laboratory of Crop Genetic Improvement & Ecology and Physiology, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Ji'nan, 250100, Shandong Province, China.; Key Lab of Plant Stress Research, College of Life Sciences, Shandong Normal University, Ji'nan, 250014, Shandong Province, China.; Key Laboratory of Crop Genetic Improvement & Ecology and Physiology, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Ji'nan, 250100, Shandong Province, China. wanshubo2016@163.com.; Key Laboratory of Crop Genetic Improvement & Ecology and Physiology, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Ji'nan, 250100, Shandong Province, China. liguowei@sdnu.edu.cn.; Key Lab of Plant Stress Research, College of Life Sciences, Shandong Normal University, Ji'nan, 250014, Shandong Province, China. liguowei@sdnu.edu.cn.
BACKGROUND: Small auxin-upregulated RNAs (SAURs) gene family plays important roles in plant growth, development, and stress responses. However, the function of few SAUR genes is known in the peanut (Arachis hypogaea L.), one of the world's major food legume crops. This study aimed to perform a comprehensive identification of the SAUR gene family from the peanut genome. RESULTS: The genome-wide analysis revealed that a total of 162 SAUR genes were identified in the peanut genome. The phylogenetic analysis indicated that the SAUR proteins were classified into eight subfamilies. The SAUR gene family experienced a remarkable expansion after tetraploidization, which contributed to the tandem duplication events first occurring in subgenome A and then segmental duplication events occurring between A and B subgenomes. The expression profiles based on transcriptomic data showed that SAUR genes were dominantly expressed in the leaves, pistils, perianth, and peg tips, and were widely involved in tolerance against abiotic stresses. A total of 18 AhSAUR genes selected from different subfamilies randomly presented 4 major expression patterns according to their expression characteristics in response to indole-3-acetic acid. The members from the same subfamily showed a similar expression pattern. Furthermore, the functional analysis revealed that AhSAUR3 played a negative role in response to drought tolerance. CONCLUSIONS: This study provided insights into the evolution and function of the SAUR gene family and may serve as a resource for further functional research on AhSAUR genes.
PMID: 35387613
Tree Physiol , IF:4.196 , 2022 May , V42 (5) : P1059-1069 doi: 10.1093/treephys/tpab155
The mycorrhizal-induced growth promotion and insect resistance reduction in Populus alba x P. berolinensis seedlings: a multi-omics study.
Department of Forestry School of Forestry, Northeast Forestry University, 26 Hexing Road, Xiangfang District, Harbin 150040, P. R. China.; College of Forestry Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Xiangfang District, Harbin 150040, P. R. China.; Department of Economics College of Economics and Management, Northeast Forestry University, 26 Hexing Road, Xiangfang District, Harbin 150040, P. R.China.; Department of Landscape Architecture College of Landscape Architecture, Northeast Forestry University, 26 Hexing Road, Xiangfang District, Harbin 150040, P. R. China.
Arbuscular mycorrhizal (AM) fungi are an alternative to chemical insecticides or fertilizers, and there is an urgent need to extend the application of AM fungi to woody plants. This study aims to investigate the growth and resistance against the gypsy moth larvae (Lymantria dispar) in Glomus intraradices-colonized Populus alba x P. berolinensis seedlings, and to unravel the transcriptome and metabolome phenotypes recruited by AM fungus colonization that affect plant growth and insect resistance. Our results showed a positive mycorrhizal growth response, i.e., growth and biomass of mycorrhizal seedlings were enhanced. However, AM fungus inoculation reduced the resistance of poplar to gypsy moth larvae, as evidenced by the decreased carbon/nitrogen ratio in leaves, as well as the increased larval growth and shortened larval developmental duration. Transcriptome analysis revealed that in both auxin and gibberellin signaling transductions, all nodes were responsive to AM symbiosis and most differentially expressed genes belonging to effectors were up-regulated in mycorrhizal seedlings. Furthermore, the two key enzymes (4-coumarate-CoA ligase and trans-cinnamate 4-monooxygenase) involved in the synthesis of p-Coumaroyl-CoA, an initial metabolite in flavonoid biosynthesis and the first rate-limiting enzyme (chalcone synthase) in flavonoid biosynthesis, were down-regulated at the transcriptional level. Consistent with the transcriptome results, metabolome analysis found that the amounts of all differentially accumulated flavonoid compounds (e.g., catechin and quercetin) identified in mycorrhizal seedlings were decreased. Taken together, these findings highlight the diverse outcomes of AM fungi-host plant-insect interaction and reveal the regulatory network of the positive mycorrhizal growth response and mycorrhizal-induced reduction of insect resistance in poplar.
PMID: 35022794
Tree Physiol , IF:4.196 , 2022 May , V42 (5) : P971-988 doi: 10.1093/treephys/tpab165
Comparable and adaptable strategies to waterlogging stress regulated by adventitious roots between two contrasting species.
School of Ecological and Environmental Sciences, Hainan University, No. 58 Renmin Road, Meilan District, Haikou 570228, China.; Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, No. 58 Renmin Road, Meilan District, Haikou 570228, China.; School of Life Sciences, Hainan University, No. 58 Renmin Road, Meilan District, Haikou 570228, China.; School of Plant Protection, Hainan University, No. 58 Renmin Road, Meilan District, Haikou 570228, China.; Center for Eco-Environmental Restoration Engineering of Hainan Province, No. 58 Renmin Road, Meilan District, Haikou 570228, China.
Cleistocalyx operculatus and Syzygium cumini possess a certain waterlogging tolerance. However, the comparable and adaptable strategies to waterlogging stress between these two species on the basis of waterlogging adventitious root (AR) regulation were still unclear. In this study, the plant performance in response to AR regulation based on AR removal (AR-R) and exogenous hormone application was investigated in terms of plant morphology, physiology, photosynthesis and AR traits. Results showed that C. operculatus possesses stronger waterlogging tolerance than S. cumini based on waterlogging tolerance coefficient, which is mainly due to the higher root biomass, root porosity and length, and activity of ARs, and shorter emergence time of ARs in C. operculatus than in S. cumini. The AR-R treatment increased activity and porosity of primary root, and induced a large amount of up-vertical ARs from the primary root systems in C. operculatus, while similar adaptive morphological changes in roots did not occur in AR-R-treated S. cumini. Exogenous abscisic acid (ABA) application had better effects on alleviating waterlogging damages than exogenous auxin (IAA) in balancing endogenous hormones (ABA and zeatin riboside), promoting AR development (porosity and activity, and the ratio of cortex area to stele area), improving the photosynthesis process and the antioxidant system (soluble protein, free proline and peroxidase). Moreover, under waterlogging conditions, exogenous ABA application induced greater increases in net photosynthesis rate, stomatal conductance, chlorophyll b and carotenoid in S. cumini than in C. operculatus, which suggested that S. cumini responded more positively and efficiently to exogenous ABA application than C. operculatus under waterlogging conditions. Thus, the findings provided new insights into the waterlogging adaptable strategies in waterlogging tolerant woody species on the basis of ARs and could provide scientific guidance for the application of these two species during revegetation activities in wetlands. Cleistocalyx operculatus could alternatively form a majority of up-vertical adventitious roots (ARs) from the primary roots after removing the normal ARs, but Syzygium cumini could not.Cleistocalyx operculatus possessed positive strategies to waterlogging stress, while S. cumini used traditional passive strategies.Exogenous abscisic acid (ABA) application had better effects on alleviating waterlogging damages in both species than exogenous auxin application.Syzygium cumini could more positively and efficiently respond to exogenous ABA application than C. operculatus.Waterlogging tolerance coefficient was significantly controlled by the chlorophyll contents and AR factors in C. operculatus and the AR factors and O2- in S. cumini.The best development of the AR number (ARN) and AR length (ARL) in exogenous ABA-treated C. operculatus may be closely related with positive zeatin riboside accumulation.The development of ARN and ARL was more important to waterlogging tolerance than that of AR porosity under waterlogging conditions.
PMID: 34875093
Microorganisms , IF:4.128 , 2022 Apr , V10 (5) doi: 10.3390/microorganisms10050935
The Effects of Rhizosphere Inoculation with Pseudomonas mandelii on Formation of Apoplast Barriers, HvPIP2 Aquaporins and Hydraulic Conductance of Barley.
Ufa Institute of Biology, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya, 69, 450054 Ufa, Russia.; Institute of Biochemistry and Genetics, Ufa Federal Research Center, Russian Academy of Sciences, 450054 Ufa, Russia.
Pseudomonas mandelii strain IB-Ki14 has recently been shown to strengthen the apoplastic barriers of salt-stressed plants, which prevents the entry of toxic sodium. It was of interest to find out whether the same effect manifests itself in the absence of salinity and how this affects the hydraulic conductivity of barley plants. Berberine staining confirmed that the bacterial treatment enhanced the deposition of lignin and suberin and formation of Casparian bands in the roots of barley plants. The calculation of hydraulic conductance by relating transpiration to leaf water potential showed that it did not decrease in bacteria-treated plants. We hypothesized that reduced apoplastic conductivity could be compensated by the higher conductivity of the water pathway across the membranes. This assumption was confirmed by the results of the immunolocalization of HvPIP2;5 aquaporins with specific antibodies, showing their increased abundance around the areas of the endodermis and exodermis of bacteria-treated plants. The immunolocalization with antibodies against auxins and abscisic acid revealed elevated levels of these hormones in the roots of plants treated with bacteria. This root accumulation of hormones is likely to be associated with the ability of Pseudomonas mandelii IB-Ki14 to synthesize these hormones. The involvement of abscisic acid in the control of aquaporin abundance and auxins-in the regulation of and formation of apoplast barriers-is discussed.
PMID: 35630379
Microorganisms , IF:4.128 , 2022 Apr , V10 (5) doi: 10.3390/microorganisms10050867
Synergistic Plant-Microbe Interactions between Endophytic Actinobacteria and Their Role in Plant Growth Promotion and Biological Control of Cotton under Salt Stress.
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.; Department of Biological, Marine Sciences and Environmental Agriculture, Institute for Post Graduate Environmental Studies, Arish University, Al-Arish 45511, Egypt.; Department of Environmental Protection, Faculty of Environmental Agricultural Sciences, Arish University, Al-Arish 45511, Egypt.; Heilongjiang Academy of Black Soil Conservation & Utilization, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China.; Department of Industrial Biotechnology, Genetic Engineering and Biotechnology Research Institute (GEBRI), University of Sadat City, Sadat City 32897, Egypt.; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.; State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Bacterial endophytes are well-acknowledged inoculants to promote plant growth and enhance their resistance toward various pathogens and environmental stresses. In the present study, 71 endophytic strains associated with the medicinal plant Thymus roseus were screened for their plant growth promotion (PGP), and the applicability of potent strains as bioinoculant has been evaluated. Regarding PGP traits, the percentage of strains were positive for the siderophore production (84%), auxin synthesis (69%), diazotrophs (76%), phosphate solubilization (79%), and production of lytic enzymes (i.e., cellulase (64%), lipase (62%), protease (61%), chitinase (34%), and displayed antagonistic activity against Verticillium dahliae (74%) in vitro. The inoculation of strain XIEG05 and XIEG12 enhanced plant tolerance to salt stress significantly (p < 0.05) through the promotion of shoot, root development, and reduced the activities of antioxidant enzymes (SOD, POD, and CAT), compared with uninoculated controls in vivo. Furthermore, inoculation of strain XIEG57 was capable of reducing cotton disease incidence (DI) symptoms caused by V. dahliae at all tested salt concentrations. The GC-MS analysis showed that many compounds are known to have antimicrobial and antifungal activity. Our findings provide valuable information for applying strains XIEG05 and XIEG12 as bioinoculant fertilizers and biological control agent of cotton under saline soil conditions.
PMID: 35630312
Planta , IF:4.116 , 2022 May , V255 (6) : P123 doi: 10.1007/s00425-022-03908-0
Genome-wide characterization and expression analysis of SAUR gene family in Melon (Cucumis melo L.).
Key Laboratory of Herbage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010070, China.; Key Laboratory of Herbage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010070, China. chegen@imu.edu.cn.; Key Laboratory of Herbage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010070, China. lshasi@imu.edu.cn.
MAIN CONCLUSION: We identified 66 melon SAUR genes by bioinformatic analyses. CmSAUR19, 38, 58, 62 genes are specifically expressed in different stages of fruit growth, suggesting their participation in regulating fruit development. Auxin plays a crucial role in plant growth by regulating the multiple auxin response genes. However, in melon (Cucumis melo L.), the functions of the auxin early response gene family SAUR (Small auxin up RNA) genes in fruit development are still poorly understood. Through genome-wide characterization of CmSAUR family in melon, we identified a total of 66 CmSAUR genes. The open reading frames of the CmSAUR genes ranged from 234 to 525 bp, containing only one exon and lacking introns. Chromosomal position and phylogenetic tree analyses found that the two gene clusters in the melon chromosome are highly homologous in the Cucurbitaceae plants. Among the four conserved motifs in CmSAUR proteins, motif 1, motif 2, and motif 3 located in most of the family protein sequences, and motif 4 showed a close correlation with the two gene clusters. The CmSAUR28 and CmSAUR58 genes have auxin response elements located in the promoters, suggesting they may be involved in the auxin signaling pathway to regulate fruit development. Through transcriptomic profiling in the four developmental stages of fruit and different lateral organs, we selected 16 differentially-expressed SAUR genes for performing further expression analyses. qRT-PCR results showed that five SAUR genes are specifically expressed in flower organs and ovaries. CmSAUR19 and CmSAUR58 were significantly accumulated in the early developmental stage of the fruit. CmSAUR38 and CmAUR62 showed high expression in the climacteric and post-climacteric stages, suggesting their specific role in controlling fruit ripening. This work provides a foundation for further exploring the function of the SAUR gene in fruit development.
PMID: 35552537
Planta , IF:4.116 , 2022 Apr , V255 (5) : P101 doi: 10.1007/s00425-022-03883-6
PdeHCA2 affects biomass in Populus by regulating plant architecture, the transition from primary to secondary growth, and photosynthesis.
Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; The Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.; Sino-Australia Plant Cell Wall Research Centre, State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A and F University, Hangzhou, 311300, China.; Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, College of Life Sciences, Shihezi University, Shihezi, 832003, China.; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China. chaoqing@ibcas.ac.cn.; University of Chinese Academy of Sciences, Beijing, 100049, China. chaoqing@ibcas.ac.cn.; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China. wangbc@ibcas.ac.cn.; University of Chinese Academy of Sciences, Beijing, 100049, China. wangbc@ibcas.ac.cn.
MAIN CONCLUSION: PdeHCA2 regulates the transition from primary to secondary growth, plant architecture, and affects photosynthesis by targeting PdeBRC1 and controlling the anatomy of the mesophyll, and intercellular space, respectively. Branching, secondary growth, and photosynthesis are vital developmental processes of woody plants that determine plant architecture and timber yield. However, the mechanisms underlying these processes are unknown. Here, we report that the Populus transcription factor High Cambium Activity 2 (PdeHCA2) plays a role in the transition from primary to secondary growth, vascular development, and branching. In Populus, PdeHCA2 is expressed in undifferentiated provascular cells during primary growth, in phloem cells during secondary growth, and in leaf veins, which is different from the expression pattern of its homolog in Arabidopsis. Overexpression of PdeHCA2 has pleiotropic effects on shoot and leaf development; overexpression lines showed delayed growth of shoots and leaves, reduced photosynthesis, and abnormal shoot branching. In addition, auxin-, cytokinin-, and photosynthesis-related genes were differentially regulated in these lines. Electrophoretic mobility shift assays and transcriptome analysis indicated that PdeHCA2 directly up-regulates the expression of BRANCHED1 and the MADS-box gene PdeAGL9, which regulate plant architecture, by binding to cis-elements in the promoters of these genes. Taken together, our findings suggest that HCA2 regulates several processes in woody plants including vascular development, photosynthesis, and branching by affecting the proliferation and differentiation of parenchyma cells.
PMID: 35397691
Genes (Basel) , IF:4.096 , 2022 May , V13 (5) doi: 10.3390/genes13050817
Novel Role of AaMYBC1 in Regulating Actinidia arguta Vine Architecture by Elongating Internode Based on Multi-Omics Analysis of Transgenic Tobacco.
Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China.; Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang 332900, China.; Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
The internode length affects the status of fruiting branches and shapes the vine architecture. MYB TFs (transcription factors) have been widely studied and reported to control many biological processes including secondary metabolism, abiotic stresses, growth and development, etc. However, the roles of MYB TFs in regulating internode length remain poorly understood. Here, we demonstrated that a secondary metabolism-related R2R3-MYB TF AaMYBC1 from Actinidia arguta was involved in the regulation of internode length by combined analysis of transcriptome and metabolome of transgenic tobacco plants. The metabolome analysis of OE (over-expressed tobacco) and WT (wild-typed tobacco) showed that there were a total of 1000 metabolites, 176 of which had significant differences. A key metabolite pme1651 annotated as indole 3-acetic acid belonged to phytohormone that was involved in internode length regulation. The RNA-seq analysis presented 446 differentially expressed genes (DEGs) between OE and WT, 14 of which were common DEGs in KEGG and GO enrichment. Through the combined analysis of metabolome and transcriptome in transgenic and wild-type tobacco, three key genes including two SAUR and a GH3 gene were possibly involved in internode elongation. Finally, a regulatory module was deduced to show the role of AaMYBC1 in internode elongation. Our results proposed a molecular mechanism of AaMYBC1 regulating internode length by mediated auxin signaling, implying the potential role in regulating the vine architecture.
PMID: 35627204
Plant Mol Biol , IF:4.076 , 2022 May doi: 10.1007/s11103-022-01268-7
Generalist endophyte Phomopsis liquidambaris colonization of Oryza sativa L. promotes plant growth under nitrogen starvation.
Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, Nanjing, China.; Centre for Novel Agricultural Products, Department of Biology, University of York, YO10 5DD, York, United Kingdom.; Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, Nanjing, China. daichuanchao@njnu.edu.cn.
Fungal endophytes establish symbiotic relationships with host plants, which results in a mutual growth benefit. However, little is known about the plant genetic response underpinning endophyte colonization. Phomopsis liquidambaris usually lives as an endophyte in a wide range of asymptomatic hosts and promotes biotic and abiotic stress resistance. In this study, we show that under low nitrogen conditions P. liquidambaris promotes rice growth in a hydroponic system, which is free of other microorganisms. In order to gain insights into the mechanisms of plant colonization by P. liquidambaris under low nitrogen conditions, we compared root and shoot transcriptome profiles of root-inoculated rice at different colonization stages. We determined that genes related to plant growth promotion, such as gibberellin and auxin related genes, were up-regulated at all developmental stages both locally and systemically. The largest group of up-regulated genes (in both roots and shoots) were related to flavonoid biosynthesis, which is involved in plant growth as well as antimicrobial compounds. Furthermore, genes encoding plant defense-related endopeptidase inhibitors were strongly up-regulated at the early stage of colonization. Together, these results provide new insights into the molecular mechanisms of plant-microbe mutualism and the promotion of plant growth by a fungal endophyte under nitrogen-deficient conditions.
PMID: 35522401
Plant Mol Biol , IF:4.076 , 2022 May , V109 (1-2) : P13-28 doi: 10.1007/s11103-022-01261-0
AUXIN RESPONSE FACTOR 16 (StARF16) regulates defense gene StNPR1 upon infection with necrotrophic pathogen in potato.
Biology Division, Molecular Plant Biology Lab, Indian Institute of Science Education and Research (IISER Pune), Pune, 411008, Maharashtra, India.; Department of Crop Genetics, John Innes Centre, Norwich, UK.; Biology Division, Molecular Plant Biology Lab, Indian Institute of Science Education and Research (IISER Pune), Pune, 411008, Maharashtra, India. akb@iiserpune.ac.in.
KEY MESSAGE: We demonstrate a new regulatory mechanism in the jasmonic acid (JA) and salicylic acid (SA) mediated crosstalk in potato defense response, wherein, miR160 target StARF16 (a gene involved in growth and development) binds to the promoter of StNPR1 (a defense gene) and negatively regulates its expression to suppress the SA pathway. Overall, our study establishes the importance of StARF16 in regulation of StNPR1 during JA mediated defense response upon necrotrophic pathogen interaction. Plants employ antagonistic crosstalk between salicylic acid (SA) and jasmonic acid (JA) to effectively defend them from pathogens. During biotrophic pathogen attack, SA pathway activates and suppresses the JA pathway via NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1). However, upon necrotrophic pathogen attack, how JA-mediated defense response suppresses the SA pathway, is still not well-understood. Recently StARF10 (AUXIN RESPONSE FACTOR), a miR160 target, has been shown to regulate SA and binds to the promoter of StGH3.6 (GRETCHEN HAGEN3), a gene proposed to maintain the balance between the free SA and auxin in plants. In the current study, we investigated the role of StARF16 (a miR160 target) in the regulation of the defense gene StNPR1 in potato upon activation of the JA pathway. We observed that a negative correlation exists between StNPR1 and StARF16 upon infection with the pathogen. The results were further confirmed through the exogenous application of SA and JA. Using yeast one-hybrid assay, we demonstrated that StARF16 binds to the StNPR1 promoter through putative ARF binding sites. Additionally, through protoplast transfection and chromatin immunoprecipitation experiments, we showed that StARF16 could bind to the StNPR1 promoter and regulate its expression. Co-transfection assays using promoter deletion constructs established that ARF binding sites are present in the 2.6 kb sequence upstream to the StNPR1 gene and play a key role in its regulation during infection. In summary, we demonstrate the importance of StARF16 in the regulation of StNPR1, and thus SA pathway, during JA-mediated defense response upon necrotrophic pathogen interaction.
PMID: 35380408
Plant Mol Biol , IF:4.076 , 2022 May , V109 (1-2) : P1-12 doi: 10.1007/s11103-022-01258-9
TOPLESS in the regulation of plant immunity.
415, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.; 415, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India. ashis_nandi@mail.jnu.ac.in.
KEY MESSAGE: This review presents the multiple ways how topless and topless-related proteins regulate defense activation in plants and help in optimizing the defense-growth tradeoff. Eukaryotic gene expression is tightly regulated at various levels by hormones, transcription regulators, post-translational modifications, and transcriptional coregulators. TOPLESS (TPL)/TOPLESS-related (TPR) corepressors regulate gene expression by interacting with other transcription factors. TPRs regulate auxin, gibberellins, jasmonic acid, strigolactone, and brassinosteroid signaling in plants. In general, except for GA, TPLs suppress these signaling pathways to prevent unwanted activation of hormone signaling. The association of TPL/TPRs in these hormonal signaling reflects a wide role of this class of corepressors in plants' normal and stress physiology. The involvement of TPL in immune responses was first demonstrated a decade ago as a repressor of DND1 and DND2 that are negative regulators of plant immune response. Over the last decade, several research groups have established a larger role of TPL/TPRs in plant immunity during both pattern- and effector-triggered immunity. Very recent research unraveled the significant involvement of TPRs in balancing the growth and defense trade-off. TPRs, along with proteasomal degradation complex, miRNA, and phasiRNA, suppress the activation of autoimmunity in plants under normal conditions and promote defense under pathogen attack.
PMID: 35347548
Plant Mol Biol , IF:4.076 , 2022 May , V109 (1-2) : P51-65 doi: 10.1007/s11103-022-01255-y
Eucalyptus grandis AUX/INDOLE-3-ACETIC ACID 13 (EgrIAA13) is a novel transcriptional regulator of xylogenesis.
School of Ecosystem and Forest Sciences, The University of Melbourne, Creswick, VIC, 3363, Australia. nadeeshani.karannagoda@agriculture.vic.gov.au.; Centre for AgriBioscience, Agriculture Victoria, AgriBio, Bundoora, Victoria, 3083, Australia. nadeeshani.karannagoda@agriculture.vic.gov.au.; School of Ecosystem and Forest Sciences, The University of Melbourne, Creswick, VIC, 3363, Australia.; Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa.; Laboratoire de Recherche en Sciences Vegetales, Universite de Toulouse III, CNRS, UPS, UMR 5546, 24 Chemin de Borde Rouge, 31320, Castanet-Tolosan, France.
KEY MESSAGE: Our Induced Somatic Sector Analysis and protein-protein interaction experiments demonstrate that Eucalyptus grandis IAA13 regulates xylem fibre and vessel development, potentially via EgrIAA13 modules involving ARF2, ARF5, ARF6 and ARF19. Auxin is a crucial phytohormone regulating multiple aspects of plant growth and differentiation, including regulation of vascular cambium activity, xylogenesis and its responsiveness towards gravitropic stress. Although the regulation of these biological processes greatly depends on auxin and regulators of the auxin signalling pathway, many of their specific functions remain unclear. Therefore, the present study aims to functionally characterise Eucalyptus grandis AUX/INDOLE-3-ACETIC ACID 13 (EgrIAA13), a member of the auxin signalling pathway. In Eucalyptus and Populus, EgrIAA13 and its orthologs are preferentially expressed in the xylogenic tissues and downregulated in tension wood. Therefore, to further investigate EgrIAA13 and its function during xylogenesis, we conducted subcellular localisation and Induced Somatic Sector Analysis experiments using overexpression and RNAi knockdown constructs of EgrIAA13 to create transgenic tissue sectors on growing stems of Eucalyptus and Populus. Since Aux/IAAs interact with Auxin Responsive Factors (ARFs), in silico predictions of IAA13-ARF interactions were explored and experimentally validated via yeast-2-hybrid experiments. Our results demonstrate that EgrIAA13 localises to the nucleus and that downregulation of EgrIAA13 impedes Eucalyptus xylem fibre and vessel development. We also observed that EgrIAA13 interacts with Eucalyptus ARF2, ARF5, ARF6 and ARF19A. Based on these results, we conclude that EgrIAA13 is a regulator of Eucalyptus xylogenesis and postulate that the observed phenotypes are likely to result from alterations in the auxin-responsive transcriptome via IAA13-ARF modules such as EgrIAA13-EgrARF5. Our results provide the first insights into the regulatory role of EgrIAA13 during xylogenesis.
PMID: 35292886
Plant Mol Biol , IF:4.076 , 2022 May , V109 (1-2) : P29-50 doi: 10.1007/s11103-022-01254-z
Transcriptome analysis of a near-isogenic line and its recurrent parent reveals the role of Pup1 QTL in phosphorus deficiency tolerance of rice at tillering stage.
Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India. sureshkumar3_in@yahoo.co.uk.; Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; Decode Genomics Private Limited, New Delhi, India.; Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India.; Indian Council of Agricultural Research, New Delhi, India.
Phosphorus (P) is essential for cellular processes like respiration, photosynthesis, biosynthesis of membrane phospholipids, etc. To cope with P deficiency stress, plants adopt reprograming of the expression of genes involved in different metabolic/signaling pathways for survival, growth, and development. Plants use transcriptional, post-transcriptional, and/or post-translational machinery to achieve P homeostasis. Several transcription factors (TFs), miRNAs, and P transporters play important roles in P deficiency tolerance; however, the underlying mechanisms responsible for P deficiency tolerance remain poorly understood. Studies on P starvation/deficiency responses in plants at early (seedling) stage of growth have been reported but only a few of them focused on molecular responses of the plant at advanced (tillering or reproductive) stage of growth. To decipher the strategies adopted by rice at tillering stage under P deficiency stress, a pair of contrasting genotypes [Pusa-44 (a high-yielding, P deficiency sensitive cultivar) and its near-isogenic line (NIL-23, P deficiency tolerant) for Pup1 QTL] was used for morphophysiological, biochemical, and molecular analyses. Comparative analyses of shoot and root tissues from 45-day-old plants grown hydroponically under P sufficient (16 ppm) or P deficient (4 ppm) medium confirmed some of the known morphophysiological responses. Moreover, RNA-seq analysis revealed the important roles of phosphate transporters, TFs, auxin-responsive proteins, modulation in the cell wall, fatty acid metabolism, and chromatin architecture/epigenetic modifications in providing P deficiency tolerance to NIL-23, which were brought in due to the introgression of the Pup1 QTL in Pusa-44. This study provides insights into the molecular functions of Pup1 for P deficiency tolerance, which might be utilized to improve P-use efficiency of rice for better productivity in P deficient soils. KEY MESSAGE: Introgression of Pup1 QTL in high-yielding rice cultivar modulates mainly phosphate transporters, TFs, auxin-responsive proteins, cell wall structure, fatty acid metabolism, and chromatin architecture/epigenetic modifications at tillering stage of growth under phosphorus deficiency stress.
PMID: 35275352
Phytochemistry , IF:4.072 , 2022 May , V200 : P113219 doi: 10.1016/j.phytochem.2022.113219
Complexity of the auxin biosynthetic network in Arabidopsis hypocotyls is revealed by multiple stable-labeled precursors.
Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: mkreiser@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: tangx575@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: ggardner@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: cohen047@umn.edu.
Auxin is a key regulator of plant development and in Arabidopsis thaliana can be synthesized through multiple pathways; however, the contributions of various biosynthetic pathways to specific developmental processes are largely unknown. To trace the involvement of various biosynthetic routes to indole-3-acetic acid (IAA) under conditions that induce adventitious root formation in Arabidopsis hypocotyls, we treated seedlings with three different stable isotope-labeled precursors ([(13)C6]anthranilate, [(15)N1]indole, and [(13)C3]serine) and monitored label incorporation into a number of proposed biosynthesis intermediates as well as IAA. We also employed inhibitors targeting tryptophan aminotransferases and flavin monooxygenases of the IPyA pathway, and treatment with these inhibitors differentially altered the labeling patterns from all three precursors into intermediate compounds and IAA. [(13)C3]Serine was used to trace utilization of tryptophan (Trp) and downstream intermediates by monitoring (13)C incorporation into Trp, indole-3-pyruvic acid (IPyA), and IAA; most (13)C incorporation into IAA was eliminated with inhibitor treatments, suggesting Trp-dependent IAA biosynthesis through the IPyA pathway is a dominant contributor to the auxin pool in de-etiolating hypocotyls that can be effectively blocked using chemical inhibitors. Labeling treatment with both [(13)C6]anthranilate and [(15)N1]indole simultaneously resulted in higher label incorporation into IAA through [(15)N1]indole than through [(13)C6]anthranilate; however, this trend was reversed in the proposed precursors that were monitored, with the majority of isotope label originating from [(13)C6]anthranilate. An even greater proportion of IAA became [(15)N1]-labeled compared to [(13)C6]-labeled in seedlings treated with IPyA pathway inhibitors, suggesting that, when the IPyA pathway is blocked, IAA biosynthesis from labeled indole may also come from an origin independent of the measured pool of Trp in these tissues.
PMID: 35523282
J Proteomics , IF:4.044 , 2022 Apr , V257 : P104455 doi: 10.1016/j.jprot.2021.104455
Comparative transcriptomic and proteomic profiling reveals molecular models of light signal regulation of shade tolerance in bowl lotus (Nelumbo nucifera).
School of Design, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: 1033261039@sjtu.edu.cn.; School of Design, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: w1713819157@sjtu.edu.cn.; School of Design, Shanghai Jiao Tong University, Shanghai 200240, China.; School of Design, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: liutao13759@sjtu.edu.cn.; School of Design, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: zhengx.ts@sjtu.edu.cn.
Bowl lotus is categorized as a heliophyte, and shaded environments can severely retard its development and blossoming. We conducted a comparative omics study of light response difference between two cultivars, 'HongYunDieYing' (shade tolerant) and 'YingYing' (shade intolerant), to understand the mechanisms behind the shade tolerance response. The results indicated that 'HongYunDieYing' had a faster light signal response than that in 'YingYing'. Furthermore, 214 proteins in 'HongYunDieYing' and 171 proteins in 'YingYing' were differentially expressed at both the transcriptional and protein levels. These correlated members were mainly involved in photosynthesis, metabolism, secondary metabolites, ribosome, and protein biosynthesis. However, glycolysis/gluconeogenesis, carbon metabolism, fatty acid metabolism, glutathione metabolism, and hormone signaling, were unique to 'HongYunDieYing'. The molecular model of light signal regulation of shade tolerance was constructed: the upstream light signal transduction related gene (cryptochrome 1, phytohormone B, phytochrome-interacting factor 3/5, ELONGATED HYPOCOTYL 5, and SUPPRESSOR OF PHYA-1) played a decisive role in regulating shade tolerance traits. Some transcription factors (MYBs, bHLHs and WRKYs) and hormone signaling (auxin, gibberellin and ethylene) were involved in mediating light signaling to regulate downstream biological events. These regulators and biological processes synergistically regulated the shade tolerance of lotus. SIGNIFICANCE: Lotus requires sufficient sunlight for growth and development, and shaded environments will severely retard lotus growth and blossoming. At present, there are few reports on the systematic identification and characterization of light signal response-related regulators in lotus. This study focuses on the comparative analysis two bowl lotus cultivars with the different shade tolerance traits at transcriptome and proteome levels to uncover the novel insight of the light signal-related biological network and potential candidates involved in the mechanism. The results provide a theoretical basis for the bowl lotus breeding and the expansion of its applications.
PMID: 34923171
BMC Genomics , IF:3.969 , 2022 Apr , V23 (1) : P329 doi: 10.1186/s12864-022-08556-y
Identification of ARF family in blueberry and its potential involvement of fruit development and pH stress response.
College of Plant Science, Jilin University, Changchun, China.; Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Research & Development Center of Blueberry, Beijing, 100083, China.; College of Plant Science, Jilin University, Changchun, China. hanjy@jlu.edu.cn.; College of Plant Science, Jilin University, Changchun, China. shmbian@jlu.edu.cn.
BACKGROUND: Auxin responsive factor (ARF) family is one of core components in auxin signalling pathway, which governs diverse developmental processes and stress responses. Blueberry is an economically important berry-bearing crop and prefers to acidic soil. However, the understandings of ARF family has not yet been reported in blueberry. RESULTS: In the present study, 60 ARF genes (VcARF) were identified in blueberry, and they showed diverse gene structures and motif compositions among the groups and similar within each group in the phylogenetic tree. Noticeably, 9 digenic, 5 trigenic and 6 tetragenic VcARF pairs exhibited more than 95% identity to each other. Computational analysis indicated that 23 VcARFs harbored the miRNA responsive element (MRE) of miR160 or miR167 like other plant ARF genes. Interestingly, the MRE of miR156d/h-3p was observed in the 5'UTR of 3 VcARFs, suggesting a potentially novel post-transcriptional control. Furthermore, the transcript accumulations of VcARFs were investigated during fruit development, and three categories of transcript profiles were observed, implying different functional roles. Meanwhile, the expressions of VcARFs to different pH conditions (pH4.5 and pH6.5) were surveyed in pH-sensitive and tolerant blueberry species, and a number of VcARFs showed different transcript accumulations. More importantly, distinct transcriptional response to pH stress (pH6.5) were observed for several VcARFs (such as VcARF6s and VcARF19-3/19-4) between pH-sensitive and tolerant species, suggesting their potential roles in adaption to pH stress. CONCLUSIONS: Sixty VcARF genes were identified and characterized, and their transcript profiles were surveyed during fruit development and in response to pH stress. These findings will contribute to future research for eliciting the functional roles of VcARFs and regulatory mechanisms, especially fruit development and adaption to pH stress.
PMID: 35477362
Plants (Basel) , IF:3.935 , 2022 May , V11 (10) doi: 10.3390/plants11101335
ADA2b and GCN5 Affect Cytokinin Signaling by Modulating Histone Acetylation and Gene Expression during Root Growth of Arabidopsis thaliana.
Department of Botany, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.; Postgraduate Program Studies "Applications of Biology-Biotechnology, Molecular and Microbial Analysis of Food and Products", School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.; Natural Products Research Centre of Excellence (NatPro-AUTh), Center of Interdisciplinary Research and Innovation of Aristotle University of Thessaloniki (CIRI-AUTh), 57001 Thessaloniki, Greece.
In Arabidopsis thaliana, the histone acetyltransferase GCN5 and the associated coactivator ADA2b regulate root growth and affect gene expression. The cytokinin signaling reporter TCS::GFP was introduced into gcn5-1, ada2b-1, and ada2a-2, as well as the ada2a-2ada2b-1 mutants. The early root growth (4 to 7 days post-germination) was analyzed using cellular and molecular approaches. TCS signal accumulated from the fourth to seventh days of root growth in the wild-type columella cells. In contrast, ada2b-1 and gcn5-1 and ada2a-2ada2b-1 double mutants displayed reduced TCS expression relative to wild type. Gene expression analysis showed that genes associated with cytokinin homeostasis were downregulated in the roots of gcn5-1 and ada2b-1 mutants compared to wild-type plants. H3K14 acetylation was affected in the promoters of cytokinin synthesis and catabolism genes during root growth of Arabidopsis. Therefore, GCN5 and ADA2b are positive regulators of cytokinin signaling during root growth by modulating histone acetylation and the expression of genes involved in cytokinin synthesis and catabolism. Auxin application in the roots of wild-type seedlings increased TCS::GFP expression. In contrast, ada2b and ada2ada2b mutant plants do not show the auxin-induced TCS signal, suggesting that GCN5 and ADA2b are required for the auxin-induced cytokinin signaling in early root growth.
PMID: 35631760
Plants (Basel) , IF:3.935 , 2022 May , V11 (10) doi: 10.3390/plants11101304
Tryptophan Levels as a Marker of Auxins and Nitric Oxide Signaling.
Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Agrobiotechnology Building, Public University of Navarre (UPNA), Avda. de Pamplona 123, E-31192 Mutilva, Spain.; Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.; Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA), Ed. 'Los Acebos', Campus de Arrosadia, E-31006 Pamplona, Spain.
The aromatic amino acid tryptophan is the main precursor for indole-3-acetic acid (IAA), which involves various parallel routes in plants, with indole-3-acetaldoxime (IAOx) being one of the most common intermediates. Auxin signaling is well known to interact with free radical nitric oxide (NO) to perform a more complex effect, including the regulation of root organogenesis and nitrogen nutrition. To fathom the link between IAA and NO, we use a metabolomic approach to analyze the contents of low-molecular-mass molecules in cultured cells of Arabidopsis thaliana after the application of S-nitrosoglutathione (GSNO), an NO donor or IAOx. We separated the crude extracts of the plant cells through ion-exchange columns, and subsequent fractions were analyzed by gas chromatography-mass spectrometry (GC-MS), thus identifying 26 compounds. A principal component analysis (PCA) was performed on N-metabolism-related compounds, as classified by the Kyoto Encyclopedia of Genes and Genomes (KEGG). The differences observed between controls and treatments are mainly explained by the differences in Trp contents, which are much higher in controls. Thus, the Trp is a shared response in both auxin- and NO-mediated signaling, evidencing some common signaling mechanism to both GSNO and IAOx. The differences in the low-molecular-mass-identified compounds between GSNO- and IAOx-treated cells are mainly explained by their concentrations in benzenepropanoic acid, which is highly associated with IAA levels, and salicylic acid, which is related to glutathione. These results show that the contents in Trp can be a marker for the study of auxin and NO signaling.
PMID: 35631729
Plants (Basel) , IF:3.935 , 2022 May , V11 (9) doi: 10.3390/plants11091273
Genome-Wide Characterization, Evolutionary Analysis of ARF Gene Family, and the Role of SaARF4 in Cd Accumulation of Sedum alfredii Hance.
Key Laboratory of Three Gorges Regional Plant Genetic & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang 443000, China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China.; Key Laboratory of Tree Breeding of Zhejiang Province, The Research Institute of Subtropical of Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.; Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Auxin response factors (ARFs) play important roles in plant development and environmental adaption. However, the function of ARFs in cadmium (Cd) accumulation are still unknown. Here, 23 SaARFs were detected in the genome of hyperaccumulating ecotype of Sedum alfredii Hance (HE), and they were not evenly distributed on the chromosomes. Their protein domains remained highly conservative. SaARFs in the phylogenetic tree can be divided into three groups. Genes in the group contained three introns at most. However, over ten introns were found in other two groups. Collinearity relationships were exhibited among ten SaARFs. The reasons for generating SaARFs may be segmental duplication and rearrangements. Collinearity analysis among different species revealed that more collinear genes of SaARFs can be found in the species with close relationships of HE. A total of eight elements in SaARFs promoters were related with abiotic stress. The qRT-PCR results indicated that four SaARFs can respond to Cd stress. Moreover, that there may be functional redundancy among six SaARFs. The adaptive selection and functional divergence analysis indicated that SaARF4 may undergo positive selection pressure and an adaptive-evolution process. Overexpressing SaARF4 effectively declined Cd accumulation. Eleven single nucleotide polymorphism (SNP) sites relevant to Cd accumulation can be detected in SaARF4. Among them, only one SNP site can alter the sequence of the SaARF4 protein, but the SaARF4 mutant of this site did not cause a significant difference in cadmium content, compared with wild-type plants. SaARFs may be involved in Cd-stress responses, and SaARF4 may be applied for decreasing Cd accumulation of plants.
PMID: 35567274
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (9) doi: 10.3390/plants11091191
Transcription Profile of Auxin Related Genes during Positively Gravitropic Hypocotyl Curvature of Brassica rapa.
Biology Department, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.; Cemvita Factory, 9350 Kirby Drive, Suite 100, Houston, TX 77054, USA.
Unlike typical negative gravitropic curvature, young hypocotyls of Brassica rapa and other dicots exhibit positive gravitropism. This positive curvature occurs at the base of the hypocotyl and is followed by the typical negative gravity-induced curvature. We investigated the role of auxin in both positive and negative hypocotyl curvature by examining the transcription of PIN1, PIN3, IAA5 and ARG1 in curving tissue. We compared tissue extraction of the convex and concave flank with Solid Phase Gene Extraction (SPGE). Based on Ubiquitin1 (UBQ1) as a reference gene, the log (2) fold change of all examined genes was determined. Transcription of the examined genes varied during the graviresponse suggesting that these genes affect differential elongation. The transcription of all genes was upregulated in the lower flank and downregulated in the upper flank during the initial downward curving period. After 48 h, the transcription profile reversed, suggesting that the ensuing negative gravicurvature is controlled by the same genes as the positive gravicurvature. High-spatial resolution profiling using SPGE revealed that the transcription profile of the examined genes was spatially distinct within the curving tissue. The comparison of the hypocotyl transcription profile with the root tip indicated that the tip tissue is a suitable reference for curving hypocotyls and that root and hypocotyl curvature are controlled by the same physiological processes.
PMID: 35567192
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (8) doi: 10.3390/plants11081082
Low Concentration of Anti-Auxin and Anti-Fungal Agent Accelerates the PLB Regeneration of Dendrobium okinawense under Green LED.
The United Graduate School of Agricultural Sciences, Ehime University, Matsuyama 790-8556, Japan.; Faculty of Agriculture, Kochi University, Kochi 783-8502, Japan.; Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
Dendrobium okinawense is an endangered epiphytic orchid, and there has been no scientific report so far on its propagation. Protocorm is a mass of cells, and protocorm-like bodies (PLBs) are lookalike protocorms produced by vegetative explants in vitro. Regeneration of PLBs is a widely used technique for orchid micropropagation. We used different light-emitting diodes (LEDs) for the PLB regeneration of D. okinawense. The number of PLBs and fresh weight were increased by 81.1% and 80.8%, respectively, under green LED over the white fluorescent (WF) light. We added different concentrations of PCIB (p-Chlorophenoxyisobutyric acid, an anti-auxin) and HMI (3-Hydroxy-5-methyl isoxazole, an anti-fungal agent) in culture media. The number of PLBs was increased in media having 0.01 mg/L of PCIB (35.9%) compared to control (no PCIB), whereas 19.3% increased in media having 0.01 mL/L of HMI compared to control (no HMI). Green LED in combination with 0.01 mg/L of PCIB significantly increased the number of PLBs (69.0%) compared to the WF-without PCIB combination. In LEDs-PCIB and LED-HMI combinations, HMI did not show better PLBs regeneration compared with PCIB. The results suggested that a combination of low concentrations of PCIB and green LED have the potential to accelerate PLB regeneration of D. okinawense.
PMID: 35448811
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (8) doi: 10.3390/plants11081068
One-Week Scutellar Somatic Embryogenesis in the Monocot Brachypodium distachyon.
Universite Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.; Universite Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France.
Plant somatic embryogenesis (SE) is a natural process of vegetative propagation. It can be induced in tissue cultures to investigate developmental transitions, to create transgenic or edited lines, or to multiply valuable crops. We studied the induction of SE in the scutellum of monocots with Brachypodium distachyon as a model system. Towards the in-depth analysis of SE initiation, we determined the earliest stages at which somatic scutellar cells acquired an embryogenic fate, then switched to a morphogenetic mode in a regeneration sequence involving treatments with exogenous hormones: first an auxin (2,4-D) then a cytokinin (kinetin). Our observations indicated that secondary somatic embryos could already develop in the proliferative calli derived from immature zygotic embryo tissues within one week from the start of in vitro culture. Cell states and tissue identity were deduced from detailed histological examination, and in situ hybridization was performed to map the expression of key developmental genes. The fast SE induction method we describe here facilitates the mechanistic study of the processes involved and may significantly shorten the production of transgenic or gene-edited plants.
PMID: 35448796
Plants (Basel) , IF:3.935 , 2022 Apr , V11 (8) doi: 10.3390/plants11081035
Sucrose Synthase and Fructokinase Are Required for Proper Meristematic and Vascular Development.
Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion 7505101, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Sucrose synthase (SuSy) and fructokinase (FRK) work together to control carbohydrate flux in sink tissues. SuSy cleaves sucrose into fructose and UDP-glucose; whereas FRK phosphorylates fructose. Previous results have shown that suppression of the SUS1,3&4 genes by SUS-RNAi alters auxin transport in the shoot apical meristems of tomato plants and affects cotyledons and leaf structure; whereas antisense suppression of FRK2 affects vascular development. To explore the joint developmental roles of SuSy and FRK, we crossed SUS-RNAi plants with FRK2-antisense plants to create double-mutant plants. The double-mutant plants exhibited novel phenotypes that were absent from the parent lines. About a third of the plants showed arrested shoot apical meristem around the transition to flowering and developed ectopic meristems. Use of the auxin reporter DR5::VENUS revealed a significantly reduced auxin response in the shoot apical meristems of the double-mutant, indicating that auxin levels were low. Altered inflorescence phyllotaxis and significant disorientation of vascular tissues were also observed. In addition, the fruits and the seeds of the double-mutant plants were very small and the seeds had very low germination rates. These results show that SUS1,3&4 and FRK2 enzymes are jointly essential for proper meristematic and vascular development, and for fruit and seed development.
PMID: 35448763
Biol Lett , IF:3.703 , 2022 May , V18 (5) : P20210629 doi: 10.1098/rsbl.2021.0629
Aerial (+)-borneol modulates root morphology, auxin signalling and meristematic activity in Arabidopsis roots.
Center for Ecological Research, Kyoto University, Otsu 520-2113, Japan.; Department of Agrobiological Resources, Faculty of Agriculture, Meijo University, Nagoya 468-8502, Japan.; Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan.; Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.; Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan.; Graduate School of Sciences and Technology for Innovation (Faculty of Agriculture), Yamaguchi University, Yamaguchi 753-8515, Japan.; Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba 305-8572, Japan.; Agro-Biotechnology Research Center (AgTech), Graduate School of Agricultural and Life Sciences (GSALS), University of Tokyo, Tokyo 113-8657, Japan.; Genome-Edited Crop Development Group, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba 305-8604, Japan.; Research Institute for Sustainable Humanosphere, Kyoto University, Uji 611-0011, Japan.; National Institute for Environmental Studies, Tsukuba 305-8506, Japan.
One of the characteristic aspects of odour sensing in humans is the activation of olfactory receptors in a slightly different manner in response to different enantiomers. Here, we focused on whether plants showed enantiomer-specific response similar to that in humans. We exposed Arabidopsis seedlings to methanol (control) and (+)- or (-)-borneol, and found that only (+)-borneol reduced the root length. Furthermore, the root-tip width was more increased upon (+)-borneol exposure than upon (-)-borneol exposure. In addition, root-hair formation was observed near the root tip in response to (+)-borneol. Auxin signalling was strongly reduced in the root tip following exposure to (+)-borneol, but was detected following exposure to (-)-borneol and methanol. Similarly, in the root tip, the activity of cyclin B1:1 was detected on exposure to (-)-borneol and methanol, but not on exposure to (+)-borneol, indicating that (+)-borneol inhibits the meristematic activity in the root. These results partially explain the (+)-borneol-specific reduction in the root length of Arabidopsis. Our results indicate the presence of a sensing system specific for (+)-borneol in Arabidopsis.
PMID: 35506238
Gene , IF:3.688 , 2022 May , V833 : P146592 doi: 10.1016/j.gene.2022.146592
Comparative transcriptome profiling of sweetpotato storage roots during curing-mediated wound healing.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; R&D Center, Genolution Inc., 63, Magokjungang 8-ro 3-gil, Gangseo-gu, Seoul 07793, Republic of Korea.; Department of Biology Education, IALS, Gyeongsang National University, Jinju 52828, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea.; Bioenergy Crop Research Institute, National Institute of Crop Science, Rural Development Administration, 199 Muan-ro, Muan-gun 58545, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea. Electronic address: sskwak@kribb.re.kr.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea. Electronic address: hskim@kribb.re.kr.
Sweetpotato (Ipomoea batatas L. Lam) is an economically important crop that is cultivated for its storage roots. Storage roots provide a source of valuable nutrients, processed foods, animal feeds, and pigments. Sweetpotato storage roots spoil during post-harvest handling because of wounding, which makes them more susceptible to disease-causing microorganisms. Curing to promote wound healing is a common method to control microbial spoilage during post-harvest storage. However, molecular mechanisms underlying the process of curing in sweetpotato storage roots are unknown. To better understand the biology behind curing, the transcriptome of the sweetpotato cultivar, Pungwonmi, was studied using RNA-seq. Storage roots of sweetpotato were treated at 33 degrees C (Curing) and 13 degrees C (Control) for 3 days. RNA-seq data identified 78,781 unigenes and 3,366 differentially expressed genes by over log2 fold change (FC) > 2 and <-2. During curing, DEGs encoded genes related to drought/salt stress responses, phyto-hormones (e.g., auxin, ethylene and jasmonic acid), and proteolysis, were up-regulated, whereas those related to redox state, phyto-hormones (e.g., salicylic acid and brassinosteroids), and lignin and flavonoid biosynthesis were down-regulated. Additionally, among the candidate genes, DEGs encoded genes related to proteolysis and pathogen defense, such as protease inhibitors and lipid transfer proteins, were highly up-regulated during curing and storage. This study provides a valuable resource to further understand the molecular basis of curing-mediated wound healing in sweetpotato storage roots. Moreover, genes revealed in this work could present targets for the development of sweetpotato varieties with improved post-harvest storage characteristics.
PMID: 35605748
Gene , IF:3.688 , 2022 Jun , V829 : P146494 doi: 10.1016/j.gene.2022.146494
Whole genome duplication and dispersed duplication characterize the evolution of the plant PINOID gene family across plant species.
State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou, China.; Department of Biology, California State University East Bay, Hayward, CA, United States of America.; State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing, China.; State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou, China. Electronic address: ligt18@lzu.edu.cn.
PINOID is a kinase belonging to the AGCVIII family, which regulates the polar distribution of PIN proteins and plays an important role in plant geotropism. However, the origin and evolutionary history of this gene family is not fully known. In this study, we identified 79 similar sequences across 17 plant species genomes (PINOID, D6PK, PINOID2, "hypothetical kinase"). Our results show that the AGCVIII kinase family may have originated from related "Hypothetical Kinases" that come out sister to the rest of the gene family members. These kinases differentiated their functions are found in different plant classes: D6PK in moss and PINOID and PINOID2 evolving in angiosperms including the pioneer plant Amborella trichopoda. Our study investigates the evolution of PINOID kinases from a phylogenetic perspective giving us insight into how this important plant signal transduction network switch evolved to play a fundamental and important function in plant growth and development. We highlight the importance of whole genome duplications and dispersed duplications as opposed to tandem duplications in the evolution of this gene family.
PMID: 35447241
Gene , IF:3.688 , 2022 May , V823 : P146320 doi: 10.1016/j.gene.2022.146320
Tomato zonate spot virus induced hypersensitive resistance via an auxin-related pathway in pepper.
Institute of Biotechnology and Germplasm Resources, Yunnan Academy of Agricultural Sciences, Yunnan ProvincialKey Laboratory of Agricultural Biotechnology, Key Lab of Southwestern Crop Gene Resource and GermplasmInnovation, Ministry of Agriculture, KunmingYunnan 650204, China.; Kunming Institute of Botany, Chinese Academy of Science, Kunming Yunnan 650201, China.; Institute of Biotechnology and Germplasm Resources, Yunnan Academy of Agricultural Sciences, Yunnan ProvincialKey Laboratory of Agricultural Biotechnology, Key Lab of Southwestern Crop Gene Resource and GermplasmInnovation, Ministry of Agriculture, KunmingYunnan 650204, China; Life Science College, Southwest Forestry University, Kunming Yunnan 650224, China.; Life Science College, Southwest Forestry University, Kunming Yunnan 650224, China.; Yunnan University of Chinese Medicine, Kunming Yunnan 650500, China.
Tomato zonate spotvirus (TZSV) often incurs significant losses in many food and ornamental crops in Yunnan province, China, and the surrounding areas. The pepper (Capsicum chinensePI152225)can develop hypersensitive resistance following infection with TZSV, through an as yet unknown mechanism. The transcriptome dataset showed a total of 45.81 GB of clean data were obtained from six libraries, and the average percentage of the reads mapped to the pepper genome was over 90.00 %. A total of 1403 differentially expressed genes (DEGs) were obtained after TZSV infection, including 825significantly up-regulated genes and 578 down-regulated genes. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that most up-regulated DEGs were involved in basal defenses. RT-qPCR, and virus induced gene silencing (VIGS) were used preliminarily to identifyBBC_22506 and BBC_18917, among total of 71 differentially expressed genes (DEGs), that play a key role in mediating the auxin-induced signaling pathway that might take part in hypersensitive response (HR) conferred resistance to viral infection in pepper (PI152225) byTZSV. This is the first study on the mechanism of auxin resistance, involved in defense responses of pepper against viral diseases, which lay the foundation for further study on the pathogenic mechanism of TZSV, as well as the mechanism of resistance to TZSV, in peppers.
PMID: 35218893
Gene , IF:3.688 , 2022 Apr , V818 : P146214 doi: 10.1016/j.gene.2022.146214
Whole genome re-sequencing and transcriptome reveal an alteration in hormone signal transduction in a more-branching mutant of apple.
Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: ghj042@163.com.; College of Horticulture, Hebei Agricultural University, Baoding, Hebei 071001, China. Electronic address: liguofang@hebau.edu.cn.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: qdsnky@163.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: 774572825@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: huangyuehy@126.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: 1196328026@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: zhangruifen316@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: songerg9@126.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: guanglisha@126.com.
Branch number is an important trait in grafted apple breeding and cultivation. To provide new information on molecular mechanisms of apple branching, whole reduced-representation genomes and transcriptome of a wild-type (WT) apple (Malus spectabilis) and its more-branching (MB) mutant at the branching stage were examined in this study. Comparison of WT and MB genomes against the Malus domestica reference genome identified 14,908,939 single nucleotide polymorphisms (SNPs) and 173,315 insertions and deletions (InDels) in WT and 1,483,221 SNPs and 1,725,977 InDels in MB. Analysis of the genetic variation between MB and WT revealed 1,048,575 SNPs and 37,327 InDels. Among them, 24,303 SNPs and 891 InDels mapped to coding regions of 5,072 and 596 genes, respectively. GO and KEGG functional annotation of 3,846 and 944 genes, respectively, identified 32 variant genes related to plant hormone signal transduction that were involved in auxin, cytokinin, gibberellin, abscisic acid, ethylene, and brassinosteroid pathways. The transcriptome pathways of plant hormone signal transduction and zeatin biosynthesis were also significantly enriched during MB branching. Furthermore, transcriptome data suggested the regulatory roles of auxin signaling, increase of cytokinin and genes of cytokinin synthesis and signaling, and the suppressed abscisic acid signaling. Our findings suggest that branching development in apple is regulated by plant hormone signal transduction.
PMID: 35066064
Gene , IF:3.688 , 2022 Apr , V817 : P146170 doi: 10.1016/j.gene.2021.146170
Comparative transcriptome analysis reveals distinct responsive biological processes in radish genotypes contrasting for Plasmodiophora brassicae interaction.
Institute of Vegetables Research, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.; Institute of Vegetables Research, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. Electronic address: weiqz@mail.zaas.ac.cn.; Horticultural Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650205, China.; Institute of Vegetables Research, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. Electronic address: baocl@mail.zaas.ac.cn.
Plasmodiophora brassicae is a protozoan pathogen that causes clubroot disease, which is one of the most destructive diseases for Brassica crops, including radish. However, little is known about the molecular mechanism of clubroot resistance in radish. In this study, we performed a comparative transcriptome analysis between resistant and susceptible radish inoculated with P. brassicae. More differentially expressed genes (DEGs) were identified at 28 days after inoculation (DAI) compared to 7 DAI in both genotypes. Gene ontology (GO) and KEGG enrichment indicated that stress/defense response, secondary metabolic biosynthesis, hormone metabolic process, and cell periphery are directly involved in the defense response process. Further analysis of the transcriptome revealed that effector-triggered immunity (ETI) plays key roles in the defense response. The plant hormones jasmonic acid (JA), ethylene (ET), and abscisic acid (ABA) related genes are activated in clubroot defense in the resistant line. Auxin (AUX) hormone related genes are activated in the developing galls of susceptible radish. Our study provides a global transcriptional overview for clubroot development for insights into the P. brassicae defense mechanisms in radish.
PMID: 35031420
Gene , IF:3.688 , 2022 Apr , V817 : P146168 doi: 10.1016/j.gene.2021.146168
Building an embryo: An auxin gene toolkit for zygotic and somatic embryogenesis in Brazilian pine.
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of Sao Paulo, Rua do Matao, 277, Sao Paulo, SP, Brazil. Electronic address: paulaelbl@gmail.com.; Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of Sao Paulo, Rua do Matao, 277, Sao Paulo, SP, Brazil; Department of Computer Science, Institute of Mathematics and Statistics, University of Sao Paulo, Sao Paulo, SP, Brazil.; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, United States.; Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of Sao Paulo, Rua do Matao, 277, Sao Paulo, SP, Brazil.; Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of Sao Paulo, Rua do Matao, 277, Sao Paulo, SP, Brazil; Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, Sao Paulo, SP, Brazil.; Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
Many studies in the model species Arabidopsis thaliana characterized genes involved in embryo formation. However, much remains to be learned about the portfolio of genes that are involved in signal transduction and transcriptional regulation during plant embryo development in other species, particularly in an evolutionary context, especially considering that some genes involved in embryo patterning are not exclusive of land plants. This study, used a combination of domain architecture phylostratigraphy and phylogenetic reconstruction to investigate the evolutionary history of embryo patterning and auxin metabolism (EPAM) genes in Viridiplantae. This approach shed light on the co-optation of auxin metabolism and other molecular mechanisms that contributed to the radiation of land plants, and specifically to embryo formation. These results have potential to assist conservation programs, by directing the development of tools for obtaining somatic embryos. In this context, we employed this methodology with critically endangered and non-model species Araucaria angustifolia, the Brazilian pine, which is current focus of conservation efforts using somatic embryogenesis. So far, this approach had little success since somatic embryos fail to completely develop. By profiling the expression of genes that we identified as necessary for the emergence of land-plant embryos, we found striking differences between zygotic and somatic embryos that might explain the developmental arrest and be used to improve A. angustifolia somatic culture.
PMID: 34995731
BMC Microbiol , IF:3.605 , 2022 Apr , V22 (1) : P101 doi: 10.1186/s12866-022-02507-z
Colonization with non-mycorrhizal culturable endophytic fungi enhances orchid growth and indole acetic acid production.
Central Department of Botany, Tribhuvan University, Kathmandu, 44613, Nepal.; Daffodil Agro Biological Research Center, Lalitpur, 44700, Nepal.; National Centre for Microbial Resource, National Centre for Cell Science, NCCS Complex, Savitribai Phule Pune University Campus, Ganeshkhind, Pune, 411007, India.; School of Sciences, SAGE University, Katara Hills, Bhopal, MP, India.; Division of Microbiology and Biotechnology, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, Karnataka, 575018, India.; Department of Plant and Soil Science, Texas Tech University, Box 42122, Lubbock, TX, 79409, USA.; Central Department of Botany, Tribhuvan University, Kathmandu, 44613, Nepal. b.pant@cdbtu.edu.np.
BACKGROUND: Symbiotic associations of endophytic fungi have been proved by possessing an ability to produce hormones and metabolites for their host plant. Members of the Orchidaceae are obligate mycorrhizal species but a non-mycorrhizal association needs more investigation for their ability to promote plant growth and produce plant growth hormones. In the present study, endophytic fungi were isolated from the roots of Dendrobium longicornu Lindl., to investigate the root colonizing activity and role in plant growth and development. RESULTS: Among 23 fungal isolates were identified both by morphological and molecular technique as Penicillium sp., Fusarium sp., Coniochaeta sp., Alternaria sp., and Cladosporium sp. The dominate species were Coniochaeta sp. and Cladosporium sp. The dominant species as per the isolation was Coniochaeta sp. These fungal strains were screened for growth-promoting activity of Cymbidium aloifolium (plantlet) consider as cross genus interaction and Dendrobium longicornu (protocorms) as a host plant in in-vitro condition. Importantly, Cladosporium sp., and Coniochaeta sp. showed successful colonization and peloton formation with roots of C. aloifolium. Moreover, it also enhanced acclimatization of plantlets. Fungal elicitors from nine fungal isolates enhanced the growth of the in vitro grown protocorms of D. longicornu. Key bioactive compounds detected in the fungal colonized plant extract were 2H-pyran-2-one, Cyclopropanecarboxylic acid, Oleic Acid and d-Mannitol, which may have a potential role in plant-microbe interaction. All fungal endophytes were able to synthesize the indole acetic acid (IAA) in presence of tryptophan. Moreover, fungal extract DLCCR7 treated with DL-tryptophan yielded a greater IAA concentration of 43 mug per ml than the other extracts. The iaaM gene involved in IAA synthesis pathway was amplified using iaaM gene primers successfully from Alternaria sp., Cladosporium sp., and Coniochaeta sp. CONCLUSIONS: Hence, this study confirms the production of IAA by endophytes and demonstrated their host as well as cross-genus plant growth-promoting potential by producing metabolites required for the growth of the plant.
PMID: 35418028
Protoplasma , IF:3.356 , 2022 May doi: 10.1007/s00709-022-01773-y
Genome-wide identification of Aux/IAA and ARF gene families in bread wheat (Triticum aestivum L.).
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India.; Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021, India. param@genomeindia.org.
Wheat (Triticum aestivum L.) is one of the most important food crops in the world. Somatic embryogenesis is an event that is triggered by the presence of auxin hormone for the induction of somatic cells to get converted to embryonic cells. Somatic embryogenesis represents the most important process of totipotency of plants. The role of auxins is widely understood during various stages of embryogenesis including polarity establishment, de-differentiation, re-differentiations, and morphogenesis. Many of the Aux/IAAs and ARFs which are part of auxin signaling components have been identified to play various roles during embryogenesis. In this analysis, the Aux/IAAs and ARFs of T. aestivum have been analyzed at the genome-scale; their structure, function, and evolutionary relatedness were determined. Several Aux/IAAs and ARFs components of T. aestivum have been found to exclusively regulate axis formation, meristem commitment, and other re-differentiation processes by differential expression studies.
PMID: 35606614
Protoplasma , IF:3.356 , 2022 May , V259 (3) : P823-832 doi: 10.1007/s00709-021-01697-z
Plant root development: is the classical theory for auxin-regulated root growth false?
Institut fur Biologiedidaktik, Universitat zu Koln, Cologne, Germany. h.edelmann@uni-koeln.de.
One of the longest standing theories and, therein-based, regulation-model of plant root development, posits the inhibitory action of auxin (IAA, indolylacetic acid) on elongation growth of root cells. This effect, as induced by exogenously supplied IAA, served as the foundation stone for root growth regulation. For decades, auxin ruled the day and only allowed hormonal side players to be somehow involved, or in some way affected. However, this copiously reiterated, apparent cardinal role of auxin only applies in roots immersed in solutions; it vanishes as soon as IAA-supplied roots are not surrounded by liquid. When roots grow in humid air, exogenous IAA has no inhibitory effect on elongation growth of maize roots, regardless of whether it is applied basipetally from the top of the root or to the entire residual seedling immersed in IAA solution. Nevertheless, such treatment leads to pronounced root-borne ethylene emission and lateral rooting, illustrating and confirming thereby induced auxin presence and its effect on the root - yet, not on root cell elongation. Based on these findings, a new root growth regulatory model is proposed. In this model, it is not IAA, but IAA-triggered ethylene which plays the cardinal regulatory role - taking effect, or not - depending on the external circumstances. In this model, in water- or solution-incubated roots, IAA-dependent ethylene acts due to its accumulation within the root proper by inhibited/restrained diffusion into the liquid phase. In roots exposed to moist air or gas, there is no effect on cell elongation, since IAA-triggered ethylene diffuses out of the root without an impact on growth.
PMID: 34515860
Mol Genet Genomics , IF:3.291 , 2022 May , V297 (3) : P635-654 doi: 10.1007/s00438-022-01870-w
Identification of potential MTAs and candidate genes for juice quality- and yield-related traits in Saccharum clones: a genome-wide association and comparative genomic study.
Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India.; Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; Division of Crop Improvement, ICAR-Indian Institute of Sugarcane Research, Lucknow, Uttar Pradesh, 226002, India.; Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India. govindsbi1912@gmail.com.
Sugarcane is an economically important commercial crop which provides raw material for the production of sugar, jaggery, bioethanol, biomass and other by-products. Sugarcane breeding till today heavily relies on conventional breeding approaches which is time consuming, laborious and costly. Integration of marker-assisted selection (MAS) in sugarcane genetic improvement programs for difficult to select traits like sucrose content, resistance to pests and diseases and tolerance to abiotic stresses will accelerate varietal development. In the present study, association mapping approach was used to identify QTLs and genes associated with sucrose and other important yield-contributing traits. A mapping panel of 110 diverse sugarcane genotypes and 148 microsatellite primers were used for structured association mapping study. An optimal subpopulation number (DeltaK) of 5 was identified by structure analysis. GWAS analysis using TASSEL identified a total of 110 MTAs which were localized into 27 QTLs by GLM and MLM (Q + K, PC + K) approaches. Among the 24 QTLs sequenced, 12 were able to identify potential candidate genes, viz., starch branching enzyme, starch synthase 4, sugar transporters and G3P-DH related to carbohydrate metabolism and hormone pathway-related genes ethylene insensitive 3-like 1, reversion to ethylene sensitive1-like, and auxin response factor associated to juice quality- and yield-related traits. Six markers, NKS 5_185, SCB 270_144, SCB 370_256, NKS 46_176 and UGSM 648_245, associated with juice quality traits and marker SMC31CUQ_304 associated with NMC were validated and identified as significantly associated to the traits by one-way ANOVA analysis. In conclusion, 24 potential QTLs identified in the present study could be used in sugarcane breeding programs after further validation in larger population. The candidate genes from carbohydrate and hormone response pathway presented in this study could be manipulated with genome editing approaches to further improve sugarcane crop.
PMID: 35257240
PLoS One , IF:3.24 , 2022 , V17 (4) : Pe0261908 doi: 10.1371/journal.pone.0261908
Linnemannia elongata (Mortierellaceae) stimulates Arabidopsis thaliana aerial growth and responses to auxin, ethylene, and reactive oxygen species.
Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America.; Department of Plant Biology, Michigan State University, East Lansing, Michigan, United States of America.; Department of Biology, Michigan Duke University, Durham, North Carolina, United States of America.; Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America.; Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America.; Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan, United States of America.
Harnessing the plant microbiome has the potential to improve agricultural yields and protect plants against pathogens and/or abiotic stresses, while also relieving economic and environmental costs of crop production. While previous studies have gained valuable insights into the underlying genetics facilitating plant-fungal interactions, these have largely been skewed towards certain fungal clades (e.g. arbuscular mycorrhizal fungi). Several different phyla of fungi have been shown to positively impact plant growth rates, including Mortierellaceae fungi. However, the extent of the plant growth promotion (PGP) phenotype(s), their underlying mechanism(s), and the impact of bacterial endosymbionts on fungal-plant interactions remain poorly understood for Mortierellaceae. In this study, we focused on the symbiosis between soil fungus Linnemannia elongata (Mortierellaceae) and Arabidopsis thaliana (Brassicaceae), as both organisms have high-quality reference genomes and transcriptomes available, and their lifestyles and growth requirements are conducive to research conditions. Further, L. elongata can host bacterial endosymbionts related to Mollicutes and Burkholderia. The role of these endobacteria on facilitating fungal-plant associations, including potentially further promoting plant growth, remains completely unexplored. We measured Arabidopsis aerial growth at early and late life stages, seed production, and used mRNA sequencing to characterize differentially expressed plant genes in response to fungal inoculation with and without bacterial endosymbionts. We found that L. elongata improved aerial plant growth, seed mass and altered the plant transcriptome, including the upregulation of genes involved in plant hormones and "response to oxidative stress", "defense response to bacterium", and "defense response to fungus". Furthermore, the expression of genes in certain phytohormone biosynthetic pathways were found to be modified in plants treated with L. elongata. Notably, the presence of Mollicutes- or Burkholderia-related endosymbionts in Linnemannia did not impact the expression of genes in Arabidopsis or overall growth rates. Together, these results indicate that beneficial plant growth promotion and seed mass impacts of L. elongata on Arabidopsis are likely driven by plant hormone and defense transcription responses after plant-fungal contact, and that plant phenotypic and transcriptional responses are independent of whether the fungal symbiont is colonized by Mollicutes or Burkholderia-related endohyphal bacteria.
PMID: 35413060
G3 (Bethesda) , IF:3.154 , 2022 May , V12 (5) doi: 10.1093/g3journal/jkac057
Genome-wide analysis of AAAG and ACGT cis-elements in Arabidopsis thaliana reveals their involvement with genes downregulated under jasmonic acid response in an orientation independent manner.
Department of Biological Sciences, Birla Institute of Technology and Science-Pilani, Zuarinagar, Goa 403726, India.; Department of Biological Sciences, Birla Institute of Technology and Science-Pilani, Pilani, Jhunjhunu, Rajasthan 333031, India.; Department of Computer Science and Information Systems, Birla Institute of Technology and Science-Pilani, Zuarinagar, Sancoale, Goa 403726, India.; Faculty of Bioscience, Institute of Biosciences and Technology, Shri Ramswaroop Memorial University, Barabanki, Uttar Pradesh 225003, India.
Cis-regulatory elements are regions of noncoding DNA that regulate the transcription of neighboring genes. The study of cis-element architecture that functions in transcription regulation are essential. AAAG and ACGT are a class of cis-regulatory elements, known to interact with Dof and bZIP transcription factors respectively, and are known to regulate the expression of auxin response, gibberellin response, floral development, light response, seed storage proteins genes, biotic and abiotic stress genes in plants. Analysis of the frequency of occurrence of AAAG and ACGT motifs from varying spacer lengths (0-30 base pair) between these 2 motifs in both possible orientations-AAAG (N) ACGT and ACGT (N) AAAG, in the promoters and genome of Arabidopsis thaliana which indicated preferred orientation of AAAG (N) ACGT over ACGT (N) AAAG across the genome and in promoters. Further, microarray analysis revealed the involvement of these motifs in the genes downregulated under jasmonic acid response in an orientation-independent manner. These results were further confirmed by the transient expression studies with promoter-reporter cassettes carrying AAAG and ACGT motifs in both orientations. Furthermore, cluster analysis on genes with AAAG (N) ACGT and ACGT (N) AAAG motifs orientations revealed clusters of genes to be involved in ABA signaling, transcriptional regulation, DNA binding, and metal ion binding. These findings can be utilized in designing synthetic promoters for the development of stress-tolerant transgenic plants and also provides an insight into the roles of these motifs in transcriptional regulation.
PMID: 35302624
Funct Plant Biol , IF:3.101 , 2022 May doi: 10.1071/FP21315
DELAY OF GERMINATION 1 (DOG1) regulates dormancy in dimorphic seeds of Xanthium strumarium.
Seed dormancy ensures plant survival but many mechanisms remain unclear. A high-throughput RNA-seq analysis investigated the mechanisms involved in the establishment of dormancy in dimorphic seeds of Xanthium strumarium (L.) developing in one single burr. Results showed that DOG1, the main dormancy gene in Arabidopsis thaliana L., was over-represented in the dormant seed leading to the formation of two seeds with different cell wall properties. Less expression of DME/EMB1649, UBP26, EMF2, MOM, SNL2, and AGO4 in the non-dormant seed was observed, which function in the chromatin remodelling of dormancy-associated genes through DNA methylation. However, higher levels of ATXR7/SDG25, ELF6, and JMJ16/PKDM7D in the non-dormant seed that act at the level of histone demethylation and activate germination were found. Dramatically lower expression in the splicing factors SUA, PWI, and FY in non-dormant seed may indicate that variation in RNA splicing for ABA sensitivity and transcriptional elongation control of DOG1 is of importance for inducing seed dormancy. Seed size and germination may be influenced by respiratory factors, and alterations in ABA content and auxin distribution and responses. TOR (a serine/threonine-protein kinase) is likely at the centre of a regulatory hub controlling seed metabolism, maturation, and germination. Over-representation of the respiration-associated genes (ACO3, PEPC3, and D2HGDH) was detected in non-dormant seed, suggesting differential energy supplies in the two seeds. Degradation of ABA biosynthesis and/or proper auxin signalling in the large seed may control germinability, and suppression of endoreduplication in the small seed may be a mechanism for cell differentiation and cell size determination.
PMID: 35569923
PeerJ , IF:2.984 , 2022 , V10 : Pe13438 doi: 10.7717/peerj.13438
The Microphenotron: a novel method for screening plant growth-promoting rhizobacteria.
Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Punjab, Pakistan.; Department of Microbiology, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS) Quetta, Quetta, Balochistan, Pakistan.
Background: The 'Microphenotron' is an automated screening platform that uses 96-well microtiter plates to test the response of seedlings to natural products. This system allows monitoring the phenotypic effect of a large number of small molecules. Here, this model system was used to study the effect of phytohormones produced by plant growth-promoting rhizobacteria (PGPR) on the growth of wild-type and mutant lines of Arabidopsis thaliana. Methods: In the present study, high-throughput screening based on 'Microphenotron' was used to screen PGPRs. Rhizobacteria were isolated from the rhizosphere of Acacia Arabica, which was growing in saline habitats. The phylogeny of these rhizobacteria was determined by 16S rRNA gene sequencing. Strains were screened for plant growth-promoting traits such as auxin production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and phosphate solubilization. Ultra-Performance Liquid Chromatography (UPLC) was used to detect the presence of different indolic compounds. Finally, PGPR were evaluated to enhance the growth of A. thaliana in the 'Microphenotron' system and pot trials. Results: Selected rhizobacteria strains showed positive results for multiple plant-growth promoting traits. For instance, strain (S-6) of Bacillus endophyticus exhibited the highest ACC-deaminase activity. UPLC analysis indicated the presence of different indolic compounds in bacterial extracts that included indole lactic acid (ILA), indole carboxylic acid (ICA), and indole-3-acetic acid (IAA). Two strains (S-7 and S-11) of Psychrobacter alimentarius produced the most IAA, ICA and ILA. A screening bioassay through 96-well microtiter plates with wild-type Col. N6000 showed an increase in root growth and proliferation. The highest twofold increase was recorded in root growth with B. thuringiensis S-26 and B. thuringiensis S-50. In pot trials, mutant lines of A. thaliana impaired for auxin signaling showed that B. endophyticus S-6, Psy. alimenterius S-11, Enterobacter asburiae S-24 and B. thuringiensis S-26 used auxin signaling for plant growth promotion. Similarly, for ethylene insensitive mutant lines (ein2.5 and etr1), Prolinoborus fasciculus S-3, B. endophyticus S-6, Psy. alimenterius S-7, E. asburiae S-24, and B. thuringiensis S-26 showed the involvement of ethylene signaling. However, the growth promotion pattern for most of the strains indicated the involvement of other mechanisms in enhancing plant growth. The result of Microphenotron assays generally agreed with pot trials with mutant and wild type A. thaliana varieties. Bacterial strains that induced the highest growth response by these cultivars in the 'Microphenotron' promoted plant growth in pot trials. This suggests that Microphenotron can accelerate the evaluation of PGPR for agricultural applications.
PMID: 35586133
J Struct Biol , IF:2.867 , 2022 Jun , V214 (2) : P107857 doi: 10.1016/j.jsb.2022.107857
Structural and biochemical basis for the substrate specificity of Pad-1, an indole-3-pyruvic acid aminotransferase in auxin homeostasis.
Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.; Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea. Electronic address: srheesnu@snu.ac.kr.
Phytohormone indole-3-acetic acid (IAA) plays a vital role in regulating plant growth and development. Tryptophan-dependent IAA biosynthesis participates in IAA homeostasis by producing IAA via two sequential reactions, which involve a conversion of tryptophan to indole-3-pyruvic acid (IPyA) by tryptophan aminotransferase (TAA1) followed by the irreversible formation of IAA in the second reaction. Pad-1 from Solanaceae plants regulates IAA levels by catalyzing a reverse reaction of the first step of IAA biosynthesis. Pad-1 is a pyridoxal phosphate (PLP)-dependent aminotransferase, with IPyA as the amino acceptor and l-glutamine as the amino donor. Currently, the structural and functional basis for the substrate specificity of Pad-1 remains poorly understood. In this study, we carried out structural and kinetic analyses of Pad-1 from Solanum melongena. Pad-1 is a homodimeric enzyme, with coenzyme PLP present between a central large alpha/beta domain and a protruding small domain. The active site of Pad-1 includes a vacancy near the phosphate group (P-side) and the 3'-O (O-side) of PLP. These features are distinct from those of TAA1, which is homologous in an overall structure with Pad-1 but includes only the P-side region in the active site. Kinetic analysis suggests that P-side residues constitute a binding pocket for l-glutamine, and O-side residues of Phe124 and Ile350 are involved in the binding of IPyA. These studies illuminate distinct differences in the active site between Pad-1 and TAA1, and provide structural and functional insights into the substrate specificity of Pad-1.
PMID: 35395410
Transgenic Res , IF:2.788 , 2022 Jun , V31 (3) : P325-340 doi: 10.1007/s11248-022-00303-z
Development of a facile genetic transformation system for the Spanish elite rice paella genotype Bomba.
Applied Plant Biotechnology Group, Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Lleida, Spain.; ICREA, Catalan Institute for Research and Advanced Studies, Barcelona, Spain.; Applied Plant Biotechnology Group, Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Lleida, Spain. teresa.capell@udl.cat.
We report the development of an efficient and reproducible genetic transformation system for the recalcitrant Spanish elite rice paella genotype, Bomba. Preconditioned embryos derived from dry seeds were bombarded with gold particles carrying a plasmid containing a screenable and a selectable marker. We confirmed integration and expression of hpt and gusA in the rice genome. Transformation frequency was ca: 10% in several independent experiments. We show Mendelian inheritance of the input transgenes and zygosity determination of the transgenic lines in the T1 generation. A unique and critical step for the regeneration of plants from transformed tissue was shading during the early stages of regeneration, combined with a specific cytokinin:auxin ration at the onset of shifting callus to regeneration media.
PMID: 35416603
Arch Microbiol , IF:2.552 , 2022 May , V204 (6) : P316 doi: 10.1007/s00203-022-02909-7
Exploring plant growth-promoting rhizobacteria as stress alleviators: a methodological insight.
Departamento de Biodiversidad y Biologia Experimental, Facultad de Ciencias Exactas y Naturales. Instituto de Micologia y Botanica, Consejo Nacional de Investigaciones Cientificas y Tecnologicas (INMIBO-CONICET), Universidad de Buenos Aires (UBA), Lab. 69, 4 Piso, Pabellon II, Ciudad Universitaria, Intendente Guiraldes 2160, 1428, Buenos Aires, Argentina. ifdellamonica@gmail.com.; Division Agroalimentaria, Universidad Tecnologica de la Selva, Ocosingo, 29950, Chiapas, Mexico.; Departamento de Biodiversidad y Biologia Experimental, Facultad de Ciencias Exactas y Naturales. Instituto de Micologia y Botanica, Consejo Nacional de Investigaciones Cientificas y Tecnologicas (INMIBO-CONICET), Universidad de Buenos Aires (UBA), Lab. 69, 4 Piso, Pabellon II, Ciudad Universitaria, Intendente Guiraldes 2160, 1428, Buenos Aires, Argentina.; Laboratorio de Edafologia y Ambiente, Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, 50000, Toluca, Estado de Mexico, Mexico.; Laboratorio de Edafologia y Ambiente, Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, 50000, Toluca, Estado de Mexico, Mexico. gyanezo@uaemex.mx.
Rhizospheric and root-endophyte bacteria can stimulate plant growth through diverse biochemical mechanisms and pathways, particularly under biotic and abiotic stresses. For this reason, biotechnological trends on plant growth-promoting rhizobacteria (PGPR) application as biofertilizers, bioremediators, and stress alleviators are gaining increasing interest as ecofriendly strategies for sustainable agriculture management and soil restoration. The first steps needed to implement these technologies are isolation, screening, and characterization of PGPR that can be potentially applied as bioinoculants to alleviate biotic and/or abiotic stresses. Therefore, a complete and accurate methodological study and laboratory techniques are required to warrant the correct achievement of these steps. This review compiles and details the fundamentals, methods, and procedures of key protocols used in isolation and characterization of PGPR for plant stress alleviation.
PMID: 35556177
Mol Biol Rep , IF:2.316 , 2022 May doi: 10.1007/s11033-022-07548-1
Overexpression of TaLAX3-1B alters the stomatal aperture and improves the salt stress resistance of tobacco.
College of Agriculture, Guizhou University, Guiyang, 550025, China.; Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China.; College of Agriculture, Guizhou University, Guiyang, 550025, China. xrhgz@163.com.; Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China. xrhgz@163.com.
BACKGROUND: Stomata, which play important roles in both optimizing photosynthesis efficiency and adapting to stress, are closely related to IAA and ABA. In plants, the auxin influx carrier LAX3 has been found to play roles in development and stress tolerance. However, the function of LAX3 in stomata and in response to salt stress remains largely unknown. METHODS AND RESULTS: Here, we show that overexpression of wheat TaLAX3-1B in tobacco results in a decrease in stomatal aperture and a relatively closed state of the stomata. In addition, the stomatal movement of the OxTaLAX3-1B lines was less sensitive to ABA than that of the WT. Consistently, compared with the WT, the OxTaLAX3-1B lines showed significantly higher expression of stomate-, IAA- and ABA-related genes and endogenous IAA and ABA contents. Furthermore, compared with the WT, the OxTaLAX3-1B lines exhibited higher proline content, salt stress-related gene expression and ROS antioxidant enzyme activity but lower MDA content and ROS accumulation after salt treatment. CONCLUSIONS: The present results suggest that TaLAX3-1B plays a positive role in regulating stomatal closure and enhancing salt stress tolerance.
PMID: 35624389
Biosci Biotechnol Biochem , IF:2.043 , 2022 May doi: 10.1093/bbb/zbac070
Facilitation of auxin biosynthesis and metabolism by salt stress in rice plants.
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
To investigate the effects of salt stress on the auxin in rice plants, we analyzed indole-3-acetic acid (IAA) and its metabolites in hydroponically grown rice plant seedlings (Oryza sativa cv. Nipponbare) and in the culture medium using LC-ESI/MS/MS. We found that the IAA level in the culture medium was increased about 20-fold due to salt stress treatment, while those in the shoots and roots were increased by less than twofold. The culture medium also contained high amounts of oxidized metabolites such as OxIAA, DiOxIAA, DiOxIAA-Glu, and DiOxIAA-Asp. The total amount of IAA and its metabolites in the shoots, roots, and culture medium was significantly increased with salt treatment. A salt stress-responsive increase in the IAA metabolites was observed in nine tested cultivars of rice. The results indicate that salt stress facilitates the metabolic turnover of IAA in rice plants and may open new insight into the role of auxin.
PMID: 35580591
Plant Commun , 2022 Apr : P100327 doi: 10.1016/j.xplc.2022.100327
Right time, right place: The dynamic role of hormones in rhizobial infection and nodulation of legumes.
Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia.; Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia. Electronic address: eloise.foo@utas.edu.au.
Many legume plants form beneficial associations with rhizobial bacteria that are hosted in new plant root organs, nodules, in which atmospheric nitrogen is fixed. This association requires the precise coordination of two separate programs, infection in the epidermis and nodule organogenesis in the cortex. There is extensive literature indicating key roles for plant hormones during nodulation, but a detailed analysis of the spatial and temporal roles of plant hormones during the different stages of nodulation is required. This review analyses the current literature on hormone regulation of infection and organogenesis to reveal the differential roles and interactions of auxin, cytokinin, brassinosteroids, ethylene, and gibberellins during epidermal infection and cortical nodule initiation, development, and function. With the exception of auxin, all of these hormones suppress infection events. By contrast, there is evidence that all of these hormones promote nodule organogenesis, except ethylene, which suppresses nodule initiation. This differential role for many of the hormones between the epidermal and cortical programs is striking. Future work is required to fully examine hormone interactions and create a robust model that integrates this knowledge into our understanding of nodulation pathways.
PMID: 35605199
Biotechnol Biofuels Bioprod , 2022 May , V15 (1) : P55 doi: 10.1186/s13068-022-02155-5
Physiological and comparative transcriptome analyses reveal the mechanisms underlying waterlogging tolerance in a rapeseed anthocyanin-more mutant.
School of Life Sciences, Jiangsu University, Zhenjiang, China.; School of Life Sciences, Jiangsu University, Zhenjiang, China. xltan@ujs.edu.cn.
BACKGROUND: Rapeseed (Brassica napus) is the second largest oil crop worldwide. It is widely used in food, energy production and the chemical industry, as well as being an ornamental. Consequently, it has a large economic value and developmental potential. Waterlogging is an important abiotic stress that restricts plant growth and development. However, little is known about the molecular mechanisms underlying waterlogging tolerance in B. napus. RESULTS: In the present study, the physiological changes and transcriptomes of germination-stage rapeseed in response to waterlogging stress were investigated in the B. napus cultivar 'Zhongshuang 11' (ZS11) and its anthocyanin-more (am) mutant, which was identified in our previous study. The mutant showed stronger waterlogging tolerance compared with ZS11, and waterlogging stress significantly increased anthocyanin, soluble sugar and malondialdehyde contents and decreased chlorophyll contents in the mutant after 12 days of waterlogging. An RNA-seq analysis identified 1370 and 2336 differently expressed genes (DEGs) responding to waterlogging stress in ZS11 and am, respectively. An enrichment analysis revealed that the DEGs in ZS11 were predominately involved in carbohydrate metabolism, whereas those in the am mutant were particularly enriched in plant hormone signal transduction and response to endogenous stimulation. In total, 299 DEGs were identified as anthocyanin biosynthesis-related structural genes (24) and regulatory genes encoding transcription factors (275), which may explain the increased anthocyanin content in the am mutant. A total of 110 genes clustered in the plant hormone signal transduction pathway were also identified as DEGs, including 70 involved in auxin and ethylene signal transduction that were significantly changed in the mutant. Furthermore, the expression levels of 16 DEGs with putative roles in anthocyanin accumulation and biotic/abiotic stress responses were validated by quantitative real-time PCR as being consistent with the transcriptome profiles. CONCLUSION: This study provides new insights into the molecular mechanisms of increased anthocyanin contents in rapeseed in response to waterlogging stress, which should be useful for reducing the damage caused by waterlogging stress and for further breeding new rapeseed varieties with high waterlogging tolerance.
PMID: 35596185
Open Life Sci , 2022 , V17 (1) : P438-446 doi: 10.1515/biol-2022-0043
Application of exogenous auxin and gibberellin regulates the bolting of lettuce (Lactuca sativa L.).
Beijing Key Laboratory of New Technology in Agricultural Application, Beijing University of Agriculture, National Demonstration Center for Experimental Plant Production Education, Plant Science and Technology College, Beijing University of Agriculture, Beijing, P.R. China.
Plant bolting is regulated and controlled by various internal and external factors. We aimed to provide an improved method for breeding to determine whether there is a synergism between hormones and to explore the regulatory effect of plant hormones on the bolting of leaf lettuce. Lettuce plants were sprayed with exogenous auxin and gibberellin separately or in combination. The specific bolting period was determined by the change in stem length and cytological observation. The dynamic changes in endogenous hormones and genes closely related to bolting were analyzed. Treatment with gibberellin alone and the combined application of auxin and gibberellin induced bolting on the fourth day, and treatment with auxin alone resulted in bolting on the eighth day. In the early bolting stage, the auxin contents in the stems of the treatment groups, especially the combined gibberellin and auxin group, were higher than those of the control group. After the application of exogenous auxin and gibberellin, we found that the expression of the ARF8 and GID1 genes was upregulated. Based on the results of our study, combined treatment with exogenous gibberellin and auxin was the best method to promote the bolting of leaf lettuce, and the ARF8 and GID1 genes are closely related to this process.
PMID: 35582624