Cell , IF:41.582 , 2022 Mar , V185 (6) : P967-979.e12 doi: 10.1016/j.cell.2022.01.026
Synthetic mammalian signaling circuits for robust cell population control.
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Primordium Labs, Arcadia, CA 91006, USA.; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA.; Department of Biology, Stanford University, Stanford, CA 94305, USA.; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA.; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA. Electronic address: melowitz@caltech.edu.
In multicellular organisms, cells actively sense and control their own population density. Synthetic mammalian quorum-sensing circuits could provide insight into principles of population control and extend cell therapies. However, a key challenge is reducing their inherent sensitivity to "cheater" mutations that evade control. Here, we repurposed the plant hormone auxin to enable orthogonal mammalian cell-cell communication and quorum sensing. We designed a paradoxical population control circuit, termed "Paradaux," in which auxin stimulates and inhibits net cell growth at different concentrations. This circuit limited population size over extended timescales of up to 42 days of continuous culture. By contrast, when operating in a non-paradoxical regime, population control became more susceptible to mutational escape. These results establish auxin as a versatile "private" communication system and demonstrate that paradoxical circuit architectures can provide robust population control.
PMID: 35235768
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
Nat Plants , IF:15.793 , 2022 Mar , V8 (3) : P269-280 doi: 10.1038/s41477-022-01111-3
Specification of leaf dorsiventrality via a prepatterned binary readout of a uniform auxin input.
Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland.; Center for Plant Molecular Biology, University of Tubingen, Tubingen, Germany.; NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam.; Center for Plant Molecular Biology, University of Tubingen, Tubingen, Germany. marja.timmermans@zmbp.uni-tuebingen.de.
Developmental boundaries play an important role in coordinating the growth and patterning of lateral organs. In plants, specification of dorsiventrality is critical to leaf morphogenesis. Despite its central importance, the mechanism by which leaf primordia acquire adaxial versus abaxial cell fates to establish dorsiventrality remains a topic of much debate. Here, by combining time-lapse confocal imaging, cell lineage tracing and molecular genetic analyses, we demonstrate that a stable boundary between adaxial and abaxial cell fates is specified several plastochrons before primordium emergence when high auxin levels accumulate on a meristem prepattern formed by the AS2 and KAN1 transcription factors. This occurrence triggers a transient induction of ARF3 and an auxin transcriptional response in AS2-marked progenitors that distinguishes adaxial from abaxial identity. As the primordium emerges, dynamic shifts in auxin distribution and auxin-related gene expression gradually resolve this initial polarity into the stable regulatory network known to maintain adaxial-abaxial polarity within the developing organ. Our data show that spatial information from an AS2-KAN1 meristem prepattern governs the conversion of a uniform auxin input into an ARF-dependent binary auxin response output to specify adaxial-abaxial polarity. Auxin thus serves as a single morphogenic signal that orchestrates distinct, spatially separated responses to coordinate the positioning and emergence of a new organ with its patterning.
PMID: 35318449
Mol Plant , IF:13.164 , 2022 Mar , V15 (3) : P504-519 doi: 10.1016/j.molp.2022.01.004
Wheat breeding history reveals synergistic selection of pleiotropic genomic sites for plant architecture and grain yield.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: liaili@caas.cn.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Novogene Bioinformatics Institute, Beijing 100083, China.; Collaborative Innovation Center of Crop Stress Biology & Institute of Plant Stress Biology, School of Life Science, Henan University, Kaifeng 475004, China.; Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.; The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: xdfu@genetics.ac.cn.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: zhangxueyong@caas.cn.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: malong@caas.cn.
Diversity surveys of crop germplasm are important for gaining insights into the genomic basis for plant architecture and grain yield improvement, which is still poorly understood in wheat. In this study, we exome sequenced 287 wheat accessions that were collected in the past 100 years. Population genetics analysis identified that 6.7% of the wheat genome falls within the selective sweeps between landraces and cultivars, which harbors the genes known for yield improvement. These regions were asymmetrically distributed on the A and B subgenomes with regulatory genes being favorably selected. Genome-wide association study (GWAS) identified genomic loci associated with traits for yield potential, and two underlying genes, TaARF12 encoding an auxin response factor and TaDEP1 encoding the G-protein gamma-subunit, were located and characterized to pleiotropically regulate both plant height and grain weight. Elite single-nucleotide haplotypes with increased allele frequency in cultivars relative to the landraces were identified and found to have accumulated over the course of breeding. Interestingly, we found that TaARF12 and TaDEP1 function in epistasis with the classical plant height Rht-1 locus, leading to propose a "Green Revolution"-based working model for historical wheat breeding. Collectively, our study identifies selection signatures that fine-tune the gibberellin pathway during modern wheat breeding and provides a wealth of genomic diversity resources for the wheat research community.
PMID: 35026438
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 Mar 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 Mar 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, CH-1700 Fribourg, 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 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-localised with ABCBs.
PMID: 35302640
Plant Cell , IF:11.277 , 2022 Mar doi: 10.1093/plcell/koac080
Genetic control of branching patterns in grass inflorescences.
Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132 USA.
Inflorescence branching in the grasses controls the number of florets and hence the number of seeds. Recent data on the underlying genetics come primarily from rice and maize, although new data are accumulating in other systems as well. This review focuses on a window in developmental time from the production of primary branches by the inflorescence meristem through to the production of glumes, which indicate the transition to producing a spikelet. Several major developmental regulatory modules appear to be conserved among most or all grasses. Placement and development of primary branches is controlled by conserved auxin regulatory genes. Subtending bracts are repressed by a network including TASSELSHEATH4, and axillary branch meristems are regulated largely by signaling centers that are adjacent to but not within the meristems themselves. Gradients of SBP-like and APETALA2-like proteins and their microRNA regulators extend along the inflorescence axis and the branches, governing the transition from production of branches to production of spikelets. The relative speed of this transition determines the extent of secondary and higher order branching. This inflorescence regulatory network is modified within individual species, particularly as regards formation of secondary branches. Differences between species are caused both by modifications of gene expression and regulators and by presence or absence of critical genes. The unified networks described here may provide tools for investigating orphan crops and grasses other than the well-studied maize and rice.
PMID: 35258600
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Mar , V119 (11) : Pe2118220119 doi: 10.1073/pnas.2118220119
Proteome-wide cellular thermal shift assay reveals unexpected cross-talk between brassinosteroid and auxin signaling.
Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Pelago Bioscience AB, 171 48 Solna, Sweden.; Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.; Department of Biomolecular Medicine, Ghent University, 9052 Ghent, Belgium.; Center for Medical Biotechnology, VIB, 9052 Ghent, Belgium.; VIB Proteomics Core, 9052 Ghent, Belgium.
SignificanceChemical genetics, which investigates biological processes using small molecules, is gaining interest in plant research. However, a major challenge is to uncover the mode of action of the small molecules. Here, we applied the cellular thermal shift assay coupled with mass spectrometry (CETSA MS) to intact Arabidopsis cells and showed that bikinin, the plant-specific glycogen synthase kinase 3 (GSK3) inhibitor, changed the thermal stability of some of its direct targets and putative GSK3-interacting proteins. In combination with phosphoproteomics, we also revealed that GSK3s phosphorylated the auxin carrier PIN-FORMED1 and regulated its polarity that is required for the vascular patterning in the leaf.
PMID: 35254915
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Mar , V119 (10) : Pe2116549119 doi: 10.1073/pnas.2116549119
Auxin methylation by IAMT1, duplicated in the legume lineage, promotes root nodule development in Lotus japonicus.
National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan.; School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan.
Significance IAA carboxyl methyltransferase 1 (IAMT1) converts auxin (IAA) into its methyl ester (MeIAA). IAMT1 is reportedly critical for shoot development of the nonsymbiotic plant Arabidopsis. On the other hand, the function of IAMT1 in roots is unknown. Here, we found that IAMT1 is duplicated in the legume lineage, which evolved root nodule symbiosis. In the model legume Lotus japonicus, one of two paralogs (named IAMT1a) was mainly expressed in root epidermis, but its function is required in the adjacent cell layer, root cortex, where it promotes nodule development. Application of MeIAA, but not IAA, significantly induced NIN, a master regulator of nodule development, without rhizobia. These findings illuminate our understanding of intertissue communication acquired during evolution of root nodule symbiosis.
PMID: 35235457
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 Mar 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 Mar 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
J Hazard Mater , IF:10.588 , 2022 Jul , V433 : P128769 doi: 10.1016/j.jhazmat.2022.128769
LncRNA PMAT-PtoMYB46 module represses PtoMATE and PtoARF2 promoting Pb(2+) uptake and plant growth in poplar.
National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; School of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, PR China.; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China.; Linnean Center for Plant Biology, Department of Plant Biology, Swedish University of Agricultural Sciences, Box 7080, SE-750 07 Uppsala, Sweden.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Science, Umea, Sweden.; Department of Forest and Conservation Sciences, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; School of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, PR China. Electronic address: DeqiangZhang@bjfu.edu.cn.
Lead (Pb(2+)) is one of the most toxic heavy-metal contaminants. Fast-growing woody plants with substantial biomass are ideal for bioremediation. However, the transcriptional regulation of Pb(2+) uptake in woody plants remains unclear. Here, we identified 226 Pb(2+)-induced, differentially expressed long non-coding RNAs (DELs) in Populus tomentosa. Functional annotation revealed that these DELs mainly regulate carbon metabolism, biosynthesis of secondary metabolites, energy metabolism, and signal transduction through their potential target genes. Association and epistasis analysis showed that the lncRNA PMAT (Pb(2+)-induced multidrug and toxic compound extrusion (MATE) antisense lncRNA) interacts epistatically with PtoMYB46 to regulate leaf dry weight, photosynthesis rate, and transketolase activity. Genetic transformation and molecular assays showed that PtoMYB46 reduces the expression of PtoMATE directly or indirectly through PMAT, thereby reducing the secretion of citric acid (CA) and ultimately promoting Pb(2+) uptake. Meanwhile, PtoMYB46 targets auxin response factor 2 (ARF2) and reduces its expression, thus positively regulating plant growth. We concluded that the PMAT-PtoMYB46-PtoMATE-PtoARF2 regulatory module control Pb(2+) tolerance, uptake, and plant growth. This study demonstrates the involvement of lncRNAs in response to Pb(2+) in poplar, yielding new insight into the potential for developing genetically improved woody plant varieties for phytoremediating lead-contaminated soils.
PMID: 35364535
New Phytol , IF:10.151 , 2022 Apr doi: 10.1111/nph.18159
ARFs 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, Univ. Lyon, ENS de Lyon, UCB Lyon1, CNRS, INRA, Lyon, France.
In plants, most developmental programs depend on auxin action. The best described model of auxin signaling pathway that explains most, but not all, auxin transcriptional responses relies on a derepression mechanism. Repressors called Aux/IAAs (Auxin/Indole-3-Acetic Acid) interact with ARFs (Auxin Response Factors), the transcription factors of the auxin signaling pathway, leading to a repression of 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 thaliana which has 22 ARFs, only 5 of them fit into the model since they are the ones able to interact with Aux/IAAs. The 17 left have a limited capacity to interact with the repressors and their mechanism is still unclear. ARF-Aux/IAA differential interaction is one of the many examples of ARFs biochemical and structural diversification that affects ARFs action and therefore, auxin transcriptional responses. A deeper understanding of the structural properties of ARFs is fundamental to better explain the action of auxin in plants.
PMID: 35434800
New Phytol , IF:10.151 , 2022 Mar doi: 10.1111/nph.18128
Arbuscular mycorrhizal symbiosis enhances tomato lateral root formation by modulating CEP2 peptide expression.
Institute of Plant Biology, Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan.
Plant lateral root (LR) growth usually is stimulated by arbuscular mycorrhizal (AM) symbiosis. However, the molecular mechanism is still unclear. We used gene expression analysis, peptide treatment and virus-induced gene alteration assays to demonstrate that C-terminally encoded peptide (CEP2) expression in tomato was downregulated during AM symbiosis to mitigate its negative effect on LR formation through an auxin-related pathway. We showed that enhanced LR density and downregulated CEP2 expression were observed during mycorrhizal symbiosis. Synthetic CEP2 peptide treatment reduced LR density and impaired the expression of genes involved in indole-3-butyric acid (IBA, the precursor of IAA) to IAA conversion, auxin polar transport and the LR-related signaling pathway; however, application of IBA or synthetic auxin 1-naphthaleneacetic acid (NAA) to the roots may rescue both defective LR formation and reduced gene expression. CEP receptor 1 (CEPR1) might be the receptor of CEP2 because its knockdown plants did not respond to CEP2 treatment. Most importantly, the LR density of CEP2 overexpression or knockdown plants could not be further increased by AM inoculation, suggesting that CEP2 was critical for AM-induced LR formation. These results indicated that AM symbiosis may regulate root development by modulating CEP2, which affects the auxin-related pathway.
PMID: 35358343
New Phytol , IF:10.151 , 2022 Mar doi: 10.1111/nph.18114
Inactivation of the entire Arabidopsis group II GH3s confers tolerance to salinity and water deficit.
Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences, 901 83, Umea, Sweden.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, Slechtitelu 27, Olomouc, Czech Republic.; Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, USA.
Indole-3-acetic acid (IAA) controls a plethora of developmental processes. Thus, regulation of its concentration is of great relevance for plant performance. Cellular IAA concentration depends on its transport, biosynthesis and the various pathways for IAA inactivation, including oxidation and conjugation. Group II members of the GRETCHEN HAGEN 3 (GH3) gene family code for acyl acid amido synthetases catalysing the conjugation of IAA to amino acids. However, the high degree of functional redundancy among them has hampered thorough analysis of their roles in plant development. In this work, we generated an Arabidopsis gh3.1,2,3,4,5,6,9,17 (gh3oct) mutant to knock out the group II GH3 pathway. The gh3oct plants had an elaborated root architecture, showed an increased tolerance to different osmotic stresses, including an IAA-dependent tolerance to salinity, and were more tolerant to water deficit. Indole-3-acetic acid metabolite quantification in gh3oct plants suggested the existence of additional GH3-like enzymes in IAA metabolism. Moreover, our data suggested that 2-oxindole-3-acetic acid production depends, at least in part, on the GH3 pathway. Targeted stress-hormone analysis further suggested involvement of abscisic acid in the differential response to salinity of gh3oct plants. Taken together, our data provide new insights into the roles of group II GH3s in IAA metabolism and hormone-regulated plant development.
PMID: 35322877
New Phytol , IF:10.151 , 2022 Mar doi: 10.1111/nph.18111
MicroRNA172 controls inflorescence meristem size through regulation of APETALA2 in Arabidopsis.
Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany.; Institute of Systems, Integrative, and Molecular Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
The APETALA2 (AP2) transcription factor regulates flower development, floral transition and shoot apical meristem (SAM) maintenance in Arabidopsis. AP2 is also regulated at the post-transcriptional level by microRNA172 (miR172), but the contribution of this to SAM maintenance is poorly understood. We generated transgenic plants carrying a form of AP2 that is resistant to miR172 (rAP2) or carrying a wild-type AP2 susceptible to miR172. Phenotypic and genetic analyses were performed on these lines and mir172 mutants to study the role of AP2 regulation by miR172 on meristem size and the rate of flower production. We found that rAP2 enlarges the inflorescence meristem by increasing cell size and cell number. Misexpression of rAP2 from heterologous promoters showed that AP2 acts in the central zone (CZ) and organizing center (OC) to increase SAM size. Furthermore, we found that AP2 is negatively regulated by AUXIN RESPONSE FACTOR 3 (ARF3). However, genetic analyses indicated that ARF3 also influences SAM size and flower production rate independently of AP2. The study identifies miR172/AP2 as a regulatory module controlling inflorescence meristem size and suggests that transcriptional regulation of AP2 by ARF3 fine-tunes SAM size determination.
PMID: 35318684
New Phytol , IF:10.151 , 2022 Mar doi: 10.1111/nph.18110
KAI2 regulates seedling development by mediating light-induced remodelling of auxin transport.
School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, SE-901 83, Umea, Sweden.; Sainsbury Laboratory Cambridge University, Bateman Street, Cambridge, CB2 1LR, UK.; Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, 85354, Freising, Germany.; Genetics, Faculty of Biology, LMU Munich, Grosshaderner St. 4, 82152, Martinsried, Germany.
Photomorphogenic remodelling of seedling growth is a key developmental transition in the plant life cycle. The alpha/beta-hydrolase signalling protein KARRIKIN-INSENSITIVE2 (KAI2), a close homologue of the strigolactone receptor DWARF14 (D14), is involved in this process, but it is unclear how the effects of KAI2 on development are mediated. Here, using a combination of physiological, pharmacological, genetic and imaging approaches in Arabidopsis thaliana (Heynh.) we show that kai2 phenotypes arise because of a failure to downregulate auxin transport from the seedling shoot apex towards the root system, rather than a failure to respond to light per se. We demonstrate that KAI2 controls the light-induced remodelling of the PIN-mediated auxin transport system in seedlings, promoting a reduction in PIN7 abundance in older tissues, and an increase of PIN1/PIN2 abundance in the root meristem. We show that removing PIN3, PIN4 and PIN7 from kai2 mutants, or pharmacological inhibition of auxin transport and synthesis, is sufficient to suppress most kai2 seedling phenotypes. We conclude that KAI2 regulates seedling morphogenesis by its effects on the auxin transport system. We propose that KAI2 is not required for the light-mediated changes in PIN gene expression but is required for the appropriate changes in PIN protein abundance within cells.
PMID: 35313031
New Phytol , IF:10.151 , 2022 Jun , V234 (5) : P1735-1752 doi: 10.1111/nph.18079
SAV4 is required for ethylene-induced root hair growth through stabilizing PIN2 auxin transporter in Arabidopsis.
School of Life Sciences, Xiamen Plant Genetics Key Laboratory and State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiang'an South Road, Xiamen, Fujian Province, 361102, China.
Root hair development is regulated by hormonal and environmental cues, such as ethylene and low phosphate. Auxin efflux carrier PIN2 (PIN-FORMED 2) plays an important role in establishing a proper auxin gradient in root tips, which is required for root hair development. Ethylene promotes root hair development through increasing PIN2 abundance in root tips, which subsequently leads to enhanced expression of auxin reporter genes. However, how PIN2 is regulated remains obscure. Here, we report that Arabidopsis thaliana sav4 (shade avoidance 4) mutant exhibits defects in ethylene-induced root hair development and in establishing a proper auxin gradient in root tips. Ethylene treatment increased SAV4 abundance in root tips. SAV4 and PIN2 co-localize to the shootward plasma membrane (PM) of root tip epidermal cells. SAV4 directly interacts with the PIN2 hydrophilic region (PIN2HL) and regulates PIN2 abundance on the PM. Vacuolar degradation of PIN2 is suppressed by ethylene, which was weakened in sav4 mutant. Furthermore, SAV4 affects the formation of PIN2 clusters and its lateral diffusion on the PM. In summary, we identified SAV4 as a novel regulator of PIN2 that enhances PIN2 membrane clustering and stability through direct protein-protein interactions. Our study revealed a new layer of regulation on PIN2 dynamics.
PMID: 35274300
New Phytol , IF:10.151 , 2022 Jun , V234 (5) : P1832-1847 doi: 10.1111/nph.18078
Comparative transcriptomics of fungal endophytes in co-culture with their moss host Dicranum scoparium reveals fungal trophic lability and moss unchanged to slightly increased growth rates.
Department of Biology, Duke University, 130 Science Drive, Durham, NC, 27708, USA.; North Florida Research and Education Center, University of Florida, 155 Research Road, Quincy, FL, 32351, USA.; Biodiversity Research Center, Academia Sinica, 128 Academia Road, Section 2, Taipei, 11529, Taiwan.; Soil and Water Sciences Department, University of Florida, 1692 McCarty Drive, Gainesville, FL, 32611, USA.; School of Plant Sciences and Department of Ecology and Evolutionary Biology, University of Arizona, 1140 E. South Campus Drive, Tucson, AZ, 85721, USA.; Department of Ecology and Evolutionary Biology, University of Tennessee, 1416 Circle Drive, Knoxville, TN, 37996, USA.; Department of Agronomy, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan.
Mosses harbor fungi whose interactions within their hosts remain largely unexplored. Trophic ranges of fungal endophytes from the moss Dicranum scoparium were hypothesized to encompass saprotrophism. This moss is an ideal host to study fungal trophic lability because of its natural senescence gradient, and because it can be grown axenically. Dicranum scoparium was co-cultured with each of eight endophytic fungi isolated from naturally occurring D. scoparium. Moss growth rates, and gene expression levels (RNA sequencing) of fungi and D. scoparium, were compared between axenic and co-culture treatments. Functional lability of two fungal endophytes was tested by comparing their RNA expression levels when colonizing living vs dead gametophytes. Growth rates of D. scoparium were unchanged, or increased, when in co-culture. One fungal isolate (Hyaloscyphaceae sp.) that promoted moss growth was associated with differential expression of auxin-related genes. When grown with living vs dead gametophytes, Coniochaeta sp. switched from having upregulated carbohydrate transporter activity to upregulated oxidation-based degradation, suggesting an endophytism to saprotrophism transition. However, no such transition was detected for Hyaloscyphaceae sp. Individually, fungal endophytes did not negatively impact growth rates of D. scoparium. Our results support the long-standing hypothesis that some fungal endophytes can switch to saprotrophism.
PMID: 35263447
New Phytol , IF:10.151 , 2022 Apr , V234 (2) : P494-512 doi: 10.1111/nph.18008
A rice single cell transcriptomic atlas defines the developmental trajectories of rice floret and inflorescence meristems.
Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.; NovelBio Bio-Pharm Technology Co. Ltd, Shanghai, 201114, China.; Crop Breeding & Cultivation Research Institute, Shanghai Academy of Agriculture Sciences, Shanghai, 201403, China.; Max Planck Institute for Plant Breeding Research, Cologne, D50829, Germany.; School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia.
Rice inflorescence development determines yield and relies on the activity of axillary meristems (AMs); however, high-resolution analysis of its early development is lacking. Here, we have used high-throughput single-cell RNA sequencing to profile 37 571 rice inflorescence cells and constructed a genome-scale gene expression resource covering the inflorescence-to-floret transition during early reproductive development. The differentiation trajectories of florets and AMs were reconstructed, and discrete cell types and groups of regulators in the highly heterogeneous young inflorescence were identified and then validated by in situ hybridization and with fluorescent marker lines. Our data demonstrate that a WOX transcription factor, DWARF TILLER1, regulates flower meristem activity, and provide evidence for the role of auxin in rice inflorescence branching by exploring the expression and biological role of the auxin importer OsAUX1. Our comprehensive transcriptomic atlas of early rice inflorescence development, supported by genetic evidence, provides single-cell-level insights into AM differentiation and floret development.
PMID: 35118670
New Phytol , IF:10.151 , 2022 Apr , V234 (1) : P149-163 doi: 10.1111/nph.17969
CLAVATA modulates auxin homeostasis and transport to regulate stem cell identity and plant shape in a moss.
School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.; Division of Psychological Medicine & Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff University School of Medicine, Heath Park, Cardiff, CF14 4XN, UK.; Laboratory of Growth Regulators, Faculty of Science of Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, Slechtitelu 27, Olomouc, 78371, Czech Republic.; Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
The CLAVATA pathway is a key regulator of stem cell function in the multicellular shoot tips of Arabidopsis, where it acts via the WUSCHEL transcription factor to modulate hormone homeostasis. Broad-scale evolutionary comparisons have shown that CLAVATA is a conserved regulator of land plant stem cell function, but CLAVATA acts independently of WUSCHEL-like (WOX) proteins in bryophytes. The relationship between CLAVATA, hormone homeostasis and the evolution of land plant stem cell functions is unknown. Here we show that in the moss, Physcomitrella (Physcomitrium patens), CLAVATA affects stem cell activity by modulating hormone homeostasis. CLAVATA pathway genes are expressed in the tip cells of filamentous tissues, regulating cell identity, filament branching, plant spread and auxin synthesis. The receptor-like kinase PpRPK2 plays the major role, and Pprpk2 mutants have abnormal responses to cytokinin, auxin and auxin transport inhibition, and show reduced expression of PIN auxin transporters. We propose a model whereby PpRPK2 modulates auxin gradients in filaments to determine stem cell identity and overall plant form. Our data indicate that CLAVATA-mediated auxin homeostasis is a fundamental property of plant stem cell function, probably exhibited by the last shared common ancestor of land plants.
PMID: 35032334
New Phytol , IF:10.151 , 2022 Apr , V234 (2) : P513-526 doi: 10.1111/nph.17882
Genetic variation in YIGE1 contributes to ear length and grain yield in maize.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.; Wisconsin Institutes for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA.; Department of Molecular Physiology, Max-Planck-Institute of Molecular Plant Physiology, Am Muhlenberg 1, Potsdam-Golm, 14476, Germany.; Hubei Hongshan Laboratory, Wuhan, 430070, China.
Ear length (EL), which is controlled by quantitative trait loci (QTLs), is an important component of grain yield and as such is a key target trait in maize breeding. However, very few EL QTLs have been cloned, and their molecular mechanisms are largely unknown. Here, using a genome wide association study (GWAS), we identified a QTL, YIGE1, which encodes an unknown protein that regulates EL by affecting pistillate floret number. Overexpression of YIGE1 increased female inflorescence meristem (IM) size, increased EL and kernel number per row (KNPR), and thus enhanced grain yield. By contrast, CRISPR/Cas9 knockout and Mutator insertion mutant lines of YIGE1 displayed decreased IM size and EL. A single-nucleotide polymorphism (SNP) located in the regulatory region of YIGE1 had a large effect on its promoter strength, which positively affected EL by increasing gene expression. Further analysis shows that YIGE1 may be involved in sugar and auxin signal pathways to regulate maize ear development, thus affecting IM activity and floret production in maize inflorescence morphogenesis. These findings provide new insights into ear development and will ultimately facilitate maize molecular breeding.
PMID: 34837389
New Phytol , IF:10.151 , 2022 Apr , V234 (2) : P560-577 doi: 10.1111/nph.17878
Phytochrome interacting factor 3 regulates pollen mitotic division through auxin signalling and sugar metabolism pathways in tomato.
Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.; Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg, 69120, Germany.; Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agricultural, Zhejiang University, Hangzhou, 310058, China.
The development of viable pollen determines male fertility, and is crucial for reproduction in flowering plants. Phytochrome interacting factor 3 (PIF3) acts as a central regulator of plant growth and development, but its relationship with pollen development has not been determined. Through genetic, histological and transcriptomic analyses, we identified an essential role for SlPIF3 in regulating tomato (Solanum lycopersicum) pollen development. Knocking out SlPIF3 using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 resulted in pollen mitosis I arrest, and a failure to form viable pollen. We further demonstrated that both glutamate synthase 1 (SlGLT1) and cell wall invertase 9 (SlCWIN9), involved in auxin and sugar homeostasis, respectively, colocalised with SlPIF3 in the anthers and were directly regulated by SlPIF3. Knockout of either SlGLT1 or SlCWIN9 phenocopied the pollen phenotype of SlPIF3 knockout (Slpif3) lines. Slpif3 fertility was partially restored by exogenous auxin indole-3-acetic acid in a dose-dependent manner. This study reveals a mechanism by which SlPIF3 regulates pollen development and highlights a new strategy for creating hormone-regulated genic male sterile lines for tomato hybrid seed production.
PMID: 34812499
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 Mar doi: 10.1093/plphys/kiac150
APYRASE1/2 mediate red light-induced de-etiolation growth in Arabidopsis seedlings.
Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712.
In etiolated seedlings, red light (R) activates phytochrome and initiates signals that generate major changes at molecular and physiological levels. These changes include inhibition of hypocotyl growth and promotion of the growth of primary roots, apical hooks, and cotyledons. An earlier report showed that the sharp decrease in hypocotyl growth rapidly induced by R was accompanied by an equally rapid decrease in the transcript and protein levels of two closely related apyrases (nucleoside triphosphate-diphosphohydrolases) in Arabidopsis (Arabidopsis thaliana), APY1 and APY2, enzymes whose expression alters auxin transport and growth in seedlings. Here, we report that single knockouts of either apyrase inhibits R-induced promotion of the growth of primary roots, apical hooks, and cotyledons, and RNAi-induced suppression of APY1 expression in the background of apy2 inhibits R-induced apical hook opening. When R-irradiated primary roots and apical hook-cotyledons began to show a gradual increase in their growth relative to dark controls, they concurrently showed increased levels of apyrase protein, but in hook-cotyledon tissue, this occurred without parallel increases in their transcripts. In wild-type seedlings whose root growth is suppressed by the photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the R-induced increased APY expression in roots was also inhibited. In unirradiated plants, the constitutive expression of APY2 promoted both hook opening and changes in the transcript abundance of Small Auxin Upregulated RNA (SAUR), SAUR17 and SAUR50 that help mediate de-etiolation. These results provide evidence that the expression of APY1/APY2 is regulated by R and that APY1/APY2 participate in the signaling pathway by which phytochrome induces differential growth changes in different tissues of etiolated seedlings.
PMID: 35357495
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac138
MicroRNA858a, its encoded peptide, and phytosulfokine regulate Arabidopsis growth and development.
CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research (CSIR-NBRI), Rana Pratap Marg, Lucknow-226001, India.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India.; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, India.
Small molecules, such as peptides and miRNAs, are crucial regulators of plant growth. Here, we show the importance of cross-talk between miPEP858a (microRNA858a-encoded peptide)/miR858a and phytosulfokine (PSK4) in regulating plant growth and development in Arabidopsis (Arabidopsis thaliana). Genome-wide expression analysis suggested modulated expression of PSK4 in miR858a mutants and miR858a-overexpressing (miR858aOX) plants. The silencing of PSK4 in miR858aOX plants compromised growth, whereas overexpression of PSK4 in the miR858a mutant rescued the developmental defects. The exogenous application of synthetic PSK4 further complemented the plant development in mutant plants. Exogenous treatment of synthetic miPEP858a in the PSK4 mutant led to clathrin-mediated internalization of the peptide; however, it did not enhance growth as is the case in wild-type plants. We also demonstrated that MYB3 is an important molecular component participating in the miPEP858a/miR858a-PSK4 module. Finally, our work highlights the signaling between miR858a/miPEP858a-MYB3-PSK4 in modulating the expression of key elements involved in auxin responses, leading to the regulation of growth.
PMID: 35325214
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac133
Pivotal roles of ELONGATED HYPOCOTYL5 in regulation of plant development and fruit metabolism in tomato.
Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.; Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240.; Joint Center for Single Cell Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, China.; Instrumental Analysis Center of Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
The transcription factor ELONGATED HYPOCOTYL5 (HY5) plays critical roles in plant photomorphogenesis. Previous studies on HY5 have mainly focused on the seedling stage in Arabidopsis (Arabidopsis thaliana), and its functions in other plant species have not been well characterized, particularly at adult stages of development. In this report, we investigated the functions of tomato (Solanum lycopersicum) HY5 (SlHY5) from seedlings to adult plants with a focus on fruits. Genome-edited slhy5 mutants exhibited typical compromised photomorphogenesis in response to various light conditions. The slhy5 mutants showed reduced primary root length and secondary root number, which is associated with altered auxin signaling. SlHY5 promoted chlorophyII biosynthesis from seedling to adult stages. Notably, the promotive role of SlHY5 on chlorophyII accumulation was more pronounced on the illuminated side of green fruits than on their shaded side. Consistent with this light-dependent effect, we determined that SlHY5 protein is stabilized by light. Transcriptome and metabolome analyses in fruits revealed that SlHY5 has major functions in the regulation of metabolism, including the biosynthesis of phenylpropanoids and steroidal glycoalkaloids. These data demonstrate that SlHY5 performs both shared and distinct functions in relation to its Arabidopsis counterpart. The manipulation of SlHY5 represents a powerful tool to influence the two vital agricultural traits of seedling fitness and fruit quality in tomato.
PMID: 35312008
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac099
Maize miR167-ARF3/30-polyamine oxidase 1 module-regulated H2O2 production confers resistance to maize chlorotic mottle virus.
State Key Laboratory for Agro-Biotechnology and Department of Plant Pathology, China Agricultural University, Beijing 100193, China.; International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, Nairobi, Kenya.; College of Agronomy, China Agricultural University, Beijing 100193, China.; Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China.; College of Agronomy, Yunnan Agricultural University, Kunming 650201, China.
Maize chlorotic mottle virus (MCMV) is the key pathogen causing maize lethal necrosis (MLN). Due to the sharply increased incidence of MLN in many countries, there is an urgent need to identify resistant lines and uncover the underlying resistance mechanism. Here, we showed that the abundance of maize (Zea mays) microR167 (Zma-miR167) positively modulates the degree of resistance to MCMV. Zma-miR167 directly targets Auxin Response Factor3 (ZmARF3) and ZmARF30, both of which negatively regulate resistance to MCMV. RNA-sequencing coupled with gene expression assays revealed that both ZmARF3 and ZmARF30 directly bind the promoter of Polyamine Oxidase 1 (ZmPAO1) and activate its expression. Knockdown or inhibition of enzymatic activity of ZmPAO1 suppressed MCMV infection. Nevertheless, MCMV-encoded p31 protein directly targets ZmPAO1 and enhances the enzyme activity to counteract Zma-miR167-mediated defense to some degree. We uncovered a role of the Zma-miR167-ZmARF3/30 module for restricting MCMV infection by regulating ZmPAO1 expression, while MCMV employs p31 to counteract this defense.
PMID: 35298645
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac115
Pleiotropic and Non-redundant Effects of an Auxin Importer in Setaria and Maize.
Donald Danforth Plant Science Center, 975 North Warson Rd, Saint Louis, MO, 63132, USA.; Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK 74078, USA.; Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, 301 Christopher Bond Life Sciences Center, Columbia, MO 65211, USA.
Directional transport of auxin is critical for inflorescence and floral development in flowering plants, but the role of auxin influx carriers (AUX1 proteins) has been largely overlooked. Taking advantage of available AUX1 mutants in green millet (Setaria viridis) and maize (Zea mays), we uncover previously unreported aspects of plant development that are affected by auxin influx, including higher order branches in the inflorescence, stigma branch number, glume (floral bract) development, and plant fertility. However, disruption of auxin flux does not affect all parts of the plant, with little obvious effect on inflorescence meristem size, time to flowering, and anther morphology. In double mutant studies in maize, disruptions of ZmAUX1 also affect vegetative development. A GFP-tagged construct of the Setaria AUX1 protein Sparse Panicle1 (SPP1) under its native promoter showed that SPP1 localizes to the plasma membrane of outer tissue layers in both roots and inflorescences, and accumulates specifically in inflorescence branch meristems, consistent with the mutant phenotype and expected auxin maxima. RNA-seq analysis indicated that most gene expression modules are conserved between mutant and wild-type plants, with only a few hundred genes differentially expressed in spp1 inflorescences. Using CRISPR-Cas9 technology, we disrupted SPP1 and the other four AUX1 homologs in S. viridis. SPP1 has a larger effect on inflorescence development than the others, although all contribute to plant height, tiller formation, and lea, and root development. The AUX1 importers are thus not fully redundant in S. viridis. Our detailed phenotypic characterization plus a stable GFP-tagged line offer tools for future dissection of the function of auxin influx proteins.
PMID: 35285930
Plant Physiol , IF:8.34 , 2022 Mar , V188 (4) : P2228-2240 doi: 10.1093/plphys/kiab571
Type 2C protein phosphatase clade D family members dephosphorylate guard cell plasma membrane H+-ATPase.
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.; Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota 55108, USA.; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan.
Plasma membrane (PM) H+-ATPase in guard cells is activated by phosphorylation of the penultimate residue, threonine (Thr), in response to blue and red light, promoting stomatal opening. Previous in vitro biochemical investigation suggested that Mg2+- and Mn2+-dependent membrane-localized type 2C protein phosphatase (PP2C)-like activity mediates the dephosphorylation of PM H+-ATPase in guard cells. PP2C clade D (PP2C.D) was later demonstrated to be involved in PM H+-ATPase dephosphorylation during auxin-induced cell expansion in Arabidopsis (Arabidopsis thaliana). However, it is unclear whether PP2C.D phosphatases are involved in PM H+-ATPase dephosphorylation in guard cells. Transient expression experiments using Arabidopsis mesophyll cell protoplasts revealed that all PP2C.D isoforms dephosphorylate the endogenous PM H+-ATPase. We further analyzed PP2C.D6/8/9, which display higher expression levels than other isoforms in guard cells, observing that pp2c.d6, pp2c.d8, and pp2c.d9 single mutants showed similar light-induced stomatal opening and phosphorylation status of PM H+-ATPase in guard cells as Col-0. In contrast, the pp2c.d6/9 double mutant displayed wider stomatal apertures and greater PM H+-ATPase phosphorylation in response to blue light, but delayed dephosphorylation of PM H+-ATPase in guard cells; the pp2c.d6/8/9 triple mutant showed similar phenotypes to those of the pp2c.d6/9 double mutant. Taken together, these results indicate that PP2C.D6 and PP2C.D9 redundantly mediate PM H+-ATPase dephosphorylation in guard cells. Curiously, unlike auxin-induced cell expansion in seedlings, auxin had no effect on the phosphorylation status of PM H+-ATPase in guard cells.
PMID: 34894269
Plant Physiol , IF:8.34 , 2022 Mar , V188 (3) : P1604-1616 doi: 10.1093/plphys/kiab587
Root electrotropism in Arabidopsis does not depend on auxin distribution but requires cytokinin biosynthesis.
Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
Efficient foraging by plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms range from sensing gravity (gravitropism), light (phototropism), water (hydrotropism), touch (thigmotropism), and more. Electrotropism, also known as galvanotropism, is the phenomenon of aligning growth with external electric fields and currents. Although root electrotropism has been observed in a few species since the end of the 19th century, its molecular and physical mechanisms remain elusive, limiting its comparison with the more well-defined sensing pathways in plants. Here, we provide a quantitative and molecular characterization of root electrotropism in the model system Arabidopsis (Arabidopsis thaliana), showing that it does not depend on an asymmetric distribution of the plant hormone auxin, but instead requires the biosynthesis of a second hormone, cytokinin. We also show that the dose-response kinetics of the early steps of root electrotropism follows a power law analogous to the one observed in some physiological reactions in animals. Future studies involving more extensive molecular and quantitative characterization of root electrotropism would represent a step toward a better understanding of signal integration in plants and would also serve as an independent outgroup for comparative analysis of electroreception in animals and fungi.
PMID: 34893912
Plant Physiol , IF:8.34 , 2022 Mar , V188 (3) : P1686-1708 doi: 10.1093/plphys/kiab565
The positive feedback regulatory loop of miR160-Auxin Response Factor 17-HYPONASTIC LEAVES 1 mediates drought tolerance in apple trees.
State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.; State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
Drought stress tolerance is a complex trait regulated by multiple factors. Here, we demonstrate that the miRNA160-Auxin Response Factor 17 (ARF17)-HYPONASTIC LEAVES 1 module is crucial for apple (Malus domestica) drought tolerance. Using stable transgenic plants, we found that drought tolerance was improved by higher levels of Mdm-miR160 or MdHYL1 and by decreased levels of MdARF17, whereas reductions in MdHYL1 or increases in MdARF17 led to greater drought sensitivity. Further study revealed that modulation of drought tolerance was achieved through regulation of drought-responsive miRNA levels by MdARF17 and MdHYL1; MdARF17 interacted with MdHYL1 and bound to the promoter of MdHYL1. Genetic analysis further suggested that MdHYL1 is a direct downstream target of MdARF17. Importantly, MdARF17 and MdHYL1 regulated the abundance of Mdm-miR160. In addition, the Mdm-miR160-MdARF17-MdHYL1 module regulated adventitious root development. We also found that Mdm-miR160 can move from the scion to the rootstock in apple and tomato (Solanum lycopersicum), thereby improving root development and drought tolerance of the rootstock. Our study revealed the mechanisms by which the positive feedback loop of Mdm-miR160-MdARF17-MdHYL1 influences apple drought tolerance.
PMID: 34893896
Plant Physiol , IF:8.34 , 2022 Mar , V188 (4) : P2289-2307 doi: 10.1093/plphys/kiab536
Piriformospora indica recruits host-derived putrescine for growth promotion in plants.
National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India.
Growth promotion induced by the endosymbiont Piriformospora indica has been observed in various plants; however, except growth phytohormones, specific functional metabolites involved in P. indica-mediated growth promotion are unknown. Here, we used a gas chromatography-mass spectrometry-based untargeted metabolite analysis to identify tomato (Solanum lycopersicum) metabolites whose levels were altered during P. indica-mediated growth promotion. Metabolomic multivariate analysis revealed several primary metabolites with altered levels, with putrescine (Put) induced most significantly in roots during the interaction. Further, our results indicated that P. indica modulates the arginine decarboxylase (ADC)-mediated Put biosynthesis pathway via induction of SlADC1 in tomato. Piriformospora indica did not promote growth in Sladc1-(virus-induced gene silencing of SlADC1) lines of tomato and showed less colonization. Furthermore, using LC-MS/MS we showed that Put promoted growth by elevation of auxin (indole-3-acetic acid) and gibberellin (GA4 and GA7) levels in tomato. In Arabidopsis (Arabidopsis thaliana) adc knockout mutants, P. indica colonization also decreased and showed no plant growth promotion, and this response was rescued upon exogenous application of Put. Put is also important for hyphal growth of P. indica, indicating that it is co-adapted by both host and microbe. Taken together, we conclude that Put is an essential metabolite and its biosynthesis in plants is crucial for P. indica-mediated plant growth promotion and fungal growth.
PMID: 34791442
Curr Opin Plant Biol , IF:7.834 , 2022 Apr , V66 : P102194 doi: 10.1016/j.pbi.2022.102194
Connecting primary and specialized metabolism: Amino acid conjugation of phytohormones by GRETCHEN HAGEN 3 (GH3) acyl acid amido synthetases.
Department of Biology, Washington University in St. Louis, St. Louis, MO 63130 USA. Electronic address: jjez@wustl.edu.
GRETCHEN HAGEN 3 (GH3) acyl acid amido synthetases catalyze the ATP-dependent conjugation of phytohormones with amino acids. Traditionally, GH3 proteins are associated with synthesis of the bioactive jasmonate hormone (+)-7- iso -jasmonoyl-l-isoleucine (JA-Ile) and conjugation of indole-3-acetic acid (IAA) with amino acids that tag the hormone for degradation and/or storage. Modifications of JA and IAA by GH3 acyl acid amido synthetases help maintain phytohormones homeostasis. Recent studies broaden the roles of GH3 proteins to include the regulation of JA biosynthesis; the modification of other auxins (i.e., phenylacetic acid and indole-3-butyric acid); the conjugation of auxinic herbicides, such as 4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy)butyric acid, and dicamba; and the missing step in the isochorismate pathway for the biosynthesis of salicylic acid. The GH3 protein family joins the growing number of versatile enzyme families that blur the line between primary and specialized metabolism for an increasing range of biology functions.
PMID: 35219141
Free Radic Biol Med , IF:7.376 , 2022 Mar , V182 : P192-205 doi: 10.1016/j.freeradbiomed.2022.02.034
Heme oxygenase-nitric oxide crosstalk-mediated iron homeostasis in plants under oxidative stress.
Department of Botany, Gargi College, University of Delhi, India. Electronic address: singh.neha.du@gmail.com.; Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi, 110007, India. Electronic address: bhatlasc@gmail.com.
Plant growth under abiotic stress conditions significantly enhances intracellular generation of reactive oxygen species (ROS). Oxidative status of plant cells is directly affected by the modulation of iron homeostasis. Among mammals and plants, heme oxygenase-1 (HO-1) is a well-known antioxidant enzyme. It catalyzes oxygenation of heme, thereby producing Fe(2+), CO and biliverdin as byproducts. The antioxidant potential of HO-1 is primarily due to its catalytic reaction byproducts. Biliverdin and bilirubin possess conjugated pi-electrons which escalate the ability of these biomolecules to scavenge free radicals. CO also enhances the ROS scavenging ability of plants cells by upregulating catalase and peroxidase activity. Enhanced expression of HO-1 in plants under oxidative stress accompanies sequestration of iron in specialized iron storage proteins localized in plastids and mitochondria, namely ferritin for Fe(3+) storage and frataxin for storage of Fe-S clusters, respectively. Nitric oxide (NO) crosstalks with HO-1 at multiple levels, more so in plants under oxidative stress, in order to maintain intracellular iron status. Formation of dinitrosyl-iron complexes (DNICs) significantly prevents Fenton reaction during oxidative stress. DNICs also release NO upon dissociation in target cells over long distance in plants. They also function as antioxidants against superoxide anions and lipidic free radicals. A number of NO-modulated transcription factors also facilitate iron homeostasis in plant cells. Plants facing oxidative stress exhibit modulation of lateral root formation by HO-1 through NO and auxin-dependent pathways. The present review provides an in-depth analysis of the structure-function relationship of HO-1 in plants and mammals, correlating them with their adaptive mechanisms of survival under stress.
PMID: 35247570
Plant Cell Environ , IF:7.228 , 2022 Mar doi: 10.1111/pce.14316
A novel calmodulin-interacting Domain of Unknown Function 506 protein represses root hair elongation in Arabidopsis.
Noble Research Institute LLC, Ardmore, Oklahoma, USA.
Domain of Unknown Function 506 proteins are ubiquitous in plants. The phosphorus (P) stress-inducible REPRESSOR OF EXCESSIVE ROOT HAIR GROWTH1 (AtRXR1) gene encodes the first characterized DUF506. AtRXR1 inhibits root hair elongation by interacting with RabD2c GTPase. However, functions of other P-responsive DUF506 genes are still missing. Here, we selected two additional P-inducible DUF506 genes for further investigation. The expression of both genes was induced by auxin. Under P-stress, At3g07350 gene expressed ubiquitously in seedlings, whereas At1g62420 (AtRXR3) expression was strongest in roots. AtRXR3 overexpressors and knockouts had shorter and longer root hairs, respectively. A functional AtRXR3-green fluorescent protein fusion localized to root epidermal cells. Chromatin immunoprecipitation and quantitative reverse-transcriptase-polymerase chain reaction revealed that AtRXR3 was transcriptionally activated by RSL4. Bimolecular fluorescence complementation and calmodulin (CaM)-binding assays showed that AtRXR3 interacted with CaM in the presence of Ca(2+) . Moreover, cytosolic Ca(2+) ([Ca(2+) ]cyt ) oscillations in root hairs of rxr3 mutants exhibited elevated frequencies and dampened amplitudes compared to those of wild type. Thus, AtRXR3 is another DUF506 protein that attenuates P-limitation-induced root hair growth through mechanisms that involve RSL4 and interaction with CaM to modulate tip-focused [Ca(2+) ]cyt oscillations.
PMID: 35312071
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
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 Mar doi: 10.1111/jipb.13256
Testing the polar auxin transport model with a selective plasma membrane H(+) -ATPase inhibitor.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.; Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.; Department of Dermatology, Peking University First Hospital, Beijing, 10034, China.; Iomics Biosciences Inc., Beijing, 100102, China.; College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
Auxin is unique among plant hormones in that its function requires polarized transport across plant cells. A chemiosmotic model was proposed to explain how polar auxin transport is derived by the H+ gradient across the plasma membrane established by plasma membrane H+-ATPases (PM H+-ATPases). However, a classical genetic approach by mutations in PM H+-ATPase members did not result in the ablation of polar auxin distribution, possibly due to functional redundancy in this gene family. To confirm the crucial role of PM H+-ATPases in the polar auxin transport model (PATM), we employed a chemical genetic approach. Through a chemical screen, we identified protonstatin-1 (PS-1), a selective small-molecule inhibitor of PM H+-ATPase activity that inhibits auxin transport. Assays with transgenic plants and yeast strains showed that the activity of PM H+-ATPases affects auxin uptake as well as acropetal and basipetal polar auxin transport. We propose that PS-1 can be used as a tool to interrogate the function of PM H+-ATPases. Our results support the chemiosmotic model in which PM H+-ATPase itself plays a fundamental role in polar auxin transport. This article is protected by copyright. All rights reserved.
PMID: 35352470
J Integr Plant Biol , IF:7.061 , 2022 Mar 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 GFP-tagged PIN1 and PIN3 accumulated at higher levels in b1l lateral root primordia. B1L interacts with the exocyst, and b1l shows 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. This article is protected by copyright. All rights reserved.
PMID: 35249253
J Integr Plant Biol , IF:7.061 , 2022 Apr , V64 (4) : P859-870 doi: 10.1111/jipb.13237
Symplastic communication in the root cap directs auxin distribution to modulate root development.
College of Life Sciences, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; The Department of Plant Systems Physiology, Radboud University, Nijmegen, 6500, The Netherlands.
Root cap not only protects root meristem, but also detects and transduces the signals of environmental changes to affect root development. The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments. However, it is unclear how the symplastic communication between root cap cells affects root growth. Here we exploit an inducible system to specifically block the symplastic communication in the root cap. Transient blockage of plasmodesmata (PD) in differentiated collumella cells severely impairs the root development in Arabidopsis, in particular in the stem cell niche and the proximal meristem. The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution. In the later stage, the cell division in proximal meristem is inhibited, presumably due to the reduced auxin level in the root cap. Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development.
PMID: 35199475
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 Mar doi: 10.1093/jxb/erac119
Impaired auxin signaling increases vein and stomatal density but reduces hydraulic efficiency and ultimately net photosynthesis.
Departamento de Biologia Vegetal, Universidade Federal de Vicosa, Vicosa, 36570-900, Brazil.; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, 27695, USA.
Auxins are known to regulate xylem development in plants, however, their effects on water transport efficiency are poorly known. Here we used tomato plants of the diageotropica mutant (dgt), which has impaired function of a Cyclophilin 1 cis/trans isomerase involved in auxin signaling, and its corresponding wild type (WT) to explore its effects on plant hydraulics and leaf gas exchange. The xylem conduits of dgt showed a reduced hydraulically-weighted vessel diameter (Dh) (24-43%) and conduit number (25-58%) in petioles and stems, resulting in lower theoretical hydraulic conductivities (Kt); on the other hand, no changes in root Dh and Kt were observed. The measured stem and leaf hydraulic conductances of dgt agreed with the Kt values and were lower (up to 81%) as well; however, despite dgt and WT showed similar root Dh and Kt, the measured root hydraulic conductance of dgt was 75% lower. The dgt mutation increased the vein and stomata density, which could potentially increase photosynthesis. Nevertheless, even presenting the same photosynthetic capacity of WT plants, the dgt showed a photosynthetic rate c. 25% lower, coupled with a stomatal conductance reduction of 52%. These results clearly demonstrate that increases in Dv and Ds only result in higher leaf gas exchange when accompanied by higher hydraulic efficiency.
PMID: 35312771
J Exp Bot , IF:6.992 , 2022 Mar doi: 10.1093/jxb/erac111
Phytomelatonin as a central molecule in plant disease resistance.
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Crops, Hainan University, Haikou, Hainan province, 570228, China.; Department of Cellular and Structural Biology, UT Health San Antonio, Long School of Medicine, San Antonio, TX, USA.
Melatonin is an essential phytohormone in the regulation of many plant processes, including both during plant development and in response to stress. Pathogen infections cause serious damage to plants and reduce agricultural production. Recent studies indicate that melatonin plays important roles in alleviating bacterial, fungal and viral diseases in plants and post-harvest fruits. Herein, we summarize information related to the effects of melatonin on plant disease resistance. Melatonin, reactive oxygen species (ROS) and reactive nitrogen species (RNS) form a complex loop during plant-pathogen interaction to regulate plant disease resistance. Moreover, melatonin also has crosstalk with other phytohormones including salicylic acid (SA), jasmonic acid (JA), auxin, abscisic acid (ABA) which further activates plant defense genes. Melatonin not only plays an important role in plant immunity, but also in alleviating pathogen pathogenicity. We also summarize the known processes by which melatonin mediates pathogen pathogenicity via negatively regulating the expression levels of genes related to cell viability as well as virulence-related genes. The multiple mechanisms underlying melatonin influences on both plant immunity and pathogen pathogenicity support the recognition of the essential nature of melatonin in plant-pathogen interactions, highlighting phytomelatonin as a critical molecule in plant immune responses.
PMID: 35298631
J Exp Bot , IF:6.992 , 2022 Mar doi: 10.1093/jxb/erac088
Cytokinin oxidase/dehydrogenase family genes exhibit functional divergence and overlap in rice growth and development, especially in control of tillering.
College of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry, Nanjing 210095, People's Republic of China.
Cytokinins play key roles in plant growth and development; hence, cytokinin biosynthesis and degradation have been extensively studied. Cytokinin oxidase/dehydrogenases (CKXs) are a group of enzymes that regulate oxidative cleavage to maintain cytokinin homeostasis. In rice, 11 OsCKX genes have been identified to date; however, most of their functions remain unknown. Here, we comprehensively analyzed the expression patterns and functions of OsCKX genes. Using CRISPR/Cas9 technology, we constructed mutants of all OsCKX genes to determine the functions of OsCKXs in rice development. The results revealed that the single osckx and higher-order osckx4 osckx9 mutant lines showed functional overlap and subfunctionalization. Notably, the osckx1 osckx2 and osckx4 osckx9 double mutants displayed contrasting phenotypic changes in tiller number and panicle size compared to the wild type. Moreover, we identified several genes with significantly altered expression in osckx4 and osckx9 single and double mutant plants. Many differentially expressed genes were found to be associated with auxin and cytokinin pathways. Additionally, the cytokinins in osckx4 osckx9 mutants were increased compared to the wild type. Overall, our findings provide new insights into the functions of OsCKX genes in rice growth and may be used as a foundation for future studies aimed at improving rice yield.
PMID: 35247044
J Exp Bot , IF:6.992 , 2022 Mar doi: 10.1093/jxb/erac083
Nitrate-dependent regulation of miR444-OsMADS27 signaling cascade controls root development in rice.
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India.; SASTRA University, Thirumalaisamudram, Thanjavur 613401, India.
Nitrate is an important nutrient and a key signaling molecule for plant development. A number of transcription factors involved in the process of nitrate response and their regulatory mechanisms have been identified. However, little is known about the nitrate sensor transcription factors and their regulatory mechanisms among crop plants. In this study, we identified functions of a nitrate-responsive miR444:MADS-box transcription factor OsMADS27 module and its downstream targets mediating rice root growth and stress responses. Transgenic rice plants expressing miR444 target mimic improved rice root growth. Although miR444 has the potential to target multiple genes, we identified OsMADS27 as the major miR444 target that regulates the expression of nitrate transporters, as well as several key genes including expansins and those associated with auxin signaling promote root growth. In agreement with this, overexpression of miRNA-resistant OsMADS27 improved root development and tolerance to stresses, while its silencing suppressed root growth. OsMADS27-mediated a robust stress tolerance in plants through its ability to bind to the promoters of specific stress regulators as observed in ChIP-Seq analysis. Our results provide evidence of nitrate-dependent miR444-OsMADS27 signaling cascade involved in the regulation of rice root growth as well as its surprising role in stress responses.
PMID: 35243491
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 Mar , V73 (5) : P1327-1343 doi: 10.1093/jxb/erab504
Lysophosphatidic acid acyltransferases: a link with intracellular protein trafficking in Arabidopsis root cells?
CNRS, University of Bordeaux, Laboratoire de Biogenese Membranaire, UMR 5200, 33140 Villenave d'Ornon, France.; LEB Aquitaine Transfert-ADERA, INRA Bordeaux Aquitaine, 33140 Villenave d'Ornon, France.; Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK.; Bordeaux Imaging Center, UMS 3420 CNRS, US004 INSERM, University of Bordeaux, 33000 Bordeaux, France.
Phosphatidic acid (PA) and lysophosphatidic acid acyltransferases (LPAATs) might be critical for the secretory pathway. Four extra-plastidial LPAATs (LPAAT2, 3, 4, and 5) were identified in Arabidopsis thaliana. These AtLPAATs display a specific enzymatic activity converting lysophosphatidic acid to PA and are located in the endomembrane system. We investigate a putative role for AtLPAATs 3, 4, and 5 in the secretory pathway of root cells through genetical (knockout mutants), biochemical (activity inhibitor, lipid analyses), and imaging (live and immuno-confocal microscopy) approaches. Treating a lpaat4;lpaat5 double mutant with the LPAAT inhibitor CI976 produced a significant decrease in primary root growth. The trafficking of the auxin transporter PIN2 was disturbed in this lpaat4;lpaat5 double mutant treated with CI976, whereas trafficking of H+-ATPases was unaffected. The lpaat4;lpaat5 double mutant is sensitive to salt stress, and the trafficking of the aquaporin PIP2;7 to the plasma membrane in the lpaat4;lpaat5 double mutant treated with CI976 was reduced. We measured the amounts of neo-synthesized PA in roots, and found a decrease in PA only in the lpaat4;lpaat5 double mutant treated with CI976, suggesting that the protein trafficking impairment was due to a critical PA concentration threshold.
PMID: 34982825
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 Mar , 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 Apr 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, India.; School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India.; School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India.; School of Biology, Indian Institute of Science Education and Research, Pune, Maharashtra, India.; Laboratory of Plant-Microbe Interactions, Regional Center for Biotechnology, Faridabad, Haryana, India.
Shoot-borne adventitious/crown roots form highly derived fibrous root system in grasses. Molecular mechanisms controlling their development remains largely unknown. 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 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. OsWOX10, and OsPLT1 regulate both, shoot-borne crown roots, and root-borne lateral roots, but OsPLT2 specifically controls lateral root development. OsPLT1 activates local auxin biosynthesis genes to promote crown root development. Interestingly, OsPLT genes rescue lateral root primordia outgrowth defects of Arabidopsis plt mutant, demonstrating their conserved role in root primordia outgrowth irrespective of their developmental origin. Together, our findings unveil a molecular framework of tissue trans-differentiation during root primordia establishment, leading to 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 Mar , V11 (7) doi: 10.3390/cells11071100
WRKY Gene Family Drives Dormancy Release in Onion Bulbs.
Dipartimento di Scienze Agrarie, Alimentari e Forestali, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy.; Dipartimento Agraria, Universita Mediterranea di Reggio Calabria, 89124 Reggio Calabria, Italy.; Plant Breeding, Wageningen University and Research Centre, P.O. Box 386, 6700 AJ Wageningen, The Netherlands.; CREA Research Centre for Plant Protection and Certification, 00156 Roma, Italy.; Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche-STEBICEF, Universita degli Studi di Palermo, Viale delle Scienze Ed. 17, 90128 Palermo, Italy.; National Research Council of Italy, Institute of Biosciences and Bioresources (CNR-IBBR), 90128 Palermo, Italy.
Onion (Allium cepa L.) is an important bulb crop grown worldwide. Dormancy in bulbous plants is an important physiological state mainly regulated by a complex gene network that determines a stop of vegetative growth during unfavorable seasons. Limited knowledge on the molecular mechanisms that regulate dormancy in onion were available until now. Here, a comparison between uninfected and onion yellow dwarf virus (OYDV)-infected onion bulbs highlighted an altered dormancy in the virus-infected plants, causing several symptoms, such as leaf striping, growth reduction, early bulb sprouting and rooting, as well as a lower abscisic acid (ABA) level at the start of dormancy. Furthermore, by comparing three dormancy stages, almost five thousand four hundred (5390) differentially expressed genes (DEGs) were found in uninfected bulbs, while the number of DEGs was significantly reduced (1322) in OYDV-infected bulbs. Genes involved in cell wall modification, proteolysis, and hormone signaling, such as ABA, gibberellins (GAs), indole-3-acetic acid (IAA), and brassinosteroids (BRs), that have already been reported as key dormancy-related pathways, were the most enriched ones in the healthy plants. Interestingly, several transcription factors (TFs) were up-regulated in the uninfected bulbs, among them three genes belonging to the WRKY family, for the first time characterized in onion, were identified during dormancy release. The involvement of specific WRKY genes in breaking dormancy in onion was confirmed by GO enrichment and network analysis, highlighting a correlation between AcWRKY32 and genes driving plant development, cell wall modification, and division via gibberellin and auxin homeostasis, two key processes in dormancy release. Overall, we present, for the first time, a detailed molecular analysis of the dormancy process, a description of the WRKY-TF family in onion, providing a better understanding of the role played by AcWRKY32 in the bulb dormancy release. The TF co-expressed genes may represent targets for controlling the early sprouting in onion, laying the foundations for novel breeding programs to improve shelf life and reduce postharvest.
PMID: 35406664
Cells , IF:6.6 , 2022 Mar , V11 (5) doi: 10.3390/cells11050863
Insights into the Histone Acetylation-Mediated Regulation of the Transcription Factor Genes That Control the Embryogenic Transition in the Somatic Cells of Arabidopsis.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, 40-007 Katowice, Poland.; Centre for Bioinformatics and Data Analysis, Medical University of Bialystok, 15-269 Bialystok, Poland.
Somatic embryogenesis (SE), which is a process that involves the in vitro-induced embryogenic reprogramming of plant somatic cells, requires dynamic changes in the cell transcriptome. These changes are fine-tuned by many genetic and epigenetic factors, including posttranslational histone modifications such as histone acetylation. Antagonistically acting enzymes, histone acetyltransferases (HATs) and deacetylases (HDACs), which control histone acetylation in many developmental processes, are believed to control SE. However, the function of specific HAT/HDACs and the genes that are subjected to histone acetylation-mediated regulation during SE have yet to be revealed. Here, we present the global and gene-specific changes in histone acetylation in Arabidopsis explants that are undergoing SE. In the TSA (trichostatin A)-induced SE, we demonstrate that H3 and H4 acetylation might control the expression of the critical transcription factor (TF) genes of a vital role in SE, including LEC1, LEC2 (LEAFY COTYLEDON 1; 2), FUS3 (FUSCA 3) and MYB118 (MYB DOMAIN PROTEIN 118). Within the HATs and HDACs, which mainly positively regulate SE, we identified HDA19 as negatively affecting SE by regulating LEC1, LEC2 and BBM. Finally, we provide some evidence on the role of HDA19 in the histone acetylation-mediated regulation of LEC2 during SE. Our results reveal an essential function of histone acetylation in the epigenetic mechanisms that control the TF genes that play critical roles in the embryogenic reprogramming of plant somatic cells. The results implicate the complexity of Hac-related gene regulation in embryogenic induction and point to differences in the regulatory mechanisms that are involved in auxin- and TSA-induced SE.
PMID: 35269485
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
Plant J , IF:6.417 , 2022 Apr , V110 (2) : P325-336 doi: 10.1111/tpj.15710
NS encodes an auxin transporter that regulates the 'numerous spines' trait in cucumber (Cucumis sativus) fruit.
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Fruit spine is an important agronomic trait in cucumber and the "numerous spines (ns)" cucumber varieties are popular in Europe and West Asia. Although the classical genetic locus of ns was reported more than two decades ago, the NS gene has not been cloned yet. In this study, nine genetic loci for the different densities of fruit spines were identified by a genome-wide association study. Among the nine loci, fsdG2.1 was closely associated with the classical genetic locus ns, which harbors a candidate gene Csa2G264590. Overexpression of Csa2G264590 resulted in lower fruit spine density, and the knockout mutant generated by CRISPR/Cas9 displayed an increased spine density, demonstrating that the Csa2G264590 gene is NS. NS is specifically expressed in the fruit peel and spine. Genetic analysis showed that NS regulates fruit spine development independently of the tuberculate gene, Tu, which regulates spine development on tubercules; the cucumber glabrous mutants csgl1 and csgl3 are epistatic to ns. Furthermore, we found that auxin levels in the fruit peel and spine were significantly lower in the knockout mutant ns-cr. Moreover, RNA-sequencing showed that the plant hormone signal transduction pathway was enriched. Notably, most of the auxin responsive Aux/IAA family genes were downregulated in ns-cr. Haplotype analysis showed that the non-functional haplotype of NS exists exclusively in the Eurasian cucumber backgrounds. Taken together, the cloning of NS gene provides new insights into the regulatory network of fruit spine development.
PMID: 35181968
Plant J , IF:6.417 , 2022 Apr , V110 (1) : P71-87 doi: 10.1111/tpj.15654
The submergence tolerance regulator SUB1A differentially coordinates molecular adaptation to submergence in mature and growing leaves of rice (Oryza sativa L.).
School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.; Department of Bioscience and Biotechnology, Fukui Prefectural University, Eiheiji, Fukui, 910-1195, Japan.
A typical adaptive response to submergence regulated by SUB1A, the ethylene-responsive transcription factor gene, is the restricted elongation of the uppermost leaves. However, the molecular and physiological functions of SUB1A have been characterized using entire shoot tissues, most of which are mature leaves that do not elongate under submergence. We aimed to identify leaf-type-specific and overlapping adaptations coordinated in SUB1A-dependent and -independent manners. To this end, we compared the transcriptomic and hormonal responses to submergence between mature and growing leaves using rice genotypes with and without SUB1A. Monosaccharide, branched-chain amino acid, and nucleoside metabolism, associated with ATP synthesis, were commonly activated in both leaf types regardless of genotype. In both leaf types, pathways involved in carbohydrate and nitrogen metabolism were suppressed by SUB1A, with more severe restriction in growing leaves that have a greater energy demand if SUB1A is absent. In growing leaves, accumulation of and responsiveness to growth-regulating hormones were properly modulated by SUB1A, which correlated with restricted elongation. In mature leaves, submergence-induced auxin accumulation was suppressed by SUB1A. This study demonstrates that different sets of hormonal pathways, both of which are modulated by SUB1A, contribute to distinct adaptive responses to submergence in mature and growing rice leaves.
PMID: 34978355
Org Lett , IF:6.005 , 2022 Mar , V24 (8) : P1616-1619 doi: 10.1021/acs.orglett.2c00121
Photoassisted Cross-Coupling Reaction of alpha-Chlorocarbonyl Compounds with Arylboronic Acids.
Department of Synthetic Chemistry and Biological Chemistry, Kyoto University, Katsura, Kyoto 615-8510, Japan.; Division of Applied Chemistry, Okayama University, Tsushimanaka, Okayama 700-8530, Japan.
A Suzuki-Miyaura cross-coupling reaction of alpha-chloroacetates or alpha-chloroacetamides with arylboronic acids is made possible by visible-light irradiation. This reaction provides a useful method for the synthesis of alpha-arylacetates and alpha-arylacetamides from chlorides under mild reaction conditions. An indole-3-acetic acid derivative that is the key intermediate of the plant hormone auxin can be synthesized from 1-Boc-indole in two steps by combining an iridium-catalyzed C-H borylation and a palladium-catalyzed cross-coupling reaction.
PMID: 35191697
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
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (7) doi: 10.3390/ijms23073945
Jasmonate Signaling Pathway Modulates Plant Defense, Growth, and Their Trade-Offs.
State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou 311300, China.
Lipid-derived jasmonates (JAs) play a crucial role in a variety of plant development and defense mechanisms. In recent years, significant progress has been made toward understanding the JA signaling pathway. In this review, we discuss JA biosynthesis, as well as its core signaling pathway, termination mechanisms, and the evolutionary origin of JA signaling. JA regulates not only plant regeneration, reproductive growth, and vegetative growth but also the responses of plants to stresses, including pathogen as well as virus infection, herbivore attack, and abiotic stresses. We also focus on the JA signaling pathway, considering its crosstalk with the gibberellin (GA), auxin, and phytochrome signaling pathways for mediation of the trade-offs between growth and defense. In summary, JA signals regulate multiple outputs of plant defense and growth and act to balance growth and defense in order to adapt to complex environments.
PMID: 35409303
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (7) doi: 10.3390/ijms23073891
Exploring the Contribution of Autophagy to the Excess-Sucrose Response in Arabidopsis thaliana.
Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
Autophagy is an essential intracellular eukaryotic recycling mechanism, functioning in, among others, carbon starvation. Surprisingly, although autophagy-deficient plants (atg mutants) are hypersensitive to carbon starvation, metabolic analysis revealed that they accumulate sugars under such conditions. In plants, sugars serve as both an energy source and as signaling molecules, affecting many developmental processes, including root and shoot formation. We thus set out to understand the interplay between autophagy and sucrose excess, comparing wild-type and atg mutant seedlings. The presented work showed that autophagy contributes to primary root elongation arrest under conditions of exogenous sucrose and glucose excess but not during fructose or mannitol treatment. Minor or no alterations in starch and primary metabolites were observed between atg mutants and wild-type plants, indicating that the sucrose response relates to its signaling and not its metabolic role. Extensive proteomic analysis of roots performed to further understand the mechanism found an accumulation of proteins essential for ROS reduction and auxin maintenance, which are necessary for root elongation, in atg plants under sucrose excess. The analysis also suggested mitochondrial and peroxisomal involvement in the autophagy-mediated sucrose response. This research increases our knowledge of the complex interplay between autophagy and sugar signaling in plants.
PMID: 35409249
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (7) doi: 10.3390/ijms23073704
Exploring the Effect of Methyl Jasmonate on the Expression of microRNAs Involved in Biosynthesis of Active Compounds of Rosemary Cell Suspension Cultures through RNA-Sequencing.
Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; College of Food and Biological Engineering, Fujian Polytechnic Normal University, Fuqing 350300, China.
Our aim in the experiment was to study the effects of methyl jasmonates (MeJA) on the active compounds of rosemary suspension cells, the metabolites' change of contents under different concentrations of MeJA, including 0 (CK), 10 (M10), 50 (M50) and 100 muM MeJA (M100). The results demonstrated that MeJA treatments promoted the accumulation of rosmarinic acid (RA), carnosic acid (CA), flavonoids, jasmonate (JA), gibberellin (GA), and auxin (IAA); but reduced the accumulations of abscisic acid (ABA), salicylic acid (SA), and aspartate (Asp). In addition, 50 and 100 muM MeJA promoted the accumulation of alanine (Ala) and glutamate (Glu), and 50 muM MeJA promoted the accumulation of linoleic acid and alpha-linolenic acid in rosemary suspension cells. Comparative RNA-sequencing analysis of different concentrations of MeJA showed that a total of 30, 61, and 39 miRNAs were differentially expressed in the comparisons of CKvsM10, CKvsM50, CKvsM100, respectively. The analysis of the target genes of the differentially expressed miRNAs showed that plant hormone signal transduction, linoleic acid, and alpha-linolenic acid metabolism-related genes were significantly enriched. In addition, we found that miR160a-5p target ARF, miR171d_1 and miR171f_3 target DELLA, miR171b-3p target ETR, and miR156a target BRI1, which played a key role in rosemary suspension cells under MeJA treatments. qRT-PCR of 12 differentially expressed miRNAs and their target genes showed a high correlation between the RNA-seq and the qRT-PCR result. Amplification culture of rosemary suspension cells in a 5 L stirred bioreactor showed that cell biomass accumulation in the bioreactor was less than that in the shake flask under the same conditions, and the whole cultivation period was extended to 14 d. Taken together, MeJA promoted the synthesis of the active compounds in rosemary suspension cells in a wide concentration range via concentration-dependent differential expression patterns. This study provided an overall view of the miRNAs responding to MeJA in rosemary.
PMID: 35409063
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (7) doi: 10.3390/ijms23073576
Melatonin Positively Regulates Both Dark- and Age-Induced Leaf Senescence by Reducing ROS Accumulation and Modulating Abscisic Acid and Auxin Biosynthesis in Cucumber Plants.
State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
Melatonin (MT), as a signaling molecule, plays a vital role in regulating leaf senescence in plants. This study aimed to verify the antioxidant roles of MT in delaying dark- or age-induced leaf senescence of cucumber plants. The results showed that endogenous MT responds to darkness and overexpression of CsASMT, the key gene of MT synthesis, and delays leaf senescence stimulated by darkness, as manifested by significantly lower malonaldehyde (MDA) and reactive oxygen species (ROS) contents as well as higher activities and gene expression of antioxidant enzymes compared to the control. Moreover, MT suppressed both age- or dark-induced leaf senescence of cucumber, as evidenced by a decrease in senescence-related gene SAG20 and cell-death-related gene PDCD expression and ROS content and an increase in antioxidant capacity and chlorophyll biosynthesis compared with the H2O-treated seedlings. Meanwhile, the suppression of age-induced leaf senescence by melatonin was also reflected by the reduction in abscisic acid (ABA) biosynthesis and signaling pathways as well as the promotion of auxin (IAA) biosynthesis and signaling pathways in cucumber plants in the solar greenhouse. Combining the results of the two separate experiments, we demonstrated that MT acts as a powerful antioxidant to alleviate leaf senescence by activating the antioxidant system and IAA synthesis and signaling while inhibiting ABA synthesis and signaling in cucumber plants.
PMID: 35408936
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (7) doi: 10.3390/ijms23073422
Integration of Light and Auxin Signaling in Shade Plants: From Mechanisms to Opportunities in Urban Agriculture.
Laboratory of Space Biology, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China.; Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China.
With intensification of urbanization throughout the world, food security is being threatened by the population surge, frequent occurrence of extreme climate events, limited area of available cultivated land, insufficient utilization of urban space, and other factors. Determining the means by which high-yielding and high-quality crops can be produced in a limited space is an urgent priority for plant scientists. Dense planting, vertical production, and indoor cultivation are effective ways to make full use of space and improve the crop yield. The results of physiological and molecular analyses of the model plant species Arabidopsis thaliana have shown that the plant response to shade is the key to regulating the plant response to changes in light intensity and quality by integrating light and auxin signals. In this study, we have summarized the major molecular mechanisms of shade avoidance and shade tolerance in plants. In addition, the biotechnological strategies of enhancing plant shade tolerance are discussed. More importantly, cultivating crop varieties with strong shade tolerance could provide effective strategies for dense planting, vertical production, and indoor cultivation in urban agriculture in the future.
PMID: 35408782
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (6) doi: 10.3390/ijms23063090
BoPEP4, a C-Terminally Encoded Plant Elicitor Peptide from Broccoli, Plays a Role in Salinity Stress Tolerance.
Department of Biotechnology, College of Life Science, Northeast Agricultural University, Harbin 150030, China.
Plant peptide hormones play various roles in plant development, pathogen defense and abiotic stress tolerance. Plant elicitor peptides (Peps) are a type of damage-associated molecular pattern (DAMP) derived from precursor protein PROPEPs. In this study, we identified nine PROPEP genes in the broccoli genome. qRT-PCR analysis indicated that the expression levels of BoPROPEPs were induced by NaCl, ABA, heat, SA and P. syringae DC3000 treatments. In order to study the functions of Peps in salinity stress response, we synthesized BoPep4 peptide, the precursor gene of which, BoPROPEP4, was significantly responsive to NaCl treatment, and carried out a salinity stress assay by exogenous application of BoPep4 in broccoli sprouts. The results showed that the application of 100 nM BoPep4 enhanced tolerance to 200 mM NaCl in broccoli by reducing the Na(+)/K(+) ratio and promoting accumulation of wax and cutin in leaves. Further RNA-seq analysis identified 663 differentially expressed genes (DGEs) under combined treatment with BoPep4 and NaCl compared with NaCl treatment, as well as 1776 genes differentially expressed specifically upon BoPep4 and NaCl treatment. GO and KEGG analyses of these DEGs indicated that most genes were enriched in auxin and ABA signal transduction, as well as wax and cutin biosynthesis. Collectively, this study shows that there was crosstalk between peptide hormone BoPep4 signaling and some well-established signaling pathways under salinity stress in broccoli sprouts, which implies an essential function of BoPep4 in salinity stress defense.
PMID: 35328511
Int J Mol Sci , IF:5.923 , 2022 Mar , V23 (6) doi: 10.3390/ijms23062936
The Photoperiod Stress Response in Arabidopsis thaliana Depends on Auxin Acting as an Antagonist to the Protectant Cytokinin.
Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universitat Berlin, D-14195 Berlin, Germany.; Laboratory of Growth Regulators, Faculty of Science, Palacky University & Institute of Experimental Botany, The Czech Academy of Sciences, Slechtitelu 27, CZ-783 71 Olomouc, Czech Republic.
Fluctuating environmental conditions trigger adaptive responses in plants, which are regulated by phytohormones. During photoperiod stress caused by a prolongation of the light period, cytokinin (CK) has a protective function. Auxin often acts as an antagonist of CK in developmental processes and stress responses. Here, we investigated the regulation of the photoperiod stress response in Arabidopsis thaliana by auxin and its interaction with CK. Transcriptome analysis revealed an altered transcript abundance of numerous auxin metabolism and signaling genes after photoperiod stress treatment. The changes appeared earlier and were stronger in the photoperiod-stress-sensitive CK receptor mutant arabidopsis histidine kinase 2 (ahk2),3 compared to wild-type plants. The concentrations of indole-3-acetic acid (IAA), IAA-Glc and IAA-Asp increased in both genotypes, but the increases were more pronounced in ahk2,3. Genetic analysis revealed that the gain-of-function YUCCA 1 (YUC1) mutant, yuc1D, displayed an increased photoperiod stress sensitivity. In contrast, a loss of the auxin receptors TRANSPORT-INHIBITOR-RESISTANT 1 (TIR1), AUXIN SIGNALING F-BOX 2 (AFB2) and AFB3 in wild-type and ahk2,3 background caused a reduced photoperiod stress response. Overall, this study revealed that auxin promotes response to photoperiod stress antagonizing the protective CK.
PMID: 35328357
PLoS Genet , IF:5.917 , 2022 Mar , V18 (3) : Pe1010077 doi: 10.1371/journal.pgen.1010077
PIN3 positively regulates the late initiation of ovule primordia in Arabidopsis thaliana.
School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, China.; Zhiyuan College, Shanghai Jiao Tong University, Shanghai, China.; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
Ovule initiation determines the maximum ovule number and has great impact on seed number and yield. However, the regulation of ovule initiation remains largely elusive. We previously reported that most of the ovule primordia initiate asynchronously at floral stage 9 and PINFORMED1 (PIN1) polarization and auxin distribution contributed to this process. Here, we further demonstrate that a small amount of ovule primordia initiate at floral stage 10 when the existing ovules initiated at floral stage 9 start to differentiate. Genetic analysis revealed that the absence of PIN3 function leads to the reduction in pistil size and the lack of late-initiated ovules, suggesting PIN3 promotes the late ovule initiation process and pistil growth. Physiological analysis illustrated that, unlike picloram, exogenous application of NAA can't restore these defective phenotypes, implying that PIN3-mediated polar auxin transport is required for the late ovule initiation and pistil length. qRT-PCR results indicated that the expression of SEEDSTICK (STK) is up-regulated under auxin analogues treatment while is down-regulated in pin3 mutants. Meanwhile, overexpressing STK rescues pin3 phenotypes, suggesting STK participates in PIN3-mediated late ovule initiation possibly by promoting pistil growth. Furthermore, brassinosteroid influences the late ovule initiation through positively regulating PIN3 expression. Collectively, this study demonstrates that PIN3 promotes the late ovule initiation and contributes to the extra ovule number. Our results give important clues for increasing seed number and yield of cruciferous and leguminous crops.
PMID: 35245283
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
Front Plant Sci , IF:5.753 , 2022 , V13 : P761244 doi: 10.3389/fpls.2022.761244
Insights Into MicroRNA-Mediated Regulation of Flowering Time in Cotton Through Small RNA Sequencing.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
The timing of flowering is a key determinant for plant reproductive. It has been demonstrated that microRNAs (miRNAs) play an important role in transition from the vegetative to reproductive stage in cotton; however, knowledge remains limited about the regulatory role of miRNAs involved in flowering time regulation in cotton. To elucidate the molecular basis of miRNAs in response to flowering time in cotton, we performed high-throughput small RNA sequencing at the fifth true leaf stage. We identified 56 and 43 miRNAs that were significantly up- and downregulated in two elite early flowering cultivars (EFC) compared with two late flowering cultivars (LFC), respectively. The miRNA targets by RNA sequencing analysis showed that GhSPL4 in SBP transcription factor family targeted by GhmiR156 was significantly upregulated in EFCs. Co-expression regulatory network analysis (WGCNA) revealed that GhSOC1, GhAP1, GhFD, GhCOL3, and GhAGL16 act as node genes in the auxin- and gibberellin-mediated flowering time regulatory networks in cotton. Therefore, elucidation of miRNA-mediated flowering time regulatory network will contribute to our understanding of molecular mechanisms underlying flowering time in cotton.
PMID: 35432420
Front Plant Sci , IF:5.753 , 2022 , V13 : P865302 doi: 10.3389/fpls.2022.865302
Regulation of Phytohormones on the Growth and Development of Plant Root Hair.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.; College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
The tubular-shaped unicellular extensions of plant epidermal cells known as root hairs are important components of plant roots and play crucial roles in absorbing nutrients and water and in responding to stress. The growth and development of root hair include, mainly, fate determination of root hair cells, root hair initiation, and root hair elongation. Phytohormones play important regulatory roles as signal molecules in the growth and development of root hair. In this review, we describe the regulatory roles of auxin, ethylene (ETH), jasmonate (JA), abscisic acid (ABA), gibberellin (GA), strigolactone (SL), cytokinin (CK), and brassinosteroid (BR) in the growth and development of plant root hairs. Auxin, ETH, and CK play positive regulation while BR plays negative regulation in the fate determination of root hair cells; Auxin, ETH, JA, CK, and ABA play positive regulation while BR plays negative regulation in the root hair initiation; Auxin, ETH, CK, and JA play positive regulation while BR, GA, and ABA play negative regulation in the root hair elongation. Phytohormones regulate root hair growth and development mainly by regulating transcription of root hair associated genes, including WEREWOLF (WER), GLABRA2 (GL2), CAPRICE (CPC), and HAIR DEFECTIVE 6 (RHD6). Auxin and ETH play vital roles in this regulation, with JA, ABA, SL, and BR interacting with auxin and ETH to regulate further the growth and development of root hairs.
PMID: 35401627
Front Plant Sci , IF:5.753 , 2022 , V13 : P819658 doi: 10.3389/fpls.2022.819658
Multidimensional Role of Silicon to Activate Resilient Plant Growth and to Mitigate Abiotic Stress.
Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, India.; Centre of Research for Development, University of Kashmir, Srinagar, India.; Department of Biotechnology, School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Oil Crops Research Institute, Center of Legume Crop Genetics and Systems Biology/College of Agriculture, Fujian Agriculture and Forestry University (FAFU), Fuzhou, China.; Department of Chemistry, University of Kashmir, Srinagar, India.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Science, Hangzhou, China.; Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia.; Division of Genetics and Plant Breeding, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, India.; Proteomics Laboratory, Division of Plant Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Srinagar, India.
Sustainable agricultural production is critically antagonistic by fluctuating unfavorable environmental conditions. The introduction of mineral elements emerged as the most exciting and magical aspect, apart from the novel intervention of traditional and applied strategies to defend the abiotic stress conditions. The silicon (Si) has ameliorating impacts by regulating diverse functionalities on enhancing the growth and development of crop plants. Si is categorized as a non-essential element since crop plants accumulate less during normal environmental conditions. Studies on the application of Si in plants highlight the beneficial role of Si during extreme stressful conditions through modulation of several metabolites during abiotic stress conditions. Phytohormones are primary plant metabolites positively regulated by Si during abiotic stress conditions. Phytohormones play a pivotal role in crop plants' broad-spectrum biochemical and physiological aspects during normal and extreme environmental conditions. Frontline phytohormones include auxin, cytokinin, ethylene, gibberellin, salicylic acid, abscisic acid, brassinosteroids, and jasmonic acid. These phytohormones are internally correlated with Si in regulating abiotic stress tolerance mechanisms. This review explores insights into the role of Si in enhancing the phytohormone metabolism and its role in maintaining the physiological and biochemical well-being of crop plants during diverse abiotic stresses. Moreover, in-depth information about Si's pivotal role in inducing abiotic stress tolerance in crop plants through metabolic and molecular modulations is elaborated. Furthermore, the potential of various high throughput technologies has also been discussed in improving Si-induced multiple stress tolerance. In addition, a special emphasis is engrossed in the role of Si in achieving sustainable agricultural growth and global food security.
PMID: 35401625
Front Plant Sci , IF:5.753 , 2022 , V13 : P861706 doi: 10.3389/fpls.2022.861706
GhLBDs Promote Callus Initiation and Act as Selectable Markers to Increase Transformation Efficiency.
Engineering Research Centre of Cotton, Ministry of Education, College of Agriculture, Xinjiang Agricultural University, Urumqi, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.; Research Base of State Key Laboratory of Cotton Biology, Henan Normal University, Xinxiang, China.
Detached organs or differentiated tissues could form a mass of pluripotent cells termed as callus on an auxin-rich medium, the underlying molecular mechanism of which remains elusive in cotton. LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor is a key regulator of plant cell totipotency/pluripotency, and a number of cotton GhLBDs with high-level differential expression during the callus induction process have been identified. Their overexpression in cotton calli fostered promotions in and callus induction without exogenous auxin. Expression analysis and histological observation using paraffin sectioning suggested that the first 72 h on culture is a key time point for callus initiation, whereby the GhLBDs showed high transcript abundance and enlarged calli that were rapidly developed from procambium and cambium. GhLBDs' expression level could be precisely modulated by the gradient concentrations of exogenous auxin, whereas auxin transport inhibitor 2,3,5-triiodobenzoic acid could severely inhibit its expression. The LBD-mediated callus formation was also dependent on the expression levels of GhLBDs. Further, a beta-estradiol-inducible promoter pER8 was used to drive GhLBD18-1 expression, which led to rapid callus proliferation, suggesting that pER8/GhLBD18-1 could be used as a selectable marker system to replace the existing antibiotic/herbicide-resistance selectable markers in plant transformation. Our study provides new insights for callus initiation regulatory mechanism and strategies for improving transformation efficiency in cotton.
PMID: 35401622
Front Plant Sci , IF:5.753 , 2022 , V13 : P865542 doi: 10.3389/fpls.2022.865542
Phytohormonal Regulation Through Protein S-Nitrosylation Under Stress.
Laboratory of Plant Molecular Pathology and Functional Genomics, Department of Plant Biosciences, School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea.; Laboratory of Cell Biology, Department of Entomology, Abdul Wali Khan University, Mardan, Pakistan.; Department of Horticultural Sciences, Kyungpook National University, Daegu, South Korea.
The liaison between Nitric oxide (NO) and phytohormones regulates a myriad of physiological processes at the cellular level. The interaction between NO and phytohormones is mainly influenced by NO-mediated post-translational modifications (PTMs) under basal as well as induced conditions. Protein S-nitrosylation is the most prominent and widely studied PTM among others. It is the selective but reversible redox-based covalent addition of a NO moiety to the sulfhydryl group of cysteine (Cys) molecule(s) on a target protein to form S-nitrosothiols. This process may involve either direct S-nitrosylation or indirect S-nitrosylation followed by transfer of NO group from one thiol to another (transnitrosylation). During S-nitrosylation, NO can directly target Cys residue (s) of key genes involved in hormone signaling thereby regulating their function. The phytohormones regulated by NO in this manner includes abscisic acid, auxin, gibberellic acid, cytokinin, ethylene, salicylic acid, jasmonic acid, brassinosteroid, and strigolactone during various metabolic and physiological conditions and environmental stress responses. S-nitrosylation of key proteins involved in the phytohormonal network occurs during their synthesis, degradation, or signaling roles depending upon the response required to maintain cellular homeostasis. This review presents the interaction between NO and phytohormones and the role of the canonical NO-mediated post-translational modification particularly, S-nitrosylation of key proteins involved in the phytohormonal networks under biotic and abiotic stresses.
PMID: 35401598
Front Plant Sci , IF:5.753 , 2022 , V13 : P830840 doi: 10.3389/fpls.2022.830840
Antagonistic Effect of Sucrose Availability and Auxin on Rosa Axillary Bud Metabolism and Signaling, Based on the Transcriptomics and Metabolomics Analysis.
Dryland-Technology Key Laboratory of Shandong Province, College of Agronomy, Qingdao Agricultural University, Qingdao, China.; Institut Agro, University of Angers INRAE, IRHS, SFR QUASAV, Angers, France.; Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Universite Paris-Sud, Universite d'Evry, Universite Paris-Saclay, Gif-sur-Yvette, France.; Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Universite Paris-Saclay, Versailles, France.
Shoot branching is crucial for successful plant development and plant response to environmental factors. Extensive investigations have revealed the involvement of an intricate regulatory network including hormones and sugars. Recent studies have demonstrated that two major systemic regulators-auxin and sugar-antagonistically regulate plant branching. However, little is known regarding the molecular mechanisms involved in this crosstalk. We carried out two complementary untargeted approaches-RNA-seq and metabolomics-on explant stem buds fed with different concentrations of auxin and sucrose resulting in dormant and non-dormant buds. Buds responded to the combined effect of auxin and sugar by massive reprogramming of the transcriptome and metabolome. The antagonistic effect of sucrose and auxin targeted several important physiological processes, including sink strength, the amino acid metabolism, the sulfate metabolism, ribosome biogenesis, the nucleic acid metabolism, and phytohormone signaling. Further experiments revealed a role of the TOR-kinase signaling pathway in bud outgrowth through at least downregulation of Rosa hybrida BRANCHED1 (RhBRC1). These new findings represent a cornerstone to further investigate the diverse molecular mechanisms that drive the integration of endogenous factors during shoot branching.
PMID: 35392520
Front Plant Sci , IF:5.753 , 2022 , V13 : P857611 doi: 10.3389/fpls.2022.857611
miR160 Interacts in vivo With Pinus pinaster AUXIN RESPONSE FACTOR 18 Target Site and Negatively Regulates Its Expression During Conifer Somatic Embryo Development.
Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal.; Instituto Gulbenkian de Ciencia, Oeiras, Portugal.; GREEN-IT Bioresources for Sustainability, ITQB NOVA, Oeiras, Portugal.; INESC-ID, Instituto Superior Tecnico, Universidade de Lisboa, Lisbon, Portugal.; Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid (UCM), Madrid, Spain.; Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Coimbra, Portugal.; Instituto de Biologia Experimental e Tecnologica, Oeiras, Portugal.
MicroRNAs (miRNAs) are key regulators of several plant developmental processes including embryogenesis. Most miRNA families are conserved across major groups of plant species, but their regulatory roles have been studied mainly in model species like Arabidopsis and other angiosperms. In gymnosperms, miRNA-dependent regulation has been less studied since functional approaches in these species are often difficult to establish. Given the fundamental roles of auxin signaling in somatic embryogenesis (SE) induction and embryo development, we investigated a previously predicted interaction between miR160 and a putative target encoding AUXIN RESPONSE FACTOR 18 in Pinus pinaster (PpARF18) embryonic tissues. Phylogenetic analysis of AUXIN RESPONSE FACTOR 18 (ARF18) from Pinus pinaster and Picea abies, used here as a model system of conifer embryogenesis, showed their close relatedness to AUXIN RESPONSE FACTOR (ARF) genes known to be targeted by miR160 in other species, including Arabidopsis ARF10 and ARF16. By using a luciferase (LUC) reporter system for miRNA activity in Arabidopsis protoplasts, we have confirmed that P. pinaster miR160 (ppi-miR160) interacts in vivo with PpARF18 target site. When the primary miR160 from P. pinaster was overexpressed in protoplasts under non-limiting levels of ARGONAUTE1, a significant increase of miR160 target cleavage activity was observed. In contrast, co-expression of the primary miRNA and the target mimic MIM160 led to a decrease of miR160 activity. Our results further support that this interaction is functional during consecutive stages of SE in the conifer model P. abies. Expression analyses conducted in five stages of development, from proembryogenic masses (PEMs) to the mature embryo, show that conifer ARF18 is negatively regulated by miR160 toward the fully developed mature embryo when miR160 reached its highest expression level. This study reports the first in vivo validation of a predicted target site of a conifer miRNA supporting the conservation of miR160 interaction with ARF targets in gymnosperms. The approach used here should be useful for future characterization of miRNA functions in conifer embryogenesis.
PMID: 35371172
Front Plant Sci , IF:5.753 , 2022 , V13 : P842832 doi: 10.3389/fpls.2022.842832
Silicon Application Differentially Modulates Root Morphology and Expression of PIN and YUCCA Family Genes in Soybean (Glycine max L.).
Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea.
Silicon (Si) is absorbed and accumulated by some plant species; it has been shown to improve plant growth and performance. The beneficial role of Si in plants is based on the fundamental assumptions, and the biological function of Si is still being researched due to its complex nature, distinctiveness, and interaction. The present study included two distinct experiment sets: a screening test and an advanced test. In the initial examination, we used 21 soybean (Glycine max L.) cultivars. Following the evaluation, we chose four cultivars to investigate further. In particular, the positive response cultivars, Taeseon and Geomjeongsaeol, showed a 14% increase in net photosynthesis (P N ), and a 19-26% increase in transpiration in Si-treated plants when compared to the control plants. Si-treated Taeseon, Geomjeongsaeol, and Somyongkong, Mallikong cultivars showed significant differences in root morphological traits (RMTs) and root system architecture (RSA) when compared to the control plants. Taeseon and Geomjeongsaeol showed a 26 and 46% increase in total root length (TRL) after Si application, respectively, compared to the control, whereas Mallikong and Somyongkong showed 26 and 20% decrease in TRL after Si treatment, respectively, compared to the control. The Si application enhanced the overall RMTs and RSA traits in Taeseon and Geomjeongsaeol; however, the other two cultivars, Somyongkong and Mallikong, showed a decrease in such RMTs and RATs. Furthermore, to understand the underlying molecular mechanism and the response of various cultivars, we measured the Si content and analyzed the gene expression of genes involved in auxin transport and root formation and development. We showed that the Si content significantly increased in the Si-treated Somyongkong (28%) and Taeseon (30%) compared to the control cultivars. Overall, our results suggested that Si affects root development as well as the genes involved in the auxin synthesis, transport pathway, and modulates root growth leading to cultivar-dependent variation in soybeans.
PMID: 35371163
Front Plant Sci , IF:5.753 , 2022 , V13 : P849532 doi: 10.3389/fpls.2022.849532
MAG2 and MAL Regulate Vesicle Trafficking and Auxin Homeostasis With Functional Redundancy.
Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, College of Life Sciences, Ministry of Education, Northeast Forestry University, Harbin, China.; Institute of Crop Science, Zhejiang University, Hangzhou, China.; Shanghai Center for Plant Stress Biology, Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
Auxin is a central phytohormone and controls almost all aspects of plant development and stress response. Auxin homeostasis is coordinately regulated by biosynthesis, catabolism, transport, conjugation, and deposition. Endoplasmic reticulum (ER)-localized MAIGO2 (MAG2) complex mediates tethering of arriving vesicles to the ER membrane, and it is crucial for ER export trafficking. Despite important regulatory roles of MAG2 in vesicle trafficking, the mag2 mutant had mild developmental abnormalities. MAG2 has one homolog protein, MAG2-Like (MAL), and the mal-1 mutant also had slight developmental phenotypes. In order to investigate MAG2 and MAL regulatory function in plant development, we generated the mag2-1 mal-1 double mutant. As expected, the double mutant exhibited serious developmental defects and more alteration in stress response compared with single mutants and wild type. Proteomic analysis revealed that signaling, metabolism, and stress response in mag2-1 mal-1 were affected, especially membrane trafficking and auxin biosynthesis, signaling, and transport. Biochemical and cell biological analysis indicated that the mag2-1 mal-1 double mutant had more serious defects in vesicle transport than the mag2-1 and mal-1 single mutants. The auxin distribution and abundance of auxin transporters were altered significantly in the mag2-1 and mal-1 single mutants and mag2-1 mal-1 double mutant. Our findings suggest that MAG2 and MAL regulate plant development and auxin homeostasis by controlling membrane trafficking, with functional redundancy.
PMID: 35371137
Front Plant Sci , IF:5.753 , 2022 , V13 : P797433 doi: 10.3389/fpls.2022.797433
Comparative Transcriptome Analysis of Hard and Tender Fruit Spines of Cucumber to Identify Genes Involved in the Morphological Development of Fruit Spines.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.; Committee of Agriculture and Rural Areas of Jinshan District, Shanghai, China.; Tianjin Derit Seeds Company Limited, Tianjin, China.
The spines of cucumber fruit not only have important commercial value but are also a classical tissue to study cell division and differentiation modes of multicellular trichomes. It has been reported that CsTs (C-type Lectin receptor-like kinase) can influence the development of fruit spines. In this study, we took a pair of cucumber materials defined as hard (Ts, wild type) and tender spines (ts, mutant) and defined the developmental process of fruit spines as consisting of four stages (stage I to stage IV) by continuously observing by microscope and SEM. Comparisons of transcriptome profiles at different development stages of wild-type spines showed that 803 and 722 genes were upregulated in the stalk (stage II and stage III) and base (stage IV) development stages of fruit spines, respectively. The function analysis of DEGs showed that genes related to auxin polar transport and HD-ZIP transcription factor are significantly upregulated during the development of the stalk. bHLH transcription factors and cytoskeleton-related genes were significantly upregulated during the development of the base. In addition, stage III is the key point for the difference between wild-type and mutant spines. We detected 628 DEGs between wild type and mutant at stage III. These DEGs are mainly involved in the calcium signaling of the cytoskeleton and auxin polar transport. Coincidentally, we found that CsVTI11, a factor involved in auxin signal transmission, can interact with CsTs in vivo, but this interaction does not occur between CsVTI11 and Csts, further suggesting that CsTs may regulate the development of fruit spines by influencing cell polarity. These results provide useful tools to study the molecular networks associated with cucumber fruit spine development and elucidate the biological pathways that C-type Lectin receptor-like kinase plays in regulating the development of fruit spines.
PMID: 35371132
Front Plant Sci , IF:5.753 , 2022 , V13 : P866193 doi: 10.3389/fpls.2022.866193
Molecular Dissection Unveiling Dwarfing Effects of Plant Growth Retardants on Pomegranate.
College of Agriculture, Anhui Science and Technology University, Fengyang, China.; State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Guangzhou, China.; State Key Laboratory of Biocontrol, School of Life Science, Sun Yat-sen University, Guangzhou, China.; School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China.
Dwarfed stature is a desired trait for modern orchard production systems. One effective strategy for dwarfing cultivation is exogenously applying plant growth retardants (PGRs) to plants. However, for many economic fruit trees, the current knowledge on the regulatory mechanisms underlying the dwarfing effect of PGRs is limited, which largely restricts the agricultural application of PGRs. In this study, we exogenously applied three kinds of PGRs [paclobutrazol, daminozide (B9), and mannitol] to the seedlings of pomegranate (Punica granatum L.) and performed comparative transcriptome analysis to elucidate the molecular features of PGR-induced dwarfing in pomegranates. Our results showed that all the three PGRs could significantly suppress plant growth of pomegranate. The inhibition of auxin biosynthetic processes, as well as auxin-mediated shoot development, may be considered as the main reason for the dwarfing. Besides that, different PGRs were also found to induce dwarfing via specific mechanisms, for example, cellular response to strigolactone was particularly suppressed by the application of paclobutrazol, while the level of carbohydrate homeostasis and metabolism were downregulated in conditions of either B9 or mannitol treatments. Furthermore, exogenous PGR application was supposed to cause adverse impacts on the normal physiological process of pomegranate seedlings, which may bring extra burden to pomegranate plants. These novel findings unveiled the genetic basis underlying the dwarfing in pomegranates, which provides deeper insights into PGR-mediated dwarfing cultivation of pomegranates.
PMID: 35360308
Front Plant Sci , IF:5.753 , 2022 , V13 : P833747 doi: 10.3389/fpls.2022.833747
ARF6s Identification and Function Analysis Provide Insights Into Flower Development of Punica granatum L.
Co-innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.; College of Forestry, Nanjing Forestry University, Nanjing, China.
Based on the genome and small-RNA sequencing of pomegranate, miRNA167 and three target genes PgARF6 were identified in "Taishanhong" genome. Three PgARF6 genes and their corresponding protein sequences, expression patterns in pomegranate flower development and under exogenous hormones treatments were systematically analyzed in this paper. We found that PgARF6s are nuclear proteins with conserved structures. However, PgARF6s had different protein structures and expression profiles in pomegranate flower development. At the critical stages of pomegranate ovule sterility (8.1-14.0 mm), the expression levels of PgARF6s in bisexual flowers were lower than those in functional male flowers. Interestingly, PgARF6c expression level was significantly higher than PgARF6a and PgARF6b. Under the treatment of exogenous IBA and 6-BA, PgARF6s were down-regulated, and the expression of PgARF6c was significantly inhibited. PgmiR167a and PgmiR167d had the binding site on PgARF6 genes sequences, and PgARF6a has the directly targeted regulatory relationship with PgmiR167a in pomegranate. At the critical stage of ovule development (8.1-12.0 mm), exogenous IBA and 6-BA promoted the content of GA and ZR accumulation, inhibited BR accumulation. There was a strong correlation between the expression of PgARF6a and PgARF6b. Under exogenous hormone treatment, the content of ZR, BR, GA, and ABA were negatively correlated with the expressions of PgARF6 genes. However, JA was positively correlated with PgARF6a and PgARF6c under IBA treatment. Thus, our results provide new evidence for PgARF6 genes involving in ovule sterility in pomegranate flowers.
PMID: 35321445
FEBS J , IF:5.542 , 2022 Apr , V289 (7) : P1731-1745 doi: 10.1111/febs.16210
Plant programmed cell death meets auxin signalling.
School of Biology and Environmental Science, Science Centre, University College Dublin, Dublin, Ireland.
Both auxin signalling and programmed cell death (PCD) are essential components of a normally functioning plant. Auxin underpins plant growth and development, as well as regulating plant defences against environmental stresses. PCD, a genetically controlled pathway for selective elimination of redundant, damaged or infected cells, is also a key element of many developmental processes and stress response mechanisms in plants. An increasing body of evidence suggests that auxin signalling and PCD regulation are often connected. While generally auxin appears to suppress cell death, it has also been shown to promote PCD events, most likely via stimulation of ethylene biosynthesis. Intriguingly, certain cells undergoing PCD have also been suggested to control the distribution of auxin in plant tissues, by either releasing a burst of auxin or creating an anatomical barrier to auxin transport and distribution. These recent findings indicate novel roles of localized PCD events in the context of plant development such as control of root architecture, or tissue regeneration following injury, and suggest exciting possibilities for incorporation of this knowledge into crop improvement strategies.
PMID: 34543510
J Agric Food Chem , IF:5.279 , 2022 Mar , V70 (9) : P2777-2788 doi: 10.1021/acs.jafc.1c07224
Regulatory Mechanism of the Constitutive Photomorphogenesis 9 Signalosome Complex in Response to Abiotic Stress in Plants.
College of Life Science, Key Laboratory of Straw Biology and Higher Value Application, Ministry of Education, Jilin Agricultural University, Changchun, Jilin 130118, People's Republic of China.; School of Public Health, Jilin Medical University, Jilin, Jilin 132013, People's Republic of China.; Food Science and Engineering, Jilin Agricultural University, Changchun, Jilin 130118, People's Republic of China.; College of Food and Biotechnology, Changchun Polytechnic, Changchun, Jilin 130033, People's Republic of China.; College of Resources and Environment, Jilin Agricultural University, Changchun, Jilin 130118, People's Republic of China.
The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is a highly conserved protein complex that regulates signaling pathways in plants under abiotic stress. We discuss the potential molecular mechanisms of CSN under abiotic stress, including oxidative stress with reactive oxygen species signaling, salt stress with jasmonic acid, gibberellic acid, and abscisic acid signaling, high-temperature stress with auxin signaling, and optical radiation with DNA damage and repair response. We conclude that CSN likely participates in affecting antioxidant biosynthesis and hormone signaling by targeting receptors, kinases, and transcription factors in response to abiotic stress, which potentially provides valuable information for engineering stress-tolerant crops.
PMID: 35199516
J Agric Food Chem , IF:5.279 , 2022 Mar , V70 (8) : P2545-2553 doi: 10.1021/acs.jafc.1c07750
Dicationic Herbicidal Ionic Liquids Comprising Two Active Ingredients Exhibiting Different Modes of Action.
Department of Chemical Technology, Poznan University of Technology, Poznan 60-965, Poland.; Institute of Plant Protection - National Research Institute, Poznan 60-318, Poland.
In the framework of this study, dicationic herbicidal ionic liquids (HILs) containing tetramethylene-1,4-bis(decyldimethylammonium) and dodecylmethylene-1,12-bis(decyldimethylammonium), including two different herbicidal anions exhibiting different modes of action, were synthesized and characterized. One herbicide incorporated into the HILs was a tribenuron-methyl belonging to ALS inhibitors, while the second herbicidal anion was a synthetic auxin that acts as a growth regulator, namely 2,4-dichlorophenoxyacetate (2,4-D), 2-(2,4-dichlorophenoxy)propionate, (2,4-DP), 2,4,5-trichlorophenoxyacetate (2,4,5-T), 4-chloro-2-methylphenoxyacetiate (MCPA), 2-(4-chloro-2-methylphenoxy)propionate (MCPP), and 4-chlorophenoxyacetate (4-CPA). The obtained products were found to be unstable and decomposed, which can be attributed to the presence of an additional methyl group within the sulfonylurea bridge of the tribenuron-methyl. The synthesized HILs exhibited good affinity with polar and semipolar solvents, with ethyl acetate and hexane as the only solvents that did not dissolve the HILs. Greenhouse tests demonstrated that most of the obtained HILs were more effective than the reference herbicide containing tribenuron-methyl. The length of the alkyl chain in the cation also influenced the effectiveness of the HILs. Better effects were observed for dodecylmethylene-1,12-bis(decyldimethylammonium) cations compared to tetramethylene-1,4-bis(decyldimethylammonium). Therefore, the novel dicatonic HILs showed to integrate the advent of the combination of the different herbicides into a single molecule, enhance herbicidal efficacy, and reduce the risk of weed resistance due to the various modes of action of the applied treatment.
PMID: 35170944
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 Methods , IF:4.993 , 2022 Mar , V18 (1) : P38 doi: 10.1186/s13007-022-00864-4
MultipleXLab: A high-throughput portable live-imaging root phenotyping platform using deep learning and computer vision.
Laboratory of Plant Cell and Developmental Biology (LPCDB), Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.; Ipsumio B.V., High Tech Campus, 5656, Eindhoven, AE, Netherlands.; Sensors Lab, Advanced Membranes and Porous Materials Center (AMPMC), Computer, Electrical and Mathematical Science and Engineering (CEMSE), KAUST, Thuwal, Saudi Arabia.; Laboratory of Plant Cell and Developmental Biology (LPCDB), Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia. Ikram.Blilou@kaust.edu.sa.
BACKGROUND: Profiling the plant root architecture is vital for selecting resilient crops that can efficiently take up water and nutrients. The high-performance imaging tools available to study root-growth dynamics with the optimal resolution are costly and stationary. In addition, performing nondestructive high-throughput phenotyping to extract the structural and morphological features of roots remains challenging. RESULTS: We developed the MultipleXLab: a modular, mobile, and cost-effective setup to tackle these limitations. The system can continuously monitor thousands of seeds from germination to root development based on a conventional camera attached to a motorized multiaxis-rotational stage and custom-built 3D-printed plate holder with integrated light-emitting diode lighting. We also developed an image segmentation model based on deep learning that allows the users to analyze the data automatically. We tested the MultipleXLab to monitor seed germination and root growth of Arabidopsis developmental, cell cycle, and auxin transport mutants non-invasively at high-throughput and showed that the system provides robust data and allows precise evaluation of germination index and hourly growth rate between mutants. CONCLUSION: MultipleXLab provides a flexible and user-friendly root phenotyping platform that is an attractive mobile alternative to high-end imaging platforms and stationary growth chambers. It can be used in numerous applications by plant biologists, the seed industry, crop scientists, and breeding companies.
PMID: 35346267
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 Mar , V63 (3) : P384-400 doi: 10.1093/pcp/pcac004
Diminished Auxin Signaling Triggers Cellular Reprogramming by Inducing a Regeneration Factor in the Liverwort Marchantia polymorpha.
Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502 Japan.; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510 Japan.; RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, 230-0045 Japan.; Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan.; Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601 Japan.
Regeneration in land plants is accompanied by the establishment of new stem cells, which often involves reactivation of the cell division potential in differentiated cells. The phytohormone auxin plays pivotal roles in this process. In bryophytes, regeneration is enhanced by the removal of the apex and repressed by exogenously applied auxin, which has long been proposed as a form of apical dominance. However, the molecular basis behind these observations remains unexplored. Here, we demonstrate that in the liverwort Marchantia polymorpha, the level of endogenous auxin is transiently decreased in the cut surface of decapitated explants, and identify by transcriptome analysis a key transcription factor gene, LOW-AUXIN RESPONSIVE (MpLAXR), which is induced upon auxin reduction. Loss of MpLAXR function resulted in delayed cell cycle reactivation, and transient expression of MpLAXR was sufficient to overcome the inhibition of regeneration by exogenously applied auxin. Furthermore, ectopic expression of MpLAXR caused cell proliferation in normally quiescent tissues. Together, these data indicate that decapitation causes a reduction of auxin level at the cut surface, where, in response, MpLAXR is up-regulated to trigger cellular reprogramming. MpLAXR is an ortholog of Arabidopsis ENHANCER OF SHOOT REGENERATION 1/DORNROSCHEN, which has dual functions as a shoot regeneration factor and a regulator of axillary meristem initiation, the latter of which requires a low auxin level. Thus, our findings provide insights into stem cell regulation as well as apical dominance establishment in land plants.
PMID: 35001102
Plant Cell Physiol , IF:4.927 , 2022 Mar , V63 (3) : P305-316 doi: 10.1093/pcp/pcab172
Auxin Efflux Transporters OsPIN1c and OsPIN1d Function Redundantly in Regulating Rice (Oryza sativa L.) Panicle Development.
College of Agriculture, Nanjing Agricultural University, No.1 Weigang, Nanjing 210095, People's Republic of China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, No.1 Weigang, Nanjing 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry, Nanjing Agricultural University, No.1 Weigang, Nanjing 210095, People's Republic of China.
The essential role of auxin in plant growth and development is well known. Pathways related to auxin synthesis, transport and signaling have been extensively studied in recent years, and the PIN-FORMED (PIN) protein family has been identified as being pivotal for polar auxin transport and distribution. However, research focused on the functional characterization of PIN proteins in rice is still lacking. In this study, we investigated the expression and function of OsPIN1c and OsPIN1d in the japonica rice variety (Nipponbare) using gene knockout and high-throughput RNA sequencing analysis. The results showed that OsPIN1c and OsPIN1d were mainly expressed in young panicles and exhibited a redundant function. Furthermore, OsPIN1c or OsPIN1d loss-of-function mutants presented a mild phenotype compared with the wild type. However, in addition to significantly decreased plant height and tiller number, panicle development was severely disrupted in double-mutant lines of OsPIN1c and OsPIN1d. Severe defects included smaller inflorescence meristem and panicle sizes, fewer primary branches, elongated bract leaves, non-degraded hair and no spikelet growth. Interestingly, ospin1cd-3, a double-mutant line with functional retention of OsPIN1d, showed milder defects than those observed in other mutants. Additionally, several critical regulators of reproductive development, such as OsPID, LAX1, OsMADS1 and OsSPL14/IPA1, were differentially expressed in ospin1c-1 ospin1d-1, supporting the hypothesis that OsPIN1c and OsPIN1d are involved in regulating panicle development. Therefore, this study provides novel insights into the auxin pathways that regulate plant reproductive development in monocots.
PMID: 34888695
Pest Manag Sci , IF:4.845 , 2022 Mar doi: 10.1002/ps.6863
Soybean Dose-Response to 2,4-D and Dicamba at Vegetative and Reproductive Growth Stages.
Former Graduate Student, Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America.; Research Technician, Department of Agronomy and Horticulture, University of Nebraska-Lincoln, West Central Research and Extension Center, North Platte, NE, 69101, United States of America.; Former Graduate Student, Department of Agronomy and Horticulture, University of Nebraska-Lincoln, West Central Research and Extension Center, North Platte, NE, 69101, United States of America.; Endowed Chair, Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America.; Extension Specialist, Department of Agronomy and Horticulture, University of Nebraska-Lincoln, West Central Research and Extension Center, North Platte, NE, 69101, United States of America.; Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, 39762, United States of America.; Commercial Agronomist, Corteva Agriscience, Wilmington, DE, 19805, United States of America.; Extension Weed Scientist, Department of Crop, Soil and Environmental Sciences, University of Arkansas, Lonoke, AR, 72086, United States of America.
PMID: 35254733
Appl Environ Microbiol , IF:4.792 , 2022 Mar , V88 (6) : Pe0216021 doi: 10.1128/aem.02160-21
Phloroglucinol Promotes Fucoxanthin Synthesis by Activating the cis-Zeatin and Brassinolide Pathways in Thalassiosira pseudonana.
College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China.; School of Marine Sciences, Ningbo University, Ningbo, China.; Affiliated Hospital of Medical School of Ningbo University, Ningbo, China.
Phloroglucinol improves shoot formation and somatic embryogenesis in several horticultural and grain crops, but its function in microalgae remains unclear. Here, we found that sufficiently high concentrations of phloroglucinol significantly increased fucoxanthin synthesis, growth, and photosynthetic efficiency in the microalga Thalassiosira pseudonana. These results suggested that the role of phloroglucinol is conserved across higher plants and microalgae. Further analysis showed that, after phloroglucinol treatment, the contents of cis-zeatin and brassinolide in T. pseudonana increased significantly, while the contents of trans-zeatin, N(6)-isopentenyladenine (iP), auxin, and gibberellin were unaffected. Indeed, functional studies showed that the effects of cis-zeatin and brassinolide in T. pseudonana were similar to those of phloroglucinol. Knockout of key enzyme genes in the cis-zeatin synthesis pathway of T. pseudonana or treatment of T. pseudonana with a brassinolide synthesis inhibitor (brassinazole) significantly reduced growth and fucoxanthin content in T. pseudonana, and phloroglucinol treatment partially alleviated these inhibitory effects. However, phloroglucinol treatment was ineffective when the cis-zeatin and brassinolide pathways were simultaneously inhibited. These results suggested that the cis-zeatin and brassinolide signaling pathways are independent regulators of fucoxanthin synthesis in T. pseudonana and that phloroglucinol affects both pathways. Thus, this study not only characterizes the mechanism by which phloroglucinol promotes fucoxanthin synthesis but also demonstrates the roles of cis-zeatin and brassinolide in T. pseudonana. IMPORTANCE Here, we demonstrate that phloroglucinol, a growth promoter in higher plants, also increases growth and fucoxanthin synthesis in the microalga Thalassiosira pseudonana and therefore may have substantial practical application for industrial fucoxanthin production. Phloroglucinol treatment also induced the synthesis of cis-zeatin and brassinolide in T. pseudonana, and the cis-zeatin and brassinolide signaling pathways were implicated in the phloroglucinol-driven increases in T. pseudonana growth and fucoxanthin synthesis. Thus, our work clarified the molecular mechanism of phloroglucinol promoting the growth and fucoxanthin synthesis of Thalassiosira pseudonana and suggested that cis-zeatin and brassinolide, in addition to phloroglucinol, have potential utility as inducers of increased microalgal fucoxanthin production.
PMID: 35108066
Plant Sci , IF:4.729 , 2022 Apr , V317 : P110995 doi: 10.1016/j.plantsci.2021.110995
Gibberellins regulate lateral root development that is associated with auxin and cell wall metabolisms in cucumber.
State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Vegetable Germplasm Innovation and Utilization of Hebei, Collaborative Innovation Center of Vegetable Industry in Hebei, College of Horticulture, Hebei Agricultural University, Baoding, 071001, China. Electronic address: bingbing-cai@163.com.; College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China. Electronic address: 903067078@qq.com.; College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China. Electronic address: sunh95@163.com.; National Centre for Plant Gene Research (Beijing), Innovation Academy for Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. Electronic address: liucuimei@genetics.ac.cn.; National Centre for Plant Gene Research (Beijing), Innovation Academy for Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China. Electronic address: jfchu@genetics.ac.cn.; College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China; State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, Tai'an, Shandong, 271018, China. Electronic address: zhren@sdau.edu.cn.; State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Vegetable Germplasm Innovation and Utilization of Hebei, Collaborative Innovation Center of Vegetable Industry in Hebei, College of Horticulture, Hebei Agricultural University, Baoding, 071001, China. Electronic address: lqsdau@163.com.
Cucumber is an economically important crop cultivated worldwide. Gibberellins (GAs) play important roles in the development of lateral roots (LRs), which are critical for plant stress tolerance and productivity. Therefore, it is of great importance for cucumber production to study the role of GAs in LR development. Here, the results showed that GAs regulated cucumber LR development in a concentration-dependent manner. Treatment with 1, 10, 50 and 100 muM GA3 significantly increased secondary root length, tertiary root number and length. Of these, 50 muM GA3 treatment had strong effects on increasing root dry weight and the root/shoot dry weight ratio. Pairwise comparisons identified 417 down-regulated genes enriched for GA metabolism-related processes and 447 up-regulated genes enriched for cell wall metabolism-related processes in GA3-treated roots. A total of 3523 non-redundant DEGs were identified in our RNA-Seq data through pairwise comparisons and linear factorial modeling. Of these, most of the genes involved in auxin and cell wall metabolisms were up-regulated in GA3-treated roots. Our findings not only shed light on LR regulation mediated by GA but also offer an important resource for functional studies of candidate genes putatively involved in the regulation of LR development in cucumber and other crops.
PMID: 35193752
Front Genet , IF:4.599 , 2021 , V12 : P805771 doi: 10.3389/fgene.2021.805771
RNA-Seq and Gene Regulatory Network Analyses Uncover Candidate Genes in the Early Defense to Two Hemibiotrophic Colletorichum spp. in Strawberry.
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States.; Department of Horticultural Science, North Carolina State University, Raleigh, NC, United States.; Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States.
Two hemibiotrophic pathogens, Colletotrichum acutatum (Ca) and C. gloeosporioides (Cg), cause anthracnose fruit rot and anthracnose crown rot in strawberry (Fragaria x ananassa Duchesne), respectively. Both Ca and Cg can initially infect through a brief biotrophic phase, which is associated with the production of intracellular primary hyphae that can infect host cells without causing cell death and establishing hemibiotrophic infection (HBI) or quiescent (latent infections) in leaf tissues. The Ca and Cg HBI in nurseries and subsequent distribution of asymptomatic infected transplants to fruit production fields is the major source of anthracnose epidemics in North Carolina. In the absence of complete resistance, strawberry varieties with good fruit quality showing rate-reducing resistance have frequently been used as a source of resistance to Ca and Cg. However, the molecular mechanisms underlying the rate-reducing resistance or susceptibility to Ca and Cg are still unknown. We performed comparative transcriptome analyses to examine how rate-reducing resistant genotype NCS 10-147 and susceptible genotype 'Chandler' respond to Ca and Cg and identify molecular events between 0 and 48 h after the pathogen-inoculated and mock-inoculated leaf tissues. Although plant response to both Ca and Cg at the same timepoint was not similar, more genes in the resistant interaction were upregulated at 24 hpi with Ca compared with those at 48 hpi. In contrast, a few genes were upregulated in the resistant interaction at 48 hpi with Cg. Resistance response to both Ca and Cg was associated with upregulation of MLP-like protein 44, LRR receptor-like serine/threonine-protein kinase, and auxin signaling pathway, whereas susceptibility was linked to modulation of the phenylpropanoid pathway. Gene regulatory network inference analysis revealed candidate transcription factors (TFs) such as GATA5 and MYB-10, and their downstream targets were upregulated in resistant interactions. Our results provide valuable insights into transcriptional changes during resistant and susceptible interactions, which can further facilitate assessing candidate genes necessary for resistance to two hemibiotrophic Colletotrichum spp. in strawberry.
PMID: 35360413
Plant Cell Rep , IF:4.57 , 2022 Mar 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 Apr , V41 (4) : P921-934 doi: 10.1007/s00299-021-02828-9
miR390-tasiRNA3-ARF4 pathway is involved in regulating flowering time in woodland strawberry.
Liaoning Key Laboratory of Strawberry Breeding and Cultivation, College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China.; Analytical and Testing Center, Shenyang Agricultural University, Shenyang, 110866, China.; Liaoning Key Laboratory of Strawberry Breeding and Cultivation, College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China. lihe@syau.edu.cn.
KEY MESSAGE: miR390-tasiRNA3-ARF4 pathway was identified in woodland strawberry. FvemiR390 was involved in the regulation of flowering time, and miR390-tasiRNA3-ARF4 regulated flowering time through FveAP1/FveFUL in woodland strawberry. miRNA is an important type of regulator, and widely involved in plant growth, development and stress response. As a conserved miRNA family, the function of miR390 has been studied in many species, but poorly understood in woodland strawberry. In this study, we found that the members of miR390 family were highly conservative, and FvemiR390a and FvemiR390b have the same mature sequence. Therefore, we chose FveMIR390a to generate FvemiR390 mature sequence for functional studies. Subsequently, the result of transient gene expression assay proved that FvemiR390 negatively regulates FveARF4 through miR390-tasiRNA3-ARF4 pathway. Using transgenic plants, we discovered that the overexpression of FveMIR390a delayed flowering in woodland strawberry. Further studies revealed that the expressions of FveAP1 and FveFUL were lower in transgenic plants, which indicates miR390-tasiRNA3-ARF4 pathway delays flowering time through the FveAP1/FveFUL in woodland strawberry. Moreover, the expression of FvemiR390 responded to exogenous hormones, which also provides a reference for the application of exogenous hormones in regulating the flowering time of woodland strawberry.
PMID: 34985575
Microb Ecol , IF:4.552 , 2022 Mar doi: 10.1007/s00248-022-01998-7
Microorganisms Associated with the Ambrosial Beetle Xyleborus affinis with Plant Growth-Promotion Activity in Arabidopsis Seedlings and Antifungal Activity Against Phytopathogenic Fungus Fusarium sp. INECOL_BM-06.
Red de Estudios Moleculares Avanzados, Instituto de Ecologia A.C, Xalapa, 91073, Veracruz, Mexico.; Red de Biodiversidad Y Sistematica, Instituto de Ecologia A.C, Carretera Antigua a Coatepec 351, El Haya, 91073, Xalapa, Veracruz, Mexico.; Red de Estudios Moleculares Avanzados, Instituto de Ecologia A.C, Xalapa, 91073, Veracruz, Mexico. randy.ortiz@inecol.mx.; Catedra CONACyT en el Instituto de Ecologia, A.C., Carretera Antigua a Coatepec 351, El Haya, C.P. 91073, Xalapa, Veracruz, Mexico. randy.ortiz@inecol.mx.
Plants interact with a great diversity of microorganisms or insects throughout their life cycle in the environment. Plant and insect interactions are common; besides, a great variety of microorganisms associated with insects can induce pathogenic damage in the host, as mutualist phytopathogenic fungus. However, there are other microorganisms present in the insect-fungal association, whose biological/ecological activities and functions during plant interaction are unknown. In the present work evaluated, the role of microorganisms associated with Xyleborus affinis, an important beetle species within the Xyleborini tribe, is characterized by attacking many plant species, some of which are of agricultural and forestry importance. We isolated six strains of microorganisms associated with X. affinis shown as plant growth-promoting activity and altered the root system architecture independent of auxin-signaling pathway in Arabidopsis seedlings and antifungal activity against the phytopathogenic fungus Fusarium sp. INECOL_BM-06. In addition, evaluating the tripartite interaction plant-microorganism-fungus, interestingly, we found that microorganisms can induce protection against the phytopathogenic fungus Fusarium sp. INECOL_BM-06 involving the jasmonic acid-signaling pathway and independent of salicylic acid-signaling pathway. Our results showed the important role of this microorganisms during the plant- and insect-microorganism interactions, and the biological potential use of these microorganisms as novel agents of biological control in the crops of agricultural and forestry is important.
PMID: 35357520
Molecules , IF:4.411 , 2022 Mar , V27 (6) doi: 10.3390/molecules27061804
Changes in Endogenous Phytohormones of Gerbera jamesonii Axillary Shoots Multiplied under Different Light Emitting Diodes Light Quality.
Department of Ornamental Plants and Garden Art, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, 29 Listopada 54, 31-425 Krakow, Poland.; Department of Developmental Biology, The Franciszek Gorski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Krakow, Poland.
Light quality is essential in in vitro cultures for morphogenesis process. Light emitting diodes system (LED) allows adjustment as desired and the most appropriate light spectrum. The study analyzed the influence of different LED light quality on the balance of endogenous phytohormones and related compounds (PhRC) in in vitro multiplied axillary shoots of Gerbera jamesonii. Over a duration of 40 days, the shoots were exposed to 100% red light, 100% blue light, red and blue light at a 7:3 ratio with control fluorescent lamps. Every 10 days plant tissues were tested for their PhRC content with the use of an ultra-high performance liquid chromatography (UHPLC). Shoots' morphometric features were analyzed after a multiplication cycle. We identified 35 PhRC including twelve cytokinins, seven auxins, nine gibberellins, and seven stress-related phytohormones. Compounds content varied from 0.00052 nmol/g to 168.15 nmol/g of dry weight (DW). The most abundant group were stress-related phytohormones (particularly benzoic and salicylic acids), and the least abundant were cytokinins (about 370 times smaller content). LED light did not disturb the endogenous phytohormone balance, and more effectively mitigated the stress experienced by in vitro grown plants than the fluorescent lamps. The stress was most effectively reduced under the red LED. Red and red:blue light lowered tissue auxin levels. Blue LED light lowered the shoot multiplication rate and their height, and induced the highest content of gibberellins at the last stage of the culture.
PMID: 35335168
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
Sci Rep , IF:4.379 , 2022 Mar , V12 (1) : P4750 doi: 10.1038/s41598-022-08558-6
Terrestrial arthropods broadly possess endogenous phytohormones auxin and cytokinins.
Department of Biological Resource Science, Faculty of Agriculture, Saga University, Saga, 840-8502, Japan. tokudam@cc.saga-u.ac.jp.; The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, 890-0065, Japan. tokudam@cc.saga-u.ac.jp.; Department of Food and Life Sciences, Ibaraki University, Ami, Ibaraki, 300-0393, Japan.; Department of Biological Resource Science, Faculty of Agriculture, Saga University, Saga, 840-8502, Japan.; The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, 890-0065, Japan.; Present address: Koshi Research Station, Institute for Plant Protection, NARO, Kumamoto, 861-1192, Japan.
Some herbivorous insects possess the ability to synthesize phytohormones and are considered to use them for manipulating their host plants, but how these insects acquired the ability remains unclear. We investigated endogenous levels of auxin (IAA) and cytokinins (iP and tZ), including their ribosides (iPR and tZR), in various terrestrial arthropod taxa. Surprisingly, IAA was detected in all arthropods analysed. In contrast, tZ and/or tZR was detected only in some taxa. Endogenous levels of IAA were not significantly different among groups with different feeding habits, but gall inducers possessed significantly higher levels of iPR, tZ and tZR. Ancestral state reconstruction of the ability to synthesize tZ and tZR revealed that the trait has only been acquired in taxa containing gall inducers. Our results strongly suggest critical role of the cytokinin synthetic ability in the evolution of gall-inducing habit and IAA has some function in arthropods.
PMID: 35306514
Sci Rep , IF:4.379 , 2022 Mar , V12 (1) : P3595 doi: 10.1038/s41598-022-07637-y
Expression profiling of TaARGOS homoeologous drought responsive genes in bread wheat.
Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan. kashif_ahmed01@yahoo.com.; Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan.; National Agricultural Research Centre (NARC), Islamabad, Pakistan.; College of Agriculture, Nanjing Agricultural University, Najing, China.
Drought tolerant germplasm is needed to increase crop production, since water scarcity is a critical bottleneck in crop productivity worldwide. Auxin Regulated Gene involved in Organ Size (ARGOS) is a large protein family of transcription factors that plays a vital role in organ size, plant growth, development, and abiotic stress responses in plants. Although, the ARGOS gene family has been discovered and functionalized in a variety of crop plants, but a comprehensive and systematic investigation of ARGOS genes in locally used commercial wheat cultivars is still yet to be reported. The relative expression of three highly conserved TaARGOS homoeologous genes (TaARGOS-A, TaARGOS-B, TaARGOS-D) was studied in three drought-tolerant (Pakistan-2013, NARC-2009 and NR-499) and three sensitive (Borlaug-2016, NR-514 and NR-516) wheat genotypes under osmotic stress, induced by PEG-6000 at 0 (exogenous control), 2, 4, 6, and 12 h. The normalization of target genes was done using beta-actin as endogenous control, whereas DREB3, as a marker gene was also transcribed, reinforcing the prevalence of dehydration in all stress treatments. Real-time quantitative PCR revealed that osmotic stress induced expression of the three TaARGOS transcripts in different wheat seedlings at distinct timepoints. Overall, all genes exhibited significantly higher expression in the drought-tolerant genotypes as compared to the sensitive ones. For instance, the expression profile of TaARGOS-A and TaARGOS-D showed more than threefold increase at 2 h and six to sevenfold increase after 4 h of osmotic stress. However, after 6 h of osmotic stress these genes started to downregulate, and the lowest gene expression was noticed after 12 h of osmotic stress. Among all the homoeologous genes, TaARGOS-D, in particular, had a more significant influence on controlling plant growth and drought tolerance as it showed the highest expression. Altogether, TaARGOSs are involved in seedling establishment and overall plant growth. In addition, the tolerant group of genotypes had a much greater relative fold expression than the sensitive genotypes. Ultimately, Pakistan-2013 showed the highest relative expression of the studied genes than other genotypes which shows its proficiency to mitigate osmotic stress. Therefore, it could be cultivated in arid and semi-arid regions under moisture-deficient regimes. These findings advocated the molecular mechanism and regulatory roles of TaARGOS genes in plant growth and osmotic stress tolerance in contrasting groups of wheat genotypes, accompanied by the genetic nature of identified genotypes in terms of their potential for drought tolerance.
PMID: 35246579
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 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
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P149 doi: 10.1186/s12870-022-03539-3
miR390 family of Cymbidium goeringii is involved in the development of reproductive organs in transgenic Arabidopsis.
College of Landscape Architecture, Nanjing Forestry University, 210037, Nanjing, Jiangsu Province, China.; Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, 310021, Hangzhou, Zhejiang Province, China.; College of Landscape Architecture, Nanjing Forestry University, 210037, Nanjing, Jiangsu Province, China. hufengrong2003@sina.com.
BACKGROUND: miR390s is an ancient family with a high level of conservation among plant miRNAs. Through the auxin signal transduction pathway, miR390 participates in diverse biological processes of plant growth and development. As an important Chinese traditional orchid, Cymbidium goeringii has unique flower shape and elegant fragrance. But its development has been greatly restricted because of the low flower bud differentiation and the difficult reproduction. This study aims to provide guidance for the role of cgo-miR390 in reproductive organ development to enhance the ornamental and economic value of Cymbidium. RESULTS: MIR390a, MIR390b and MIR390c of C. goeringii were cloned, and their length ranged from 130 to 150 nt. Each precursor sequence of cgo-miR390 contains 2 to 3 mature miRNAs. Three kinds of cgo-miR390s displayed distinct temporal and spatial expression patterns during floral development in C. goeringii. The overexpression of MIR390s alters morphology and function of stamens and pistils in Arabidopsis, such as enlargement of anther aspect ratio and separation of stylar and stigmas, which affects the development of fruits and seeds. In particular, the pollen amount decreased and the seed abortion rate increased in cgo-MIR390c-overexpressed plants. CONCLUSIONS: cgo-miR390 family affected the development of reproductive organs in transgenic Arabidopsis. The study provides references for the genetic improvement for orchid with potentially great economic benefit.
PMID: 35346036
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P133 doi: 10.1186/s12870-022-03524-w
Wound-induced signals regulate root organogenesis in Arabidopsis explants.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Korea.; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon, 34113, Korea.; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, 34113, Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Korea. hyojunlee@kribb.re.kr.; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon, 34113, Korea. hyojunlee@kribb.re.kr.
BACKGROUND: Reactive oxygen species (ROS) and calcium ions (Ca(2+)) are representative signals of plant wound responses. Wounding triggers cell fate transition in detached plant tissues and induces de novo root organogenesis. While the hormonal regulation of root organogenesis has been widely studied, the role of early wound signals including ROS and Ca(2+) remains largely unknown. RESULTS: We identified that ROS and Ca(2+) are required for de novo root organogenesis, but have different functions in Arabidopsis explants. The inhibition of the ROS and Ca(2+) signals delayed root development in detached leaves. Examination of the auxin signaling pathways indicated that ROS and Ca(2+) did not affect auxin biosynthesis and transport in explants. Additionally, the expression of key genes related to auxin signals during root organogenesis was not significantly affected by the inhibition of ROS and Ca(2+) signals. The addition of auxin partially restored the suppression of root development by the ROS inhibitor; however, auxin supplementation did not affect root organogenesis in Ca(2+)-depleted explants. CONCLUSIONS: Our results indicate that, while both ROS and Ca(2+) are key molecules, at least in part of the auxin signals acts downstream of ROS signaling, and Ca(2+) acts downstream of auxin during de novo root organogenesis in leaf explants.
PMID: 35317749
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P112 doi: 10.1186/s12870-022-03459-2
Transcriptome analysis reveals key developmental and metabolic regulatory aspects of oil palm (Elaeis guineensis Jacq.) during zygotic embryo development.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570228, China.; Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences / Hainan Key Laboratory of Tropical Oil Crops Biology, Wenchang, 571339, China.; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570228, China. chenping08213@163.com.; Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences / Hainan Key Laboratory of Tropical Oil Crops Biology, Wenchang, 571339, China. jeromejeyakumarj@gmail.com.
BACKGROUND: Oil palm is the most efficient oil-producing crop in the world, and the yield of palm oil is associated with embryonic development. However, a comprehensive understanding of zygotic embryo development at the molecular level remains elusive. In order to address this issue, we report the transcriptomic analysis of zygotic embryo development in oil palm, specifically focusing on regulatory genes involved in important biological pathways. RESULTS: In this study, three cDNA libraries were prepared from embryos at S1 (early-stage), S2 (middle-stage), and S3 (late-stage). There were 16,367, 16,500, and 18,012 genes characterized at the S1, S2, and S3 stages of embryonic development, respectively. A total of 1522, 2698, and 142 genes were differentially expressed in S1 vs S2, S1 vs S3, and S2 vs S3, respectively. Using Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to identify key genes and pathways. In the hormone signaling pathway, genes related to auxin antagonize the output of cytokinin which regulates the development of embryo meristem. The genes related to abscisic acid negatively regulating the synthesis of gibberellin were strongly up-regulated in the mid-late stage of embryonic development. The results were reported the early synthesis and mid-late degradation of sucrose, as well as the activation of the continuous degradation pathway of temporary starch, providing the nutrients needed for differentiation of the embryonic cell. Moreover, the transcripts of genes involved in fatty acid synthesis were also abundantly accumulated in the zygotic embryos. CONCLUSION: Taken together, our research provides a new perspective on the developmental and metabolic regulation of zygotic embryo development at the transcriptional level in oil palm.
PMID: 35279075
BMC Plant Biol , IF:4.215 , 2022 Mar , V22 (1) : P110 doi: 10.1186/s12870-022-03470-7
Maize plant architecture trait QTL mapping and candidate gene identification based on multiple environments and double populations.
College of Bioscience, Jilin Agricultural University, Changchun, 130118, China.; College of Agriculture, Jilin Agricultural University, Changchun, 130118, China.; College of Agriculture, Jilin Agricultural University, Changchun, 130118, China. 1533104768@qq.com.
BACKGROUND: The plant architecture traits of maize determine the yield. Plant height, ear position, leaf angle above the primary ear and internode length above the primary ear together determine the canopy structure and photosynthetic efficiency of maize and at the same time affect lodging and disease resistance. A flat and tall plant architecture confers an obvious advantage in the yield of a single plant but is not conducive to dense planting and results in high rates of lodging; thus, it has been gradually eliminated in production. Although using plants that are too compact, short and density tolerant can increase the yield per unit area to a certain extent, the photosynthetic efficiency of such plants is low, ultimately limiting yield increases. Genetic mapping is an effective method for the improvement of plant architecture to identify candidate genes for regulating plant architecture traits. RESULTS: To find the best balance between the yield per plant and the yield per unit area of maize, in this study, the F2:3 pedigree population and a RIL population with the same male parent were used to identify QTL for plant height (PH), ear height (EH), leaf angle and internode length above the primary ear (LAE and ILE) in Changchun and Gongzhuling for 5 consecutive years (2016-2020). A total of 11, 13, 23 and 13 QTL were identified for PH, EH, LAE, and ILE, respectively. A pleiotropic consistent QTL for PH overlapped with that for EH on chromosome 3, with a phenotypic variation explanation rate from 6.809% to 21.96%. In addition, there were major consistent QTL for LAE and ILE, and the maximum phenotypic contribution rates were 24.226% and 30.748%, respectively. Three candidate genes were mined from the three consistent QTL regions and were involved in the gibberellin-activated signal pathway, brassinolide signal transduction pathway and auxin-activated signal pathway, respectively. Analysis of the expression levels of the three genes showed that they were actively expressed during the jointing stage of vigorous maize growth. CONCLUSIONS: In this study, three consistent major QTL related to plant type traits were identified and three candidate genes were screened. These results lay a foundation for the cloning of related functional genes and marker-assisted breeding of related functional genes.
PMID: 35277127
Mol Plant Microbe Interact , IF:4.171 , 2022 Mar , V35 (3) : P215-229 doi: 10.1094/MPMI-05-21-0118-R
Bradyrhizobium japonicum IRAT FA3 Alters Arabidopsis thaliana Root Architecture via Regulation of Auxin Efflux Transporters PIN2, PIN3, PIN7, and ABCB19.
Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, CA 92521, U.S.A.
Beneficial rhizobacteria can stimulate changes in plant root development. Although root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant-growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild-type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7, and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Cocultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7, and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7, or abcb19 mutants, suggesting independent roles for PIN3, PIN7, and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum's influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.[Formula: see text] Copyright (c) 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
PMID: 34941379
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 Mar , V13 (3) doi: 10.3390/genes13030515
High Resistance to Quinclorac in Multiple-Resistant Echinochloa colona Associated with Elevated Stress Tolerance Gene Expression and Enriched Xenobiotic Detoxification Pathway.
Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR 72704, USA.; Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA.; Genomics and Bioinformatics Facility, Clemson University, Clemson, SC 29634, USA.; Center for Human Genetics, Clemson University, Greenwood, SC 29646, USA.; Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA.
Echinochloa colona and other species in this genus are a threat to global rice production and food security. Quinclorac, an auxin mimic, is a common herbicide for grass weed control in rice, and Echinochloa spp. have evolved resistance to it. The complete mode of quinclorac action and subsequent evolution of resistance is not fully understood. We analyzed the de novo transcriptome of multiple-herbicide-resistant (ECO-R) and herbicide-susceptible genotypes in response to quinclorac. Several biological processes were constitutively upregulated in ECO-R, including carbon metabolism, photosynthesis, and ureide metabolism, indicating improved metabolic efficiency. The transcriptional change in ECO-R following quinclorac treatment indicates an efficient response, with upregulation of trehalose biosynthesis, which is also known for abiotic stress mitigation. Detoxification-related genes were induced in ECO-R, mainly the UDP-glycosyltransferase (UGT) family, most likely enhancing quinclorac metabolism. The transcriptome data also revealed that many antioxidant defense elements were uniquely elevated in ECO-R to protect against the auxin-mediated oxidative stress. We propose that upon quinclorac treatment, ECO-R detoxifies quinclorac utilizing UGT genes, which modify quinclorac using the sufficient supply of UDP-glucose from the elevated trehalose pathway. Thus, we present the first report of upregulation of trehalose synthesis and its association with the herbicide detoxification pathway as an adaptive mechanism to herbicide stress in Echinochloa, resulting in high resistance.
PMID: 35328069
Genes (Basel) , IF:4.096 , 2022 Mar , V13 (3) doi: 10.3390/genes13030469
Effect of the PmARF6 Gene from Masson Pine (Pinus massoniana) on the Development of Arabidopsis.
Key Laboratory of Forestry Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.; Wenzhou Key laboratory of Resource Plant Innovation and Utilization, Zhejiang Institute of Subtropical Crops, Wenzhou 325005, China.
Masson pine (Pinus massoniana) is a core industrial tree species that is used for afforestation in southern China. Previous studies have shown that Auxin Response Factors (ARFs) are involved in the growth and development of various species, but the function of ARFs in Masson pine is unclear. In this research, we cloned and identified Masson pine ARF6 cDNA (PmARF6). The results showed that PmARF6 encodes a protein of 681 amino acids that is highly expressed in female flowers. Subcellular analysis showed that the PmARF6 protein occurred predominantly in the nucleus and cytomembrane of Masson pine cells. Compared with wild-type (WT) Arabidopsis, transgenic Arabidopsis plants overexpressing PmARF6 had fewer rosette leaves, and their flower development was slower. These results suggest that overexpression of PmARF6 may inhibit the flower and leaf development of Masson pine and provide new insights into the underlying developmental mechanism.
PMID: 35328022
Plant Genome , IF:4.089 , 2022 Mar : Pe20199 doi: 10.1002/tpg2.20199
Differential gene expression in tall fescue tissues in response to water deficit.
Dep. of Plant and Soil Sciences, Univ. of Kentucky, Lexington, KY, 40546-0312, USA.; Dep. of Plant Pathology, Univ. of Kentucky, Lexington, KY, 40546-0312, USA.; USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY, 40546-0091, USA.
Tall fescue (Festuca arundinacea Schreb.) is a popular pasture and turf grass particularly known for drought resistance, allowing for its persistence in locations that are unfavorable for other cool-season grasses. Also, its seed-borne fungal symbiont (endophyte) Epichloe coenophiala, which resides in the crown and pseudostem, can be a contributing factor in its drought tolerance. Because it contains the apical meristems, crown survival under drought stress is critical to plant survival as well as the endophyte. In this study, we subjected tall fescue plants with their endophyte to water-deficit stress or, as controls with normal watering, then compared plant transcriptome responses in four vegetative tissues: leaf blades, pseudostem, crown, and roots. A transcript was designated a differentially expressed gene (DEG) if it exhibited at least a twofold expression difference between stress and control samples with an adjusted p value of .001. Pathway analysis of the DEGs across all tissue types included photosynthesis, carbohydrate metabolism, phytohormone biosynthesis and signaling, cellular organization, and a transcriptional regulation. While no specific pathway was observed to be differentially expressed in the crown, genes encoding auxin response factors, nuclear pore anchors, structural maintenance of chromosomes, and class XI myosin proteins were more highly differentially expressed in crown than in the other vegetative tissues, suggesting that regulation in expression of these genes in the crown may aid in survival of the meristems in the crown.
PMID: 35322562
Plant Mol Biol , IF:4.076 , 2022 Apr 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 Mar 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 Mar 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 Mar 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 Apr , V196 : P113103 doi: 10.1016/j.phytochem.2022.113103
Identification of TabZIP family members with possible roles in the response to auxin in wheat roots.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China.; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: zhonghuawang@nwafu.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: bbrwangjun@nwafu.edu.cn.
Auxin regulates root development and is considered a potential target for improving crop yield. In this study, we identified 22 basic leucine zipper transcription factors (bZIP TFs) that responded to two concentrations (1 and 50 muM) of indole-acetic acid (IAA) during wheat root development by transcriptome analysis. In addition, we identified 176 TabZIP genes from the wheat genome. Phylogenetic classification and gene structure analysis indicated that the 22 auxin-responsive TabZIPs were divided into groups 1 to 9 (except group 3) with different functions. Phenotypic analysis showed that knocking out Arabidopsis AtHY5, which is the homologous gene of TabZIP6D_147 (one of the downregulated auxin-responsive TabZIPs under both 1 and 50 muM IAA that belonged to group 4), resulted in insensitivity to IAA, while the phenotype of TabZIP6D_147/hy5 complementary lines recovered to that of the wild type, suggesting that downregulated TabZIP6D_147 plays a negative role in the auxin signalling pathway. These results revealed that auxin-responsive TabZIP genes may play different roles in root architecture in the response to the two concentrations of auxin.
PMID: 35091213
Phytopathology , IF:4.025 , 2022 Apr , V112 (4) : P842-851 doi: 10.1094/PHYTO-05-21-0189-R
The Role of the Wheat Reduced height (Rht)-DELLA Mutants and Associated Hormones in Infection by Claviceps purpurea, the Causal Agent of Ergot.
National Institute of Agricultural Botany, Cambridge CB3 0LE, United Kingdom.; Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas, Universidad Politecnica de Valencia, Valencia 46022, Spain.
Partial resistance to the biotrophic fungal pathogen Claviceps purpurea, causal agent of ergot, has been found that colocates with mutant alleles of the wheat Reduced height (Rht) loci on chromosomes 4B and 4D. These Rht loci represent the wheat orthologs of the Arabidopsis Della genes. To investigate the role of the Rht mutant DELLA proteins in ergot resistance, we assessed C. purpurea infection in wheat near-isogenic lines (NILs) carrying the gibberellic acid (GA)-insensitive semidwarf alleles Rht-B1b and Rht-D1b and the severe dwarf alleles Rht-B1c and Rht-D1c. NILs of the GA-sensitive alleles Rht8 (chromosome 2D) and Rht12 (chromosome 5A) were also included. A general trend toward increased resistance to C. purpurea, with smaller and lighter sclerotia, was observed on the NILs Rht-B1b, Rht-D1b, Rht-B1c, and Rht-D1c, and also on Rht8. Levels of the bioactive GA4 and the auxin indole-3-acetic acid increased after inoculation with C. purpurea, following similar patterns and implicating a potential auxin-mediated induction of GA biosynthesis. In contrast, jasmonic acid (JA) levels fell in the parental lines 'Mercia' and 'Maris Huntsman' after inoculation with C. purpurea, but increased in all the Rht-mutant NILs. Inoculation with C. purpurea did not show any informative changes in the levels of salicylic acid. Our results suggest that GA-mediated degradation of the DELLA proteins and down-regulation of JA-signaling pathways supports infection of wheat by C. purpurea. As these responses are generally associated with necrotrophic fungal pathogens, we propose that the biotroph C. purpurea may have a necrotrophic growth stage.
PMID: 34698539
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 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
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (7) doi: 10.3390/plants11070949
Expression of a Cytochrome P450 Gene from Bermuda Grass Cynodon dactylon in Soybean Confers Tolerance to Multiple Herbicides.
State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310000, China.; Hangzhou Ruifeng Biosciences Co., Ltd., 1500 Wenyi Road, Building 1, Room 103, Hangzhou 310000, China.; Agricultural Experiment Station, Zhejiang University, Hangzhou 310000, China.
Bermuda grass (Cynodon dactylon) is notoriously difficult to control with some commonly used herbicides. We cloned a cytochrome P450 gene from Bermuda grass, named P450-N-Z1, which was found to confer tolerance to multiple herbicides in transgenic Arabidopsis. These herbicides include: (1) acetolactate synthase (ALS) inhibitor herbicides nicosulfuron and penoxsulam; (2) p-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide mesotrione; (3) synthetic auxin herbicide dicamba; (4) photosynthesis inhibitor bentazon. We further generated transgenic soybean plants expressing P450-N-Z1, and found that these transgenic soybean plants gained robust tolerance to nicosulfuron, flazasulfuron, and 2,4-dichlorophenoxyacetic acid (2,4-D) in greenhouse assays. A field trial demonstrated that transgenic soybean is tolerant to flazasulfuron and 2,4-D at 4-fold and 2-fold the recommended rates, respectively. Furthermore, we also demonstrated that flazasulfuron and dicamba are much more rapidly degraded in vivo in the transgenic soybean than in non-transgenic soybean. Therefore, P450-N-Z1 may be utilized for engineering transgenic crops for herbicide tolerance.
PMID: 35406929
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (7) doi: 10.3390/plants11070913
Effects of Auxin (Indole-3-butyric Acid) on Adventitious Root Formation in Peach-Based Prunus Rootstocks.
Instituto de Bioingenieria, Universidad Miguel Hernandez, 03202 Elche, Spain.; Departmento de Nutricion Vegetal, CEBAS-CSIC, 30100 Murcia, Spain.; Department of Pomology, Estacion Experimental de Aula Dei-CSIC, 50059 Zaragoza, Spain.; Invisa Biotecnologia Vegetal S.L., 30410 Caravaca de la Cruz, Spain.
Several Prunus species are among the most important cultivated stone fruits in the Mediterranean region, and there is an urgent need to obtain rootstocks with specific adaptations to challenging environmental conditions. The development of adventitious roots (ARs) is an evolutionary mechanism of high relevance for stress tolerance, which has led to the development of environmentally resilient plants. As a first step towards understanding the genetic determinants involved in AR formation in Prunus sp., we evaluated the rooting of hardwood cuttings from five Prunus rootstocks (Adafuel, Adarcias, Cadaman, Garnem, and GF 677) grown in hydroponics. We found that auxin-induced callus and rooting responses were strongly genotype-dependent. To investigate the molecular mechanisms involved in these differential responses, we performed a time-series study of AR formation in two rootstocks with contrasting rooting performance, Garnem and GF 677, by culturing in vitro microcuttings with and without auxin treatment (0.9 mg/L of indole-3-butyric acid [IBA]). Despite showing a similar histological structure, Garnem and GF677 rootstocks displayed dynamic changes in endogenous hormone homeostasis involving metabolites such as indole-3-acetic acid (IAA) conjugated to aspartic acid (IAA-Asp), and these changes could explain the differences observed during rooting.
PMID: 35406893
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (6) doi: 10.3390/plants11060775
Synergistic Modulation of Seed Metabolites and Enzymatic Antioxidants Tweaks Moisture Stress Tolerance in Non-Cultivated Traditional Rice Genotypes during Germination.
Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore 641003, India.; School of Agriculture and Biosciences, Karunya Institute of Technology and Sciences, Karunya Nagar, Coimbatore 641114, India.; Department of Plant Breeding and Genetics, Agricultural College & Research Institute, Tamil Nadu Agricultural University, Killikulam 628252, India.; Crop Production Division, ICAR-National Rice Research Institute, Cuttack 753006, India.; Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore 641003, India.; Department of Food Science and Nutrition, College of Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.; Department of Biology, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.; Department of Physical Sport Science, College of Education, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.; Department of Biotechnology, Faculty of Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
Traditional rice landraces are treasures for novel genes to develop climate-resilient cultivars. Seed viability and germination determine rice productivity under moisture stress. The present study evaluated 100 rice genotypes, including 85 traditional landraces and 15 improved cultivars from various agro-ecological zones of Tamil Nadu, along with moisture-stress-susceptible (IR 64) and moisture-stress-tolerant (IR 64 Drt1) checks. The landraces were screened over a range of osmotic potentials, namely (-) 1.0 MPa, (-) 1.25 MPa and (-) 1.5 MPa, for a period of 5 days in PEG-induced moisture stress. Physio-morphological traits, such as rate of germination, root and shoot length, vigor index, R/S ratio and relative water content (RWC), were assessed during early moisture stress at the maximum OP of (-) 1.5 MPa. The seed macromolecules, phytohormones (giberellic acid, auxin (IAA), cytokinin and abscisic acid), osmolytes and enzymatic antioxidants (catalase and superoxide dismutase) varied significantly between moisture stress and control treatments. The genotype Kuliyadichan registered more IAA and giberellic acid (44% and 35%, respectively, over moisture-stress-tolerant check (IR 64 Drt1), whereas all the landraces showed an elevated catalase activity, thus indicating that the tolerant landraces effectively eliminate oxidative damages. High-performance liquid chromatography analysis showed a reduction in cytokinin and an increase in ABA level under induced moisture stress. Hence, the inherent moisture-stress tolerance of six traditional landraces, such as Kuliyadichan, Rajalakshmi, Sahbhagi Dhan, Nootripathu, Chandaikar and Mallikar, was associated with metabolic responses, such as activation of hydrolytic enzymes, hormonal crosstalk, ROS signaling and antioxidant enzymes (especially catalase), when compared to the susceptible check, IR 64. Hence, these traditional rice landraces can serve as potential donors for introgression or pyramiding moisture-stress-tolerance traits toward developing climate-resilient rice cultivars.
PMID: 35336657
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (6) doi: 10.3390/plants11060743
5-Aminolevulinic Acid and 24-Epibrassinolide Improve the Drought Stress Resilience and Productivity of Banana Plants.
Agricultural Botany Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.; Horticulture Department, Faculty of Desert and Environmental Agriculture, Matrouh University, Fouka 51511, Egypt.; Agricultural Botany Department, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt.; Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences SGGW, 02-776 Warsaw, Poland.; Institute of Technology and Life Sciences, National Research Institute, Falenty, Al.Hrabska 3, 05-090 Pruszkow, Poland.; Technological Institute of Sonora, 818 South Ferbero 5th Street, Ciudad Obregon 85000, Mexico.; Department of Bioengineering, West Pomeranian University of Technology, 71-434 Szczecin, Poland.; Water Relations and Field Irrigation Department, Agricultural and Biological Research Institute, National Research Center, Giza 12622, Egypt.; Soil, Water and Environment Research Institute (SWERI), Agricultural Research Center, Giza 12619, Egypt.; Department of Horticulture, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt.
Plant growth, development, and productivity are adversely affected under drought conditions. Previous findings indicated that 5-aminolevulinic acid (ALA) and 24-epibrassinolide (EBL) play an important role in the plant response to adverse environmental conditions. This study demonstrated the role of ALA and EBL on oxidative stress and photosynthetic capacity of drought-stressed 'Williams' banana grown under the Egyptian semi-arid conditions. Exogenous application of either ALA or EBL at concentrations of 15, 30, and 45 mg.L(-1) significantly restored plant photosynthetic activity and increased productivity under reduced irrigation; this was equivalent to 75% of the plant's total water requirements. Both compounds significantly reduced drought-induced oxidative damages by increasing antioxidant enzyme activities (superoxide dismutase 'SOD', catalase 'CAT', and peroxidase 'POD') and preserving chloroplast structure. Lipid peroxidation, electrolyte loss and free non-radical H2O2 formation in the chloroplast were noticeably reduced compared to the control, but chlorophyll content and photosynthetic oxygen evolution were increased. Nutrient uptake, auxin and cytokinin levels were also improved with the reduced abscisic acid levels. The results indicated that ALA and EBL could reduce the accumulation of reactive oxygen species and maintain the stability of the chloroplast membrane structure under drought stress. This study suggests that the use of ALA or EBL at 30 mg.L(-1) can promote the growth, productivity and fruit quality of drought-stressed banana plants.
PMID: 35336624
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (6) doi: 10.3390/plants11060721
Auxin-Producing Bacteria from Duckweeds Have Different Colonization Patterns and Effects on Plant Morphology.
Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.; Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA.; Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
The role of auxin in plant-microbe interaction has primarily been studied using indole-3-acetic acid (IAA)-producing pathogenic or plant-growth-promoting bacteria. However, the IAA biosynthesis pathway in bacteria involves indole-related compounds (IRCs) and intermediates with less known functions. Here, we seek to understand changes in plant response to multiple plant-associated bacteria taxa and strains that differ in their ability to produce IRCs. We had previously studied 47 bacterial strains isolated from several duckweed species and determined that 79% of these strains produced IRCs in culture, such as IAA, indole lactic acid (ILA), and indole. Using Arabidopsis thaliana as our model plant with excellent genetic tools, we performed binary association assays on a subset of these strains to evaluate morphological responses in the plant host and the mode of bacterial colonization. Of the 21 tested strains, only four high-quantity IAA-producing Microbacterium strains caused an auxin root phenotype. Compared to the commonly used colorimetric Salkowski assay, auxin concentration determined by LC-MS was a superior indicator of a bacteria's ability to cause an auxin root phenotype. Studies with the auxin response mutant axr1-3 provided further genetic support for the role of auxin signaling in mediating the root morphology response to IAA-producing bacteria strains. Interestingly, our microscopy results also revealed new evidence for the role of the conserved AXR1 gene in endophytic colonization of IAA-producing Azospirillum baldaniorum Sp245 via the guard cells.
PMID: 35336603
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (5) doi: 10.3390/plants11050707
Red Light and Glucose Enhance Cytokinin-Mediated Bud Initial Formation in Physcomitrium patens.
School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar 752050, Odisha, India.; Homi Bhabha National Institute (HBNI), Training School Complex, Anushakti Nagar, Mumbai 400094, Maharashtra, India.
Growth and development of Physcomitrium patens is endogenously regulated by phytohormones such as auxin and cytokinin. Auxin induces the transition of chloronema to caulonema. This transition is also regulated by additional factors such as quantity and quality of light, carbon supply, and other phytohormones such as strigolactones and precursors of gibberrelic acid. On the other hand, cytokinins induce the formation of bud initials following caulonema differentiation. However, the influence of external factors such as light or nutrient supply on cytokinin-mediated bud initial formation has not been demonstrated in Physcomitrium patens. This study deals with the effect of light quality and nutrient supply on cytokinin-mediated bud initial formation. Bud initial formation has been observed in wild type plants in different light conditions such as white, red, and blue light in response to exogenously supplied cytokinin as well as glucose. In addition, budding assay has been demonstrated in the cry1a mutant of Physcomitrium in different light conditions. The results indicate that carbon supply and red light enhance the cytokinin response, while blue light inhibits this process in Physcomitrium.
PMID: 35270177
Plants (Basel) , IF:3.935 , 2022 Mar , V11 (5) doi: 10.3390/plants11050683
Gene Expression Analysis of Potato (Solanum tuberosum L.) Lipoxygenase Cascade and Oxylipin Signature under Abiotic Stress.
Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, P.O. Box 30, 420111 Kazan, Russia.
The metabolism of polyunsaturated fatty acids through the lipoxygenase-catalyzed step and subsequent reactions is referred to as the lipoxygenase (LOX) pathway. The components of this system, such as jasmonates, are involved in growth, development and defense reactions of plants. In this report, we focus on dynamics of expression of different LOX pathway genes and activities of target enzymes with three abiotic stress factors: darkness, salinity and herbicide toxicity. To obtain a more complete picture, the expression profiles of marker genes for salicylic acid, abscisic acid, ethylene, auxin and gibberellin-dependent signaling systems under the same stresses were also analyzed. The gene expression in Solanum tuberosum plants was analyzed using qRT-PCR, and we found that the LOX-cascade-related genes responded to darkness, salinity and herbicide toxicity in different ways. We detected activation of a number of 9-LOX pathway genes; however, in contrast to studies associated with biotic stress (infection), the 9-divinyl ether synthase branch of the LOX cascade was inhibited under all three stresses. GC-MS analysis of the oxylipin profiles also showed the main activity of the 9-LOX-cascade-related enzymes after treatment with herbicide and darkness.
PMID: 35270153
J Appl Microbiol , IF:3.772 , 2022 Apr , V132 (4) : P3226-3248 doi: 10.1111/jam.15317
Rhizospheric and endophytic Pseudomonas aeruginosa in edible vegetable plants share molecular and metabolic traits with clinical isolates.
Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.; Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA.; Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA.
AIM: Pseudomonas aeruginosa, a leading opportunistic pathogen causing hospital-acquired infections, is also commonly found in agricultural settings. However, there are minimal attempts to examine the molecular and functional attributes shared by agricultural and clinical strains of P. aeruginosa. This study investigates the presence of P. aeruginosa in edible vegetable plants (including salad vegetables) and analyses the evolutionary and metabolic relatedness of the agricultural and clinical strains. METHODS AND RESULTS: Eighteen rhizospheric and endophytic P. aeruginosa strains were isolated from cucumber, tomato, eggplant, and chili directly from the farms. The identity of these strains was confirmed using biochemical and molecular assays. The genetic and metabolic traits of these plant-associated P. aeruginosa isolates were compared with clinical strains. DNA fingerprinting and 16S rDNA-based phylogenetic analyses revealed that the plant- and human-associated strains are evolutionarily related. Both agricultural and clinical isolates possessed plant-beneficial properties, including mineral solubilization to release essential nutrients (phosphorous, potassium, and zinc), ammonification, and the ability to release extracellular pyocyanin, siderophore, and indole-3 acetic acid. CONCLUSION: These findings suggest that rhizospheric and endophytic P. aeruginosa strains are genetically and functionally analogous to the clinical isolates. In addition, the genotypic and phenotypic traits do not correlate with plant sources or ecosystems. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reconfirms that edible plants are the potential source for human and animal transmission of P. aeruginosa.
PMID: 34608722
Proteins , IF:3.756 , 2022 Apr , V90 (4) : P1005-1024 doi: 10.1002/prot.26293
Identification, analysis, and modeling of the YUCCA protein family genome-wide in Coffea canephora.
Centro de Investigacion Cientifica de Yucatan, Unidad de Bioquimica y Biologia Molecular de Plantas, Merida, Mexico.
Auxin is involved in almost every aspect of plant growth and development, from embryogenesis to senescence. Indole-3-acetic acid (IAA) is the main known natural auxin that is synthesized by enzymes tryptophan aminotransferase of arabidopsis (TAA) and YUCCA (YUC) of the flavin-containing monooxygenases family (FMO) from one of the tryptophan-dependent pathways. Genome-wide identification and comprehensive analysis of the YUC-protein family have been conducted in Coffea canephora in the present study. A total of 10 members CcYUC gene family were identified in C. canephora. Phylogenetic analysis revealed that the CcYUC protein family is evolutionarily conserved, and they consist of four groups. In contrast, bioinformatic analysis predicted a hydrophobic transmembrane helix (TMH) for one CcYUC (YUC10) member only. Isoelectric point (pI), molecular mass (Ms), signal peptide, subcellular localization, and phosphorylation sites were predicted for CcYUC proteins. YUC enzymes require the prosthetic group flavin adenine dinucleotide (FAD) and the cofactor nicotinamide adenine dinucleotide phosphate (NADPH) for their enzymatic activity. Therefore, we include the molecular docking for CcYUC2-FAD-NADPH-IPyA and yucasin, which is a specific inhibitor for YUC activity. The docking results showed FAD and NADPH binding at the big and small domain sites, respectively, in CcYUC2. IPyA binds very close to FAD along the big domain, and yucasin competes for the same site as IPA, blocking IAA production. Furthermore, in silico point mutations affect the stability of the CcYUC2-4 proteins.
PMID: 34890079
Gene , IF:3.688 , 2022 Apr , 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 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
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 Mar 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, K.K. Birla Goa campus, 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, K.K. Birla Goa campus, Zuarinagar, Sancoale, Goa 403726, India.; Institute of Biosciences and Technology,Shri Ramswaroop Memorial University, Lucknow-Deva Road, Barabanki, Uttar Pradesh 225003, India.
Cis-regulatory elements are regions of non-coding 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. Analysisof the frequency of occurrence of AAAG and ACGT motifs from varying spacer lengths (0 to 30 base pair) between these two 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
Plant Biol (Stuttg) , IF:3.081 , 2022 Mar doi: 10.1111/plb.13417
Hydrogen sulphide (H2 S) in the hidden half: Role in root growth, stress signalling and rhizospheric interactions.
Microbiology Laboratory, Department of Botany, University of North Bengal, Darjeeling, India.; Plant Biochemistry Laboratory, Department of Botany, University of North Bengal, Darjeeling, India.; Department of Biology, Faculty of Science, College of Haql, University of Tabuk, Tabuk, Saudi Arabia.; Department of Botany, Jangipur College, University of Kalyani, Jangipur, India.
Apart from nitric oxide (NO) and carbon monoxide (CO), hydrogen sulphide (H2 S) has emerged as a potential gasotransmitter that has regulatory roles in root differentiation, proliferation and stress signalling. H2 S metabolism in plants exhibits spatio-temporal differences that are intimately associated with sulphide signalling in the cytosol and other subcellular components, e.g. chloroplast and mitochondria. H2 S biosynthesis in plant organs uses both enzymatic and non-enzymatic pathways. H2 S generation in roots and aerial organs is modulated by developmental phase and changes in environmental stimuli. H2 S has an influential role in root development and in the nodulation process. Studies have revealed that H2 S is a part of the auxin and NO signalling pathways in roots, which induce lateral root formation. At the molecular level, exogenous application of H2 S regulates expression of several transcription factors, viz. LBD (Lateral organ Boundaries Domain), MYB (myeloblastosis) and AP2/ERF (Apetala 2/ Ethylene Response Factor), which stimulate upregulation of PpLBD16 (Lateral organ boundaries domain 16), thereby significantly increasing the number of lateral roots. Concomitantly, H2 S acts as a crucial signalling molecule in roots during various abiotic stresses, e.g. drought, salinity heavy metals (HMs), etc., and augments stress tolerance in plants. Interestingly, extensive crosstalk exists between H2 S, NO, ABA, calcium and ethylene during stress, which escalate plant defence and regulate plant growth and productivity. Hence, the present review will elaborate the role of H2 S in root development, stress alleviation, legume-Rhizobium symbiosis and rhizosphere signalling. The review also examines the mechanism of H2 S-mediated abiotic stress mitigation and cross-talk with other signaling molecules.
PMID: 35334141
Plant Biol (Stuttg) , IF:3.081 , 2022 Apr , V24 (3) : P450-457 doi: 10.1111/plb.13392
Vascular traits of stem galls: Cell increment versus morphogenetic constraints in wood anatomy.
Laboratorio de Anatomia Vegetal, Departamento de Botanica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.; Laboratorio de Fisiologia Vegetal, Departamento de Botanica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Eremanthus erythropappus hosts globoid stem galls induced by Neolasioptera sp. (Diptera: Cecidomyiidae) close to the stem apex, which do not compromise the shoot apical meristem (SAM). We hypothesize that maintenance of the SAM, as well as the increasing number of leaves per branch and of galled stem lengths and diameters, are a consequence of alterations in vascular cells and, consequently, in the priority for water flow from non-galled stems to the stem galls. Our study focuses on the globoid stem galls to evaluate if gall induction and development promote changes in structure and function of secondary xylem cells. Anatomical, cytological, histometric and physiological methods were used to analyse non-galled stem branches (NGS), mature globoid stem galls and stem portions below and above the galls. These analyses revealed that vessel elements are larger in stem galls and in stem portions above the galls. Under Neolasioptera sp. induction activity, the vascular cambium of E. erythropappus produces less numerous but larger vessel elements and overproduces parenchyma cells. Contrary to the vascular constriction hypothesis proposed for bacterial galls, the vascular traits of the Neolasioptera sp. stem galls on E. erythropappus result in priority for water flow to galls and the non-galled portions above the galls, allowing the maintenance of galled stem growth and development.
PMID: 35098632
Plant Biol (Stuttg) , IF:3.081 , 2022 Apr , V24 (3) : P492-501 doi: 10.1111/plb.13386
Plant hormone profile and control over isoprene biosynthesis in a tropical tree Ficus septica.
The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan.; Department of Biosciences, Teikyo University, Utsunomiya, Tochigi, Japan.; Advanced Instrumental Analysis Center, Teikyo University, Tochigi, Japan.; Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.; School of the Environment and Safety Engineering, Biofuels Institute, Jiangsu University, Zhenjiang, Jiangsu, China.; Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan.; Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan.
Plant hormone signalling and the circadian clock have been implicated in the transcriptional control of isoprene biosynthesis. To gain more insight into the hormonal control of isoprene biosynthesis, the present study measured plant hormone concentrations in jasmonic acid (JA)-treated leaves of our previous model study, examined their relationship with gene expression of isoprene synthase (IspS) and hormone signalling transcription factors. Of the plant hormones, IAA and JA-Ile and their related transcription factors (MYC2 and SAUR21) were significantly correlated with IspS gene expression. Concentrations of cytokinins, isopentenyladenine (iP), trans-zeatin riboside (tZR) and cis-zeatin riboside (cZR), were similarly significantly correlated with IspS expression. However, there was no significant correlation between their related transcription factor (ARR-B) and IspS expression. The circadian clock-related gene PRR7, but not the transcription factor LHY, was highly correlated with IspS expression. These results suggest that the hormonal balance between JA-Ile and IAA plays a central role in transcriptional regulation of IspS through the transcription factors MYC2 and SAUR21, the early auxin responsive genes. The putative cis-acting elements for SAUR on the IspS promoter (TGTCNN and CATATG), in addition to the G-box for MYC2, support the above proposal. These results provide insightful information on the core components of plant hormone-related regulation of IspS under coordination with the circadian clock genes.
PMID: 35050526
J Struct Biol , IF:2.867 , 2022 Apr : 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 Apr 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
Mol Biol Rep , IF:2.316 , 2022 Mar doi: 10.1007/s11033-022-07354-9
Phosphorus homeostasis: acquisition, sensing, and long-distance signaling in plants.
Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India.; ICAR- Indian Agricultural Statistical Research Institute, New Delhi, India.; Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India. arunatyagi19@yahoo.com.
Phosphorus (P), an essential nutrient required by plants often becomes the limiting factor for plant growth and development. Plants employ various mechanisms to sense the continuously changing P content in the soil. Transcription factors, such as SHORT ROOT (SHR), AUXIN RESPONSE FACTOR19 (ARF19), and ETHYLENE-INSENSITIVE3 (EIN3) regulate the growth of primary roots, root hairs, and lateral roots under low P. Crop improvement strategies under low P depend either on improving P acquisition efficiency or increasing P utilization. The various phosphate transporters (PTs) are involved in the uptake and transport of P from the soil to various plant cellular organelles. A plethora of regulatory elements including transcription factors, microRNAs and several proteins play a critical role in the regulation of coordinated cellular P homeostasis. Among these, the well-established P starvation signaling pathway comprising of central transcriptional factor phosphate starvation response (PHR), microRNA399 (miR399) as a long-distance signal molecule, and PHOSPHATE 2 (PHO2), an E2 ubiquitin conjugase is crucial in the regulation of phosphorus starvation responsive genes. Under PHR control, several classes of PHTs, microRNAs, and proteins modulate root architecture, and metabolic processes to enable plants to adapt to low P. Even though sucrose and inositol phosphates are known to influence the phosphorus starvation response genes, the exact mechanism of regulation is still unclear. In this review, a basic understanding of P homeostasis under low P in plants and all the above aspects are discussed.
PMID: 35318578
Evodevo , IF:2.25 , 2022 Mar , V13 (1) : P8 doi: 10.1186/s13227-022-00192-7
Fossils and plant evolution: structural fingerprints and modularity in the evo-devo paradigm.
Department of Biological Sciences, California Polytechnic State University Humboldt, Arcata, CA, 95521, USA. mihai@humboldt.edu.; Department of Environmental and Plant Biology, Ohio University, Athens, OH, 45701, USA.; Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA.
Fossils constitute the principal repository of data that allow for independent tests of hypotheses of biological evolution derived from observations of the extant biota. Traditionally, transformational series of structure, consisting of sequences of fossils of the same lineage through time, have been employed to reconstruct and interpret morphological evolution. More recently, a move toward an updated paradigm was fueled by the deliberate integration of developmental thinking in the inclusion of fossils in reconstruction of morphological evolution. The vehicle for this is provided by structural fingerprints-recognizable morphological and anatomical structures generated by (and reflective of) the deployment of specific genes and regulatory pathways during development. Furthermore, because the regulation of plant development is both modular and hierarchical in nature, combining structural fingerprints recognized in the fossil record with our understanding of the developmental regulation of those structures produces a powerful tool for understanding plant evolution. This is particularly true when the systematic distribution of specific developmental regulatory mechanisms and modules is viewed within an evolutionary (paleo-evo-devo) framework. Here, we discuss several advances in understanding the processes and patterns of evolution, achieved by tracking structural fingerprints with their underlying regulatory modules across lineages, living and fossil: the role of polar auxin regulation in the cellular patterning of secondary xylem and the parallel evolution of arborescence in lycophytes and seed plants; the morphology and life history of early polysporangiophytes and tracheophytes; the role of modularity in the parallel evolution of leaves in euphyllophytes; leaf meristematic activity and the parallel evolution of venation patterns among euphyllophytes; mosaic deployment of regulatory modules and the diverse modes of secondary growth of euphyllophytes; modularity and hierarchy in developmental regulation and the evolution of equisetalean reproductive morphology. More generally, inclusion of plant fossils in the evo-devo paradigm has informed discussions on the evolution of growth patterns and growth responses, sporophyte body plans and their homology, sequences of character evolution, and the evolution of reproductive systems.
PMID: 35236418
Adv Biol (Weinh) , 2022 Apr , V6 (4) : Pe2100953 doi: 10.1002/adbi.202100953
Probing DNA - Transcription Factor Interactions Using Single-Molecule Fluorescence Detection in Nanofluidic Devices.
Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.; Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.; Groningen Research Institute of Pharmacy, Pharmaceutical Analysis, University of Groningen, P.O. Box 196, 9700 AD, Groningen, The Netherlands.; Stichting Imec Nederland within OnePlanet Research Center, Bronland 10, Wageningen, 6708 WH, The Netherlands.; Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.
Single-molecule fluorescence detection offers powerful ways to study biomolecules and their complex interactions. Here, nanofluidic devices and camera-based, single-molecule Forster resonance energy transfer (smFRET) detection are combined to study the interactions between plant transcription factors of the auxin response factor (ARF) family and DNA oligonucleotides that contain target DNA response elements. In particular, it is shown that the binding of the unlabeled ARF DNA binding domain (ARF-DBD) to donor and acceptor labeled DNA oligonucleotides can be detected by changes in the FRET efficiency and changes in the diffusion coefficient of the DNA. In addition, this data on fluorescently labeled ARF-DBDs suggest that, at nanomolar concentrations, ARF-DBDs are exclusively present as monomers. In general, the fluidic framework of freely diffusing molecules minimizes potential surface-induced artifacts, enables high-throughput measurements, and proved to be instrumental in shedding more light on the interactions between ARF-DBDs monomers and between ARF-DBDs and their DNA response element.
PMID: 34472724