Cell , IF:41.582 , 2023 Sep doi: 10.1016/j.cell.2023.09.014
Amyloplast sedimentation repolarizes LAZYs to achieve gravity sensing in plants.
Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.; State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Key Laboratory of Vegetable Research Center, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China.; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.; State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.; The Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA; Department of Plant Biology, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA.; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China. Electronic address: chenhaodong@tsinghua.edu.cn.
Gravity controls directional growth of plants, and the classical starch-statolith hypothesis proposed more than a century ago postulates that amyloplast sedimentation in specialized cells initiates gravity sensing, but the molecular mechanism remains uncharacterized. The LAZY proteins are known as key regulators of gravitropism, and lazy mutants show striking gravitropic defects. Here, we report that gravistimulation by reorientation triggers mitogen-activated protein kinase (MAPK) signaling-mediated phosphorylation of Arabidopsis LAZY proteins basally polarized in root columella cells. Phosphorylation of LAZY increases its interaction with several translocons at the outer envelope membrane of chloroplasts (TOC) proteins on the surface of amyloplasts, facilitating enrichment of LAZY proteins on amyloplasts. Amyloplast sedimentation subsequently guides LAZY to relocate to the new lower side of the plasma membrane in columella cells, where LAZY induces asymmetrical auxin distribution and root differential growth. Together, this study provides a molecular interpretation for the starch-statolith hypothesis: the organelle-movement-triggered molecular polarity formation.
PMID: 37741279
Trends Plant Sci , IF:18.313 , 2023 Oct , V28 (10) : P1098-1100 doi: 10.1016/j.tplants.2023.07.001
25 Years of thermomorphogenesis research: milestones and perspectives.
Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany. Electronic address: marcel.quint@landw.uni-halle.de.; Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany.; School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia.; Division of Plant Sciences, University of Dundee at the James Hutton Institute, Dundee DD2 5DA, UK.; IFEVA, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina; Fundacion Instituto Leloir, C1405 BWE, Buenos Aires, Argentina.; Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada.; Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA.; School of Life Sciences, Peking University, Beijing 100871, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium; VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium.; Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.; University of Bristol, Bristol BS8 1TQ, UK.; Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh 3H9 3BF, UK.; Laboratory of Plant Physiology, Wageningen University & Research, 6708 PB Wageningen, The Netherlands.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101 Beijing, China.; Department of Biological Sciences, Sungkyunkwan University, 16419 Suwon, South Korea.; School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.; Department of Biosciences, University of Exeter, Exeter EX4 4QD, UK.; Department of Pharmaceutical Biology, Julius von Sachs Institute of Biosciences, University of Wurzburg, 97082 Wurzburg, Germany.; Department of Life Sciences, Korea University, 02841 Seoul, Korea.; Department of Chemistry, Seoul National University, 08826 Seoul, Korea; Plant Genomics and Breeding Institute, Seoul National University, 08826 Seoul, Korea.; Department of Crop Genetics, John Innes Centre, Norwich NR4 7UH, UK.; Department of Biosciences, University of Milan, 20133 Milan, Italy.; Department of Plant Responses to Stress, Centre for Research in Agricultural Genomics (CRAG), Campus UAB, 08193 Cerdanyola, Barcelona, Spain.; Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland.; Leibniz Institut fur Gemuse und Zierpflanzenbau, 14979 Grossbeeren, Germany; Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany.; Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80521, USA.; Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands. Electronic address: m.vanzanten@uu.nl.
In 1998, Bill Gray and colleagues showed that warm temperatures trigger arabidopsis hypocotyl elongation in an auxin-dependent manner. This laid the foundation for a vibrant research discipline. With several active members of the 'thermomorphogenesis' community, we here reflect on 25 years of elevated ambient temperature research and look to the future.
PMID: 37574427
Nat Plants , IF:15.793 , 2023 Sep , V9 (9) : P1500-1513 doi: 10.1038/s41477-023-01478-x
Antigravitropic PIN polarization maintains non-vertical growth in lateral roots.
School of Biology, University of Leeds, Leeds, UK.; Department of Biology, Duke University, Durham, NC, USA.; Ohio Wesleyan University, Delaware, OH, USA.; Institute of Science and Technology, Vienna, Austria.; Umea Plant Science Centre, Umea, Sweden.; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.; Tropic Biosciences Ltd, Norwich Research Park Innovation Centre, Norwich, UK.; Department of Science, Innovation and Technology, UK Government, London, UK.; University of Western Australia, Perth, Western Australia, Australia.; Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO, USA.; Department of Biology, Indiana University, Bloomington, IN, USA.; School of Biology, University of Leeds, Leeds, UK. s.kepinski@leeds.ac.uk.
Lateral roots are typically maintained at non-vertical angles with respect to gravity. These gravitropic setpoint angles are intriguing because their maintenance requires that roots are able to effect growth response both with and against the gravity vector, a phenomenon previously attributed to gravitropism acting against an antigravitropic offset mechanism. Here we show how the components mediating gravitropism in the vertical primary root-PINs and phosphatases acting upon them-are reconfigured in their regulation such that lateral root growth at a range of angles can be maintained. We show that the ability of Arabidopsis lateral roots to bend both downward and upward requires the generation of auxin asymmetries and is driven by angle-dependent variation in downward gravitropic auxin flux acting against angle-independent upward, antigravitropic flux. Further, we demonstrate a symmetry in auxin distribution in lateral roots at gravitropic setpoint angle that can be traced back to a net, balanced polarization of PIN3 and PIN7 auxin transporters in the columella. These auxin fluxes are shifted by altering PIN protein phosphoregulation in the columella, either by introducing PIN3 phosphovariant versions or via manipulation of levels of the phosphatase subunit PP2A/RCN1. Finally, we show that auxin, in addition to driving lateral root directional growth, acts within the lateral root columella to induce more vertical growth by increasing RCN1 levels, causing a downward shift in PIN3 localization, thereby diminishing the magnitude of the upward, antigravitropic auxin flux.
PMID: 37666965
Nat Plants , IF:15.793 , 2023 Sep , V9 (9) : P1514-1529 doi: 10.1038/s41477-023-01494-x
Plastid-localized amino acid metabolism coordinates rice ammonium tolerance and nitrogen use efficiency.
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Nanjing, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB-UGent Center for Plant Systems Biology, Ghent, Belgium.; Excellence and Innovation Center, Jiangsu Academy of Agricultural Sciences, Nanjing, China.; Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. Tom.Beeckman@psb.vib-ugent.be.; VIB-UGent Center for Plant Systems Biology, Ghent, Belgium. Tom.Beeckman@psb.vib-ugent.be.; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Nanjing, China. wexua@njau.edu.cn.
Ammonium toxicity affecting plant metabolism and development is a worldwide problem impeding crop production. Remarkably, rice (Oryza sativa L.) favours ammonium as its major nitrogen source in paddy fields. We set up a forward-genetic screen to decipher the molecular mechanisms conferring rice ammonium tolerance and identified rohan showing root hypersensitivity to ammonium due to a missense mutation in an argininosuccinate lyase (ASL)-encoding gene. ASL localizes to plastids and its expression is induced by ammonium. ASL alleviates ammonium-inhibited root elongation by converting the excessive glutamine to arginine. Consequently, arginine leads to auxin accumulation in the root meristem, thereby stimulating root elongation under high ammonium. Furthermore, we identified natural variation in the ASL allele between japonica and indica subspecies explaining their different root sensitivity towards ammonium. Finally, we show that ASL expression positively correlates with root ammonium tolerance and that nitrogen use efficiency and yield can be improved through a gain-of-function approach.
PMID: 37604972
Nat Commun , IF:14.919 , 2023 Sep , V14 (1) : P5800 doi: 10.1038/s41467-023-40916-4
Auxin-producing bacteria promote barley rhizosheath formation.
Center for Plant Water-use and Nutrition Regulation and College of Resources and Environment, Joint International Research Laboratory of Water and Nutrient in Crop and College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Institute of Oceanography, Minjiang University, Fuzhou, 350108, China.; Crop Functional Genomics, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.; Emmy Noether Group Root Functional Biology, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.; College of Agriculture, Yangzhou University, Yangzhou, 225000, China.; State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.; Center for Plant Water-use and Nutrition Regulation and College of Resources and Environment, Joint International Research Laboratory of Water and Nutrient in Crop and College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. wfxu@fafu.edu.cn.
The rhizosheath, or the layer of soil closely adhering to roots, can help plants to tolerate drought under moderate soil drying conditions. Rhizosheath formation is the result of poorly understood interactions between root exudates, microbes, and soil conditions. Here, we study the roles played by the soil microbiota in rhizosheath formation in barley (a dry crop). We show that barley rhizosheath formation is greater in acid soil than in alkaline soil, and inoculation with microbiota from acid soil enhances rhizosheath formation in alkaline soil. The rhizosheath-promoting activity is associated with the presence of Flavobacteriaceae and Paenibacillaceae bacteria that express genes for biosynthesis of indole-3-acetic acid (IAA, a common auxin), as determined by metagenomics and metatranscriptomics. Two bacterial strains isolated from rhizosheath (Chryseobacterium culicis and Paenibacillus polymyxa) produce IAA and enhance barley rhizosheath formation, while their IAA-defective mutants are unable to promote rhizosheath formation. Co-inoculation with the IAA-producing strains enhances barley grain yield in field experiments through an increase in spike number. Our findings contribute to our understanding of barley rhizosheath formation, and suggest potential strategies for crop improvement.
PMID: 37726263
Mol Plant , IF:13.164 , 2023 Sep doi: 10.1016/j.molp.2023.09.007
Rice roots avoid asymmetric heavy metal and salinity stress via an RBOH-ROS-auxin signaling cascade.
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: fangjie.zhao@njau.edu.cn.
Root developmental plasticity is crucial for plants to adapt to a changing soil environment, where nutrients and abiotic stress factors are distributed heterogeneously. How plant roots sense and avoid heterogeneous abiotic stress in soil remains unclear. Here, we show that, in response to asymmetric stress of heavy metals (cadmium, copper, or lead) and salt, rice roots rapidly proliferate lateral roots (LRs) in the stress-free area, thereby remodeling root architecture to avoid localized stress. Imaging and quantitative analyses of reactive oxygen species (ROS) showed that asymmetric stress induces a ROS burst in the tips of the exposed roots and simultaneously triggers rapid systemic ROS signaling to the unexposed roots. Addition of a ROS scavenger to either the stressed or stress-free area abolished systemic ROS signaling and LR proliferation induced by asymmetric stress. Asymmetric stress also enhanced cytosolic calcium (Ca(2+)) signaling; blocking Ca(2+)signaling inhibited systemic ROS propagation and LR branching in the stress-free area. We identified two plasma-membrane-localized respiratory burst oxidase homologs, OsRBOHA and OsRBOHI, as key players in systemic ROS signaling under asymmetric stress. Expression of OsRBOHA and OsRBOHI in roots was upregulated by Cd stress, and knockout of either gene reduced systemic ROS signaling and LR proliferation under asymmetric stress. Furthermore, we demonstrated that auxin signaling and cell wall remodeling act downstream of the systemic ROS signaling to promote LR development. Collectively, our study reveals an RBOH-ROS-auxin signaling cascade that enables rice roots to avoid localized stress of heavy metals and salt and provides new insight into root system plasticity in heterogenous soil.
PMID: 37735869
Plant Cell , IF:11.277 , 2023 Sep , V35 (9) : P3485-3503 doi: 10.1093/plcell/koad170
MYB112 connects light and circadian clock signals to promote hypocotyl elongation in Arabidopsis.
Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.; National Center for Transgenic Research in Plants, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing Engineering Research Center for Edible Mushroom, Beijing 100097, China.; School of Life Science, Huizhou University, Huizhou 516007, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing 100871, China.
Ambient light and the endogenous circadian clock play key roles in regulating Arabidopsis (Arabidopsis thaliana) seedling photomorphogenesis. PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) acts downstream of both light and the circadian clock to promote hypocotyl elongation. Several members of the R2R3-MYB transcription factor (TF) family, the most common type of MYB TF family in Arabidopsis, have been shown to be involved in regulating photomorphogenesis. Nonetheless, whether R2R3-MYB TFs are involved in connecting the light and clock signaling pathways during seedling photomorphogenesis remains unknown. Here, we report that MYB112, a member of the R2R3-MYB family, acts as a negative regulator of seedling photomorphogenesis in Arabidopsis. The light signal promotes the transcription and protein accumulation of MYB112. myb112 mutants exhibit short hypocotyls in both constant light and diurnal cycles. MYB112 physically interacts with PIF4 to enhance the transcription of PIF4 target genes involved in the auxin pathway, including YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE 19 (IAA19), and IAA29. Furthermore, MYB112 directly binds to the promoter of LUX ARRHYTHMO (LUX), the central component of clock oscillators, to repress its expression mainly in the afternoon and relieve LUX-inhibited expression of PIF4. Genetic evidence confirms that LUX acts downstream of MYB112 in regulating hypocotyl elongation. Thus, the enhanced transcript accumulation and transcriptional activation activity of PIF4 by MYB112 additively promotes the expression of auxin-related genes, thereby increasing auxin synthesis and signaling and fine-tuning hypocotyl growth under diurnal cycles.
PMID: 37335905
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Oct , V120 (40) : Pe2302996120 doi: 10.1073/pnas.2302996120
Trehalose-6-phosphate signaling regulates lateral root formation in Arabidopsis thaliana.
Department of Plant Biotechnology and Bioinformatics Ghent University, Ghent B-9052, Belgium.; Vlaams Instituut voor Biotechnologie Center for Plant Systems Biology, Ghent B-9052, Belgium.; Laboratory of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven B3001, Belgium.; Vlaams Instituut voor Biotechnologie-Katholieke Universiteit Leuven Center for Microbiology, Leuven B3001, Belgium.; Department of Organic and Macromolecular Chemistry, Laboratory for Organic and Bio-Organic Synthesis, Ghent University, Ghent B-9000, Belgium.; Department of Sustainable Soils and Crops, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom.; Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom.; Next Generation Chemistry, The Rosalind Franklin Institute, Didcot OX1 3TA, United Kingdom.; Department of Pharmacology, University of Oxford, Oxford OX1 3TA, United Kingdom.; Katholieke Universiteit Leuven Plant Institute, Katholieke Universiteit Leuven, Leuven B3001, Belgium.
Plant roots explore the soil for water and nutrients, thereby determining plant fitness and agricultural yield, as well as determining ground substructure, water levels, and global carbon sequestration. The colonization of the soil requires investment of carbon and energy, but how sugar and energy signaling are integrated with root branching is unknown. Here, we show through combined genetic and chemical modulation of signaling pathways that the sugar small-molecule signal, trehalose-6-phosphate (T6P) regulates root branching through master kinases SNF1-related kinase-1 (SnRK1) and Target of Rapamycin (TOR) and with the involvement of the plant hormone auxin. Increase of T6P levels both via genetic targeting in lateral root (LR) founder cells and through light-activated release of the presignaling T6P-precursor reveals that T6P increases root branching through coordinated inhibition of SnRK1 and activation of TOR. Auxin, the master regulator of LR formation, impacts this T6P function by transcriptionally down-regulating the T6P-degrader trehalose phosphate phosphatase B in LR cells. Our results reveal a regulatory energy-balance network for LR formation that links the 'sugar signal' T6P to both SnRK1 and TOR downstream of auxin.
PMID: 37748053
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Sep , V120 (39) : Pe2304513120 doi: 10.1073/pnas.2304513120
PIF4 enhances the expression of SAUR genes to promote growth in response to nitrate.
Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura, Facultad de Agronomia, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires 1417, Argentina.; Fundaciomicronn Instituto Leloir, Instituto de Investigaciones Bioquimicas de Buenos Aires, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires 1405, Argentina.; Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280.; Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108.; Instituto de Biologiotaa Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas, Universidad Politecnica de Valencia, Valencia 46022, Spain.; Departamento de Genetica Molecular y Microbiologia, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago 8331150, Chile.
Nitrate supply is fundamental to support shoot growth and crop performance, but the associated increase in stem height exacerbates the risks of lodging and yield losses. Despite their significance for agriculture, the mechanisms involved in the promotion of stem growth by nitrate remain poorly understood. Here, we show that the elongation of the hypocotyl of Arabidopsis thaliana, used as a model, responds rapidly and persistently to upshifts in nitrate concentration, rather than to the nitrate level itself. The response occurred even in shoots dissected from their roots and required NITRATE TRANSPORTER 1.1 (NRT1.1) in the phosphorylated state (but not NRT1.1 nitrate transport capacity) and NIN-LIKE PROTEIN 7 (NLP7). Nitrate increased PHYTOCHROME INTERACTING FACTOR 4 (PIF4) nuclear abundance by posttranscriptional mechanisms that depended on NRT1.1 and phytochrome B. In response to nitrate, PIF4 enhanced the expression of numerous SMALL AUXIN-UP RNA (SAUR) genes in the hypocotyl. The growth response to nitrate required PIF4, positive and negative regulators of its activity, including AUXIN RESPONSE FACTORs, and SAURs. PIF4 integrates cues from the soil (nitrate) and aerial (shade) environments adjusting plant stature to facilitate access to light.
PMID: 37725643
Curr Biol , IF:10.834 , 2023 Sep doi: 10.1016/j.cub.2023.08.061
Genome and transcriptome of Selaginella kraussiana reveal evolution of root apical meristems in vascular plants.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.; School of Life Sciences, Nantong University, Nantong 226019, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China; State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China. Electronic address: xulin@cemps.ac.cn.
The evolution of roots allowed vascular plants to adapt to land environments. Fossil evidence indicates that roots evolved independently in euphyllophytes (ferns and seed plants) and lycophytes, the two lineages of extant vascular plants. Based on a high-quality genome assembly, mRNA sequencing (mRNA-seq) data, and single-cell RNA-seq data for the lycophyte Selaginella kraussiana, we show that the two root origin events in lycophytes and euphyllophytes adopted partially similar molecular modules in the regulation of root apical meristem (RAM) development. In S. kraussiana, the RAM initiates from the rhizophore primordium guided by auxin and duplicates itself by dichotomous branching. The auxin signaling pathway directly upregulates euAINTEGUMENTAb (SkeuANTb), and then SkeuANTb directly promotes the expression of SkeuANTa and the WUSCHEL-RELATED HOMEOBOX13b (SkWOX13b) for RAM maintenance, partially similar to the molecular pathway involving the euANT-branch PLETHORA (AtPLT) genes and AtWOX5 in root initiation in the seed plant Arabidopsis thaliana. Other molecular modules, e.g., SHORT-ROOT and SCARECROW, also have partially similar expression patterns in the RAMs of S. kraussiana and A. thaliana. Overall, our study not only provides genome and transcriptome tools of S. kraussiana but also indicates the employment of some common molecular modules in RAMs during root origins in lycophytes and euphyllophytes.
PMID: 37716350
Curr Biol , IF:10.834 , 2023 Sep , V33 (18) : P3926-3941.e5 doi: 10.1016/j.cub.2023.08.040
A spatially concerted epidermal auxin signaling framework steers the root hair foraging response under low nitrogen.
Molecular Plant Nutrition, Department of Physiology & Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466 Gatersleben, Germany; State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. Electronic address: jiazt@cau.edu.cn.; Molecular Plant Nutrition, Department of Physiology & Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466 Gatersleben, Germany.; ANID - Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile; Centro de Biotecnologia Vegetal, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile.; Future Food Beacon and School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK.; Molecular Plant Nutrition, Department of Physiology & Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466 Gatersleben, Germany. Electronic address: vonwiren@ipk-gatersleben.de.
As a major determinant of the nutrient-acquiring root surface, root hairs (RHs) provide a low-input strategy to enhance nutrient uptake. Although primary and lateral roots exhibit elongation responses under mild nitrogen (N) deficiency, the foraging response of RHs and underlying regulatory mechanisms remain elusive. Employing transcriptomics and functional studies revealed a framework of molecular components composing a cascade of auxin synthesis, transport, and signaling that triggers RH elongation for N acquisition. Through upregulation of Tryptophan Aminotransferase of Arabidopsis 1 (TAA1) and YUCCA8, low N increases auxin accumulation in the root apex. Auxin is then directed to the RH differentiation zone via the auxin transport machinery, AUXIN TRANSPORTER PROTEIN 1 (AUX1) and PIN-FORMED 2 (PIN2). Upon arrival to the RH zone, auxin activates the transcription factors AUXIN RESPONSE FACTOR 6 and 8 (ARF6/8) to promote the epidermal and auxin-inducible transcriptional module ROOT HAIR DEFECTIVE 6 (RHD6)-LOTUS JAPONICA ROOT HAIRLESS-LIKE 3 (LRL3) to steer RH elongation in response to low N. Our study uncovers a spatially defined regulatory signaling cascade for N foraging by RHs, expanding the mechanistic framework of hormone-regulated nutrient sensing in plant roots.
PMID: 37699396
J Hazard Mater , IF:10.588 , 2023 Sep , V461 : P132541 doi: 10.1016/j.jhazmat.2023.132541
Genome-wide profiling of genetic variations reveals the molecular basis of aluminum stress adaptation in Tibetan wild barley.
Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; Plant Biotechnology Laboratory, Center for Viticulture & Small Fruit Research, Florida A&M University, FL 32317, USA.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China. Electronic address: wufeibo@zju.edu.cn.
Aluminum (Al) toxicity in acidic soil is a major factor affecting crop productivity. The extensive genetic diversity found in Tibetan wild barley germplasms offers a valuable reservoir of alleles associated with aluminum tolerance. Here, resequencing of two Al-tolerant barley genotypes (Tibetan wild barley accession XZ16 and cultivated barley Dayton) identified a total of 19,826,182 and 16,287,277 single nucleotide polymorphisms (SNPs), 1628,052 and 1386,973 insertions/deletions (InDels), 61,532 and 57,937 structural variations (SVs), 248,768 and 240,723 copy number variations (CNVs) in XZ16 and Dayton, respectively, and uncovered approximately 600 genes highly related to Al tolerance in barley. Comparative genomic analyses unveiled 71 key genes that contain unique genetic variants in XZ16 and are predominantly associated with organic acid exudation, Al sequestration, auxin response, and transcriptional regulation. Manipulation of these key genes at the genetic and transcriptional level is a promising strategy for developing optimal haplotype combinations and new barley cultivars with improved Al tolerance. This study represents the first comprehensive examination of genetic variation in Al-tolerant Tibetan wild barley through genome-wide profiling. The obtained results make the deep insight into the mechanisms underlying barley adaptation to Al toxicity, and identified the candidate genes useful for improvement of Al tolerance in barley.
PMID: 37716271
New Phytol , IF:10.151 , 2023 Sep doi: 10.1111/nph.19284
GH3-mediated auxin inactivation attenuates multiple stages of lateral root development.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium.; Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium.; MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.; Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium.; Department of Bioscience, Okayama University of Science, Okayama, 700-0005, Japan.; Department of Biology, University of Fribourg, Fribourg, CH-1700, Switzerland.; Computational Developmental Biology Group, Faculty of Science, Utrecht University, Utrecht, 3584 CH, the Netherlands.
Lateral root (LR) positioning and development rely on the dynamic interplay between auxin production, transport but also inactivation. Nonetheless, how the latter affects LR organogenesis remains largely uninvestigated. Here, we systematically analyze the impact of the major auxin inactivation pathway defined by GRETCHEN HAGEN3-type (GH3) auxin conjugating enzymes and DIOXYGENASE FOR AUXIN OXIDATION1 (DAO1) in all stages of LR development using reporters, genetics and inhibitors in Arabidopsis thaliana. Our data demonstrate that the gh3.1/2/3/4/5/6 hextuple (gh3hex) mutants display a higher LR density due to increased LR initiation and faster LR developmental progression, acting epistatically over dao1-1. Grafting and local inhibitor applications reveal that root and shoot GH3 activities control LR formation. The faster LR development in gh3hex is associated with GH3 expression domains in and around developing LRs. The increase in LR initiation is associated with accelerated auxin response oscillations coinciding with increases in apical meristem size and LR cap cell death rates. Our research reveals how GH3-mediated auxin inactivation attenuates LR development. Local GH3 expression in LR primordia attenuates development and emergence, whereas GH3 effects on pre-initiation stages are indirect, by modulating meristem activities that in turn coordinate root growth with LR spacing.
PMID: 37743759
New Phytol , IF:10.151 , 2023 Sep doi: 10.1111/nph.19273
Parallel tuning of semi-dwarfism via differential splicing of Brachytic1 in commercial maize and smallholder sorghum.
Corteva Agriscience, 7300 NW 62nd Ave, Johnston, IA, 50131, USA.; Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.; Department of Agronomy, Kansas State University, Manhattan, KS, 66506, USA.; Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.; Soil & Crop Sciences, Colorado State University, Plant Sciences Building, Fort Collins, CO, 11111, USA.; Napigen Inc., 200 Powder Mill Road, Delaware Innovation Space - E500, Wilmington, DE, 19803, USA.
In the current genomic era, the search and deployment of new semi-dwarf alleles have continued to develop better plant types in all cereals. We characterized an agronomically optimal semi-dwarf mutation in Zea mays L. and a parallel polymorphism in Sorghum bicolor L. We cloned the maize brachytic1 (br1-Mu) allele by a modified PCR-based Sequence Amplified Insertion Flanking Fragment (SAIFF) approach. Histology and RNA-Seq elucidated the mechanism of semi-dwarfism. GWAS linked a sorghum plant height QTL with the Br1 homolog by resequencing a West African sorghum landraces panel. The semi-dwarf br1-Mu allele encodes an MYB transcription factor78 that positively regulates stalk cell elongation by interacting with the polar auxin pathway. Semi-dwarfism is due to differential splicing and low functional Br1 wild-type transcript expression. The sorghum ortholog, SbBr1, co-segregates with the major plant height QTL qHT7.1 and is alternatively spliced. The high frequency of the Sbbr1 allele in African landraces suggests that African smallholder farmers used the semi-dwarf allele to improve plant height in sorghum long before efforts to introduce Green Revolution-style varieties in the 1960s. Surprisingly, variants for differential splicing of Brachytic1 were found in both commercial maize and smallholder sorghum, suggesting parallel tuning of plant architecture across these systems.
PMID: 37737036
New Phytol , IF:10.151 , 2023 Oct , V240 (2) : P846-862 doi: 10.1111/nph.19157
The YABBY gene SHATTERING1 controls activation rather than patterning of the abscission zone in Setaria viridis.
Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA.; Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK, 74078, USA.; College of Biological Sciences, University of Minnesota, St Paul, MN, 55108, USA.
Abscission is predetermined in specialized cell layers called the abscission zone (AZ) and activated by developmental or environmental signals. In the grass family, most identified AZ genes regulate AZ anatomy, which differs among lineages. A YABBY transcription factor, SHATTERING1 (SH1), is a domestication gene regulating abscission in multiple cereals, including rice and Setaria. In rice, SH1 inhibits lignification specifically in the AZ. However, the AZ of Setaria is nonlignified throughout, raising the question of how SH1 functions in species without lignification. Crispr-Cas9 knockout mutants of SH1 were generated in Setaria viridis and characterized with histology, cell wall and auxin immunofluorescence, transmission electron microscopy, hormonal treatment and RNA-Seq analysis. The sh1 mutant lacks shattering, as expected. No differences in cell anatomy or cell wall components including lignin were observed between sh1 and the wild-type (WT) until abscission occurs. Chloroplasts degenerated in the AZ of WT before abscission, but degeneration was suppressed by auxin treatment. Auxin distribution and expression of auxin-related genes differed between WT and sh1, with the signal of an antibody to auxin detected in the sh1 chloroplast. SH1 in Setaria is required for activation of abscission through auxin signaling, which is not reported in other grass species.
PMID: 37533135
New Phytol , IF:10.151 , 2023 Sep , V239 (6) : P2248-2264 doi: 10.1111/nph.19126
Expression quantitative trait loci mapping identified PtrXB38 as a key hub gene in adventitious root development in Populus.
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.; State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, 311300, China.; Bredesen Center for Interdisciplinary Research, University of Tennessee, Knoxville, TN, 37996, USA.; Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA.; Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA.; Department of Genetics, University of Georgia, Athens, GA, 30602, USA.; Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA.; Department of Academic Education, Central Community College - Hastings, Hastings, NE, 68902, USA.; Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.; Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA.; US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.
Plant establishment requires the formation and development of an extensive root system with architecture modulated by complex genetic networks. Here, we report the identification of the PtrXB38 gene as an expression quantitative trait loci (eQTL) hotspot, mapped using 390 leaf and 444 xylem Populus trichocarpa transcriptomes. Among predicted targets of this trans-eQTL were genes involved in plant hormone responses and root development. Overexpression of PtrXB38 in Populus led to significant increases in callusing and formation of both stem-born roots and base-born adventitious roots. Omics studies revealed that genes and proteins controlling auxin transport and signaling were involved in PtrXB38-mediated adventitious root formation. Protein-protein interaction assays indicated that PtrXB38 interacts with components of endosomal sorting complexes required for transport machinery, implying that PtrXB38-regulated root development may be mediated by regulating endocytosis pathway. Taken together, this work identified a crucial root development regulator and sheds light on the discovery of other plant developmental regulators through combining eQTL mapping and omics approaches.
PMID: 37488708
New Phytol , IF:10.151 , 2023 Oct , V240 (2) : P489-495 doi: 10.1111/nph.19123
Tale of cAMP as a second messenger in auxin signaling and beyond.
Institute of Science and Technology Austria (ISTA), Klosterneuburg, 3400, Austria.
The 3',5'-cyclic adenosine monophosphate (cAMP) is a versatile second messenger in many mammalian signaling pathways. However, its role in plants remains not well-recognized. Recent discovery of adenylate cyclase (AC) activity for transport inhibitor response 1/auxin-signaling F-box proteins (TIR1/AFB) auxin receptors and the demonstration of its importance for canonical auxin signaling put plant cAMP research back into spotlight. This insight briefly summarizes the well-established cAMP signaling pathways in mammalian cells and describes the turbulent and controversial history of plant cAMP research highlighting the major progress and the unresolved points. We also briefly review the current paradigm of auxin signaling to provide a background for the discussion on the AC activity of TIR1/AFB auxin receptors and its potential role in transcriptional auxin signaling as well as impact of these discoveries on plant cAMP research in general.
PMID: 37434303
Plant Biotechnol J , IF:9.803 , 2023 Oct , V21 (10) : P1990-2001 doi: 10.1111/pbi.14107
Grain yield improvement by genome editing of TaARF12 that decoupled peduncle and rachis development trajectories via differential regulation of gibberellin signalling in wheat.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.; The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; Triticeae Research Institute, Sichuan Agricultural University, Chengdu, China.
Plant breeding is constrained by trade-offs among different agronomic traits by the pleiotropic nature of many genes. Genes that contribute to two or more favourable traits with no penalty on yield are rarely reported, especially in wheat. Here, we describe the editing of a wheat auxin response factor TaARF12 by using CRISPR/Cas9 that rendered shorter plant height with larger spikes. Changes in plant architecture enhanced grain number per spike up to 14.7% with significantly higher thousand-grain weight and up to 11.1% of yield increase under field trials. Weighted Gene Co-Expression Network Analysis (WGCNA) of spatial-temporal transcriptome profiles revealed two hub genes: RhtL1, a DELLA domain-free Rht-1 paralog, which was up-regulated in peduncle, and TaNGR5, an organ size regulator that was up-regulated in rachis, in taarf12 plants. The up-regulation of RhtL1 in peduncle suggested the repression of GA signalling, whereas up-regulation of TaNGR5 in spike may promote GA response, a working model supported by differential expression patterns of GA biogenesis genes in the two tissues. Thus, TaARF12 complemented plant height reduction with larger spikes that gave higher grain yield. Manipulation of TaARF12 may represent a new strategy in trait pyramiding for yield improvement in wheat.
PMID: 37589238
Plant Physiol , IF:8.34 , 2023 Sep doi: 10.1093/plphys/kiad515
Peptides from conserved tandem direct repeats of SHORT-LEAF regulate gametophore development in moss P. patens.
Indian Institute of Science Education and Research (IISER-Pune), Dr. Homi Bhabha Road, Maharashtra, Pune 411008, India.; Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
Tandem direct repeat (TDR)-containing proteins, present across all domains of life, play crucial roles in plant development and defense mechanisms. Previously, we identified that disruption of a bryophyte-specific protein family, SHORT-LEAF (SHLF), possessing the longest reported TDRs, is the cause of the shlf mutant phenotype in Physcomitrium patens. shlf exhibits reduced apical dominance, altered auxin distribution, and two-fold shorter leaves. However, the molecular role of SHLF was unclear due to the absence of known conserved domains. Through a series of protein domain deletion analyses, here, we demonstrate the importance of the signal peptide and the conserved TDRs and report a minimal functional protein (miniSHLF) containing the N-terminal signal peptide and first two TDRs (N-TDR1-2). We also demonstrate that SHLF behaves as a secretory protein and that the TDRs contribute to a pool of secreted peptides essential for SHLF function. Further, we identified that the mutant secretome lacks SHLF peptides, which are abundant in WT and miniSHLF secretomes. Interestingly, shlf mutants supplemented with the secretome or peptidome from WT or miniSHLF showed complete or partial phenotypic recovery. Transcriptomic and metabolomic analyses revealed that shlf displays an elevated stress response, including high ROS activity and differential accumulation of genes and metabolites involved in the phenylpropanoid pathway, which may affect auxin distribution. The TDR-specific synthetic peptide SHLFpep3 (INIINAPLQGFKIA) also rescued the mutant phenotypes, including the altered auxin distribution, in a dosage-dependent manner and restored the mutant's stress levels. Our study shows that secretory SHLF peptides derived from conserved TDRs regulate moss gametophore development.
PMID: 37770073
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P661-676 doi: 10.1093/plphys/kiad345
WUSCHEL controls genotype-dependent shoot regeneration capacity in potato.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, South Korea.; Department of Crop Science, Chungnam National University, Daejeon 34134, South Korea.; Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon 34141, South Korea.; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon 34113, South Korea.; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, South Korea.; Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea.
Plant cells can reprogram their fate. The combinatorial actions of auxin and cytokinin dedifferentiate somatic cells to regenerate organs, which can develop into individual plants. As transgenic plants can be generated from genetically modified somatic cells through these processes, cell fate transition is an unavoidable step in crop genetic engineering. However, regeneration capacity closely depends on the genotype, and the molecular events underlying these variances remain elusive. In the present study, we demonstrated that WUSCHEL (WUS)-a homeodomain transcription factor-determines regeneration capacity in different potato (Solanum tuberosum) genotypes. Comparative analysis of shoot regeneration efficiency and expression of genes related to cell fate transition revealed that WUS expression coincided with regeneration rate in different potato genotypes. Moreover, in a high-efficiency genotype, WUS silencing suppressed shoot regeneration. Meanwhile, in a low-efficiency genotype, regeneration could be enhanced through the supplementation of a different type of cytokinin that promoted WUS expression. Computational modeling of cytokinin receptor-ligand interactions suggested that the docking pose of cytokinins mediated by hydrogen bonding with the core residues may be pivotal for WUS expression and shoot regeneration in potatoes. Furthermore, our whole-genome sequencing analysis revealed core sequence variations in the WUS promoters that differentiate low- and high-efficiency genotypes. The present study revealed that cytokinin responses, particularly WUS expression, determine shoot regeneration efficiency in different potato genotypes.
PMID: 37348867
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P537-554 doi: 10.1093/plphys/kiad352
Inhibitor AN3661 reveals biological functions of Arabidopsis CLEAVAGE and POLYADENYLATION SPECIFICITY FACTOR 73.
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.; Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA 91766, USA.
Cleavage and polyadenylation specificity factor (CPSF) is a protein complex that plays an essential biochemical role in mRNA 3'-end formation, including poly(A) signal recognition and cleavage at the poly(A) site. However, its biological functions at the organismal level are mostly unknown in multicellular eukaryotes. The study of plant CPSF73 has been hampered by the lethality of Arabidopsis (Arabidopsis thaliana) homozygous mutants of AtCPSF73-I and AtCPSF73-II. Here, we used poly(A) tag sequencing to investigate the roles of AtCPSF73-I and AtCPSF73-II in Arabidopsis treated with AN3661, an antimalarial drug with specificity for parasite CPSF73 that is homologous to plant CPSF73. Direct seed germination on an AN3661-containing medium was lethal; however, 7-d-old seedlings treated with AN3661 survived. AN3661 targeted AtCPSF73-I and AtCPSF73-II, inhibiting growth through coordinating gene expression and poly(A) site choice. Functional enrichment analysis revealed that the accumulation of ethylene and auxin jointly inhibited primary root growth. AN3661 affected poly(A) signal recognition, resulted in lower U-rich signal usage, caused transcriptional readthrough, and increased the distal poly(A) site usage. Many microRNA targets were found in the 3' untranslated region lengthened transcripts; these miRNAs may indirectly regulate the expression of these targets. Overall, this work demonstrates that AtCPSF73 plays important part in co-transcriptional regulation, affecting growth, and development in Arabidopsis.
PMID: 37335917
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P112-124 doi: 10.1093/plphys/kiad321
Axes and polarities in leaf vein formation.
Department of Biological Sciences, University of Alberta, CW-405 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada.
For multicellular organisms to develop, cells must grow, divide, and differentiate along preferential or exclusive orientations or directions. Moreover, those orientations, or axes, and directions, or polarities, must be coordinated between cells within and between tissues. Therefore, how axes and polarities are coordinated between cells is a key question in biology. In animals, such coordination mainly depends on cell migration and direct interaction between proteins protruding from the plasma membrane. Both cell movements and direct cell-cell interactions are prevented in plants by cell walls that surround plant cells and keep them apart and in place. Therefore, plants have evolved unique mechanisms to coordinate their cell axes and polarities. Here I will discuss evidence suggesting that understanding how leaf veins form may uncover those unique mechanisms. Indeed, unlike previously thought, the cell-to-cell polar transport of the plant hormone auxin along developing veins cannot account for many features of vein patterning. Instead, those features can be accounted for by models of vein patterning that combine polar auxin transport with auxin diffusion through plasmodesmata along the axis of developing veins. Though it remains unclear whether such a combination of polar transport and axial diffusion of auxin can account for the formation of the variety of vein patterns found in plant leaves, evidence suggests that such a combined mechanism may control plant developmental processes beyond vein patterning.
PMID: 37261944
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P70-82 doi: 10.1093/plphys/kiad309
Cell signaling in the shoot apical meristem.
College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.; Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China.
Distinct from animals, plants maintain organogenesis from specialized tissues termed meristems throughout life. In the shoot apex, the shoot apical meristem (SAM) produces all aerial organs, such as leaves, from its periphery. For this, the SAM needs to precisely balance stem cell renewal and differentiation, which is achieved through dynamic zonation of the SAM, and cell signaling within functional domains is key for SAM functions. The WUSCHEL-CLAVATA feedback loop plays a key role in SAM homeostasis, and recent studies have uncovered new components, expanding our understanding of the spatial expression and signaling mechanism. Advances in polar auxin transport and signaling have contributed to knowledge of the multifaceted roles of auxin in the SAM and organogenesis. Finally, single-cell techniques have expanded our understanding of the cellular functions within the shoot apex at single-cell resolution. In this review, we summarize the most up-to-date understanding of cell signaling in the SAM and focus on the multiple levels of regulation of SAM formation and maintenance.
PMID: 37224874
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P775-791 doi: 10.1093/plphys/kiad293
GmGAMYB-BINDING PROTEIN 1 promotes small auxin-up RNA gene transcription to modulate soybean maturity and height.
Key Laboratory of Soybean Biology of Ministry of Education China, Northeast Agricultural University, Harbin 150030, China.
Flowering time, maturity, and plant height are crucial agronomic traits controlled by photoperiod that affect soybean (Glycine max [L.] Merr.) yield and regional adaptability. It is important to cultivate soybean cultivars of earlier maturity that adapt to high latitudes. GAMYB-binding protein 1 (GmGBP1), a member of the SNW/SKIP family of transcriptional coregulators in soybean, is induced by short days and interacts with transcription factor GAMYB (GmGAMYB) during photoperiod control of flowering time and maturity. In the present study, GmGBP1:GmGBP1 soybean showed the phenotypes of earlier maturity and higher plant height. Chromatin immunoprecipitation sequencing (ChIP-seq) assays of GmGBP1-binding sites and RNA sequencing (RNA-seq) of differentially expressed transcripts in GmGBP1:GmGBP1 further identified potential targets of GmGBP1, including small auxin-up RNA (GmSAUR). GmSAUR:GmSAUR soybean also showed earlier maturity and higher plant height. GmGBP1 interacted with GmGAMYB, bound to the promoter of GmSAUR and promoted the expression of FLOWER LOCUS T homologs 2a (GmFT2a) and FLOWERING LOCUS D LIKE 19 (GmFDL19). Flowering repressors such as GmFT4 were negatively regulated, resulting in earlier flowering and maturity. Furthermore, the interaction of GmGBP1 with GmGAMYB increased the gibberellin (GA) signal to promote height and hypocotyl elongation by activating GmSAUR and GmSAUR bound to the promoter of the GA-positive activating regulator gibberellic acid-stimulated Arabidopsis 32 (GmGASA32). These results suggested a photoperiod regulatory pathway in which the interaction of GmGBP1 with GmGAMYB directly activated GmSAUR to promote earlier maturity and plant height in soybean.
PMID: 37204820
Plant Physiol , IF:8.34 , 2023 Aug , V193 (1) : P42-53 doi: 10.1093/plphys/kiad264
Computer models of cell polarity establishment in plants.
Centro de Biotecnologia y Genomica de Plantas, Universidad Politecnica de Madrid (UPM)-Instituto Nacional de Investigacion Agraria y Alimentaria (INIA/CSIC), Campus de Montegancedo, Pozuelo de Alarcon, Madrid, Spain.
Plant development is a complex task, and many processes involve changes in the asymmetric subcellular distribution of cell components that strongly depend on cell polarity. Cell polarity regulates anisotropic growth and polar localization of membrane proteins and helps to identify the cell's position relative to its neighbors within an organ. Cell polarity is critical in a variety of plant developmental processes, including embryogenesis, cell division, and response to external stimuli. The most conspicuous downstream effect of cell polarity is the polar transport of the phytohormone auxin, which is the only known hormone transported in a polar fashion in and out of cells by specialized exporters and importers. The biological processes behind the establishment of cell polarity are still unknown, and researchers have proposed several models that have been tested using computer simulations. The evolution of computer models has progressed in tandem with scientific discoveries, which have highlighted the importance of genetic, chemical, and mechanical input in determining cell polarity and regulating polarity-dependent processes such as anisotropic growth, protein subcellular localization, and the development of organ shapes. The purpose of this review is to provide a comprehensive overview of the current understanding of computer models of cell polarity establishment in plants, focusing on the molecular and cellular mechanisms, the proteins involved, and the current state of the field.
PMID: 37144853
PLoS Biol , IF:8.029 , 2023 Sep , V21 (9) : Pe3002305 doi: 10.1371/journal.pbio.3002305
SEC14-like condensate phase transitions at plasma membranes regulate root growth in Arabidopsis.
Department of Biology, University of Crete, Heraklion, Greece.; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece.; Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden.; Department of Organismal Biology, Physiological Botany, Linnean Centre for Plant Biology, Uppsala University, Uppsala, Sweden.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; Center for Plant Systems Biology, Ghent, Belgium.; Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.; Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, Germany.; Laboratoire Reproduction et Developpement des Plantes, ENS de Lyon, Universite Claude Bernard Lyon 1, CNRS, INRAE, Lyon, France.; Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.
Protein function can be modulated by phase transitions in their material properties, which can range from liquid- to solid-like; yet, the mechanisms that drive these transitions and whether they are important for physiology are still unknown. In the model plant Arabidopsis, we show that developmental robustness is reinforced by phase transitions of the plasma membrane-bound lipid-binding protein SEC14-like. Using imaging, genetics, and in vitro reconstitution experiments, we show that SEC14-like undergoes liquid-like phase separation in the root stem cells. Outside the stem cell niche, SEC14-like associates with the caspase-like protease separase and conserved microtubule motors at unique polar plasma membrane interfaces. In these interfaces, SEC14-like undergoes processing by separase, which promotes its liquid-to-solid transition. This transition is important for root development, as lines expressing an uncleavable SEC14-like variant or mutants of separase and associated microtubule motors show similar developmental phenotypes. Furthermore, the processed and solidified but not the liquid form of SEC14-like interacts with and regulates the polarity of the auxin efflux carrier PINFORMED2. This work demonstrates that robust development can involve liquid-to-solid transitions mediated by proteolysis at unique plasma membrane interfaces.
PMID: 37721949
Sci Total Environ , IF:7.963 , 2023 Sep , V904 : P166878 doi: 10.1016/j.scitotenv.2023.166878
Enhancing sustainability through microalgae cultivation in urban wastewater for biostimulant production and nutrient recovery.
GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain.; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: enrica.uggetti@upc.edu.
Microalgae can produce biostimulants in form of phytohormones, which are compounds that, even if applied in low concentrations, can have stimulant effects on plants growth and can enhance their quality and their resistance to stress. Considering that microalgal biomass can grow recovering nutrients from wastewater, this circular approach allows to use residues for the production of high added value compounds (such as phytohormones) at low cost. The interest on biostimulants production from microalgae have recently raised. Scientists are focused on the direct application of these cellular extracts on plants, while the number of studies on the identification of bioactive molecules, such as phytohormones, is very scarce. Two cyanobacteria strains (Synechocystis sp. (SY) and Phormidium sp. (PH)) and a chlorophyte (Scenedesmus sp. (SC)) were cultured in laboratory-scale PBRs with a working volume of 2.5 L in secondary urban wastewater varying N:P ratio in the cultures to obtain the highest productivity. The variation of N:P ratio affects microalgae growth, and SY and PH presented higher productivities (73 and 48 mg L(-1) d, respectively) under higher N:P ratio (> 22:1). Microalgal biomass was freeze-dried and phytohormones content was measured with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The three microalgae showed similar phytohormones profiles, being the auxin (indole-3-acetic acid, IAA) the most abundant (72 ng g(-1)(DW) in SY). Proteins were major macronutrient for all strains, reaching 48 %(DW) in PH culture. To optimize the biostimulants production, a balance between the production of such compounds, biomass productivity and nutrients removal should be taken into consideration. In this sense, SC was the most promising strain, showing the highest N and P removal rates (73 % and 59 %, respectively) while producing phytohormones.
PMID: 37678521
Sci Total Environ , IF:7.963 , 2023 Sep , V904 : P166644 doi: 10.1016/j.scitotenv.2023.166644
Auxin is involved in cadmium accumulation in rice through controlling nitric oxide production and the ability of cell walls to bind cadmium.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Advanced Agricultural Sciences, Zhejiang A & F University, Hangzhou 311300, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xiaofangzhu@issas.ac.cn.
Although auxin has been linked to plants' responses to cadmium (Cd) stress, the exact mechanism is yet elusive. The objective of the current investigation was to determine the role and the mechanism of auxin in controlling rice's Cd accumulation. Rice roots with Cd stress have higher endogenous auxin levels, and exogenous auxin combined Cd treatment could reduce root cell wall's hemicellulose content when compared with Cd treatment alone, which in turn reduced its fixation of Cd, as well as decreased the expression of OsCd1 (a major facilitator superfamily gene), OsNRAMP1/5 (Natural Resistance-Associated Macrophage Protein 1/5), OsZIP5/9 (Zinc Transporter 5/9), and OsHMA2 (Heavy Metal ATPase 2) that participated in Cd uptake and root to shoot translocation. Furthermore, less Cd accumulated in the shoots as a result of auxin's impact in increasing the expression of OsCAL1 (Cadmium accumulation in Leaf 1), OsABCG36/OsPDR9 (G-type ATP-binding cassette transporter/Pleiotropic drug resistance 9), and OsHMA3, which were in charge of Cd efflux and sequestering into vacuoles, respectively. Additionally, auxin decreased endogenous nitric oxide (NO) levels and antioxidant enzyme activity, while treatment of a NO scavenger-cPTIO-reduced auxin's alleviatory effects. In conclusion, the rice's ability to tolerate Cd toxicity was likely increased by the auxin-accelerated cell wall Cd exclusion mechanism, a pathway that controlled by the buildup of NO.
PMID: 37659569
Sci Total Environ , IF:7.963 , 2023 Nov , V899 : P165676 doi: 10.1016/j.scitotenv.2023.165676
Physiological and transcriptomic analyses reveal that phytohormone pathways and glutathione metabolism are involved in the arsenite toxicity response in tomatoes.
College of Horticulture, Shanxi Agricultural University, Taigu 030801, China.; Center of Experimental Education, Shanxi Agricultural University, Taigu 030801, China.; College of Horticulture, Shanxi Agricultural University, Taigu 030801, China. Electronic address: xujin@sxau.edu.cn.
The main forms of inorganic arsenic (As) in soil are arsenate [As(V)] and arsenite [As(III)]. Both forms inhibit plant growth. Here, we investigate the effects of As(III) toxicity on the growth of tomatoes by integrating physiological and transcriptomic analyses. As(III) toxicity induces oxidative damage, inhibits photosynthetic efficiency, and reduces soluble sugar levels. As(III) toxicity leads to reductions in auxin, cytokinin and jasmonic acid contents by 29 %, 39 % and 55 %, respectively, but leads to increases in the ethylene precursor 1-amino-cyclopropane carboxylic acid, abscisic acid and salicylic acid contents in roots, by 116 %, 79 % and 39 %, respectively, thereby altering phytohormone signalling pathways. The total glutathione, reduced glutathione (GSH) and oxidized glutathione (GSSG) contents are reduced by 59 %, 49 % and 94 % in roots; moreover, a high GSH/GSSG ratio is maintained through increased glutathione reductase activity (increased by 214 %) and decreased glutathione peroxidase activity (decreased by 40 %) in the roots of As(III)-treated tomato seedlings. In addition, As(III) toxicity affects the expression of genes related to the endoplasmic reticulum stress response. The altered expression of aquaporins and ABCC transporters changes the level of As(III) accumulation in plants. A set of hub genes involved in modulating As(III) toxicity responses in tomatoes was identified via a weighted gene coexpression network analysis. Taken together, these results elucidate the physiological and molecular regulatory mechanism underlying As(III) toxicity and provide a theoretical basis for selecting and breeding tomato varieties with low As(III) accumulation. Therefore, these findings are expected to be helpful in improving food safety and to developing sustainable agricultural.
PMID: 37481082
Sci Total Environ , IF:7.963 , 2023 Nov , V899 : P165667 doi: 10.1016/j.scitotenv.2023.165667
Zinc accumulation in Atriplex lentiformis is driven by plant genes and the soil microbiome.
Department of Environmental Science, The University of Arizona, Tucson, AZ 85721, USA. Electronic address: pkushwaha@arizona.edu.; School of Biological Sciences, Department of Cell and Developmental Biology & Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA.; The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.; Department of Environmental Science, The University of Arizona, Tucson, AZ 85721, USA.
Successful phytoremediation of acidic metal-contaminated mine tailings requires amendments to condition tailings properties prior to plant establishment. This conditioning process is complex and includes multiple changes in tailings bio-physico-chemical properties. The objective of this project is to identify relationships between tailings properties, the soil microbiome, and plant stress response genes during growth of Atriplex lentiformis in compost-amended (10 %, 15 %, 20 % w/w) mine tailings. Analyses include RNA-Seq for plant root gene expression, 16S rRNA amplicon sequencing for bacterial/archaeal communities, metal concentrations in both tailings and plant organs, and phenotypic measures of plant stress. Zn accumulation in A. lentiformis leaves varied with compost levels and was the highest in the intermediate treatment (15 %, TC15). Microbial analysis identified Alicyclobacillus, Hydrotalea, and Pseudolabrys taxa with the highest relative abundance in TC15, and these taxa were strongly associated with Zn accumulation. Furthermore, we identified 190 root genes with significant gene expression changes. These root genes were associated with different pathways including, abscisic acid and auxin signaling, defense responses, ion channels, metal ion binding, oxidative stress, transcription regulation, and transmembrane transport. However, root gene expression changes were not driven by the increasing levels of compost. For example, there were 15 genes that were up-regulated in TC15, whereas 106 genes were down-regulated in TC15. The variables analyzed explained 86 % of the variance in Zn accumulation in A. lentiformis leaves. Importantly, Zn accumulation was driven by Zn shoot concentrations, leaf stress symptoms, plant root genes, and microbial taxa. Therefore, our results suggest there are strong plant-microbiome associations that drive Zn accumulation in A. lentiformis and different plant gene pathways are involved in alleviating varying levels of metal stress. Future work is needed to gain a mechanistic understanding of these plant-microbiome interactions to optimize phytoremediation strategies as they will govern the success or failure of the revegetation process.
PMID: 37478925
Sci Total Environ , IF:7.963 , 2023 Nov , V897 : P165338 doi: 10.1016/j.scitotenv.2023.165338
DNA methylation mediates overgrazing-induced clonal transgenerational plasticity.
School of Ecology and Environment, Inner Mongolia University, Hohhot, China.; School of Ecology and Environment, Inner Mongolia University, Hohhot, China; Key Laboratory of Forage Breeding and Seed Production of Inner Mongolia, Inner Mongolia M-Grass Ecology and Environment (Group) Co., Ltd., Hohhot 010016, China. Electronic address: rweibo2022@163.com.; Department of Biology, Edge Hill University, Ormskirk, Lancashire L39 4QP, UK.; Industrial Crop Institute, Shanxi Agricultural University, Taiyuan, China.
Overgrazing generally induces dwarfism in grassland plants, and these phenotypic traits could be transmitted to clonal offspring even when overgrazing is excluded. However, the dwarfism-transmitted mechanism remains largely unknown, despite generally thought to be enabled by epigenetic modification. To clarify the potential role of DNA methylation on clonal transgenerational effects, we conducted a greenhouse experiment with Leymus chinensis clonal offspring from different cattle/sheep overgrazing histories via the demethylating agent 5-azacytidine. The results showed that clonal offspring from overgrazed (by cattle or sheep) parents were dwarfed and the auxin content of leaves significantly decreased compared to offspring from no-grazed parents'. The 5-azaC application generally increased the auxin content and promoted the growth of overgrazed offspring while inhibited no-grazed offspring growth. Meanwhile, there were similar trends in the expression level of genes related to auxin-responsive target genes (ARF7, ARF19), and signal transduction gene (AZF2). These results suggest that DNA methylation leads to overgrazing-induced plant transgenerational dwarfism via inhibiting auxin signal pathway.
PMID: 37414175
Curr Opin Plant Biol , IF:7.834 , 2023 Sep , V76 : P102461 doi: 10.1016/j.pbi.2023.102461
Connecting emerging with existing vasculature above and below ground.
Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland. Electronic address: noel.blancotourinan@unil.ch.; Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland. Electronic address: christian.hardtke@unil.ch.
The vascular system was essential for plants to colonize land by facilitating the transport of water, nutrients, and minerals throughout the body. Our current knowledge on the molecular-genetic control of vascular tissue specification and differentiation is mostly based on studies in the Arabidopsis primary root. To what degree these regulatory mechanisms in the root meristem can be extrapolated to vascular tissue development in other organs is a question of great interest. In this review, we discuss the most recent progress on cotyledon vein formation, with a focus on polar auxin transport-dependent and -independent mechanisms. We also provide an overview of vasculature formation in postembryonic organs, namely lateral roots, which is more complex than anticipated as several tissues of the parent root must act in a spatio-temporally coordinated manner.
PMID: 37774454
Curr Opin Plant Biol , IF:7.834 , 2023 Sep : P102451 doi: 10.1016/j.pbi.2023.102451
Hormonal regulation of inflorescence and intercalary meristems in grasses.
Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.; Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA. Electronic address: mcsteenp@missouri.edu.
Hormones played a fundamental role in improvement of yield in cereal grasses. Natural variants affecting gibberellic acid (GA) and auxin pathways were used to breed semi-dwarf varieties of rice, wheat, and sorghum, during the "Green Revolution" in the 20th century. Since then, variants with altered GA and cytokinin homeostasis have been used to breed cereals with increased grain number. These yield improvements were enabled by hormonal regulation of intercalary and inflorescence meristems. Recent advances have highlighted additional pathways, beyond the traditional CLAVATA-WUSCHEL pathway, in the regulation of auxin and cytokinin in inflorescence meristems, and have expanded our understanding of the role of GA in intercalary meristems.
PMID: 37739867
Curr Opin Plant Biol , IF:7.834 , 2023 Sep : P102445 doi: 10.1016/j.pbi.2023.102445
Regulation of PIN polarity in response to abiotic stress.
Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden. Electronic address: petra.marhava@slu.se.
Plants have evolved robust adaptive mechanisms to withstand the ever-changing environment. Tightly regulated distribution of the hormone auxin throughout the plant body controls an impressive variety of developmental processes that tailor plant growth and morphology to environmental conditions. The proper flow and directionality of auxin between cells is mainly governed by asymmetrically localized efflux carriers - PINs - ensuring proper coordination of developmental processes in plants. Discerning the molecular players and cellular dynamics involved in the establishment and maintenance of PINs in specific membrane domains, as well as their ability to readjust in response to abiotic stressors is essential for understanding how plants balance adaptability and stability. While much is known about how PINs get polarized, there is still limited knowledge about how abiotic stresses alter PIN polarity by acting on these systems. In this review, we focus on the current understanding of mechanisms involved in (re)establishing and maintaining PIN polarity under abiotic stresses.
PMID: 37714753
Curr Opin Plant Biol , IF:7.834 , 2023 Sep : P102452 doi: 10.1016/j.pbi.2023.102452
Illuminating the path to shoot meristem regeneration: Molecular insights into reprogramming cells into stem cells.
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan. Electronic address: yetkincaka.ince@riken.jp.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan. Electronic address: keiko.sugimoto@riken.jp.
Plant cells possess the ability to dedifferentiate and reprogram into stem cell-like populations, enabling the regeneration of new organs. However, the maintenance of stem cells relies on specialized microenvironments composed of distinct cell populations with specific functions. Consequently, the regeneration process necessitates the orchestrated regulation of multiple pathways across diverse cellular populations. One crucial pathway involves the transcription factor WUSCHEL HOMEOBOX 5 (WOX5), which plays a pivotal role in reprogramming cells into stem cells and promoting their conversion into shoot meristems through WUSCHEL (WUS). Additionally, cell and tissue mechanics, including cell wall modifications and mechanical stress, critically contribute to de novo shoot organogenesis by regulating polar auxin transport. Furthermore, light signaling emerges as a key regulator of plant regeneration, directly influencing expression of meristem genes and potentially influencing aforementioned pathways as well.
PMID: 37709567
Curr Opin Plant Biol , IF:7.834 , 2023 Oct , V75 : P102443 doi: 10.1016/j.pbi.2023.102443
Rapid auxin signaling: Unknowns old and new.
Institute of Science and Technology Austria (ISTA), 3400, Klosterneuburg, Austria.; Institute of Science and Technology Austria (ISTA), 3400, Klosterneuburg, Austria. Electronic address: jiri.friml@ist.ac.at.
To respond to auxin, the chief orchestrator of their multicellularity, plants evolved multiple receptor systems and signal transduction cascades. Despite decades of research, however, we are still lacking a satisfactory synthesis of various auxin signaling mechanisms. The chief discrepancy and historical controversy of the field is that of rapid and slow auxin effects on plant physiology and development. How is it possible that ions begin to trickle across the plasma membrane as soon as auxin enters the cell, even though the best-characterized transcriptional auxin pathway can take effect only after tens of minutes? Recently, unexpected progress has been made in understanding this and other unknowns of auxin signaling. We provide a perspective on these exciting developments and concepts whose general applicability might have ramifications beyond auxin signaling.
PMID: 37666097
Curr Opin Plant Biol , IF:7.834 , 2023 Oct , V75 : P102405 doi: 10.1016/j.pbi.2023.102405
Turning up the volume: How root branching adaptive responses aid water foraging.
Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK. Electronic address: p.mehra@nottingham.ac.uk.; Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK.; Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK. Electronic address: malcolm.bennett@nottingham.ac.uk.
Access to water is critical for all forms of life. Plants primarily access water through their roots. Root traits such as branching are highly sensitive to water availability, enabling plants to adapt their root architecture to match soil moisture distribution. Lateral root adaptive responses hydropatterning and xerobranching ensure new branches only form when roots are in direct contact with moist soil. Root traits are also strongly influenced by atmospheric humidity, where a rapid drop leads to a promotion of root growth and branching. The plant hormones auxin and/or abscisic acid (ABA) play key roles in regulating these adaptive responses. We discuss how these signals are part of a novel "water-sensing" mechanism that couples hormone movement with hydrodynamics to orchestrate root branching responses.
PMID: 37379661
Curr Opin Plant Biol , IF:7.834 , 2023 Oct , V75 : P102386 doi: 10.1016/j.pbi.2023.102386
Understanding signaling pathways governing the polar development of root hairs in low-temperature, nutrient-deficient environments.
Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile.; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; ANID - Millennium Science Initiative Program - Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile.; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile.; Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; ANID - Millennium Science Initiative Program - Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile. Electronic address: jestevez@leloir.org.ar.
Plants exposed to freezing and above-freezing low temperatures must employ a variety of strategies to minimize fitness loss. There is a considerable knowledge gap regarding how mild low temperatures (around 10 degrees C) affect plant growth and developmental processes, even though the majority of the molecular mechanisms that plants use to adapt to extremely low temperatures are well understood. Root hairs (RH) have become a useful model system for studying how plants regulate their growth in response to both cell-intrinsic cues and environmental inputs. Here, we'll focus on recent advances in the molecular mechanisms underpinning Arabidopsis thaliana RH growth at mild low temperatures and how these discoveries may influence our understanding of nutrient sensing mechanisms by the roots. This highlights how intricately linked mechanisms are necessary for plant development to take place under specific circumstances and to produce a coherent response, even at the level of a single RH cell.
PMID: 37352652
Plant Cell Environ , IF:7.228 , 2023 Sep doi: 10.1111/pce.14727
Ultraviolet-A1 radiation induced a more favorable light-intercepting leaf-area display than blue light and promoted plant growth.
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China.; Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.; Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Plants adjust their morphology in response to light environment by sensing an array of light cues. Though the wavelengths of ultraviolet-A1 radiation (UV-A1, 350-400 nm) are close to blue light (B, 400-500 nm) and share same flavoprotein photoreceptors, it remains poorly understood how plant responses to UV-A1 radiation could differ from those to B. We initially grown tomato plants under monochromatic red light (R, 660 nm) as control, subsequently transferred them to four dichromatic light treatments containing ~20 micromol m(-2) s(-1) of UV-A1 radiation, peaking at 370 nm (UV-A(370) ) or 400 nm (V(400) ), or B (450 nm, at ~20 or 1.5 micromol m(-2) s(-1) ), with same total photon irradiance (~200 mumol m(-2) s(-1) ). We show that UV-A(370) radiation was the most effective in inducing light-intercepting leaf-area display formation, resulting in larger leaf area and more shoot biomass, while it triggered weaker and later transcriptome-wide responses than B. Mechanistically, UV-A(370) -promoted leaf-area display response was apparent in less than 12 h and appeared as very weakly related to transcriptome level regulation, which likely depended on the auxin transportation and cell wall acidification. This study revealed wavelength-specific responses within UV-A/blue region challenging usual assumptions that the role of UV-A1 radiation function similarly as blue light in mediating plant processes.
PMID: 37743709
Plant Cell Environ , IF:7.228 , 2023 Sep doi: 10.1111/pce.14709
E3 ubiquitin ligases SINA4 and SINA11 regulate anthocyanin biosynthesis by targeting the IAA29-ARF5-1-ERF3 module in apple.
Apple Technology Innovation Center of Shandong Province, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.; CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan, China.
Auxin/indole-3-acetic acid (AUX/IAA) and auxin response factor (ARF) proteins are important components of the auxin signalling pathway, but their ubiquitination modification and the mechanism of auxin-mediated anthocyanin biosynthesis remain elusive. Here, the ARF MdARF5-1 was identified as a negative regulator of anthocyanin biosynthesis in apple, and it integrates auxin and ethylene signals by inhibiting the expression of the ethylene response factor MdERF3. The auxin repressor MdIAA29 decreased the inhibitory effect of MdARF5-1 on anthocyanin biosynthesis by attenuating the transcriptional inhibition of MdERF3 by MdARF5-1. In addition, the E3 ubiquitin ligases MdSINA4 and MdSINA11 played negative and positive regulatory roles in anthocyanin biosynthesis by targeting MdIAA29 and MdARF5-1 for ubiquitination degradation, respectively. MdSINA4 destabilized MdSINA11 to regulate anthocyanin accumulation in response to auxin signalling. In sum, our data revealed the crosstalk between auxin and ethylene signals mediated by the IAA29-ARF5-1-ERF3 module and provide new insights into the ubiquitination modification of the auxin signalling pathway.
PMID: 37658649
Plant Cell Environ , IF:7.228 , 2023 Oct , V46 (10) : P3158-3169 doi: 10.1111/pce.14645
Genetic control underlying the flowering-drought tolerance trade-off in the Antarctic plant Colobanthus quitensis.
Centro de Ecologia Integrativa, Instituto de Ciencias Biologicas, Universidad de Talca, Talca, Chile.; Instituto de Investigaciones Interdisciplinarias (I3), Universidad de Talca, Talca, Chile.; Departamento de Ciencias Naturales, Laboratorio de Genomica y Biodiversidad (LGB), Universidad del Bio-Bio, Chillan, Chile.; IFEVA (CONICET-Facultad de Agronomia, Universidad de Buenos Aires), Buenos Aires, Argentina.; Centro de Investigacion en Estudios Avanzados del Maule (CIEAM), Universidad Catolica del Maule, Talca, Chile.
Plants inhabiting environments with stressful conditions often exhibit a low number of flowers, which can be attributed to the energetic cost associated with reproduction. One of the most stressful environments for plants is the Antarctic continent, characterized by limited soil water availability and low temperatures. Induction of dehydrins like those from the COR gene family and auxin transcriptional response repressor genes (IAAs), which are involved in floral repression, has been described in response to water stress. Here, we investigated the relationship between the water deficit-induced stress response and the number of flowers in Colobanthus quitensis plants collected from populations along a latitudinal gradient. The expression levels of COR47 and IAA12 genes in response to water deficit were found to be associated with the number of flowers. The relationship was observed both in the field and growth chambers. Watering the plants in the growth chambers alleviated the stress and stimualted flowering, thereby eliminating the trade-off observed in the field. Our study provides a mechanistic understanding of the ecological constraints on plant reproduction along a water availability gradient. However, further experiments are needed to elucidate the primary role of water availability in regulating resource allocation to reproduction in plants inhibiting extreme environments.
PMID: 37309267
Mol Ecol Resour , IF:7.09 , 2023 Sep doi: 10.1111/1755-0998.13863
High-quality genome of a pioneer mangrove Laguncularia racemosa explains its advantages for intertidal zone reforestation.
State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China.; School of Ecology, Sun Yat-sen University, Shenzhen, China.; Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment & Ecology, Xiamen University, Xiamen, China.; Hainan Academy of Forestry (Hainan Academy of Mangrove), Haikou, China.
Ecological restoration of mangrove ecosystems that became susceptible to recent habitat perturbations is crucial for tropical coast conservation. The white mangrove Laguncularia racemosa, a pioneer species inhabiting intertidal environments of the Atlantic East Pacific (AEP) region, has been used for reforestation in China for decades. However, the molecular mechanisms underlying its fast growth and high adaptive potential remain unknown. Using PacBio single-molecule real-time sequencing, we completed a high-quality L. racemosa genome assembly covering 1105 Mb with scaffold N50 of 3.46 Mb. Genomic phylogeny shows that L. racemosa invaded intertidal zones during a period of global warming. Multi-level genomic convergence analyses between L. racemosa and three native dominant mangrove clades show that they experienced convergent changes in genes involved in nutrient absorption and high salinity tolerance. This may explain successful L. racemosa adaptation to stressful intertidal environments after introduction. Without recent whole-genome duplications or activated transposable elements, L. racemosa has retained many tandem gene duplications. Some of them are involved in auxin biosynthesis, intense light stress and cold stress response pathways, associated with L. racemosa's ability to grow fast under high light or cold conditions when used for reforestation. In summary, our study identifies shared mechanisms of intertidal environmental adaptation and unique genetic changes underlying fast growth in mangrove-unfavourable conditions and sheds light on the molecular mechanisms of the white mangrove utility in ecological restoration.
PMID: 37688468
Chemosphere , IF:7.086 , 2023 Nov , V340 : P139833 doi: 10.1016/j.chemosphere.2023.139833
Maximizing trace metal phytoextraction through planting methods: Role of rhizosphere fertility and microbial activities.
Lebanese University, Applied Plant Biotechnology Laboratory, Hadath, Lebanon; Universite de Lorraine, INRAE, LSE, F-54000, Nancy, France.; Universite de Lorraine, INRAE, LSE, F-54000, Nancy, France.; Lebanese University, Applied Plant Biotechnology Laboratory, Hadath, Lebanon.; Universite de Lorraine, INRAE, LSE, F-54000, Nancy, France; Centre for Mined Land Rehabilitation, SMI, University of Queensland, St Lucia, QLD, Australia.; Universite de Lorraine, INRAE, LSE, F-54000, Nancy, France. Electronic address: catherine.sirguey@univ-lorraine.fr.
Brownfields are a widespread problem in the world. The poor quality of these soils and the potential presence of contaminants can pose a significant threat to plant establishment and growth. However, it may be possible to improve their establishment with an appropriate agricultural practice. In this paper, the effects of two common planting strategies, seeding and transplanting, on the establishment and growth of the hyperaccumulator species Noccaea caerulescens and on its phytoextraction capacity were investigated. A field experiment was conducted by direct sowing of N. caerulescens seeds on a plot of contaminated Technosols in Jeandelaincourt, France. At the same time, seeds were sown on potting soil under controlled conditions. One month later, the seedlings were transplanted to the field. One year later, the results showed that transplanting improved the establishment and growth of N. caerulescens. This was due to a decrease in soil pH in the rhizosphere, which subsequently increased nutrient availability. This change in rhizosphere properties also appeared to be the key that improved microbial activities in the rhizosphere soil of transplanted plants. The observed improvement in both rhizosphere nutrient availability and microbial activities, in turn, increased auxin concentrations in the rhizosphere and consequently a more developed root system was observed in the transplanted plants. Furthermore, the Cd and Zn phytoextraction yield of transplanted plants is 2.5 and 5 times higher, respectively, than that of sown plants. In conclusion, N. caerulescens transplantation on contaminated sites seems to be an adequate strategy to improve plant growth and enhance trace metal phytoextraction.
PMID: 37595688
J Exp Bot , IF:6.992 , 2023 Sep doi: 10.1093/jxb/erad377
Plasmodiophora brassicae affects host gene expression by secreting the transcription factor-type effector PbZFE1.
Graduate School of Agricultural Science, Tohoku University, 468-1 Aramakiaza-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan.; Division of Plant Sciences, The Institute of Agrobiological Sciences, NARO (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan.; Department of Food and Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.; Strategic Planning Headquarters, National Agriculture and Food Research Organization (NARO), 3-1-1 Kan-nondai, Tsukuba, Ibaraki 305-8517, Japan.
The protist pathogen Plasmodiophora brassicae hijacks the metabolism and development of host cruciferous plants and induces clubroot formation, but little is known about its regulatory mechanisms. Previously, the Pnit2int2 sequence, a sequence around the second intron of the nitrilase gene (BrNIT2) involved in auxin biosynthesis in Brassica rapa, was identified as a specific promoter activated during clubroot formation. In this study, we hypothesized that analysis of the transcriptional regulation of Pnit2int2 could reveal how P. brassicae affects the host gene regulatory system during clubroot development. By yeast one-hybrid screening, the pathogen zinc-finger protein PbZFE1 was determined to specifically bind to Pnit2int2. Specific binding of PbZFE1 to Pnit2int2 was also confirmed by electrophoretic mobility shift assay. The binding site of PbZFE1 is essential for promoter activity of Pnit2int2 in clubbed roots of transgenic Arabidopsis thaliana (Pnit2int2-2::GUS), suggesting that PbZFE1 is indeed secreted from P. brassicae and functions within plant cells. Ectopic expression of PbZEF1 in A. thaliana delayed growth and flowering time, suggesting that PbZFE1 has significant impacts on host development and metabolic systems. Thus, P. brassicae appears to secrete PbZFE1 into host cells as a transcription factor-type effector during pathogenesis.
PMID: 37738570
J Exp Bot , IF:6.992 , 2023 Sep doi: 10.1093/jxb/erad372
ZmCCT regulates drought tolerance in maize by interacting with ZmFra a 1, E3 ligase ZmWIPF2 and auxin response factor ZmAux/IAA8.
Beijing Key Laboratory of New Technology in Agricultural Application，National Demonstration Center for Experimental Plant Production Education, Beijing University of Agriculture, Beijing, People's Republic of China.; College of Plan Protection, China Agricultural University, State Key Laboratory of Agrobiotechnology, Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, Beijing 100193, China.; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Abiotic stressors are widespread in plants and can affect their growth, productivity, and quality. Previously, the maize transcription factor ZmCCT was been proved to be involved in the photoperiod response, delayed flowering and quantitative resistance to Gibberella stalk rot. In this study, we demonstrate that ZmCCT can regulate plant drought stress. ZmCCT physically interacted with ZmFra a 1, ZmWIPF2, and ZmAux/IAA8, which localised to the cytomembrane, cytoplasm, and nucleus, respectively, both in vitro and in vivo in a yeast two-hybrid screen in response to abiotic stress. Notably, ZmCCT recruits ZmWIPF2 to the nucleus, which has strong E3 self-ubiquitination activity dependent on its RING-H2 finger domain in vitro. When treated with higher indole-3-acetic acid (IAA)/abscisic acid (ABA) ratios, the height and root length of Y331-DeltaTE increased, and this resulted in an increase in auxin and ABA tolerance. In vivo, ZmCCT promoted IAA biosynthesis in ZmCCT-overexpressed Arabidopsis. RNA-seq and DAP-seq analyses showed that ZmCCT can regulate the expression of ZmRD17, ZmAFP3, ZmPP2C and ZmARR16 under drought stress. Our finding provides a detailed overview of the molecular mechanism controlling ZmCCT functions and highlights that it HAS multiple roles in promoting stress tolerance.
PMID: 37725963
J Exp Bot , IF:6.992 , 2023 Sep doi: 10.1093/jxb/erad366
IAR4 mutation enhances cadmium toxicity by disturbing auxin homeostasis in Arabidopsis thaliana.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.; School of Molecular Science and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Western Australia 6009, Australia.
Cadmium (Cd) is highly toxic to plants, but the targets and modes of toxicity remain unclear. We isolated a Cd-hypersensitive mutant of Arabidopsis thaliana, Cd-induced short root 2 (cdsr2), in the background of the phytochelatin synthase-defective mutant cad1-3. Both cdsr2 and cdsr2 cad1-3 showed shorter roots and were more sensitive to Cd than their respective wild type. Using genomic resequencing and complementation, IAR4 was identified as the causal gene, which encodes a putative mitochondrial pyruvate dehydrogenase E1alpha subunit. cdsr2 showed decreased pyruvate dehydrogenase activity and NADH content, but markedly increased concentrations of pyruvate and alanine in roots. Both Cd stress and IAR4 mutation decreased the auxin level in the root tips and the effect was additive. A higher growth temperature rescued the phenotypes in cdsr2. Exogenous alanine inhibited root growth and decreased the auxin level in wild type. Cadmium stress suppressed the expression of genes involved in auxin biosynthesis, hydrolysis of auxin-conjugates and auxin polar transport. Our results suggest that auxin homeostasis is a key target of Cd toxicity, which is aggravated by IAR4 mutation due to decreased pyruvate dehydrogenase activity. Decreased auxin level in cdsr2 is likely caused by increased auxin-alanine conjugation and decreased energy status in roots.
PMID: 37721748
J Exp Bot , IF:6.992 , 2023 Sep , V74 (17) : P4899-4902 doi: 10.1093/jxb/erad328
Bridging pathways: SBP15 regulates GOBLET in modulating tomato axillary bud outgrowth.
Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad-500046, India.
This article comments on: Barrera-Rojas CH, Vicente MH, Brito DAP, Silva EM,Munoz Lopez A, Ferigolo LF, Carmo RM, Silva CMS, Silva GFF, Correa JPO, Notini MM, Freschi L, Cubas P, Nogueira FTS. 2023. Tomato miR156-targeted SlSBP15 represses shoot branching by modulating hormone dynamics and interacting with GOBLET and BRANCHED1b. Journal of Experimental Botany 74, 5124-5139.
PMID: 37702011
J Exp Bot , IF:6.992 , 2023 Sep doi: 10.1093/jxb/erad340
What a tangled web it weaves: Auxin coordination of stem cell maintenance and flower production.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Robust agricultural yields require consistent flower production throughout fluctuating environmental conditions. Floral primordia are produced in the inflorescence meristem, which contains a pool of continuously dividing stem cells. Daughter cells of these divisions either retain stem cell identity or are pushed to the SAM periphery, where they become competent to develop into floral primordia after receiving the appropriate signal. Thus, flower production is inherently linked to regulation of the stem cell pool. The plant hormone auxin promotes flower development as it progresses and has been shown to interact with the molecular pathways regulating stem cell maintenance. Here, we will summarize how auxin signaling contributes to stem cell maintenance and promotes flower development through the early phases of initiation, outgrowth, and floral fate establishment. Recent advances in this area suggest that auxin may serve as a signal that integrates stem cell maintenance and new flower production.
PMID: 37661937
J Exp Bot , IF:6.992 , 2023 Sep , V74 (17) : P5124-5139 doi: 10.1093/jxb/erad238
Tomato miR156-targeted SlSBP15 represses shoot branching by modulating hormone dynamics and interacting with GOBLET and BRANCHED1b.
Laboratory of Molecular Genetics of Plant Development, Escola Superior de Agricultura 'Luiz de Queiroz' (ESALQ), University of Sao Paulo (USP), Piracicaba, Sao Paulo, CEP: 13418-900, Brazil.; Plant Molecular Genetics Department, Centro Nacional de Biotecnologia-CSIC, Campus Universidad Autonoma de Madrid, Madrid, Spain.; Biosciences Institute, University of Sao Paulo (USP), Sao Paulo, CEP: 05508-090, Brazil.
The miRNA156 (miR156)/SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL/SBP) regulatory hub is highly conserved among phylogenetically distinct species, but how it interconnects multiple pathways to converge to common integrators controlling shoot architecture is still unclear. Here, we demonstrated that the miR156/SlSBP15 node modulates tomato shoot branching by connecting multiple phytohormones with classical genetic pathways regulating both axillary bud development and outgrowth. miR156-overexpressing plants (156-OE) displayed high shoot branching, whereas plants overexpressing a miR156-resistant SlSBP15 allele (rSBP15) showed arrested shoot branching. Importantly, the rSBP15 allele was able to partially restore the wild-type shoot branching phenotype in the 156-OE background. rSBP15 plants have tiny axillary buds, and their activation is dependent on shoot apex-derived auxin transport inhibition. Hormonal measurements revealed that indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations were lower in 156-OE and higher in rSBP15 axillary buds, respectively. Genetic and molecular data indicated that SlSBP15 regulates axillary bud development and outgrowth by inhibiting auxin transport and GOBLET (GOB) activity, and by interacting with tomato BRANCHED1b (SlBRC1b) to control ABA levels within axillary buds. Collectively, our data provide a new mechanism by which the miR156/SPL/SBP hub regulates shoot branching, and suggest that modulating SlSBP15 activity might have potential applications in shaping tomato shoot architecture.
PMID: 37347477
Int J Biol Macromol , IF:6.953 , 2023 Sep , V253 (Pt 4) : P126833 doi: 10.1016/j.ijbiomac.2023.126833
Genome-wide survey, molecular evolution and expression analysis of Auxin Response Factor (ARF) gene family indicating their key role in seed number per pod in pigeonpea (C. cajan L. Millsp.).
ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India. Electronic address: biochemsandhya@gmail.com.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India; ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh 208024, India.; Shoolini Univeristy of Biotechnology and Management Sciences, Himachal Pradesh 173229, India.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India. Electronic address: kish2012@gmail.com.
Auxin Response Factors (ARF) are a family of transcription factors that mediate auxin signalling and regulate multiple biological processes. Their crucial role in increasing plant biomass/yield influenced this study, where a systematic analysis of ARF gene family was carried out to identify the key proteins controlling embryo/seed developmental pathways in pigeonpea. A genome-wide scan revealed the presence of 12 ARF genes in pigeonpea, distributed across the chromosomes 1, 3, 4, 8 and 11. Domain analysis of ARF proteins showed the presence of B3 DNA binding, AUX response, and IAA domains. Majority of them are of nuclear origin, and do not exhibit the level of genomic expansion as observed in Glycine max (51 members). The duplication events seem to range from 31.6 to 42.3 million years ago (mya). Promoter analysis revealed the presence of multiple cis-acting elements related to stress responses, hormone signalling and other development processes. The expression atlas data highlighted the expression of CcARF8 in hypocotyl, bud and flower whereas, CcARF7 expression was significantly high in pod. The real-time expression of CcARF2, CcARF3 and CcARF18 was highest in genotypes with high seed number indicating their key role in regulating embryo development and determining seed set in pigeonpea.
PMID: 37709218
Int J Biol Macromol , IF:6.953 , 2023 Sep , V253 (Pt 3) : P126762 doi: 10.1016/j.ijbiomac.2023.126762
CRISPR/Cas9 mutated p-coumaroyl shikimate 3'-hydroxylase 3 gene in Populus tomentosa reveals lignin functioning on supporting tree upright.
Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China.; College of Agriculture, South China Agricultural University, Guangzhou 510642, China.; State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China.; State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China; Department of Biochemistry and Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin, Madison, WI 53726, USA.; College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China. Electronic address: qingyin.zeng@ibcas.ac.cn.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China. Electronic address: wuaimin@scau.edu.cn.
The lignin plays one of the most important roles in plant secondary metabolism. However, it is still unclear how lignin can contribute to the impressive height of wood growth. In this study, C3'H, a rate-limiting enzyme of the lignin pathway, was used as the target gene. C3'H3 was knocked out by CRISPR/Cas9 in Populus tomentosa. Compared with wild-type popular trees, c3'h3 mutants exhibited dwarf phenotypes, collapsed xylem vessels, weakened phloem thickening, decreased hydraulic conductivity and photosynthetic efficiency, and reduced auxin content, except for reduced total lignin content and significantly increased H-subunit lignin. In the c3'h3 mutant, the flavonoid biosynthesis genes CHS, CHI, F3H, DFR, ANR, and LAR were upregulated, and flavonoid metabolite accumulations were detected, indicating that decreasing the lignin biosynthesis pathway enhanced flavonoid metabolic flux. Furthermore, flavonoid metabolites, such as naringenin and hesperetin, were largely increased, while higher hesperetin content suppressed plant cell division. Thus, studying the c3'h3 mutant allows us to deduce that lignin deficiency suppresses tree growth and leads to the dwarf phenotype due to collapsed xylem and thickened phloem, limiting material exchanges and transport.
PMID: 37683750
Int J Biol Macromol , IF:6.953 , 2023 Sep , V253 (Pt 1) : P126717 doi: 10.1016/j.ijbiomac.2023.126717
Exopolysaccharides from endophytic Glutamicibacter halophytocota KLBMP 5180 functions as bio-stimulants to improve tomato plants growth and salt stress tolerance.
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China.; Jiangsu Runzhong Agricultural Technology Co., Ltd, Xinyi 221424, Jiangsu, PR China.; Xuzhou Kuaibang Biotechnology Development Co., Ltd, Xuzhou, Jiangsu, PR China.; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China. Electronic address: lululiu@jsnu.edu.cn.; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China. Electronic address: shengqin@jsnu.edu.cn.
Microbial exopolysaccharides (EPSs) can promote plants growth and protect them against various abiotic stresses, but the role of actinobacteria-produced EPSs in plant growth promoting is still less known. Here, we aim to explore the effect of EPSs from an endophyte Glutamicibacter halophytocota KLBMP 5180 on tomato seeds germination and seedlings growth under salt stress. Our study revealed that 2.0 g/L EPSs resulted in increased seed germination rate by 23.5 % and 11.0 %, respectively, under 0 and 200 mM NaCl stress conditions. Further pot experiment demonstrated that EPSs significantly promoted seedlings growth under salt stress, with increased height, root length and fibrous roots number. Plant physiological traits revealed that EPSs increased chlorophyll content, enhanced the activity of antioxidant enzymes, soluble sugar, and K(+) concentration in seedlings; malondialdehyde and Na(+) contents were reduced. Additionally, auxin, abscisic acid, jasmonic acid, and salicylic acid were accumulated significantly in seedlings after EPSs treatment. Furthermore, we identified 1233 differentially expressed genes, and they were significantly enriched in phytohormone signal transmission, phenylpropanoid biosynthesis, and protein processing in endogenous reticulum pathways, etc. Our results suggest that KLBMP 5180-produced EPSs effectively ameliorated NaCl stress in tomato plants by triggering complex regulation mechanism, and showed application potentiality in agriculture.
PMID: 37673153
Int J Biol Macromol , IF:6.953 , 2023 Aug , V247 : P125750 doi: 10.1016/j.ijbiomac.2023.125750
Auxin-responsive protein MaIAA17-like modulates fruit ripening and ripening disorders induced by cold stress in 'Fenjiao' banana.
Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center for Postharvest Technology of Horticultural Crops in South China, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou, Guangdong 510642, China.; Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center for Postharvest Technology of Horticultural Crops in South China, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou, Guangdong 510642, China; Key Laboratory of Food Processing Technology and Quality Control in Shandong Province, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, China.; Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center for Postharvest Technology of Horticultural Crops in South China, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou, Guangdong 510642, China. Electronic address: xiaoyang_zhu@scau.edu.cn.
Cold stress severely affects the banana fruit softening and de-greening, significantly inhibiting the ripening processes. However, the mechanism of ripening disorder caused by chilling injury (CI) in banana fruit remains largely unknown. Herein, MaIAA17-like, an Auxin/Indole-3-Acetic Acid (Aux/IAA) family member, was found to be highly related to the softening and de-greening in 'Fenjiao' banana. Its expression was rapidly increased with fruit ripening and then gradually decreased under normal ripening conditions (22 degrees C). Notably, cold storage severely repressed MaIAA17-like expression but was rapidly increased following ethephon treatment for ripening in fruits without CI. However, the expression repression was not reverted in fruits with serious CI symptoms after 12 days of storage at 7 degrees C. AtMaIAA17-like bound and regulated the activities of promoters of chlorophyll (MaNOL and MaSGR1), starch (MaBAM6 and MaBAM8), and cell wall (MaSUR14 and MaPL8) degradation-related genes. MaIAA17-like also interacted with ethylene-insensitive 3-binding F-box protein (MaEBF1), further activating the expression of MaNOL, MaBAM8, MaPL8, and MaSUR14. Generally, the transient overexpression of MaIAA17-like promoted fruit ripening by inducing the expression of softening and de-greening related genes. However, silencing MaIAA17-like inhibited fruit ripening by reducing the expression of softening and de-greening related genes. These results imply that MaIAA17-like modulates fruit ripening by transcriptionally upregulating the key genes related to fruit softening and de-greening.
PMID: 37453644
Development , IF:6.868 , 2023 Sep doi: 10.1242/dev.201775
N6-adenosine methylation of mRNA integrates multilevel auxin response and ground tissue development in Arabidopsis.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojova 263, CZ-160 00 Prague, Czech Republic.; Department of Functional Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 25, Brno, CZ-62500, Czech Republic.; Faculty of Science, Charles University, Vinicna 1594/7, CZ-128 00 Prague, Czech Republic.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Slechtitelu 27, CZ-78371, Olomouc, Czech Republic.; Department of Genetics, Development and Cell Biology, Iowa State University of Science and Technology, 3011 Advanced Teaching & Research Building, Ames, IA 50011-3220, USA.; Wood Development Group, Institute of Biotechnology, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.
N6-methyl adenosine (m6A) is a widespread internal mRNA modification impacting the expression of numerous genes. Here we characterize the auxin-related defects among the pleiotropic phenotypes of the hypomorphic Arabidopsis thaliana mutants with the impaired status of m6A and present that they show strong resistance to exogenously applied auxin. By compiling major published m6A datasets, we propose that among the high-confidence target transcripts emerge those encoding the main components required for auxin signaling, including the auxin receptors TIR1/AFBs and ARF transcriptional regulators. We also observe subtle changes in endogenous levels of indole-3-acetic acid (IAA) metabolites in these hypomorphic lines, which correlate with the methylation status of the IAA amidohydrolase transcripts. In addition, we reveal that the reduced m6A levels lead to defects in the endodermal patterning in the primary root arising from the impaired timing of the periclinal cell divisions. These defects can be reverted by inhibition of auxin signaling. Together, our data underline that m6A likely affects the auxin-dependent processes at multiple levels.
PMID: 37724502
Development , IF:6.868 , 2023 Oct , V150 (20) doi: 10.1242/dev.201762
The class VIII myosin ATM1 is required for root apical meristem function.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.; Broad Institute, Cambridge, MA 04212, USA.
Myosins are evolutionarily conserved motor proteins that interact with actin filaments to regulate organelle transport, cytoplasmic streaming and cell growth. Plant-specific class XI myosin proteins direct cell division and root organogenesis. However, the roles of plant-specific class VIII myosin proteins in plant growth and development are less understood. Here, we investigated the function of an auxin-regulated class VIII myosin, Arabidopsis thaliana MYOSIN 1 (ATM1), using genetics, transcriptomics and live cell microscopy. ATM1 is associated with the plasma membrane and plasmodesmata within the root apical meristem (RAM). Loss of ATM1 function results in decreased RAM size and reduced cell proliferation in a sugar-dependent manner. Auxin signaling and transcriptional responses were dampened in atm1-1 roots. Complementation of atm1-1 with a tagged ATM1 driven under the native ATM1 promoter restored root growth and cell cycle progression. Genetic analyses of atm1-1 seedlings with HEXOKINASE 1 (HXK1) and TARGET OF RAPAMYCIN COMPLEX 1 (TORC1) overexpression lines indicate that ATM1 is downstream of TOR. Collectively, these results provide previously unreported evidence that ATM1 functions to influence cell proliferation in primary roots in response to auxin and sugar cues.
PMID: 37306290
Hortic Res , IF:6.793 , 2023 Sep , V10 (9) : Puhad158 doi: 10.1093/hr/uhad158
PpARF6 acts as an integrator of auxin and ethylene signaling to promote fruit ripening in peach.
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan 430074, China.; University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China.; Hubei Hongshan Laboratory, Wuhan 430070, China.
Although auxin is known to induce ethylene biosynthesis in some Rosaceae fruit crops, the mechanisms underlying the auxin-ethylene interaction during fruit ripening remain largely unknown. Here, the regulatory role of an auxin response factor, PpARF6, in fruit ripening was investigated in peach. Peach fruits showed accelerated ripening after treatment with auxin and PpARF6 was found to be significantly induced. PpARF6 not only could induce ethylene synthesis by directly activating the transcription of ethylene biosynthetic genes, but also competed with EIN3-binding F-box proteins PpEBF1/2 for binding to ethylene-insensitive3-like proteins PpEIL2/3, thereby keeping PpEIL2/3 active. Moreover, PpARF6 showed an interaction with PpEIL2/3 to enhance the PpEIL2/3-activated transcription of ethylene biosynthetic genes. Additionally, ectopic overexpression of PpARF6 in tomato accelerated fruit ripening by promoting the expression of genes involved in ethylene synthesis and fruit texture. In summary, our results revealed a positive regulatory role of PpARF6 in peach fruit ripening via integrating auxin and ethylene signaling.
PMID: 37719277
Hortic Res , IF:6.793 , 2023 Sep , V10 (9) : Puhad148 doi: 10.1093/hr/uhad148
Jujube witches' broom phytoplasmas inhibit ZjBRC1-mediated abscisic acid metabolism to induce shoot proliferation.
College of Horticulture, Anhui Agricultural University, 130 West Changjiang Road, Hefei City 230036, Anhui Province, China.; State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 West Changjiang Road, Hefei City 230036, Anhui Province, China.; Horticulture Research Institute, Anhui Academy of Agricultural Sciences, 40 South Nongke Road, Hefei City 230031, Anhui Province, China.
Jujube witches' broom (JWB) phytoplasmas parasitize the sieve tubes of diseased phloem and cause an excessive proliferation of axillary shoots from dormant lateral buds to favour their transmission. In previous research, two JWB effectors, SJP1 and SJP2, were identified to induce lateral bud outgrowth by disrupting ZjBRC1-mediated auxin flux. However, the pathogenesis of JWB disease remains largely unknown. Here, tissue-specific transcriptional reprogramming was examined to gain insight into the genetic mechanisms acting inside jujube lateral buds under JWB phytoplasma infection. JWB phytoplasmas modulated a series of plant signalling networks involved in lateral bud development and defence, including auxin, abscisic acid (ABA), ethylene, jasmonic acid, and salicylic acid. JWB-induced bud outgrowth was accompanied by downregulation of ABA synthesis within lateral buds. ABA application rescued the bushy appearances of transgenic Arabidopsis overexpressing SJP1 and SJP2 in Col-0 and ZjBRC1 in the brc1-2 mutant. Furthermore, the expression of ZjBRC1 and ABA-related genes ZjHB40 and ZjNCED3 was negatively correlated with lateral main bud outgrowth in decapitated healthy jujube. Molecular evidence showed that ZjBRC1 interacted with ZjBRC2 via its N-terminus to activate ZjHB40 and ZjNCED3 expression and ABA accumulation in transgenic jujube calli. In addition, ZjBRC1 widely regulated differentially expressed genes related to ABA homeostasis and ABA signalling, especially by binding to and suppressing ABA receptors. Therefore, these results suggest that JWB phytoplasmas hijack the ZjBRC1-mediated ABA pathways to stimulate lateral bud outgrowth and expansion, providing a strategy to engineer plants resistant to JWB phytoplasma disease and regulate woody plant architecture to promote crop yield and quality.
PMID: 37691966
Plant J , IF:6.417 , 2023 Sep doi: 10.1111/tpj.16462
Dicer-like2b suppresses the wiry leaf phenotype in tomato induced by tobacco mosaic virus.
The College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.; Department of Ornamental Horticulture, State Key Laboratory of Agrobiotechnology, Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, College of Horticulture, China Agricultural University, Beijing, 100193, China.
Dicer-like (DCL) proteins are principal components of RNA silencing, a major defense mechanism against plant virus infections. However, their functions in suppressing virus-induced disease phenotypes remain largely unknown. Here, we identified a role for tomato (Solanum lycopersicum) DCL2b in regulating the wiry leaf phenotype during defense against tobacco mosaic virus (TMV). Knocking out SlyDCL2b promoted TMV accumulation in the leaf primordium, resulting in a wiry phenotype in distal leaves. Biochemical and bioinformatics analyses showed that 22-nt virus-derived small interfering RNAs (vsiRNAs) accumulated less abundantly in slydcl2b mutants than in wild-type plants, suggesting that SlyDCL2b-dependent 22-nt vsiRNAs are required to exclude virus from leaf primordia. Moreover, the wiry leaf phenotype was accompanied by upregulation of Auxin Response Factors (ARFs), resulting from a reduction in trans-acting siRNAs targeting ARFs (tasiARFs) in TMV-infected slydcl2b mutants. Loss of tasiARF production in the slydcl2b mutant was in turn caused by inhibition of miRNA390b function. Importantly, silencing SlyARF3 and SlyARF4 largely restored the wiry phenotype in TMV-infected slydcl2b mutants. Our work exemplifies the complex relationship between RNA viruses and the endogenous RNA silencing machinery, whereby SlyDCL2b protects the normal development of newly emerging organs by excluding virus from these regions and thus maintaining developmental silencing.
PMID: 37694805
Plant J , IF:6.417 , 2023 Sep doi: 10.1111/tpj.16456
Fluorescence-activated multi-organelle mapping of subcellular plant hormone distribution.
Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, CZ-78371, Olomouc, Czech Republic.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umea, Sweden.; Department of Chemical Biology, Faculty of Science, Palacky University, CZ-78371, Olomouc, Czech Republic.
Auxins and cytokinins are two major families of phytohormones that control most aspects of plant growth, development and plasticity. Their distribution in plants has been described, but the importance of cell- and subcellular-type specific phytohormone homeostasis remains undefined. Herein, we revealed auxin and cytokinin distribution maps showing their different organelle-specific allocations within the Arabidopsis plant cell. To do so, we have developed Fluorescence-Activated multi-Organelle Sorting (FAmOS), an innovative subcellular fractionation technique based on flow cytometric principles. FAmOS allows the simultaneous sorting of four differently labelled organelles based on their individual light scatter and fluorescence parameters while ensuring hormone metabolic stability. Our data showed different subcellular distribution of auxin and cytokinins, revealing the formation of phytohormone gradients that have been suggested by the subcellular localization of auxin and cytokinin transporters, receptors and metabolic enzymes. Both hormones showed enrichment in vacuoles, while cytokinins were also accumulated in the endoplasmic reticulum.
PMID: 37682018
Plant J , IF:6.417 , 2023 Aug doi: 10.1111/tpj.16430
Structure-activity relationship of 2,4-D correlates auxinic activity with the induction of somatic embryogenesis in Arabidopsis thaliana.
Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands.; Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomedical Research, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands.; Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 182, 20014, Donostia San Sebastian, Spain.
2,4-dichlorophenoxyacetic acid (2,4-D) is a synthetic analogue of the plant hormone auxin that is commonly used in many in vitro plant regeneration systems, such as somatic embryogenesis (SE). Its effectiveness in inducing SE, compared to the natural auxin indole-3-acetic acid (IAA), has been attributed to the stress triggered by this compound rather than its auxinic activity. However, this hypothesis has never been thoroughly tested. Here we used a library of forty 2,4-D analogues to test the structure-activity relationship with respect to the capacity to induce SE and auxinic activity in Arabidopsis thaliana. Four analogues induced SE as effectively as 2,4-D and 13 analogues induced SE but were less effective. Based on root growth inhibition and auxin response reporter expression, the 2,4-D analogues were classified into different groups, ranging from very active to not active auxin analogues. A halogen at the 4-position of the aromatic ring was important for auxinic activity, whereas a halogen at the 3-position resulted in reduced activity. Moreover, a small substitution at the carboxylate chain was tolerated, as was extending the carboxylate chain with an even number of carbons. The auxinic activity of most 2,4-D analogues was consistent with their simulated TIR1-Aux/IAA coreceptor binding characteristics. A strong correlation was observed between SE induction efficiency and auxinic activity, which is in line with our observation that 2,4-D-induced SE and stress both require TIR1/AFB auxin co-receptor function. Our data indicate that the stress-related effects triggered by 2,4-D and considered important for SE induction are downstream of auxin signalling.
PMID: 37647363
Plant J , IF:6.417 , 2023 Sep , V115 (6) : P1699-1715 doi: 10.1111/tpj.16348
ZmXYL modulates auxin-induced maize growth.
National Engineering Laboratory of Crop Stress Resistance, School of Life Science, Anhui Agricultural University, Hefei, 230036, China.; Institute of Advanced Agricultural Technology, Qilu Normal University, Jinan, 250200, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, Jinming Road, Kaifeng, 475004, China.; Faculty of Science and Engineering, School of Biological & Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.; Lab of Molecular Breeding by Design in Maize Sanya Institute, Hainan Academy of Agricultural Sciences, Sanya, 572000, China.
Plant architecture, lodging resistance, and yield are closely associated with height. In this paper, we report the identification and characterization of two allelic EMS-induced mutants of Zea mays, xyl-1, and xyl-2 that display dwarf phenotypes. The mutated gene, ZmXYL, encodes an alpha-xylosidase which functions in releasing xylosyl residue from a beta-1,4-linked glucan chain. Total alpha-xylosidase activity in the two alleles is significantly decreased compared to wild-type plants. Loss-of-function mutants of ZmXYL resulted in a decreased xylose content, an increased XXXG content in xyloglucan (XyG), and a reduced auxin content. We show that auxin has an antagonistic effect with XXXG in promoting cell divisions within mesocotyl tissue. xyl-1 and xyl-2 were less sensitive to IAA compared to B73. Based on our study, a model is proposed that places XXXG, an oligosaccharide derived from XyG and the substrate of ZmXYL, as having a negative impact on auxin homeostasis resulting in the dwarf phenotypes of the xyl mutants. Our results provide a insight into the roles of oligosaccharides released from plant cell walls as signals in mediating plant growth and development.
PMID: 37300848
Plant J , IF:6.417 , 2023 Sep , V115 (5) : P1428-1442 doi: 10.1111/tpj.16333
Auxin biosynthesis gene FveYUC4 is critical for leaf and flower morphogenesis in woodland strawberry.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, 20742, USA.
Auxin plays an essential role in plant growth and development, particularly in fruit development. The YUCCA (YUC) genes encode flavin monooxygenases that catalyze a rate-limiting step in auxin biosynthesis. Mutations that disrupt YUC gene function provide useful tools for dissecting general and specific functions of auxin during plant development. In woodland strawberry (Fragaria vesca), two ethyl methanesulfonate mutants, Y422 and Y1011, have been identified that exhibit severe defects in leaves and flowers. In particular, the width of the leaf blade is greatly reduced, and each leaflet in the mutants has fewer and deeper serrations. In addition, the number and shape of the floral organs are altered, resulting in smaller fruits. Mapping by sequencing revealed that both mutations reside in the FveYUC4 gene, and were therefore renamed as yuc4-1 and yuc4-2. Consistent with a role for FveYUC4 in auxin synthesis, free auxin and its metabolites are significantly reduced in the yuc4 leaves and flowers. This role of FveYUC4 in leaf and flower development is supported by its high and specific expression in young leaves and flower buds using GUS reporters. Furthermore, germline transformation of pYUC4::YUC4, which resulted in elevated expression of FveYUC4 in yuc4 mutants, not only rescued the leaf and flower defects but also produced parthenocarpic fruits. Taken together, our data demonstrate that FveYUC4 is essential for leaf and flower morphogenesis in woodland strawberry by providing auxin hormone at the proper time and in the right tissues.
PMID: 37248638
Plant J , IF:6.417 , 2023 Sep , V115 (5) : P1408-1427 doi: 10.1111/tpj.16330
A very long chain fatty acid responsive transcription factor, MYB93, regulates lateral root development in Arabidopsis.
Faculty of Agriculture, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi, 468-8502, Japan.; Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 478-8501, Japan.; Department of Electrical and Electronic Engineering, Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi, 468-8502, Japan.
Lateral roots (LRs) are critical to root system architecture development in plants. Although the molecular mechanisms by which auxin regulates LR development have been extensively studied, several additional regulatory systems are hypothesized to be involved. Recently, the regulatory role of very long chain fatty acids (VLCFAs) has been shown in LR development. Our analysis showed that LTPG1 and LTPG2, transporters of VLCFAs, are specifically expressed in the developing LR primordium (LRP), while the number of LRs is reduced in the ltpg1/ltpg2 double mutant. Moreover, late LRP development was hindered when the VLCFA levels were reduced by the VLCFA synthesis enzyme mutant, kcs1-5. However, the details of the regulatory mechanisms of LR development controlled by VLCFAs remain unknown. In this study, we propose a novel method to analyze the LRP development stages with high temporal resolution using a deep neural network and identify a VLCFA-responsive transcription factor, MYB93, via transcriptome analysis of kcs1-5. MYB93 showed a carbon chain length-specific expression response following treatment of VLCFAs. Furthermore, myb93 transcriptome analysis suggested that MYB93 regulated the expression of cell wall organization genes. In addition, we also found that LTPG1 and LTPG2 are involved in LR development through the formation of root cap cuticle, which is different from transcriptional regulation by VLCFAs. Our results suggest that VLCFA is a regulator of LRP development through transcription factor-mediated regulation of gene expression and the transportation of VLCFAs is also involved in LR development through root cap cuticle formation.
PMID: 37247130
Plant J , IF:6.417 , 2023 Sep , V115 (5) : P1394-1407 doi: 10.1111/tpj.16328
ELONGATED HYPOCOTYL5 (HY5) and HY5 HOMOLOGUE (HYH) maintain shade avoidance suppression in UV-B.
School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK.; School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
Reductions in red to far-red ratio (R:FR) provide plants with an unambiguous signal of vegetational shade and are monitored by phytochrome photoreceptors. Plants integrate this information with other environmental cues to determine the proximity and density of encroaching vegetation. Shade-sensitive species respond to reductions in R:FR by initiating a suite of developmental adaptations termed shade avoidance. These include the elongation of stems to facilitate light foraging. Hypocotyl elongation is driven by increased auxin biosynthesis promoted by PHYTOCHROME INTERACTING FACTORs (PIF) 4, 5 and 7. UV-B perceived by the UV RESISTANCE LOCUS 8 (UVR8) photoreceptor rapidly inhibits shade avoidance, in part by suppressing PIF4/5 transcript accumulation and destabilising PIF4/5 protein. Here, we show that longer-term inhibition of shade avoidance is sustained by ELONGATED HYPOCOTYL 5 (HY5) and HY5 HOMOLOGUE (HYH), which regulate transcriptional reprogramming of genes involved in hormone signalling and cell wall modification. HY5 and HYH are elevated in UV-B and suppress the expression of XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE (XTH) genes involved in cell wall loosening. They additionally increase expression GA2-OXIDASE1 (GA2ox1) and GA2ox2, encoding gibberellin catabolism enzymes that act redundantly to stabilise the PIF-inhibiting DELLA proteins. UVR8 therefore regulates temporally distinct signalling pathways to first rapidly inhibit and subsequently maintain suppression of shade avoidance following UV-B exposure.
PMID: 37243898
Plant J , IF:6.417 , 2023 Sep , V115 (5) : P1357-1376 doi: 10.1111/tpj.16324
PIN2/3/4 auxin carriers mediate root growth inhibition under conditions of boron deprivation in Arabidopsis.
International Research Center for Environmental Membrane Biology & Department of Horticulture, Foshan University, Foshan, 528000, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430000, China.; Microelement Research Center/Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, 430070, China.; Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava, Slovakia.; School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, Perth, 6009, Australia.; Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania, 7001, Australia.; School of Biological Sciences, University of Western Australia, Perth, 6009, Australia.; Institute of Cellular and Molecular Botany, University of Bonn, D-53115, Bonn, Germany.; Institute of Soil Science Chinese Academy of Sciences, State Key Laboratory of Soil and Sustainable Agriculture, Nanjing, 210018, China.
The mechanistic basis by which boron (B) deprivation inhibits root growth via the mediation of root apical auxin transport and distribution remains elusive. This study showed that B deprivation repressed root growth of wild-type Arabidopsis seedlings, which was related to higher auxin accumulation (observed with DII-VENUS and DR5-GFP lines) in B-deprived roots. Boron deprivation elevated the auxin content in the root apex, coinciding with upregulation of the expression levels of auxin biosynthesis-related genes (TAA1, YUC3, YUC9, and NIT1) in shoots, but not in root apices. Phenotyping experiments using auxin transport-related mutants revealed that the PIN2/3/4 carriers are involved in root growth inhibition caused by B deprivation. B deprivation not only upregulated the transcriptional levels of PIN2/3/4, but also restrained the endocytosis of PIN2/3/4 carriers (observed with PIN-Dendra2 lines), resulting in elevated protein levels of PIN2/3/4 in the plasma membrane. Overall, these results suggest that B deprivation not only enhances auxin biosynthesis in shoots by elevating the expression levels of auxin biosynthesis-related genes but also promotes the polar auxin transport from shoots to roots by upregulating the gene expression levels of PIN2/3/4, as well as restraining the endocytosis of PIN2/3/4 carriers, ultimately resulting in auxin accumulation in root apices and root growth inhibition.
PMID: 37235684
Ecotoxicol Environ Saf , IF:6.291 , 2023 Oct , V264 : P115458 doi: 10.1016/j.ecoenv.2023.115458
An arbuscular mycorrhizal fungus differentially regulates root traits and cadmium uptake in two maize varieties.
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, Yunnan, China.; College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, Yunnan, China. Electronic address: zfd97@ynau.edu.cn.
Arbuscular mycorrhizal fungi (AMF) are symbiotic fungi that colonize plant roots, and they are more common in Cd-polluted habitats. However, there is limited understanding of the response of root traits and cadmium (Cd) uptake to AMF in different crop varieties. Two maize varieties, Panyu 3 and Ludan 8, with high and low Cd uptake capacities, respectively, were cultivated as host plants in a pot experiment with Cd-polluted soil (17.1 mg/kg Cd). The effects of AMF on the growth, mineral nutrient concentration, root traits, phytohormone concentrations and Cd uptake of the two maize varieties and their comprehensive response to AMF fungal inoculation were investigated. AMF improved growth, mineral nutrient levels and root morphology and increased lignin and phytohormone concentrations in roots and Cd uptake in the two maize varieties. However, the two maize varieties, Panyu 3 and Ludan 8, had different responses to AMF, and their comprehensive response indices were 753.6% and 389.4%, respectively. The root biomass, branch number, abscisic acid concentrations, lignin concentrations and Cd uptake of maize Panyu 3 increased by 151.1%, 28.6%, 139.7%, 99.5% and 84.7%, respectively. The root biomass, average diameter, auxin concentration, lignin concentration and Cd uptake of maize Ludan 8 increased by 168.7%, 31.8%, 31.4%, 41.7% and 136.7%, respectively. Moreover, Cd uptake in roots presented very significant positive correlations with the average root diameter and abscisic acid concentration. A structural equation model indicated that the root abscisic acid concentration and root surface area had positive effects on Cd uptake by the Panyu 3 maize roots; the root abscisic acid concentration and root tip number had positive effects on Cd uptake by the Ludan 8 maize roots. Thus, AMF differentially regulated Cd uptake in the two maize varieties, and the regulatory effect was closely related to root traits and phytohormone concentrations.
PMID: 37690173
Ecotoxicol Environ Saf , IF:6.291 , 2023 Sep , V263 : P115307 doi: 10.1016/j.ecoenv.2023.115307
Molecular mechanism of thiamine in mitigating drought stress in Chinese wingnut (Pterocarya stenoptera): Insights from transcriptomics.
College of Life Sciences, Xinyang Normal University, Xinyang 464000, China.; Innovation Platform of Molecular Biology, College of Landscape and Art, Henan Agricultural University, Zhengzhou, China.; College of Life Science and Technology, Inner Mongolia Normal University, Huhehaote, China; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China. Electronic address: 20220053@imnu.edu.cn.
Urban garden plants are frequently affected by drought, which can hinder their growth, development, and greening effect. Previous studies have indicated that Chinese wingnut (Pterocarya stenoptera) responds to drought stress by increasing the expression of thiamine synthesis genes. In this study, it was found that exogenous thiamine can effectively alleviate the negative effects of drought stress on plants. Forward transcriptome sequencing and physiological tests were further conducted to reveal the molecular mechanism of thiamine in alleviating drought stress. Results showed that exogenous thiamine activated the expression of eight chlorophyll synthesis genes in Chinese wingnut under drought stress. Moreover, physiological indicators proved that chlorophyll content increased in leaves of Chinese wingnut with thiamine treatment under drought stress. Photosynthesis genes were also activated in Chinese wingnut treated with exogenous thiamine under drought stress, as supported by photosynthetic indicators PI(abs) and PI(total). Additionally, exogenous thiamine stimulated the expression of genes in the auxin-activated signaling pathway, thus attenuating the effects of drought stress. This study demonstrates the molecular mechanism of thiamine in mitigating the effects of drought stress on non-model woody plants lacking transgenic systems. This study also provides an effective method to mitigate the negative impacts of drought stress on plants.
PMID: 37499386
Mol Ecol , IF:6.185 , 2023 Sep doi: 10.1111/mec.17134
Uncovering the genetic architecture of parallel evolution.
School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia.; Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland, St Lucia, Queensland, Australia.
Identifying the genetic architecture underlying adaptive traits is exceptionally challenging in natural populations. This is because associations between traits not only mask the targets of selection but also create correlated patterns of genomic divergence that hinder our ability to isolate causal genetic effects. Here, we examine the repeated evolution of components of the auxin pathway that have contributed to the replicated loss of gravitropism (i.e. the ability of a plant to bend in response to gravity) in multiple populations of the Senecio lautus species complex in Australia. We use a powerful approach which combines parallel population genomics with association mapping in a Multiparent Advanced Generation Inter-Cross (MAGIC) population to break down genetic and trait correlations to reveal how adaptive traits evolve during replicated evolution. We sequenced auxin and shoot gravitropism-related gene regions in 80 individuals from six natural populations (three parallel divergence events) and 133 individuals from a MAGIC population derived from two of the recently diverged natural populations. We show that artificial tail selection on gravitropism in the MAGIC population recreates patterns of parallel divergence in the auxin pathway in the natural populations. We reveal a set of 55 auxin gene regions that have evolved repeatedly during the evolution of the species, of which 50 are directly associated with gravitropism divergence in the MAGIC population. Our work creates a strong link between patterns of genomic divergence and trait variation contributing to replicated evolution by natural selection, paving the way to understand the origin and maintenance of adaptations in natural populations.
PMID: 37740681
Int J Mol Sci , IF:5.923 , 2023 Sep , V24 (18) doi: 10.3390/ijms241814310
Comparison of Transcriptome between Tolerant and Susceptible Rice Cultivar Reveals Positive and Negative Regulators of Response to Rhizoctonia solani in Rice.
Institute of Plant Protection, Tianjin Academy of Agricultural Sciences, Tianjin 300381, China.; Institute of Crop Research, Tianjin Academy of Agricultural Sciences, Tianjin 300381, China.
Rice (Oryza sativa L.) is one of the world's most crucial food crops, as it currently supports more than half of the world's population. However, the presence of sheath blight (SB) caused by Rhizoctonia solani has become a significant issue for rice agriculture. This disease is responsible for causing severe yield losses each year and is a threat to global food security. The breeding of SB-resistant rice varieties requires a thorough understanding of the molecular mechanisms involved and the exploration of immune genes in rice. To this end, we conducted a screening of rice cultivars for resistance to SB and compared the transcriptome based on RNA-seq between the most tolerant and susceptible cultivars. Our study revealed significant transcriptomic differences between the tolerant cultivar ZhengDao 22 (ZD) and the most susceptible cultivar XinZhi No.1 (XZ) in response to R. solani invasion. Specifically, the tolerant cultivar showed 7066 differentially expressed genes (DEGs), while the susceptible cultivar showed only 60 DEGs. In further analysis, we observed clear differences in gene category between up- and down-regulated expression of genes (uDEGs and dDEGs) based on Gene Ontology (GO) classes in response to infection in the tolerant cultivar ZD, and then identified uDEGs related to cell surface pattern recognition receptors, the Ca(2+) ion signaling pathway, and the Mitogen-Activated Protein Kinase (MAPK) cascade that play a positive role against R. solani. In addition, DEGs of the jasmonic acid and ethylene signaling pathways were mainly positively regulated, whereas DEGs of the auxin signaling pathway were mainly negatively regulated. Transcription factors were involved in the immune response as either positive or negative regulators of the response to this pathogen. Furthermore, our results showed that chloroplasts play a crucial role and that reduced photosynthetic capacity is a critical feature of this response. The results of this research have important implications for better characterization of the molecular mechanism of SB resistance and for the development of resistant cultivars through molecular breeding methods.
PMID: 37762614
Int J Mol Sci , IF:5.923 , 2023 Sep , V24 (18) doi: 10.3390/ijms241814230
Transcriptomic and Metabolomic Analyses Reveal the Key Genes Related to Shade Tolerance in Soybean.
College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.; Institute of Specialty Crop, Chongqing Academy of Agricultural Sciences, Chongqing 402160, China.
Soybean (Glycine max) is an important crop, rich in proteins, vegetable oils and several other phytochemicals, which is often affected by light during growth. However, the specific regulatory mechanisms of leaf development under shade conditions have yet to be understood. In this study, the transcriptome and metabolome sequencing of leaves from the shade-tolerant soybean 'Nanxiadou 25' under natural light (ND1) and 50% shade rate (SHND1) were carried out, respectively. A total of 265 differentially expressed genes (DEGs) were identified, including 144 down-regulated and 121 up-regulated genes. Meanwhile, KEGG enrichment analysis of DEGs was performed and 22 DEGs were significantly enriched in the top five pathways, including histidine metabolism, riboflavin metabolism, vitamin B6 metabolism, glycerolipid metabolism and cutin, suberine and wax biosynthesis. Among all the enrichment pathways, the most DEGs were enriched in plant hormone signaling pathways with 19 DEGs being enriched. Transcription factors were screened out and 34 differentially expressed TFs (DETFs) were identified. Weighted gene co-expression network analysis (WGCNA) was performed and identified 10 core hub genes. Combined analysis of transcriptome and metabolome screened out 36 DEGs, and 12 potential candidate genes were screened out and validated by quantitative real-time polymerase chain reaction (qRT-PCR) assay, which may be related to the mechanism of shade tolerance in soybean, such as ATP phosphoribosyl transferase (ATP-PRT2), phosphocholine phosphatase (PEPC), AUXIN-RESPONSIVE PROTEIN (IAA17), PURPLE ACID PHOSPHATASE (PAP), etc. Our results provide new knowledge for the identification and function of candidate genes regulating soybean shade tolerance and provide valuable resources for the genetic dissection of soybean shade tolerance molecular breeding.
PMID: 37762532
Int J Mol Sci , IF:5.923 , 2023 Aug , V24 (17) doi: 10.3390/ijms241713445
Study on the Interactions of Cyclins with CDKs Involved in Auxin Signal during Leaf Development by WGCNA in Populus alba.
State Key Laboratory of Tree Genetics and Breeding, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100107, China.
Cell division plays an indispensable role in leaf morphogenesis, which is regulated via the complexes formed by cyclin and cyclin-dependent kinase (CDK). In this study, gene family analysis, exogenous auxin stimulation, RNA-seq and WGCNA analysis were all used to investigate the molecular mechanisms by which cell-cycle-related factors participated in the auxin signaling pathway on leaf morphogenesis. Sixty-three cyclin members and seventeen CDK members in Populus alba were identified and systematically analyzed. During the evolution, WGD was the main reason that resulted in the expansion of cyclin and CDK genes. Firstly, after a short time treating with auxin to matured leaves of seedlings, genes related to cell division including GRF and ARGOS were both upregulated to restart the transition of cells from G1-to-S phase. Secondly, with three days of continuous auxin stimulation to leaves at different developmental stages, leaves area variation, transcriptomes and hormones were analyzed. By PCA, PCoA and WGCNA analyses, the turquoise module was both positively related to leaf development and auxin. Based on the co-expression analysis and Y2H experiment, PoalbCYCD1;4, PoalbCYCD3;3 and PoalbCYCD3;5 were supposed to interact with PoalbCDKA;1, which could be the trigger to promote the G1-to-S phase transition. The ARF transcription factor might play the key role of connecting the auxin signaling pathway and cell division in leaf morphogenesis by affecting CYC-CDK complexes.
PMID: 37686248
Front Plant Sci , IF:5.753 , 2023 , V14 : P1271329 doi: 10.3389/fpls.2023.1271329
BvCPD promotes parenchyma cell and vascular bundle development in sugar beet (Beta vulgaris L.) taproot.
Sugar Beet Physiological Research Institute, Inner Mongolia Agricultural University, Hohhot, China.
Constitutive photomorpogenic dwarf (CPD) is a pivotal enzyme gene for brassinolide (BR) synthesis and plays an important role in plant growth, including increasing plant biomass and plant height, elongating cells, and promoting xylem differentiation. However, little is known about the function of the CPD gene in sugar beet. In the current study, we isolated CPD from Beta vulgaris L. (BvCPD), which encodes protein localized in the nucleus, cell membrane, and cell wall. BvCPD was strongly expressed in parenchyma cells and vascular bundles. The transgenic sugar beet overexpressing BvCPD exhibited larger diameter than that of the wild type (WT), which mainly owing to the increased number and size of parenchyma cells, the enlarged lumen and area of vessel in the xylem. Additionally, overexpression of BvCPD increased the synthesis of endogenous BR, causing changes in the content of endogenous auxin (IAA) and gibberellin (GA) and accumulation of cellulose and lignin in cambium 1-4 rings of the taproot. These results suggest that BvCPD can promote the biosynthesis of endogenous BR, improve cell wall components, promote the development of parenchyma cells and vascular bundle, thereby playing an important role in promoting the growth and development of sugar beet taproot.
PMID: 37771491
Front Plant Sci , IF:5.753 , 2023 , V14 : P1112821 doi: 10.3389/fpls.2023.1112821
A plant virus protein, NIa-pro, interacts with Indole-3-acetic acid-amido synthetase, whose levels positively correlate with disease severity.
Department of Plant Pathology, Washington State University, Pullman, WA, United States.; Institute of Biological Chemistry, Washington State University, Pullman, WA, United States.
Potato virus Y (PVY) is an economically important plant pathogen that reduces the productivity of several host plants. To develop PVY-resistant cultivars, it is essential to identify the plant-PVY interactome and decipher the biological significance of those molecular interactions. We performed a yeast two-hybrid (Y2H) screen of Nicotiana benthamiana cDNA library using PVY-encoded NIa-pro as the bait. The N. benthamiana Indole-3-acetic acid-amido synthetase (IAAS) was identified as an interactor of NIa-pro protein. The interaction was confirmed via targeted Y2H and bimolecular fluorescence complementation (BiFC) assays. NIa-pro interacts with IAAS protein and consequently increasing the stability of IAAS protein. Also, the subcellular localization of both NIa-pro and IAAS protein in the nucleus and cytosol was demonstrated. By converting free IAA (active form) to conjugated IAA (inactive form), IAAS plays a crucial regulatory role in auxin signaling. Transient silencing of IAAS in N. benthamiana plants reduced the PVY-mediated symptom induction and virus accumulation. Conversely, overexpression of IAAS enhanced symptom induction and virus accumulation in infected plants. In addition, the expression of auxin-responsive genes was found to be downregulated during PVY infection. Our findings demonstrate that PVY NIa-pro protein potentially promotes disease development via modulating auxin homeostasis.
PMID: 37767296
Front Plant Sci , IF:5.753 , 2023 , V14 : P1244743 doi: 10.3389/fpls.2023.1244743
Paired growth of cultivated and halophytic wild rice under salt stress induces bacterial endophytes and gene expression responses.
Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh.
INTRODUCTION: Utilizing salt-affected marginal lands in coastal regions can help meet the growing demand for rice. We explored a nature-based solution involving wild halophytic rice (O. coarctata, Oc) and commercial rice BRRI Dhan 67 (O. sativa, Os) grown in close proximity to each other under salt stress. METHODS: This was to investigate whether a paired planting strategy could help complement rice growth and yield under stress. We also investigated the gene expression and endophytic bacterial profiles of both Os and Oc in unpaired and paired conditions without and with salt. RESULTS: Paired plants exhibited lower salt damage indicators such as smaller reduction in plant height, electrolyte leakage and chlorophyll loss, as well as higher K(+)/Na(+) ratio under saline stress. Some of the 39 endophytic bacteria in the mutualism experiment were unique to Oc and transferred to Os when paired. Differentially expressed genes in leaves of paired Os versus unpaired Os were 1097 (994 up-regulated, 101 down-regulated) without salt and 893 (763 up-regulated, 130 down-regulated) under salt stress. The presence of Oc plants under salt stress influenced major biological processes in Os, including oxidative stress; chitinase activity; phenylalanine catabolic process and response to ABA. Protein binding and serine/threonine kinase activity were primarily affected in molecular function. The downregulated WRKY transcription factor 22 in paired conditions under salt stress played a role in the MAPK signaling pathway, reducing respiratory cell death. The upregulated auxin-responsive protein IAA18 gene, involved in hormone signaling and cell enlargement, was present only in paired plants. DISCUSSION: Our findings therefore, offer insights into developing more effective cultivation strategies for sustainable rice production.
PMID: 37746015
Front Plant Sci , IF:5.753 , 2023 , V14 : P1216680 doi: 10.3389/fpls.2023.1216680
Functional analysis of auxin derived from a symbiotic mycobiont.
Fungal Patho-Biology, Temasek Life Sciences Laboratory, Singapore, Singapore.; Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
The biosynthesis of auxin or indole-3-acetic acid by microorganisms has a major impact on plant-microbe interactions. Several beneficial microbiota are known to produce auxin, which largely influences root development and growth in the host plants. Akin to findings in rhizobacteria, recent studies have confirmed the production of auxin by plant growth-promoting fungi too. Here, we show that Penicillium citrinum isolate B9 produces auxin as deduced by liquid chromatography tandem-mass spectrometry analysis. Such fungal auxin is secreted and contributes directly to enhanced root and shoot development and overall plant growth in Arabidopsis thaliana. Furthermore, auxin production by P. citrinum likely involves more than one tryptophan-dependent pathway. Using auxin biosynthesis inhibitor L-Kynurenine, we show that the indole-3-pyruvate pathway might be one of the key biosynthetic routes involved in such auxin production. Confocal microscopy of the DR5rev:GFP Arabidopsis reporter line helped demonstrate that P. citrunum B9-derived auxin is biologically active and is able to significantly enhance auxin signaling in roots during such improved root growth and plant development. Furthermore, the phenotypic growth defects arising from impaired auxin signaling in Arabidopsis taa1 mutant or upon L-Kynurenine treatment of wild-type Arabidopsis seedlings could be significantly alleviated by fungus B9-derived auxin, thus suggesting its positive role in plant growth promotion. Collectively, our results provide clear evidence that the production of auxin is one of the main mechanisms involved in induction of the beneficial plant growth by P. citrinum.
PMID: 37745999
Front Plant Sci , IF:5.753 , 2023 , V14 : P1182074 doi: 10.3389/fpls.2023.1182074
Ticarcillin degradation product thiophene acetic acid is a novel auxin analog that promotes organogenesis in tomato.
Khalifa Center for Genetic Engineering and Biotechnology, United Arab Emirates University, Al-Ain, United Arab Emirates.; Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates.; Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates.
Efficient regeneration of transgenic plants from explants after transformation is one of the crucial steps in developing genetically modified plants with desirable traits. Identification of novel plant growth regulators and developmental regulators will assist to enhance organogenesis in culture. In this study, we observed enhanced shoot regeneration from tomato cotyledon explants in culture media containing timentin, an antibiotic frequently used to prevent Agrobacterium overgrowth after transformation. Comparative transcriptome analysis of explants grown in the presence and absence of timentin revealed several genes previously reported to play important roles in plant growth and development, including Auxin Response Factors (ARFs), GRF Interacting Factors (GIFs), Flowering Locus T (SP5G), Small auxin up-regulated RNAs (SAUR) etc. Some of the differentially expressed genes were validated by quantitative real-time PCR. We showed that ticarcillin, the main component of timentin, degrades into thiophene acetic acid (TAA) over time. TAA was detected in plant tissue grown in media containing timentin. Our results showed that TAA is indeed a plant growth regulator that promotes root organogenesis from tomato cotyledons in a manner similar to the well-known auxins, indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). In combination with the cytokinin 6-benzylaminopurine (BAP), TAA was shown to promote shoot organogenesis from tomato cotyledon in a concentration-dependent manner. To the best of our knowledge, the present study reports for the first time demonstrating the function of TAA as a growth regulator in a plant species. Our work will pave the way for future studies involving different combinations of TAA with other plant hormones which may play an important role in in vitro organogenesis of recalcitrant species. Moreover, the differentially expressed genes and long noncoding RNAs identified in our transcriptome studies may serve as contender genes for studying molecular mechanisms of shoot organogenesis.
PMID: 37731982
Front Microbiol , IF:5.64 , 2023 , V14 : P1257355 doi: 10.3389/fmicb.2023.1257355
Identification of ARF transcription factor gene family and its defense responses to bacterial infection and salicylic acid treatment in sugarcane.
National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China.; Faculte des Sciences Agronomiques, Departement de production vegetale, Laboratoire de Recherche en Biofortification, Defense et Valorisation des Cultures (BioDev), Universite de Lubumbashi, Lubumbashi, Democratic Republic of the Congo.
Auxin response factor (ARF) is a critical regulator in the auxin signaling pathway, involved in a variety of plant biological processes. Here, gene members of 24 SpapARFs and 39 SpnpARFs were identified in two genomes of Saccharum spontaneum clones AP85-441 and Np-X, respectively. Phylogenetic analysis showed that all ARF genes were clustered into four clades, which is identical to those ARF genes in maize (Zea mays) and sorghum (Sorghum bicolor). The gene structure and domain composition of this ARF family are conserved to a large degree across plant species. The SpapARF and SpnpARF genes were unevenly distributed on chromosomes 1-8 and 1-10 in the two genomes of AP85-441 and Np-X, respectively. Segmental duplication events may also contribute to this gene family expansion in S. spontaneum. The post-transcriptional regulation of ARF genes likely involves sugarcane against various stressors through a miRNA-medicated pathway. Expression levels of six representative ShARF genes were analyzed by qRT-PCR assays on two sugarcane cultivars [LCP85-384 (resistant to leaf scald) and ROC20 (susceptible to leaf scald)] triggered by Acidovorax avenae subsp. avenae (Aaa) and Xanthomonas albilineans (Xa) infections and salicylic acid (SA) treatment. ShARF04 functioned as a positive regulator under Xa and Aaa stress, whereas it was a negative regulator under SA treatment. ShARF07/17 genes played positive roles against both pathogenic bacteria and SA stresses. Additionally, ShARF22 was negatively modulated by Xa and Aaa stimuli in both cultivars, particularly LCP85-384. These findings imply that sugarcane ARFs exhibit functional redundancy and divergence against stressful conditions. This work lays the foundation for further research on ARF gene functions in sugarcane against diverse environmental stressors.
PMID: 37744907
J Biol Chem , IF:5.157 , 2023 Aug , V299 (10) : P105197 doi: 10.1016/j.jbc.2023.105197
Biochemical investigation of the tryptophan biosynthetic enzyme anthranilate phosphoribosyltransferase in plants.
Department of Biology, Williams College, Williamstown, Massachusetts, USA.; Department of Biology, Williams College, Williamstown, Massachusetts, USA. Electronic address: ckh2@williams.edu.
While mammals require the essential amino acid tryptophan (Trp) in their diet, plants and microorganisms synthesize Trp de novo. The five-step Trp pathway starts with the shikimate pathway product, chorismate. Chorismate is converted to the aromatic compound anthranilate, which is then conjugated to a phosphoribosyl sugar in the second step by anthranilate phosphoribosyltransferase (PAT1). As a single-copy gene in plants, all fixed carbon flux to indole and Trp for protein synthesis, specialized metabolism, and auxin hormone biosynthesis proceeds through PAT1. While bacterial PAT1s have been studied extensively, plant PAT1s have escaped biochemical characterization. Using a structure model, we identified putative active site residues that were variable across plants and kinetically characterized six PAT1s (Arabidopsis thaliana (thale cress), Citrus sinensis (sweet orange), Pistacia vera (pistachio), Juglans regia (English walnut), Selaginella moellendorffii (spike moss), and Physcomitrium patens (spreading earth-moss)). We probed the catalytic efficiency, substrate promiscuity, and regulation of these six enzymes and found that the C. sinensis PAT1 is highly specific for its cognate substrate, anthranilate. Investigations of site-directed mutants of the A. thaliana PAT1 uncovered an active site residue that contributes to promiscuity. While Trp inhibits bacterial PAT1 enzymes, the six plant PAT1s that we tested were not modulated by Trp. Instead, the P. patens PAT1 was inhibited by tyrosine, and the S. moellendorffii PAT1 was inhibited by phenylalanine. This structure-informed biochemical examination identified variations in activity, efficiency, specificity, and enzyme-level regulation across PAT1s from evolutionarily diverse plants.
PMID: 37659723
Plant Methods , IF:4.993 , 2023 Sep , V19 (1) : P99 doi: 10.1186/s13007-023-01078-y
Highly efficient Agrobacterium rhizogenes-mediated transformation for functional analysis in woodland strawberry.
School of Life Sciences, Guizhou Normal University, Guiyang, 550001, China.; Key Laboratory of Plant Physiology and Development Regulation, Guizhou Normal University, Guiyang, 550001, China.; Key Laboratory of State Forestry Administration on Bioaffiliationersity Conservation in Mountainous Karst Area of Southwestern China, Guizhou Normal University, Guiyang, 550001, China.; School of Life Sciences, Guizhou Normal University, Guiyang, 550001, China. huangxiaolong@gznu.edu.cn.; Key Laboratory of Plant Physiology and Development Regulation, Guizhou Normal University, Guiyang, 550001, China. huangxiaolong@gznu.edu.cn.; Key Laboratory of State Forestry Administration on Bioaffiliationersity Conservation in Mountainous Karst Area of Southwestern China, Guizhou Normal University, Guiyang, 550001, China. huangxiaolong@gznu.edu.cn.
BACKGROUND: The diploid woodland strawberry (Fragaria vesca) is an excellent model plant for investigating economically significant traits and several genetic resources within the Rosaceae family. Agrobacterium rhizogenes-mediated hairy root transformation is an alternative for exploring gene functions, especially the genes specifically expressed in roots. However, the hairy root transformation has not been established in strawberry. RESULTS: Here, we described an efficient and rapid hairy root transgenic system for strawberry using A. rhizogenes. Strain of A. rhizogenes MSU440 or C58C1 was the most suitable for hairy root transformation. The transformation efficiency was highest when tissues contained hypocotyls as explants. The optimal procedure involves A. rhizogenes at an optical density (OD(600)) of 0.7 for 10 min and co-cultivation duration for four days, achieving a transgenic efficiency of up to 71.43%. An auxin responsive promoter DR5(ver2) carrying an enhanced green fluorescent protein (eGFP) marker was transformed by A. rhizogenes MSU440, thereby generating transgenic hairy roots capable of high eGFP expression in root tip and meristem of strawberry where auxin accumulated. Finally, this system was applied for functional analysis using jGCaMP7c, which could sense calcium signals. A significant upsurge in eGFP expression in the transgenic hairy roots was displayed after adding calcium chloride. The results suggested that this approach was feasible for studying specific promoters and could be a tool to analyze gene functions in the roots of strawberries. CONCLUSION: We established a rapid and efficient hairy root transformation in strawberry by optimizing parameters, which was adequate for promoter analysis and functional characterization of candidate genes in strawberry and other rosaceous plants.
PMID: 37742022
Plant Cell Physiol , IF:4.927 , 2023 Sep , V64 (9) : P984-995 doi: 10.1093/pcp/pcad077
KAI2 Can Do: Karrikin Receptor Function in Plant Development and Response to Abiotic and Biotic Factors.
Department of Root Biology and Symbiosis, Max Planck Institute of Molecular Plant Physiology, Potsdam Science Park, Am Muhlenberg 1, Potsdam-Golm 14476, Germany.
The alpha/beta hydrolase KARRIKIN INSENSITIVE 2 (KAI2) functions as a receptor for a yet undiscovered phytohormone, provisionally termed KAI2 ligand (KL). In addition, it perceives karrikin, a butenolide compound found in the smoke of burnt plant material. KAI2-mediated signaling is involved in regulating seed germination and in shaping seedling and adult plant morphology, both above and below ground. It also governs responses to various abiotic stimuli and stresses and shapes biotic interactions. KAI2-mediated signaling is being linked to an elaborate cross-talk with other phytohormone pathways such as auxin, gibberellin, abscisic acid, ethylene and salicylic acid signaling, in addition to light and nutrient starvation signaling. Further connections will likely be revealed in the future. This article summarizes recent advances in unraveling the function of KAI2-mediated signaling and its interaction with other signaling pathways.
PMID: 37548562
Biomolecules , IF:4.879 , 2023 Sep , V13 (9) doi: 10.3390/biom13091352
Integrated Metabolomic and Transcriptomic Analysis of the Quinoa Seedling Response to High Relative Humidity Stress.
College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China.; Yuxi Academy of Agricultural Science, Yuxi 653100, China.; Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China.
Quinoa is of great interest because it is cold- and drought-resistant; however, little research has been performed on quinoa under high relative humidity (RH) stress. In this study, quinoa seedlings of a highly HR-resistant variety ("Dianli-439") and a sensitive variety ("Dianli-969") were subjected to morphological and physiological measurements and metabolome and transcriptome analyses to investigate their response to high RH stress. In total, 1060 metabolites were detected, and lipids and flavonoids were the most abundant, with 173 and 167 metabolites, respectively. In total, 13,095 differentially expressed genes were identified, and the results showed that abscisic acid, auxin, and jasmonic-acid-related genes involved in plant hormone signaling may be involved in the response of quinoa seedlings to high RH stress. The analysis of the transcription factors revealed that the AP2/ERF family may also play an important role in the response to high RH stress. We identified the possible regulatory mechanisms of the hormone signaling pathways under high RH stress. Our findings can provide a basis for the selection and identification of highly resistant quinoa varieties and the screening of the metabolite-synthesis- and gene-regulation-related mechanisms in quinoa in response to RH stress.
PMID: 37759752
Pest Manag Sci , IF:4.845 , 2023 Sep doi: 10.1002/ps.7791
Prevalence, spatial structure and evolution of resistance to acetolactate-synthase (ALS) inhibitors and 2,4-D in the major weed Papaver rhoeas (L.) assessed using a massive, country-wide sampling.
Agroecologie, INRAE, Dijon, France.; Plateforme GeT-Biopuces, TBI, Universite de Toulouse, CNRS, INRAE, INSA, Genotoul, Toulouse, France.
BACKGROUND: Corn poppy (Papaver rhoeas) is the most damaging broadleaf weed in France. Massively parallel amplicon sequencing was used to investigate the prevalence, mode of evolution and spread of resistance-endowing ALS alleles in 422 populations randomly sampled throughout poppy's range in France. Bioassays were used to detect resistance to the synthetic auxin 2,4-D in 43 of these populations. RESULTS: A total of 21,100 plants were analysed and 24 mutant ALS alleles carrying an amino-acid substitution involved or potentially involved in resistance were identified. The vast majority (97.6%) of the substitutions occurred at codon Pro197, where all six possible single-nucleotide non-synonymous substitutions plus four double-nucleotide substitutions were identified. Changes observed in the enzymatic properties of the mutant ALS isoforms could not explain the differences in prevalence among the corresponding alleles. Sequence read analysis showed that mutant ALS alleles had multiple, independent evolutionary origins, and could have evolved several times independently within an area of a few kilometres. Finally, 2,4-D resistance was associated with mutant ALS alleles in individual plants in one third of the populations assayed. CONCLUSION: The intricate geographical mosaic of mutant ALS alleles observed is the likely result of the combination of huge population sizes, multiple independent mutation events and human-mediated spread of resistance. Our work highlights the ability of poppy populations and individual plants to accumulate different ALS alleles and as yet unknown mechanisms conferring resistance to synthetic auxins. This does not bode well for the continued use of chemical herbicides to control poppy. This article is protected by copyright. All rights reserved.
PMID: 37752099
Pest Manag Sci , IF:4.845 , 2023 Oct , V79 (10) : P3581-3592 doi: 10.1002/ps.7541
Nontarget-site resistance due to rapid physiological response in 2,4-D resistant Conyza sumatrensis: reduced 2,4-D translocation and auxin-induced gene expression.
Federal Rural University of Rio de Janeiro, Department of Crop, Seropedica, Brazil.; Colorado State University, Department of Agricultural Biology, Fort Collins, Colorado, USA.; Corteva Agriscience, Field Scientist, Sao Paulo, Brazil.
BACKGROUND: Resistance to 2,4-Dichlorophenoxyacetic acid (2,4-D) has been reported in several weed species since the 1950s; however, a biotype of Conyza sumatrensis showing a novel physiology of the rapid response minutes after herbicide application was reported in 2017. The objective of this research was to investigate the mechanisms of resistance and identify transcripts associated with the rapid physiological response of C. sumatrensis to 2,4-D herbicide. RESULTS: Differences were found in 2,4-D absorption between the resistant and susceptible biotypes. Herbicide translocation was reduced in the resistant biotype compared to the susceptible. In resistant plants 98.8% of [(14) C] 2,4-D was found in the treated leaf, whereas approximately 13% translocated to other plant parts in the susceptible biotype at 96 h after treatment. Resistant plants did not metabolize [(14) C] 2,4-D and had only intact [(14) C] 2,4-D at 96 h after application, whereas susceptible plants metabolized [(14) C] 2,4-D into four detected metabolites, consistent with reversible conjugation metabolites found in other 2,4-D sensitive plant species. Pre-treatment with the cytochrome P450 inhibitor malathion did not enhance 2,4-D sensitivity in either biotype. Following treatment with 2,4-D, resistant plants showed increased expression of transcripts within plant defense response and hypersensitivity pathways, whereas both sensitive and resistant plants showed increased expression of auxin-response transcripts. CONCLUSION: Our results demonstrate that reduced 2,4-D translocation contributes to resistance in the C. sumatrensis biotype. The reduction in 2,4-D transport is likely to be a consequence of the rapid physiological response to 2,4-D in resistant C. sumatrensis. Resistant plants had increased expression of auxin-responsive transcripts, indicating that a target-site mechanism is unlikely. (c) 2023 Society of Chemical Industry.
PMID: 37178347
Appl Microbiol Biotechnol , IF:4.813 , 2023 Sep , V107 (18) : P5651-5668 doi: 10.1007/s00253-023-12667-1
Biotechnology of Passiflora edulis: role of Agrobacterium and endophytic microbes.
Department of Botany, Bhairab Ganguly College (West Bengal State University), Feeder Road, Belghoria, Kolkata, 700056, West Bengal, India.; Department of Botany, Dr. Kanailal Bhattacharyya College, Howrah, India.; Department of Life Sciences, Presidency University, Kolkata, West Bengal, India.; Department of Botany, Siddha Clinical Research Unit, Central Council for Research in Siddha, Palayamkottai, 627 002, Tamil Nadu, India.; Department of Botany, DDU Gorakhpur University, Gorakhpur, India.; Division of Pathology, Indian Veterinary Research Institute (IVRI), Izatnagar, 243 122, Bareilly, Uttar Pradesh, India.; Department of Biotechnology, School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, 144411, Punjab, India.; Plant Biotechnology Unit, Kanchi Mamunivar Government Institute for Postgraduate Studies and Research, Lawspet, Puducherry, 605 008, India. smahipal3@gmail.com.; Department of Life Sciences, Presidency University, Kolkata, West Bengal, India. abhijit.dbs@presiuniv.ac.in.
Two forms of the genus Passiflora, belonging to the Passifloraceae family, are commonly called yellow and purple passion. These perennial woody climbers are found in the cooler regions at higher altitudes and in lowlands of tropical areas. The presence of alkaloids, terpenes, stilbenes, flavonoids, glycosides, carotenoids, etc. in different parts of the plant provides several pharmacological properties. Because of the various uses in foods and pharmaceuticals, in vitro propagation of this genus has been performed hugely and is of great interest to researchers. From different explants via direct organogenesis under controlled aseptic conditions, callus, root, shoot, and somatic embryos are induced successfully. Different PGRs are augmented in the media for the rapid multiplication or organogenesis, especially, the high ratio of cytokinin and auxin in the basal media efficiently regenerates the shoot and root respectively. The in vitro regenerated plantlets are then acclimatized and hardened properly before transferring to the field conditions. Thus, the present first of its kind review on P. edulis exclusively encompasses the wide applications of biotechnology for this species alongside its organogenesis, embryogenesis, cytology, and endophytic microbes with special emphasis on the role of genetic transformation studies mediated by Agrobacterium sp. KEY POINTS: * Critical assessment on in vitro biotechnology in P. edulis. * Agrobacterium-mediated transformation in P. edulis. * Role of endophytic microbes in P. edulis.
PMID: 37505288
Plant Sci , IF:4.729 , 2023 Sep , V336 : P111866 doi: 10.1016/j.plantsci.2023.111866
The many faces of lysine acylation in proteins: Phytohormones as unexplored substrates.
Programa de Pos-graduacao em Genetica e Biologia Molecular (PPGBM), Departamento de Genetica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.; Programa de Pos-graduacao em Genetica e Biologia Molecular (PPGBM), Departamento de Genetica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Programa de Pos-graduacao em Biologia Celular e Molecular (PPGBCM), Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Biofisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: rogerio.margis@ufrgs.br.
Protein post-translational modification (PTM) is a ubiquitous process that occurs in most proteins. Lysine residues containing an epsilon-amino group are recognized as hotspots for the addition of different chemical groups. Lysine acetylation, extensively studied in histones, serves as an epigenetic hallmark capable of promoting changes in chromatin structure and availability. Acyl groups derived from molecules involved in carbohydrate and lipid metabolisms, such as lactate, succinate and hydroxybutyrate, were identified as lysine modifications of histones and other proteins. Lysine-acyltransferases do not exhibit significant substrate specificity concerning acyl donors. Furthermore, plant hormones harboring acyl groups often form conjugates with free amino acids to regulate their activity and function during plant physiological processes and responses, a process mediated by GH3 enzymes. Besides forming low-molecular weight conjugates, auxins have been shown to covalently modify proteins in bean seeds. Aside from auxins, other phytohormones with acyl groups are unexplored potential substrates for post-translational acylation of proteins. Using MS data searches, we revealed various proteins with lysine residues linked to auxin, abscisic acid, gibberellic acid, jasmonic acid, and salicylic acid. These findings raise compelling questions about the ability of plant hormones harboring carboxyl groups to serve as new candidates for protein acylation and acting in protein PTM and modulation.
PMID: 37714383
Plant Sci , IF:4.729 , 2023 Oct , V335 : P111823 doi: 10.1016/j.plantsci.2023.111823
Harmonized biochemical modification of cell walls to get permission for entrance of Azospirillum sp. to rice roots.
Laboratory of Plant Physiology, Department Biology, Golestan University, Gorgan, Iran.; Laboratory of Plant Physiology, Department Biology, Golestan University, Gorgan, Iran. Electronic address: Aghdasi1346@gmail.com.; Department of Plant Biology, Faculty of Biological Scuience, Tarbiat Modares University, Tehran, Iran.; Department of Soil and Water Research, Golestan's Agricultural and Natural Resources Research Center, Gorgan, Iran.
Biological nitrogen-fixation is important in increasing crop efficiency. Azospirillum is a nitrogen-fixing microorganism that naturally coexists with grasses roots. The present study was undertaken to clarify the role of rice root cell walls in the acceptance of two Azospirillum species, alone or in combination with indole-3-acetic acid (IAA) and gibberellic acid (GA(3)) treatments. Rice seedlings were grown in Yoshida solution for 21 days and then inoculated with A. brasilense and A. irakens in the presence of 0, 0.57, and 1.14 mM of IAA or 0, 0.29, and 0.58 mM GA(3) or a combination of 1.14 mM of IAA and 0.58 mM of GA(3). The results showed that the amount of hydrogen peroxide, lipid peroxidation, total nitrogen and activity of ferulic acid peroxidase, NADPH oxidase, nitrate reductase, pectin methyl esterase, cellulase, mannanase, xylanase and pectinase were significantly increased in inoculated samples treated with or without phytohormones. The highest activity of these enzymes was observed in A. brasilense- inoculated rice roots in auxin+gibberellin treatment. In the latter, the activity of phenylalanine ammonia lyase and wall ferulic acid peroxidase enzymes, the content of cell wall polysaccharide, lignin, and total phenolic compounds were the least, compared to controls and also with those samples which were inoculated with A. irakens. The results indicate an active role of the wall and its enzymes in allowing bacteria to enter the roots. Understanding this mechanism can improve the methods of inoculating bacteria into plants and increase crop efficiency, which will result in reduced use of chemical fertilizers and their destructive environmental effects.
PMID: 37572965
Plant Sci , IF:4.729 , 2023 Oct , V335 : P111818 doi: 10.1016/j.plantsci.2023.111818
Systems biology of root development in Populus: Review and perspectives.
Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA, USA. Electronic address: amir.ahkami@pnnl.gov.
The root system of plants consists of primary, lateral, and adventitious roots (ARs) (aka shoot-born roots). ARs arise from stem- or leaf-derived cells during post-embryonic development. Adventitious root development (ARD) through stem cuttings is the first requirement for successful establishment and growth of planted trees; however, the details of the molecular mechanisms underlying ARD are poorly understood. This knowledge is important to both basic plant biology and because of its necessary role in the successful propagation of superior cultivars of commercial woody bioenergy crops, like poplar. In this review article, the molecular mechanisms that control both endogenous (auxin) and environmentally (nutrients and microbes) regulated ARD and how these systems interact to control the rooting efficiency of poplar trees are described. Then, potential future studies in employing integrated systems biology approaches at cellular resolutions are proposed to more precisely identify the molecular mechanisms that cause AR. Using genetic transformation and genome editing approaches, this information can be used for improving ARD in economically important plants for which clonal propagation is a requirement.
PMID: 37567482
Plant Sci , IF:4.729 , 2023 Oct , V335 : P111816 doi: 10.1016/j.plantsci.2023.111816
Review: Losing JAZ4 for growth and defense.
Department of Plant Sciences, University of California, Davis, CA, USA; Horticulture and Agronomy Graduate Group, University of California, Davis, CA, USA.; Department of Plant Sciences, University of California, Davis, CA, USA.; Department of Plant Sciences, University of California, Davis, CA, USA; Plant Pathology Graduate Group, University of California, Davis, CA, USA.; Department of Plant Sciences, University of California, Davis, CA, USA. Electronic address: melotto@ucdavis.edu.
JAZ proteins are involved in the regulation of the jasmonate signaling pathway, which is responsible for various physiological processes, such as defense response, adaptation to abiotic stress, growth, and development in Arabidopsis. The conserved domains of JAZ proteins can serve as binding sites for a broad array of regulatory proteins and the diversity of these protein-protein pairings result in a variety of functional outcomes. Plant growth and defense are two physiological processes that can conflict with each other, resulting in undesirable plant trade-offs. Recent observations have revealed a distinguishing feature of JAZ4; it acts as negative regulator of both plant immunity and growth and development. We suggest that these complex biological processes can be decoupled at the JAZ4 regulatory node, due to prominent expression of JAZ4 in specific tissues and organs. This spatial separation of actions could explain the increased disease resistance and size of the plant root and shoot in the absence of JAZ4. At the tissue level, JAZ4 could play a role in crosstalk between hormones such as ethylene and auxin to control organ differentiation. Deciphering biding of JAZ4 to specific regulators in different tissues and the downstream responses is key to unraveling molecular mechanisms toward developing new crop improvement strategies.
PMID: 37543224
Plant Sci , IF:4.729 , 2023 Oct , V335 : P111782 doi: 10.1016/j.plantsci.2023.111782
MdGRF11-MdARF19-2 module acts as a positive regulator of drought resistance in apple rootstock.
College of Horticulture, China Agricultural University, Beijing 100193, PR China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Nutrition and Physiology), Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China.; College of Horticulture, China Agricultural University, Beijing 100193, PR China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Nutrition and Physiology), Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China. Electronic address: wangyi@cau.edu.cn.
14-3-3 proteins play an important role in the response of plants to drought resistance. In this study, 14-3-3 protein MdGRF11 was cloned from Malus xiaojinensis, and its positive regulation of drought resistance was verified using Orin calli and M. xiaojinensis plants. The transcription factor MdARF19-2 was further screened for interaction with this protein in vitro and in vivo. We also conducted experiments using Orin calli and found that the overexpression of MdARF19-2 decreased the level of reactive oxygen species (ROS) and increased the activity of enzymes that scavenge ROS in plant materials. This indicates that MdARF19-2 is a positive regulator in the drought resistance of plants. The drought tolerance was further improved by the overexpression of both MdGRF11 and MdARF19-2 in the calli. In addition, we examined several genes related to ROS scavenging with auxin response factor binding elements in their promoters and found that their level of expression was regulated by the MdGRF11-MdARF19-2 module. In conclusion, the enhancement of plant drought resistance by MdGRF11 could be owing to its accumulation at the protein level in response to drought, which then combined with MdARF19-2, affecting the expression of MdARF19-2 downstream genes. Thus, it scavenges ROS, which ultimately improves the resistance of plant to drought stress.
PMID: 37406680
Life Sci Alliance , IF:4.591 , 2023 Sep , V6 (9) doi: 10.26508/lsa.202302090
The mRNA decapping machinery targets LBD3/ASL9 to mediate apical hook and lateral root development.
Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.; Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.; Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Nagoya, Japan.; Crop Genetics Department, John Innes Centre, Norwich Research Park, Norwich, UK.; Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark shutko@bio.ku.dk.
Multicellular organisms perceive and transduce multiple cues to optimize development. Key transcription factors drive developmental changes, but RNA processing also contributes to tissue development. Here, we report that multiple decapping deficient mutants share developmental defects in apical hook, primary and lateral root growth. More specifically, LATERAL ORGAN BOUNDARIES DOMAIN 3 (LBD3)/ASYMMETRIC LEAVES 2-LIKE 9 (ASL9) transcripts accumulate in decapping deficient plants and can be found in complexes with decapping components. Accumulation of ASL9 inhibits apical hook and lateral root formation. Interestingly, exogenous auxin application restores lateral roots formation in both ASL9 over-expressors and mRNA decay-deficient mutants. Likewise, mutations in the cytokinin transcription factors type-B ARABIDOPSIS RESPONSE REGULATORS (B-ARRs) ARR10 and ARR12 restore the developmental defects caused by over-accumulation of capped ASL9 transcript upon ASL9 overexpression. Most importantly, loss-of-function of asl9 partially restores apical hook and lateral root formation in both dcp5-1 and pat triple decapping deficient mutants. Thus, the mRNA decay machinery directly targets ASL9 transcripts for decay, possibly to interfere with cytokinin/auxin responses, during development.
PMID: 37385753
Plant Cell Rep , IF:4.57 , 2023 Sep doi: 10.1007/s00299-023-03053-2
Dose effects of restorer gene modulate pollen fertility in cotton CMS-D2 restorer lines via auxin signaling and flavonoid biosynthesis.
National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.; National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China. zhangmeng03@caas.cn.; National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China. dr.wujianyong@live.cn.; National Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China. chaozhuxing@126.com.
Dose effects of Rf(1) gene regulated retrieval mechanism of pollen fertility for CMS-D2 cotton. Cytoplasmic male sterility conditioned by Gossypium harknessii cytoplasm (CMS-D2) is an economical pollination control system for producing hybrid cotton seeds compared to artificial and chemical emasculation methods. However, the unstable restoring ability of restorer lines is a main barrier in the large-scale application of "three-line" hybrid cotton in China. Our phenotypic investigation determined that the homozygous Rf(1)Rf(1) allelic genotype had a stronger ability to generate fertile pollen than the heterozygous Rf(1)rf(1) allelic genotype. To decipher the genetic mechanisms that control the differential levels of pollen fertility, an integrated metabolomic and transcriptomic analysis was performed at two environments using pollen grains of four cotton genotypes differing in Rf(1) alleles or cytoplasm. Totally 5,391 differential metabolite features were detected, and 369 specific differential metabolites (DMs) were identified between homozygous and heterozygous Rf(1) allelic genotypes with CMS-D2 cytoplasm. In addition, transcriptome analysis identified 2,490 differentially expressed genes (DEGs) and 96 unique hub DEGs with dynamic regulation in this comparative combination. Further integrated analyses revealed that several key DEGs and DMs involved in indole biosynthesis, flavonoid biosynthesis, and sugar metabolism had strong network linkage with fertility restoration. In vitro application of auxin analogue NAA and inhibitor Auxinole confirmed that over-activated auxin signaling might inhibit pollen development, whereas suppressing auxin signaling partially promoted pollen development in CMS-D2 cotton. Our results provide new insight into how the dosage effects of the Rf(1) gene regulate pollen fertility of CMS-D2 cotton.
PMID: 37715064
Plant Physiol Biochem , IF:4.27 , 2023 Sep , V203 : P108035 doi: 10.1016/j.plaphy.2023.108035
Metabolic pathways modulated by coumarin to inhibit seed germination and early seedling growth in Eleusine indica.
Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, 510640, PR China.; Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, 510640, PR China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.; Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, 510640, PR China. Electronic address: zhangchun_0726@163.com.
Coumarin is an allelochemical that is widely present in the plant kingdom and has great potential for weed control. However, its mechanisms of action remain largely unknown. This study employed metabolomic and transcriptomic analyses along with evaluations of amino acid profiles and related physiological indicators to investigate how coumarin inhibits the germination and seedling growth of Eleusine indica by modifying metabolic pathways. At 72 h of germination at 50 and 100 mg L(-1) coumarin, E. indica had lower levels of soluble sugar and activities of amylases and higher levels of starch, O(2)(-), H(2)O(2), auxin (IAA) and abscisic acid (ABA) compared to the control. Metabolomic analysis demonstrated that coumarin treatments had a significant impact on the pathways associated with amino acid metabolism and transport and aminoacyl-tRNA biosynthesis. Exposure to coumarin induced significant alterations in the levels of 19 amino acids, with a decrease in 15 of them, including Met, Leu and gamma-aminobutyric acid (GABA). Additionally, transcriptomic analysis showed that coumarin significantly disrupted several essential biological processes, including protein translation, secondary metabolite synthesis, and hormone signal transduction. The decrease in TCA cycle metabolite (cis-aconitate, 2-oxoglutarate, and malate) contents was associated with the suppression of transcription for related enzymes. Our findings indicate that the inhibition of germination and growth in E. indica by coumarin involves the suppression of starch conversion to sugars, modification of the amino acid profile, interference of hormone signalling and the induction of oxidative stress. The TCA cycle appears to be one of the most essential pathways affected by coumarin.
PMID: 37729857
Plant Physiol Biochem , IF:4.27 , 2023 Sep , V202 : P107982 doi: 10.1016/j.plaphy.2023.107982
Modulation of ethylene and ROS-scavenging enzymes by multifarious plant growth-promoting endophytes in tomato (Solanum lycopersicum) plants to combat Xanthomonas -induced stress.
Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh, 201313, India.; Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh, 201313, India. Electronic address: spandey5@amity.edu.; Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector 125, Noida, Uttar Pradesh, 201313, India.; G.L. Bajaj Institute of Technology and Management, Greater Noida, G.B Nagar, Uttar Pradesh, 201306, India.
The purpose of the current study was to explore root endophytes- Priestia megaterium T3 and Bacillus cereus T4 from Moringa olefiera for the suppression of leaf spot disease in tomato plants challenged with Xanthomonas vesicatoria. Both strains had plant growth-stimulating characteristics including auxin production, solubilization of inorganic phosphate and zinc complexes, and production of ammonia, siderophore, as well as hydrolytic enzymes. An agar well diffusion and fluorescence viability assay have validated the antibacterial effect of the cell-free culture supernatant of strains T3 and T4. Liquid chromatography-mass spectrometry (LC-MS) profiling has identified the secondary metabolites in the cell-free supernatant of strains T3 and T4. The bio-priming of tomato seeds with a consortium of T3 and T4 strains has significantly declined ethylene (by 0.61-fold) and hydrogen peroxide (H(2)O(2), 0.64-fold) concentration thus, maintaining a lower content of ROS-induced malondialdehyde (MDA, 0.91-fold) as compared to control counterparts. Consequently, the leaf spot disease severity was reduced by approximately 70% in consortium-treated tomato plants in contrast to their pathogen-challenged control. The consortia (T3+T4) treatment has facilitated induced systemic resistance by enhancing enzymatic activities of phenylalanine ammonia-lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO), catalase (CAT), and ascorbate oxidase (AO) to detoxify the excessive Xanthomonas-induced ROS accumulation in tomato plants. Conclusively, bacterial endophytes modulate X. vesicatoria-induced ROS response and ethylene levels in tomato plants. The current findings indicate that plant growth-promoting endophytic bacterial strains hold the potential to sustainably enhance plant growth and suppress bacterial leaf spot disease in tomato plants.
PMID: 37651951
Plant Physiol Biochem , IF:4.27 , 2023 Sep , V202 : P107932 doi: 10.1016/j.plaphy.2023.107932
Auxin-dependent regulation of growth via rolB-induced modulation of the ROS metabolism in the long-term cultivated pRiA4-transformed Rubiacordifolia L. calli.
Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia. Electronic address: gala-vera@mail.ru.; Federal Scientific Center of the East Asia Terrestrial Biodiversity of the Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia.
Gene transfer from Agrobacterium to plants is the best studied example of horizontal gene transfer (HGT) between prokaryotes and eukaryotes. The rol genes of A. rhizogenes (Rhizobium rhizogenes) provide uncontrolled root growth, or "hairy root" syndrome, the main diagnostic feature. In the present study, we investigated the stable pRiA4-transformed callus culture of Rubia cordifolia L. While untransformed callus cultures need PGRs (plant growth regulators) as an obligatory supplement, pRiA4 calli is able to achieve long-term PGR-free cultivation. For the first time, we described the pRiA4-transformed callus cultures' PGR-dependent ROS status, growth, and specialized metabolism. As we have shown, expression of the rolA and rolB but not the rolC genes is contradictory in a PGR-dependent manner. Moreover, a PGR-free pRiA4 transformed cell line is characterised as more anthraquinone (AQ) productive than an untransformed cell culture. These findings pertain to actual plant biotechnology: it could be the solution to troubles in choosing the best PGR combination for the cultivation of some rare, medicinal, and woody plants; wild-type Ri-plants and tissue cultures may become freed from legal controls on genetically modified organisms in the future. We propose possible PGR-dependent relationships between rolA and rolB as well as ROS signalling targets. The present study highlighted the high importance of the rolA gene in the regulation of combined rol gene effects and the large knowledge gap in rolA action.
PMID: 37557016
BMC Plant Biol , IF:4.215 , 2023 Sep , V23 (1) : P418 doi: 10.1186/s12870-023-04417-2
NLG1, encoding a mitochondrial membrane protein, controls leaf and grain development in rice.
Rice Research Institute of Shenyang Agricultural University/Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Shenyang, 110866, China.; State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China.; College of Life and Environmental Sciences, Hangzhou Normal University, 16 Xiasha Road, Hangzhou, 310036, China.; Rice Research Institute of Shenyang Agricultural University/Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Shenyang, 110866, China. qianqian188@hotmail.com.; State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China. qianqian188@hotmail.com.; Hainan Yazhou Bay Seed Laboratory, Sanya, Hainan, 572024, China. qianqian188@hotmail.com.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, 572024, China. qianqian188@hotmail.com.; State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China. hujiang588@163.com.
BACKGROUND: Mitochondrion is the key respiratory organ and participate in multiple anabolism and catabolism pathways in eukaryote. However, the underlying mechanism of how mitochondrial membrane proteins regulate leaf and grain development remains to be further elucidated. RESULTS: Here, a mitochondria-defective mutant narrow leaf and slender grain 1 (nlg1) was identified from an EMS-treated mutant population, which exhibits narrow leaves and slender grains. Moreover, nlg1 also presents abnormal mitochondria structure and was sensitive to the inhibitors of mitochondrial electron transport chain. Map-based cloning and transgenic functional confirmation revealed that NLG1 encodes a mitochondrial import inner membrane translocase containing a subunit Tim21. GUS staining assay and RT-qPCR suggested that NLG1 was mainly expressed in leaves and panicles. The expression level of respiratory function and auxin response related genes were significantly down-regulated in nlg1, which may be responsible for the declination of ATP production and auxin content. CONCLUSIONS: These results suggested that NLG1 plays an important role in the regulation of leaf and grain size development by maintaining mitochondrial homeostasis. Our finding provides a novel insight into the effects of mitochondria development on leaf and grain morphogenesis in rice.
PMID: 37689677
Tree Physiol , IF:4.196 , 2023 Sep , V43 (9) : P1641-1652 doi: 10.1093/treephys/tpad060
Comparative transcriptomics provides insights into the pathogenic immune response of brown leaf spots in weeping forsythia.
School of Pharmacy, Henan University, Kaifeng, North street of Jinming Road, Henan 475004, China.; Henan Province Engineering Research Center of High Value Utilization to Natural Medical Resource in Yellow River Basin, Kaifeng, North street of Jinming Road, Henan 475004, China.; School of Life Sciences, Henan University, Kaifeng, North street of Jinming Road, Henan 475004, China.; College of Life Science and Technology, Inner Mongolia Normal University, Huhehaote, Zhaowuda Road No. 81, China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, Dongxiaofu Road No. 1, China.
Weeping forsythia is an important ornamental, ecological and medicinal plant. Brown leaf spots limit the large-scale production of weeping forsythia as a medicinal crop. Alternaria alternata is a pathogen causing brown leaf spots in weeping forsythia; however, its pathogenesis and the immune response mechanisms of weeping forsythia remain unclear. In this study, we identified two mechanisms based on morphological anatomy, physiological indexes and gene expression analyses. Our results showed that A. alternata induced leaf stomata to open, invaded the mesophyll, dissolved the cell wall, destroyed the cell membrane and decreased the number of chloroplasts by up-regulating the expression of auxin-activated signaling pathway genes. Alternaria alternata also down-regulated iron-ion homeostasis and binding-related genes, which caused an increase in the levels of iron ions and reactive oxygen species in leaves. These processes eventually led to programmed cell death, destroying palisade and spongy tissues and causing the formation of iron rust spots. Alternaria alternata also caused defense and hypersensitive responses in weeping forsythia through signaling pathways mediated by flg22-like and elf18-like polypeptides, ethylene, H2O2 and bacterial secretion systems. Our study provides a theoretical basis for the control of brown leaf spots in weeping forsythia.
PMID: 37171622
FEMS Microbiol Ecol , IF:4.194 , 2023 Sep doi: 10.1093/femsec/fiad114
Plant growth Promoting activities of Pseudomonas sp. and Enterobacter sp. isolated from the rhizosphere of Vachellia gummifera in Morocco.
Centre de Biotechnologies Vegetales et Microbiennes, Biodiversite et Environnement, Faculty of sciences, Mohammed V University in Rabat, 4, Ibn Battouta Avenue, Rabat, Morocco.; Laboratoire de zoologie et de biologie generale, Faculty of sciences, Mohammed V University in Rabat, 4, Ibn Battouta Avenue, Rabat, Morocco.; Departamento de Microbiologia del Suelo y Sistemas Simbioticos Estacion Experimental del Zaidin, CSIC Apartado Postal 419, 18008, Granada, Spain.
The Moroccan endemic Vachellia gummifera grows wild under extreme desert conditions. This plant could be used as an alternative fodder for goats, and camels, in order to protect the Argan forests against overgrazing in Central and Southwestern Moroccan semi-arid areas. With the aim to improve the V. gummifera population's density in semi-arid areas, we proposed its inoculation with performing plant growth-promoting bacteria. Hence, 500 bacteria were isolated from the plant rhizosphere. From these, 291 isolates were retained for plant growth-promoting (PGP) activities assessment. Forty-four isolates showed the best phosphates solubilization potential, as well as siderophore and auxin production. The combination of REP-PCR (Repetitive Extragenic Palindromic-Polymerase Chain Reaction) fingerprinting, PGP activities, and phenotypic properties, allowed the selection of three strains for the inoculation experiments. The three selected strains' 16S rRNA sequencing showed that they are members of the Enterobacter and Pseudomonas genera. The inoculation with three strains had diverse effects on V. gummifera growth parameters. All single and combined inoculations improved the plant shoot weight by more than 200%, and the root length by up to 139%, while some combinations further improved protein and chlorophyll content, thereby improving the plant's forage value. The three selected strains constitute an effective inoculum for use in the arid and semi-arid zones of southern Morocco.
PMID: 37742210
Microorganisms , IF:4.128 , 2023 Sep , V11 (9) doi: 10.3390/microorganisms11092327
Role of Bacillus spp. Plant Growth Promoting Properties in Mitigating Biotic and Abiotic Stresses in Lowland Rice (Oryza sativa L.).
Institute of Agricultural Sciences in the Tropics and Subtropics (Hans-Ruthenberg-Institute), University of Hohenheim, Garbenstr. 13, D-70599 Stuttgart, Germany.; Department of Phytopathology, Institute of Phytomedicine, University of Hohenheim, Otto-Sander-Str. 5, D-70599 Stuttgart, Germany.
The ability of microorganisms to promote plant growth and mitigate abiotic and biotic stresses makes them an interesting tool for sustainable agriculture. Numerous studies aim to identify new, promising bacteria isolates. Traditional culture-based methods, which focus on selecting microorganisms with plant-growth-promoting traits, such as hormone production, nutrient solubilization, and antifungal properties, are widely used. This study aims to investigate the role of plant-growth-promoting properties in bacteria-mediated stress mitigation and the suitability of traditional culture-based methods as a screening tool for the identification of beneficial bacteria. To this end, we tested three endophytic Bacillus isolates, which have previously been shown to affect tolerance against iron toxicity in lowland rice, (a) for their effect on the resistance against brown spot disease, and (b) for plant-growth-promoting traits using common culture-based methods. Both B. pumilus isolates inhibited fungal growth in vitro and reduced brown spot disease in two of three rice cultivars in planta, although they tested negative for all plant-growth-promoting traits. While B. megaterium was negative for ACC deaminase activity and nutrient solubilization, it exhibited auxin production. Nevertheless, B. megaterium did not suppress brown spot disease in any of the three rice cultivars. This study shows that bacteria do not necessarily have to possess classical plant-growth-promoting properties in order to be beneficial to plants, and it emphasizes the limitation of common culture-based methods in effectively identifying beneficial bacteria. Moreover, our results highlight the significance of the interaction between bacteria and plant cultivars in determining the beneficial effects of Bacillus spp. on plants under biotic or abiotic stresses.
PMID: 37764171
Planta , IF:4.116 , 2023 Sep , V258 (5) : P89 doi: 10.1007/s00425-023-04246-5
Preserving root stem cell functionality under low oxygen stress: the role of nitric oxide and phytoglobins.
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.; Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.; Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. stasolla@ms.umanitoba.ca.
The preservation of quiescent center stem cell integrity in hypoxic roots by phytoglobins is exercised through their ability to scavenge nitric oxide and attenuate its effects on auxin transport and cell degradation. Under low oxygen stress, the retention or induction of phytoglobin expression maintains cell viability while loss or lack of induction of phytoglobin leads to cell degradation. Plants have evolved unique attributes to ensure survival in the environment in which they must exist. Common among the attributes is the ability to maintain stem cells in a quiescent (or low proliferation) state in unfriendly environments. From the seed embryo to meristematic regions of the plant, quiescent stem cells exist to regenerate the organism when environmental conditions are suitable to allow plant survival. Frequently, plants dispose of mature cells or organs in the process of acclimating to the stresses to ensure survival of meristems, the stem cells of which are capable of regenerating cells and organs that have been sacrificed, a feature not generally available to mammals. Most of the research on plant stress responses has dealt with how mature cells respond because of the difficulty of specifically examining plant meristem responses to stress. This raises the question as to whether quiescent stem cells behave in a similar fashion to mature cells in their response to stress and what factors within these critical cells determine whether they survive or degrade when exposed to environmental stress. This review attempts to examine this question with respect to the quiescent center (QC) stem cells of the root apical meristem. Emphasis is put on how varying levels of nitric oxide, influenced by the expression of phytoglobins, affect QC response to hypoxic stress.
PMID: 37759033
Planta , IF:4.116 , 2023 Sep , V258 (5) : P86 doi: 10.1007/s00425-023-04239-4
Arabidopsis root apical meristem survival during waterlogging is determined by phytoglobin through nitric oxide and auxin.
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.; Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Department of Botany and Microbiology, Faculty of Science, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt.; Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776, Warsaw, Poland.; Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. stasolla@ms.umanitoba.ca.
Over-expression of phytoglobin mitigates the degradation of the root apical meristem (RAM) caused by waterlogging through changes in nitric oxide and auxin distribution at the root tip. Plant performance to waterlogging is ameliorated by the over-expression of the Arabidopsis Phytoglobin 1 (Pgb1) which also contributes to the maintenance of a functional RAM. Hypoxia induces accumulation of ROS and damage in roots of wild type plants; these events were preceded by the exhaustion of the RAM resulting from the loss of functionality of the WOX5-expressing quiescent cells (QCs). These phenotypic deviations were exacerbated by suppression of Pgb1 and attenuated when the same gene was up-regulated. Genetic and pharmacological studies demonstrated that degradation of the RAM in hypoxic roots is attributed to a reduction in the auxin maximum at the root tip, necessary for the specification of the QC. This reduction was primarily caused by alterations in PIN-mediated auxin flow but not auxin synthesis. The expression and localization patterns of several PINs, including PIN1, 2, 3 and 4, facilitating the basipetal translocation of auxin and its distribution at the root tip, were altered in hypoxic WT and Pgb1-suppressing roots but mostly unchanged in those over-expressing Pgb1. Disruption of PIN1 and PIN2 signal in hypoxic roots suppressing Pgb1 initiated in the transition zone at 12 h and was specifically associated to the absence of Pgb1 protein in the same region. Exogenous auxin restored a functional RAM, while inhibition of the directional auxin flow exacerbated the degradation of the RAM. The regulation of root behavior by Pgb1 was mediated by nitric oxide (NO) in a model consistent with the recognized function of Pgbs as NO scavengers. Collectively, this study contributes to our understanding of the role of Pgbs in preserving root meristem function and QC niche during conditions of stress, and suggests that the root transition zone is most vulnerable to hypoxia.
PMID: 37747517
Planta , IF:4.116 , 2023 Sep , V258 (4) : P76 doi: 10.1007/s00425-023-04226-9
Regulation of early seedling establishment and root development in Arabidopsis thaliana by light and carbohydrates.
Instituto de Bioingenieria, Universidad Miguel Hernandez, 03202, Elche, Spain. tpasternak@umh.es.; Faculty for Biology, Institute of Biology II/Molecular Plant Physiology, University of Freiburg, 79104, Freiburg, Germany. tpasternak@umh.es.; Faculty for Biology, Institute of Biology II/Molecular Plant Physiology, University of Freiburg, 79104, Freiburg, Germany.; Centre for BioSystems Analysis, BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.; ScreenSYSGmbH, Engesserstr. 4a, Freiburg, 79108, Germany.; Instituto de Bioingenieria, Universidad Miguel Hernandez, 03202, Elche, Spain. jmperez@umh.es.
Root development is regulated by sucrose and light during early seedling establishment through changes in the auxin response and chromatin topology. Light is a key environmental signal that regulates plant growth and development. The impact of light on development is primarily analyzed in the above-ground tissues, but little is known about the mechanisms by which light shapes the architecture of underground roots. Our study shows that carbohydrate starvation during skotomorphogenesis is accompanied by compaction of nuclei in the root apical meristem, which prevents cell cycle progression and leads to irreversible root differentiation in the absence of external carbohydrates, as evidenced by the lack of DNA replication and increased numbers of nuclei with specific chromatin characteristics. In these conditions, induction of photomorphogenesis was unable to restore seedling growth, as overall root growth was compromised. The addition of carbohydrates, either locally or systemically by transferring seedlings to sugar-containing medium, led to the induction of adventitious root formation with rapid recovery of seedling growth. Conversely, transferring in vitro carbohydrate-grown seedlings from light to dark transiently promoted cell elongation and significantly reduced root meristem size, but did not primarily affect cell cycle kinetics. We show that, in the presence of sucrose, dark incubation does not affect zonation in the root apical meristem but leads to shortening of the proliferative and transition zones. Sugar starvation led to a rapid increase in lysine demethylation of histone H3 at position K9, which preceded a rapid decline in cell cycle activity and activation of cell differentiation. In conclusion, carbohydrates are required for cell cycle activity, epigenetics reprogramming and for postmitotic cell elongation and auxin-regulated response in the root apical meristem.
PMID: 37670114
Planta , IF:4.116 , 2023 Sep , V258 (4) : P75 doi: 10.1007/s00425-023-04230-z
Molecular understanding of anthocyanin biosynthesis activated by PAP1 and regulated by 2, 4-dichlorophenoxyacetic acid in engineered red Artemisia annua cells.
Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA.; Rice Research Institute, Sichuan Agricultural University, Chengdu, China.; Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA. dxie@ncsu.edu.
Eight promoters were cloned, from which AC and G-box cis-elements were identified. PAP1 enhanced the promoter activity. 2,4-D reduced the anthocyanin biosynthesis via downregulating the expression of the PAP1 transgene. Artemisia annua is an effective antimalarial medicinal crop. We have established anthocyanin-producing red cell cultures from this plant with the overexpression of Production of Anthocyanin Pigment 1 (PAP1) encoding a R2R3MYB transcription factor. To understand the molecular mechanism by which PAP1 activated the entire anthocyanin pathway, we mined the genomic sequences of A. annua and obtained eight promoters of the anthocyanin pathway genes. Sequence analysis identified four types of AC cis-elements from six promoters, the MYB response elements (MRE) bound by PAP1. In addition, six promoters were determined to have at least one G-box cis-element. Eight promoters were cloned for activity analysis. Dual luciferase assays showed that PAP1 significantly enhanced the promoting activity of seven promoters, indicating that PAP1 turned on the biosynthesis of anthocyanins via the activation of these pathway gene expression. To understand how 2,4-dichlorophenoxyacetic acid (2,4-D), an auxin, regulates the PAP1-activated anthocyanin biosynthesis, five different concentrations (0, 0.05, 0.5, 2.5, and 5 microM) were tested to characterize anthocyanin production and profiles. The resulting data showed that the concentrations tested decreased the fresh weight of callus growth, anthocyanin levels, and the production of anthocyanins per Petri dish. HPLC-qTOF-MS/MS-based profiling showed that these concentrations did not alter anthocyanin profiles. Real-time RT-PCR was completed to characterize the expression PAP1 and four representative pathway genes. The results showed that the five concentrations reduced the expression levels of the constitutive PAP1 transgene and three pathway genes significantly and eliminated the expression of the chalcone synthase gene either significantly or slightly. These data indicate that the constitutive PAP1 expression depends on gradients added in the medium. Based on these findings, the regulation of 2,4-D is discussed for anthocyanin engineering in red cells of A. annua.
PMID: 37668683
Genes (Basel) , IF:4.096 , 2023 Sep , V14 (9) doi: 10.3390/genes14091783
Comparative Genomics Reveals Novel Species and Insights into the Biotechnological Potential, Virulence, and Resistance of Alcaligenes.
Laboratorio de Quimica e Funcao de Proteinas e Peptideos, Centro de Biociencias e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, Brazil.
Alcaligenes is a cosmopolitan bacterial genus that exhibits diverse properties which are beneficial to plants. However, the genomic versatility of Alcaligenes has also been associated with the ability to cause opportunistic infections in humans, raising concerns about the safety of these microorganisms in biotechnological applications. Here, we report an in-depth comparative analysis of Alcaligenes species using all publicly available genomes to investigate genes associated with species, biotechnological potential, virulence, and resistance to multiple antibiotics. Phylogenomic analysis revealed that Alcaligenes consists of at least seven species, including three novel species. Pan-GWAS analysis uncovered 389 species-associated genes, including cold shock proteins (e.g., cspA) and aquaporins (e.g., aqpZ) found exclusively in the water-isolated species, Alcaligenes aquatilis. Functional annotation of plant-growth-promoting traits revealed enrichment of genes for auxin biosynthesis, siderophores, and organic acids. Genes involved in xenobiotic degradation and toxic metal tolerance were also identified. Virulome and resistome profiles provide insights into selective pressures exerted in clinical settings. Taken together, the results presented here provide the grounds for more detailed clinical and ecological studies of the genus Alcaligenes.
PMID: 37761923
Pestic Biochem Physiol , IF:3.963 , 2023 Sep , V195 : P105576 doi: 10.1016/j.pestbp.2023.105576
Multiple herbicide resistance in a Cyperus difformis population in rice field from China.
Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning 530004, China.; Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.; Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning 530004, China.; Guangxi Vocational University of Agriculture, Nanning 530007, China. Electronic address: hunanlijingbo@163.com.; Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China. Electronic address: wangyh1984@163.com.
Herbicide resistance is rapidly emerging in Cyperus difformis in rice fields across China. The response of a C. difformis population GX-35 was tested against five acetolactate synthase (ALS)-inhibiting herbicides, auxin herbicide MCPA and photosynthesis II (PSII)-inhibitor bentazone. Population GX-35 evolved multiple resistance to ALS-inhibiting herbicides (penoxsulam, bispyribac‑sodium, pyrazosulfuron-ethyl, halosulfuron-methly and imazapic) and auxin herbicide MCPA, with resistance levels of 140-, 1253-, 578-, 18-, 13-, and 21-fold, respectively, compared to the susceptible population. In this population, ALS gene expression was similar to that of the susceptible population. However, an Asp376Glu mutation in ALS gene was observed, leading to reduced inhibition of in-vitro ALS activities by five ALS-inhibiting herbicides. Furthermore, CYP71D8, CYP77A3, CYP78A5 and three ABC transporter genes (cluster-14412.23067, cluster-14412.25321, and cluster-14412.24716) over-expressed in absence of penoxsulam. On the other hand, an UGT73C1 and an ABC transporter (cluster-14412.25038) were induced by penoxsulam. Additionally, both over-expression and induction were observed for CYP74, CYP71A1, UGT88A1 and an ABC transporter (cluster-14412.21723). The GX-35 population has indeed evolved multiple herbicide resistance in China. Therefore, a diverse range of weed control tactics should be implemented in rice field.
PMID: 37666602
Plants (Basel) , IF:3.935 , 2023 Sep , V12 (18) doi: 10.3390/plants12183309
Effects and Mechanism Analysis of Non-Bagging and Bagging Cultivation on the Growth and Content Change of Specific Substances of Fuji Apple Fruit.
Shandong Institute of Pomology, Taian 271000, China.
The experiment was conducted at the Taidong Base of Shandong Institute of Pomology, Tai'an City, Shandong Province, China, from May to October 2022. Using Fuji Apple Tianhong.2/SH/Malus robusta (M. robusta) as experimental materials, the differences and mechanisms of the effects of non-bagging and bagging cultivation on the growth and changes in some substance content of Fuji apple fruits were studied. The results showed that compared with bagging, non-bagging cultivation increased single fruit weight and decreased fruit shape index, increased fruit sugar content, reduced acid content, and increased taste. It increased the content of vitamin C (VC) and protein in the fruit, increased the types and content of aromatic components in the fruit, significantly increased the activity of sugar- and acid-related enzymes, and improved the antioxidant capacity of the fruit. Compared to bagging cultivation, non-bagging cultivation improved the weight, taste (sugar acid ratio), and aroma of Fuji fruit, which is related to increasing the content of auxin (IAA), cytokinin (ZR), and salicylic acid (SA) and reducing the content of abscisic acid (ABA) in the fruit, as well as increasing the content of medium and trace elements calcium (Ca), iron (Fe), manganese (Mg), and boron (B). One of the mechanisms involved is the significant increase in gene expression related to phenylpropanoid biosynthesis, pentose and glucuronate interconversion, starch and sucrose metabolism, zeatin biosynthesis, microtubules, motor proteins microtubule movement, xyloglucan metabolic process, cell division, and peroxidase activity. In short, non-bagging cultivation is more conducive to improving the intrinsic quality and flavor development of Fuji apples, and one of the mechanisms is that non-bagging cultivation is beneficial for increasing the expression of related genes.
PMID: 37765473
Plants (Basel) , IF:3.935 , 2023 Sep , V12 (18) doi: 10.3390/plants12183284
Arabidopsis TGA256 Transcription Factors Suppress Salicylic-Acid-Induced Sucrose Starvation.
Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.; Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.; Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada.
Salicylic acid (SA) is produced by plants in response to pathogen infection. SA binds the NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPR) family of receptors to regulate both positive (NPR1) and negative (NPR3/4) plant immune responses by interacting with the clade II TGACG (TGA) motif-binding transcription factors (TGA2, TGA5, and TGA6). Here, we report that the principal metabolome-level response to SA treatment in Arabidopsis is a reduction in sucrose and other free sugars. We observed nearly identical effects in the tga256 triple mutant, which lacks all clade II TGA transcription factors. The tga256 mutant presents reduced leaf blade development and elongated hypocotyls, roots, and petioles consistent with sucrose starvation. No changes were detected in auxin levels, and mutant seedling growth could be restored to that of wild-type by sucrose supplementation. Although the retrograde signal 2-C-methyl-D-erythritol-2,4-cyclodiphosphate is known to stimulate SA biosynthesis and defense signaling, we detected no negative feedback by SA on this or any other intermediate of the 2-C-methyl-D-erythritol-4-phosphate pathway. Trehalose, a proxy for the sucrose regulator trehalose-6-phosphate (T6P), was highly reduced in tga256, suggesting that defense-related reductions in sugar availability may be controlled by changes in T6P levels. We conclude that the negative regulatory roles of TGA2/5/6 include maintaining sucrose levels in healthy plants. Disruption of TGA2/5/6-NPR3/4 inhibitory complexes by mutation or SA triggers sucrose reductions in Arabidopsis leaves, consistent with the 'pathogen starvation' hypothesis. These findings highlight sucrose availability as a mechanism by which TGA2/5/6 balance defense and development.
PMID: 37765448
Plants (Basel) , IF:3.935 , 2023 Sep , V12 (17) doi: 10.3390/plants12173171
Genome-Wide Identified MADS-Box Genes in Prunus campanulata 'Plena' and Theirs Roles in Double-Flower Development.
Wuhan Institute of Landscape Architecture, Wuhan 430081, China.; Wuhan Landscape Ecology Group Co., Ltd., Wuhan 430070, China.; School of Landscape Architecture, Beijing Forestry of University, Beijing 100083, China.
The MADS-box gene family plays key roles in flower induction, floral initiation, and floral morphogenesis in flowering plants. To understand their functions in the double-flower formation of Prunus campanulata 'Plena' (hereafter referred to as PCP), which is an excellent flowering cherry cultivar, we performed genome-wide identification of the MADS-box gene family. In this study, 71 MADS-box genes were identified and grouped into the Malpha, Mbeta, Mgamma and MIKC subfamilies according to their structures and phylogenetic relationships. All 71 MADS-box genes were located on eight chromosomes of PCP. Analysis of the cis-acting elements in the promoter region of MADS-box genes indicated that they were associated mainly with auxin, abscisic acid, gibberellin, MeJA (methyl jasmonate), and salicylic acid responsiveness, which may be involved in floral development and differentiation. By observing the floral organ phenotype, we found that the double-flower phenotype of PCP originated from petaloid stamens. The analysis of MIKC-type MADS-box genes in PCP vegetative and floral organs by qRT-PCR revealed six upregulated genes involved in petal development and three downregulated genes participating in stamen identity. Comparative analysis of petaloid stamens and normal stamens also indicated that the expression level of the AG gene (PcMADS40) was significantly reduced. Thus, we speculated that these upregulated and downregulated genes, especially PcMADS40, may lead to petaloid stamen formation and thus double flowers. This study lays a theoretical foundation for MADS-box gene identification and classification and studying the molecular mechanism underlying double flowers in other ornamental plants.
PMID: 37687417
Plants (Basel) , IF:3.935 , 2023 Sep , V12 (17) doi: 10.3390/plants12173148
Humic Substances Isolated from Recycled Biomass Trigger Jasmonic Acid Biosynthesis and Signalling.
Nucleo de Desenvolvimento de Insumos Biologicos para Agricultura (NUDIBA), Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Ave Alberto Lamego 2000, Campos dos Goytacazes 28013-602, Brazil.; Departamento de Ciencias Biologicas, Escola Superior de Agricultura ''Luiz de Queiroz'' (ESALQ), Universidade de Sao Paulo (USP), Piracicaba 05508-090, Brazil.; Centro Interdipartimentale di Ricerca CERMANU, Universita di Napoli Federico II, Via Universita 100, 80055 Portici, Italy.
Intensive agriculture maintains high crop yields through chemical inputs, which are well known for their adverse effects on environmental quality and human health. Innovative technologies are required to reduce the risk generated by the extensive and harmful use of pesticides. The plant biostimulants made from humic substances isolated from recyclable biomass offer an alternative approach to address the need for replacing conventional agrochemicals without compromising the crop yield. The stimulatory effects of humic substances are commonly associated with plant hormones, particularly auxins. However, jasmonic acid (JA) is crucial metabolite in mediating the defence responses and governing plant growth and development. This work aimed to evaluate the changes in the biosynthesis and signalling pathway of JA in tomato seedlings treated with humic acids (HA) isolated from vermicompost. We use the tomato model system cultivar Micro-Tom (MT) harbouring a reporter gene fused to a synthetic promoter that responds to jasmonic acid (JERE::GUS). The transcript levels of genes involved in JA generation and activity were also determined using qRT-PCR. The application of HA promoted plant growth and altered the JA status, as revealed by both GUS and qRT-PCR assays. Both JA enzymatic synthesis (LOX, OPR3) and JA signalling genes (JAZ and JAR) were found in higher transcription levels in plants treated with HA. In addition, ethylene (ETR4) and auxin (ARF6) signalling components were positively modulated by HA, revealing a hormonal cross-talk. Our results prove that the plant defence system linked to JA can be emulated by HA application without growth inhibition.
PMID: 37687394
IUBMB Life , IF:3.885 , 2023 Oct , V75 (10) : P880-892 doi: 10.1002/iub.2761
The long intergenic noncoding RNA ARES modulates root architecture in Arabidopsis.
Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Universite Evry, Universite Paris-Saclay, Gif-sur-Yvette, France.; Institute of Plant Sciences Paris-Saclay IPS2, Universite de Paris, Gif-sur-Yvette, France.; Instituto de Agrobiotecnologia del Litoral, CONICET, Universidad Nacional del Litoral, Santa Fe, Argentina.; Institute for Signals, Systems and Computational Intelligence, sinc(i) CONICET-Universidad Nacional del Litoral, Santa Fe, Argentina.
Long noncoding RNAs (lncRNAs) have emerged as important regulators of gene expression in plants. They have been linked to a wide range of molecular mechanisms, including epigenetics, miRNA activity, RNA processing and translation, and protein localization or stability. In Arabidopsis, characterized lncRNAs have been implicated in several physiological contexts, including plant development and the response to the environment. Here we searched for lncRNA loci located nearby key genes involved in root development and identified the lncRNA ARES (AUXIN REGULATOR ELEMENT DOWNSTREAM SOLITARYROOT) downstream of the lateral root master gene IAA14/SOLITARYROOT (SLR). Although ARES and IAA14 are co-regulated during development, the knockdown and knockout of ARES did not affect IAA14 expression. However, in response to exogenous auxin, ARES knockdown impairs the induction of its other neighboring gene encoding the transcription factor NF-YB3. Furthermore, knockdown/out of ARES results in a root developmental phenotype in control conditions. Accordingly, a transcriptomic analysis revealed that a subset of ARF7-dependent genes is deregulated. Altogether, our results hint at the lncRNA ARES as a novel regulator of the auxin response governing lateral root development, likely by modulating gene expression in trans.
PMID: 37409758
Gene , IF:3.688 , 2023 Sep , V888 : P147758 doi: 10.1016/j.gene.2023.147758
Cloning and functional analysis prohibitins protein-coding gene EuPHB1 in Eucommia ulmoides Oliver.
The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang 550025, China.; Guizhou Plant Conservation Technology Center, Biotechnology Institute of Guizhou, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China. Electronic address: dgzhao@gzu.edu.cn.
As multifunctional proteins, prohibitins(PHBs) participate in many cellular processes and play essential roles in organisms. In this study, using rapid amplification of cDNA end (RACE) technology, EuPHB1 was cloned from Eucommia ulmoides Oliver (E. ulmoides). A subcellular localization assay preliminarily located EuPHB1 in mitochondria. Then EuPHB1 was transformed into tobacco, and phenotype analyses showed that overexpression of EuPHB1 caused leaves to become chlorotic and shrivel. Furthermore, genes related to hormone and auxin signal transduction, auxin binding, and transport, such as ethylene-responsive transcription factor CRF4-like and ABC transporter B family member 11-like, were significantly inhibited in response to EuPHB1 overexpression. Its overexpression disturbs the original signal transduction pathway, thus causing the corresponding phenotypic changes in transgenic tobacco. Indeed, such overexpression caused fading of palisade tissue and an increase in the number of certain mesophyll cells. It also increased adenosine triphosphate (ATP) synthase activity, mitochondrial membrane potential, ATP content, and reactive oxygen species (ROS) levels in cells. Our results suggest that EuPHB1 expression promotes cellular energy metabolism by accelerating the oxidative phosphorylation of the mitochondrial respiratory chain. Elevated levels of EuPHB1 in the mitochondria, which helps supply the extra energy required to support rapid rates of cell division.
PMID: 37661028
J Sci Food Agric , IF:3.638 , 2023 Oct , V103 (13) : P6640-6653 doi: 10.1002/jsfa.12760
Gamma irradiation delays tomato (Solanum lycopersicum) ripening by inducing transcriptional changes.
Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Republic of Korea.; Department of Food Science and Technology, Graduate School of Chonnam National University, Gwangju, Republic of Korea.; Center for Industrialization of Agricultural and Livestock Microorganisms, Jeongeup-si, Republic of Korea.
BACKGROUND: Tomato (Solanum lycopersicum) has a relatively short shelf life as a result of rapid ripening, limiting its transportability and marketability. Recently, gamma irradiation has emerged as a viable method for delaying tomato fruit ripening. Although few studies have shown that gamma irradiation delays the ripening of tomatoes, the underlying mechanism remains unknown. Therefore, the present study aimed to examine the effects of gamma irradiation on tomato fruit ripening and the underlying mechanisms using transcriptomics. RESULTS: Following gamma irradiation, the total microbial count, weight loss, and decay rate of tomatoes significantly reduced during storage. Furthermore, the redness (a*), color change (∆E), and lycopene content of gamma-irradiated tomatoes decreased in a dose-dependent manner during storage. Moreover, gamma irradiation significantly upregulated the expression levels of genes associated with DNA, chloroplast, and oxidative damage repairs, whereas those of ethylene and auxin signaling-, ripening-, and cell wall metabolism-related, as well as carotenoid genes, were downregulated. CONCLUSION: Gamma irradiation effectively delayed ripening by downregulating the expression of ripening-related genes and inhibiting microbial growth, which prevented decay and prolonged the shelf life of tomatoes. (c) 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
PMID: 37267467
Protoplasma , IF:3.356 , 2023 Sep , V260 (5) : P1389-1405 doi: 10.1007/s00709-023-01855-5
Genome-wide investigation of ARF transcription factor gene family and its responses to abiotic stress in Coix (Coix lacryma-jobi L.).
Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, Zhejiang, China.; Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China.; Songyang Institute of Zhejiang Chinese Medical University, Lishui, 323400, China.; State Key Laboratory of Dao-Di Herbs, Beijng, 100700, China.; Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, Zhejiang, China. wangdk@zstu.edu.cn.
Auxin response factor (ARF) is an important transcription factor that regulates the expression of auxin-responsive genes by direct binding to their promoters, which play a central role in plant growth, development, and response to abiotic stresses. The availability of the entire Coix (Coix lacryma-jobi L.) genome sequence provides an opportunity to investigate the characteristics and evolutionary history of the ARF gene family in this medicine and food homology plant for the first time. In this study, a total of 27 ClARF genes were identified based on the genome-wide sequence of Coix. Twenty-four of the 27 ClARF genes were unevenly distributed on 8 chromosomes except Chr 4 and 10, and the remaining three genes (ClARF25-27) were not assigned to any chromosome. Most of the ClARF proteins were predicted to be localized to the nucleus, except ClARF24, which was localized to both the plasma membrane and nucleus. Twenty-seven ClARFs were clustered into six subgroups based on the phylogenetic analysis. Duplication analysis showed that segmental duplication, rather than tandem duplications promoting the expansion of the ClARF gene family. Synteny analysis showed that purifying selection might have been a primary driving force in the development of the ARF gene family in Coix and other investigated cereal plants. The prediction of the cis element of the promoter showed that 27 ClARF genes contain several stress response elements, suggesting that ClARFs might be involved in the abiotic stress response. Expression profile analysis shows that 27 ClARF genes were all expressed in the root, shoot, leaf, kernel, glume, and male flower of Coix with varying expression levels. Furthermore, qRT-PCR analyses revealed that the majority of ClARFs members were upregulated or downregulated in response to hormone treatment and abiotic stress. The current study expands our understanding of the functional roles of ClARFs in stress responses and provides basic information for the ClARF genes.
PMID: 37041371
G3 (Bethesda) , IF:3.154 , 2023 Aug doi: 10.1093/g3journal/jkad197
Genetic and Transcriptomic Dissection of Host Defense to Goss's Bacterial Wilt and Leaf Blight of Maize.
Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA.; Corteva Agriscience, Johnston, IA, 50131, USA.; Department of Horticulture and Natural Resources, Kansas State University, Manhattan, KS, 66506, USA.; Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA, 50010, USA.; Department of Plant Pathology, University of Florida, Gainesville, FL, 32611, USA.; Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Goss's wilt, caused by the Gram-positive actinobacterium Clavibacter nebraskensis, is an important bacterial disease of maize. The molecular and genetic mechanisms of resistance to the bacterium, or, in general, Gram-positive bacteria causing plant diseases, remain poorly understood. Here, we examined the genetic basis of Goss's wilt through differential gene expression, standard genome-wide association mapping (GWAS), extreme phenotype (XP) GWAS using highly resistant (R) and highly susceptible (S) lines, and quantitative trait locus (QTL) mapping using three bi-parental populations, identifying eleven disease association loci. Three loci were validated using near-isogenic lines or recombinant inbred lines. Our analysis indicates that Goss's wilt resistance is highly complex and major resistance genes are not commonly present. RNA sequencing of samples separately pooled from R and S lines with or without bacterial inoculation was performed, enabling identification of common and differential gene responses in R and S lines. Based on expression, in both R and S lines, the photosynthesis pathway was silenced upon infection, while stress-responsive pathways and phytohormone pathways, namely, abscisic acid, auxin, ethylene, jasmonate, and gibberellin, were markedly activated. In addition, sixty-five genes showed differential responses (up- or down-regulated) to infection in R and S lines. Combining genetic mapping and transcriptional data, individual candidate genes conferring Goss's wilt resistance were identified. Collectively, aspects of the genetic architecture of Goss's wilt resistance were revealed, providing foundational data for mechanistic studies.
PMID: 37652038
Plant Biol (Stuttg) , IF:3.081 , 2023 Oct , V25 (6) : P981-993 doi: 10.1111/plb.13565
Relationship between seasonal variation in isoprene emission and plant hormone profiles in the tropical plant 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.; Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan.; Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, China.; Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan.
In Ficus septica, the short-term control of isoprene production and, therefore, isoprene emission has been linked to the hormone balance between auxin (IAA) and jasmonic acid (JA). However, the relationship between long-term changes in isoprene emission and that of plant hormones remains unknown. This study tracked isoprene emissions from F. septica leaves, plant hormone concentrations and signalling gene expression, MEP pathway metabolite concentrations, and related enzyme gene expression for 1 year in the field to better understand the role of plant hormones and their long-term control. Seasonality of isoprenes was mainly driven by temperature- and light-dependent variations in substrate availability through the MEP route, as well as transcriptional and post-transcriptional control of isoprene synthase (IspS). Isoprene emissions are seasonally correlated with plant hormone levels. This was especially evident in the cytokinin profiles, which decreased in summer and increased in winter. Only 4-hydroxy-3-methylbut-2-butenyl-4-diphosphate (HMBDP) exhibited a positive connection with cytokinins among the MEP metabolites examined, suggesting that HMBDP and its biosynthetic enzyme, HMBDP synthase (HDS), play a role in channelling of MEP pathway metabolites to cytokinin production. Thus, it is probable that cytokinins have potential feed-forward regulation of isoprene production. Under long-term natural conditions, the hormonal balance of IAA/JA-Ile was not associated with IspS transcripts or isoprene emissions. This study builds on prior work by revealing differences between short- and long-term hormonal modulation of isoprene emissions in the tropical tree F. septica.
PMID: 37565537
Plant Direct , IF:3.038 , 2023 Sep , V7 (9) : Pe528 doi: 10.1002/pld3.528
Hormonal and proteomic analyses of southern blight disease caused by Athelia rolfsii and root chitosan priming on Cannabis sativa in an in vitro hydroponic system.
School of BioSciences University of Melbourne Melbourne Victoria Australia.; Mass Spectrometry and Proteomics Facility, Bio21 Molecular Science and Biotechnology Institute University of Melbourne Melbourne Victoria Australia.; Cannabis and Biostimulants Research Group Pty Ltd Melbourne Victoria Australia.; Australian National Phenome Centre Murdoch University Perth Western Australia Australia.
Southern blight disease, caused by the fungal pathogen Athelia rolfsii, suppresses plant growth and reduces product yield in Cannabis sativa agriculture. Mechanisms of pathology of this soil-borne disease remain poorly understood, with disease management strategies reliant upon broad-spectrum antifungal use. Exposure to chitosan, a natural elicitor, has been proposed as an alternative method to control diverse fungal diseases in an eco-friendly manner. In this study, C. sativa plants were grown in the Root-TRAPR system, a transparent hydroponic growth device, where plant roots were primed with .2% colloidal chitosan prior to A. rolfsii inoculation. Both chitosan-primed and unprimed inoculated plants displayed classical symptoms of wilting and yellowish leaves, indicating successful infection. Non-primed infected plants showed increased shoot defense responses with doubling of peroxidase and chitinase activities. The levels of growth and defense hormones including auxin, cytokinin, and jasmonic acid were increased 2-5-fold. In chitosan-primed infected plants, shoot peroxidase activity and phytohormone levels were decreased 1.5-4-fold relative to the unprimed infected plants. When compared with shoots, roots were less impacted by A. rolfsii infection, but the pathogen secreted cell wall-degrading enzymes into the root-growth solution. Chitosan priming inhibited root growth, with root lengths of chitosan-primed plants approximately 65% shorter than the control, but activated root defense responses, with root peroxidase activity increased 2.7-fold along with increased secretion of defense proteins. The results suggest that chitosan could be an alternative platform to manage southern blight disease in C. sativa cultivation; however, further optimization is required to maximize effectiveness of chitosan.
PMID: 37692128
PeerJ , IF:2.984 , 2023 , V11 : Pe15941 doi: 10.7717/peerj.15941
Identification and expression analysis of the small auxin-up RNA (SAUR) gene family in Lycium ruthenicum.
State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating, Gansu Desert Control Research Institute, Lanzhou, China.; Hubei Engineering University, Xiaogan, China.
The plant hormone auxin regulates numerous aspects of plant growth and development, and small auxin-up RNA (SAUR) is the largest family of early auxin response genes in higher plants. SAUR has been implicated in the regulation of multiple biological processes. However, no comprehensive analysis of SAUR genes has been reported in Lycium ruthenicum. L. ruthenicum is a thorny shrub with very pronounced salt and drought tolerance, and studies have shown that stem thorns are related to drought tolerance in L. ruthenicum. In this study, the identification, phylogenetic analysis, and conserved motif prediction of SAUR genes were extensively explored. Furthermore, the tissue expression patterns of selected SAUR genes were assayed with quantitative real-time polymerase chain reaction (RT-qPCR). A total of 33 putative LrSAURs were identified and divided into three clusters in a phylogenetic tree of L. ruthenicum. MEME analysis identified 10 motifs in L. ruthenicum, and the results suggested that motif 1 and motif 3 were widely distributed. Analyzing the transcriptome data of stem thorns at four developmental stages indicated that LrSAURs were differentially expressed in L. ruthenicum, and could be divided into six expression patterns. The RT-qPCR analysis of 21 genes showed that LrSAUR2, LrSAUR8, LrSAUR9, LrSAUR11, LrSAUR12, and LrSAUR19 were mainly expressed in stems and stem thorns, and may be related to stem thorn development.
PMID: 37701838
Mol Biotechnol , IF:2.695 , 2023 Sep , V65 (9) : P1414-1420 doi: 10.1007/s12033-023-00653-x
Loss-of-Function Mutation of ACTIN-RELATED PROTEIN 6 (ARP6) Impairs Root Growth in Response to Salinity Stress.
Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Vietnam.; National Institute of Medicinal Materials, Hanoi, Vietnam.; Faculty of Biotechnology, Ho Chi Minh City Open University, 97 Vo Van Tan Street, District 3, Ho Chi Minh, Vietnam.; Faculty of Biotechnology, Ho Chi Minh City Open University, 97 Vo Van Tan Street, District 3, Ho Chi Minh, Vietnam. nguyen.nhoai@ou.edu.vn.
H2A.Z-containing nucleosomes have been found to function in various developmental programs in Arabidopsis (e.g., floral transition, warm ambient temperature, and drought stress responses). The SWI2/SNF2-Related 1 Chromatin Remodeling (SWR1) complex is known to control the deposition of H2A.Z, and it has been unraveled that ACTIN-RELATED PROTEIN 6 (ARP6) is one component of this SWR1 complex. Previous studies showed that the arp6 mutant exhibited some distinguished phenotypes such as early flowering, leaf serration, elongated hypocotyl, and reduced seed germination rate in response to osmotic stress. In this study, we aimed to investigate the changes of arp6 mutant when the plants were grown in salt stress condition. The phenotypic observation showed that the arp6 mutant was more sensitive to salt stress than the wild type. Upon salt stress condition, this mutant exhibited attenuated root phenotypes such as shorter primary root length and fewer lateral root numbers. The transcript levels of stress-responsive genes, ABA INSENSITIVE 1 (ABI1) and ABI2, were found to be impaired in the arp6 mutant in comparison with wild-type plants in response to salt stress. In addition, a meta-analysis of published data indicated a number of genes involved in auxin response were induced in arp6 mutant grown in non-stress condition. These imply that the loss of H2A.Z balance (in arp6 mutant) may lead to change stress and auxin responses resulting in alternative root morphogenesis upon both normal and salinity stress conditions.
PMID: 36627550
Dose Response , IF:2.658 , 2023 Jul-Sep , V21 (3) : P15593258231198974 doi: 10.1177/15593258231198974
Valorization of Baker Yeast Industry Waste in Agriculture by Improving Germination and Growth of Barley and Pea.
Laboratory of Functional Physiology and Valorization of Bio resources, High Institute of Biotechnology of Beja, University of Jendouba, Beja, Tunisia. RINGGOLD: 243330; Vitroplant Society, Route el Mahfoura, Manouba, Tunisia.; G-TEX B CORPORATION SARL, Mahdia, Tunisia.; Biology Department, Faculty of Sciences and Arts of Muhayil Asir, King Khaled University, Muhayil Asir, Saudi Arabia.
Industrial waste still present an environmental danger for the nature and survival of all living beings. Among these toxic products, the focus has been on liquid effluents from the baker's yeast industry that cause real environmental problems mainly due to their pollutant load and the release of unpleasant odors. In order to minimize these hazards and to take advantage of these wastes for the sake of our environment, the present work consists on valorizing effluents from the baker's yeast industry on barley (Hordeum vulgare) and pea (Pisum sativum), two important agricultural products of Tunisian north-west. Results showed that this waste is characterized by its richness in organic matter, and the presence of proteins traces with high chemical and biochemical oxygen demand (COD and BOD(5)) values. Diluted effluent at a dose of 2.5 mg/g significantly improves germination of both plant seeds by germination index (GI) calculation, to reach a maximum of 190 +/- 17% and 150 +/- 14% for barley and pea, respectively. In fertigation experiment, the use of a lower dose of .62 mg/g of diluted effluent promotes plant length to reach 52 +/- 4 cm and 45 +/- 1.4 cm, respectively, for H. vulgare and P. sativum. Gas chromatography coupled to mass spectrometry (GC-MS) analysis after derivatization showed significant enhancement of auxin production in pea treated with .62 mg/g of cream compared to control with a concentration of 10.60 +/- .81 and 8.16 +/- .43 ng/gFW, respectively. In another experiment, the irrigation of pea plants with furfural, as major compound of cream, promotes length and auxin production to reach 9.89 +/- .56 ng/gFW for a furfural dose of .31 mg/g. This leads us to valorize baker's yeast effluent as an environment-friendly natural product in pea and barley agricultural and give insight to its mode of action.
PMID: 37667682
J Plant Res , IF:2.629 , 2023 Sep doi: 10.1007/s10265-023-01494-0
Plasmodesmata callose binding protein 2 contributes to the regulation of cambium/phloem formation and auxin response during the tissue reunion process in incised Arabidopsis stem.
Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.; Department of Biosciences, Teikyo University, Utsunomiya, Tochigi, 320-8551, Japan.; Advanced Instrumental Analysis Center, Teikyo University, Utsunomiya, Tochigi, 320-8551, Japan.; Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.; Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan. iwai.hiroaki.gb@u.tsukuba.ac.jp.
Plants are exposed to a variety of biotic and abiotic stresses, including wounding at the stem. The healing process (tissue reunion) begins immediately after stem wounding. The plant hormone auxin plays an important role during tissue reunion. In decapitated stems, auxin transport from the shoot apex is reduced and tissue reunion does not occur but is restored by application of indole-3-acetic acid (IAA). In this study, we found that plasmodesmata callose binding protein 2 (PDCB2) affects the expansion of the cambium/phloem region via changes in auxin response during the process of tissue reunion. PDCB2 was expressed in the cortex and endodermis on the incised side of stems 1-3 days after incision. PDCB2-knockout plants showed reduced callose deposition at plasmodesmata and DR5::GUS activity in the endodermis/cortex in the upper region of the incision accompanied by an increase in size of the cambium/phloem region during tissue reunion. In addition, PIN(PIN-FORMED)3, which is involved in lateral auxin transport, was induced by auxin in the cambium/phloem and endodermis/cortex in the upper part of the incision in wild type, but its expression of PIN3 was decreased in pdcb2 mutant. Our results suggest that PDCB2 contributes to the regulation of cambium/phloem development via auxin response.
PMID: 37707645
J Plant Res , IF:2.629 , 2023 Sep , V136 (5) : P769-780 doi: 10.1007/s10265-023-01476-2
Rhizosphere frame system enables nondestructive live-imaging of legume-rhizobium interactions in the soil.
Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan.; Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan. onko@affrc.go.jp.
Most plants interact with various soil microorganisms as they grow through the soil. Root nodule symbiosis by legumes and rhizobia is a well-known phenomenon of plant-microbe interactions in the soil. Although microscopic observations are useful for understanding the infection processes of rhizobia, nondestructive observation methods have not been established for monitoring interactions between rhizobia and soil-grown roots. In this study, we constructed Bradyrhizobium diazoefficiens strains that constitutively express different fluorescent proteins, which allows identification of tagged rhizobia by the type of fluorophores. In addition, we constructed a plant cultivation device, Rhizosphere Frame (RhizoFrame), which is a soil-filled container made of transparent acrylic plates that allows observation of roots growing along the acrylic plates. Combining fluorescent rhizobia with RhizoFrame, we established a live imaging system, RhizoFrame system, that enabled us to track the nodulation processes with fluorescence stereomicroscope while retaining spatial information about roots, rhizobia, and soil. Mixed inoculation with different fluorescent rhizobia using RhizoFrame enabled the visualization of mixed infection of a single nodule with two strains. In addition, observation of transgenic Lotus japonicus expressing auxin-responsive reporter genes indicated that RhizoFrame system could be used for a real-time and nondestructive reporter assay. Thus, the use of RhizoFrame system is expected to enhance the study of the spatiotemporal dynamics of plant-microbe interactions in the soil.
PMID: 37402088
Arch Microbiol , IF:2.552 , 2023 Sep , V205 (9) : P324 doi: 10.1007/s00203-023-03657-y
Planobacterium oryzisoli sp. nov., a novel bacterium isolated from roots of rice plant.
Department of Life Science, Dongguk University-Seoul, Goyang, 10326, South Korea.; Department of Life Science, Dongguk University-Seoul, Goyang, 10326, South Korea. tseo@dongguk.edu.
A Gram-negative, aerobic, short rod-shaped, non-motile, non-spore forming bacterium, designated strain GCR5(T), was isolated from soil of paddy field. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GCR5(T) belongs to the genus Planobacterium and is related to Planobacterium taklimakanense NCTC 13490( T) (96.1%, 16S rRNA gene sequence similarity). Colonies on R2A were white but they turn into bright yellow after exponential growth. They produce carotenoid pigment after 5-6 days of incubation, before that carotenoid pigment was not found. The major isoprenoid quinone was MK-6, and major cellular fatty acids were iso-C(15:0), anteiso-C(15:0) and iso-C(17:0) 3OH. Polar lipids include phosphatidylethanolamine, three unidentified phosphoglycolipids, three unidentified glycolipids, one unidentified aminophosphoglycolipid and five unidentified polar lipids. The strain GCR5(T) was found to have a 2,106,200 bp linear genome with G + C content of 43.7%. The ANI, dDDH and AAI values between the strain GCR5(T) and the type strains of phylogenetically related species were 60.2-71.1%, 19-24.3%, and 60.2-69.6%, respectively. The strain designated GCR5(T) produced indole acetic acid (IAA) in the presence of tryptophan only, and auxin responsive genes and tryptophan biosynthesis genes were found in its genome. Based on its polyphasic characteristics, strain GCR5(T) represents a novel species within the genus Planobacterium, for which the name Planobacterium oryzisoli sp. nov. was proposed. The type strain is GCR5(T) (= KCTC 82713( T) = TISTR 2996( T) = TBRC 15746( T)).Repositories: The draft genome and 16S rRNA gene sequences of strain GCR5(T) have been deposited at GenBank/EMBL/DDBJ under accession numbers JADKYY000000000 and MN955408, respectively.
PMID: 37656250
3 Biotech , IF:2.406 , 2023 Oct , V13 (10) : P336 doi: 10.1007/s13205-023-03751-4
Nanoparticle-mediated amelioration of drought stress in plants: a systematic review.
Department of Plant Sciences, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal, 576104 Karnataka India. GRID: grid.411639.8. ISNI: 0000 0001 0571 5193; Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal, 576104 Karnataka India. GRID: grid.411639.8. ISNI: 0000 0001 0571 5193; Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal, 576104 Karnataka India. GRID: grid.411639.8. ISNI: 0000 0001 0571 5193; Department of Public Health Genomics, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal, 576104 Karnataka India. GRID: grid.411639.8. ISNI: 0000 0001 0571 5193
Drought stress remains one of the most detrimental environmental constraints that hampers plant growth and development resulting in reduced yield and leading to economic losses. Studies have highlighted the beneficial role of carbon-based nanomaterials (NMs) such as multiwalled carbon nanotubes (MWNTs), single-walled carbon nanotubes (SWNTs), graphene, fullerene, and metal-based nanoparticles (NPs) (Ag, Au, Cu, Fe(2)O(3), TiO(2), and ZnO) in plants under unfavorable conditions such as drought. NPs help plants cope with drought by improving plant growth indices and enhancing biomass. It improves water and nutrient uptake and utilization. It helps retain water by altering the cell walls and regulating stomatal closure. The photosynthetic parameters in NP-treated plants reportedly improved with the increase in pigment content and rate of photosynthesis. Due to NP exposure, the activation of enzymatic and nonenzymatic antioxidants has reportedly improved. These antioxidants play a significant role in the defense system against stress. Studies have reported the accumulation of osmolytes and secondary metabolites. Osmolytes scavenge reactive oxygen species, which can cause oxidative stress in plants. Secondary metabolites are involved in the water retention process, thus improving plant coping strategies with stress. The deleterious effects of drought stress are alleviated by reducing malondialdehyde resulting from lipid peroxidation. Reactive oxygen species accumulation is also controlled with NP treatment. Furthermore, NPs have been reported to regulate the expression of drought-responsive genes and the biosynthesis of phytohormones such as abscisic acid, auxin, gibberellin, and cytokinin, which help plants defend against drought stress. This study reviewed 72 journal articles from 192 Google Scholar, ScienceDirect, and PubMed papers. In this review, we have discussed the impact of NP treatment on morphological, physio-biochemical, and molecular responses in monocot and dicot plants under drought conditions with an emphasis on NP uptake, transportation, and localization.
PMID: 37693636
3 Biotech , IF:2.406 , 2023 Sep , V13 (9) : P290 doi: 10.1007/s13205-023-03709-6
Recent advances in auxin biosynthesis and homeostasis.
Department of Biotechnology, School of Life Sciences, Pondicherry University, Kalapet, Pondicherry, 605014 India. GRID: grid.412517.4. ISNI: 0000 0001 2152 9956; Puducherry, India.
The plant proliferation is linked with auxins which in turn play a pivotal role in the rate of growth. Also, auxin concentrations could provide insights into the age, stress, and events leading to flowering and fruiting in the sessile plant kingdom. The role in rejuvenation and plasticity is now evidenced. Interest in plant auxins spans many decades, information from different plant families for auxin concentrations, transcriptional, and epigenetic evidences for gene regulation is evaluated here, for getting an insight into pattern of auxin biosynthesis. This biosynthesis takes place via an tryptophan-independent and tryptophan-dependent pathway. The independent pathway initiated before the tryptophan (trp) production involves indole as the primary substrate. On the other hand, the trp-dependent IAA pathway passes through the indole pyruvic acid (IPyA), indole-3-acetaldoxime (IAOx), and indole acetamide (IAM) pathways. Investigations on trp-dependent pathways involved mutants, namely yucca (1-11), taa1, nit1, cyp79b and cyp79b2, vt2 and crd, and independent mutants of tryptophan, ins are compiled here. The auxin conjugates of the IAA amide and ester-linked mutant gh3, iar, ilr, ill, iamt1, ugt, and dao are remarkable and could facilitate the assimilation of auxins. Efforts are made herein to provide an up-to-date detailed information about biosynthesis leading to plant sustenance. The vast information about auxin biosynthesis and homeostasis is consolidated in this review with a simplified model of auxin biosynthesis with keys and clues for important missing links since auxins can enable the plants to proliferate and override the environmental influence and needs to be probed for applications in sustainable agriculture. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-023-03709-6.
PMID: 37547917
Mol Biol Rep , IF:2.316 , 2023 Oct , V50 (10) : P7995-8003 doi: 10.1007/s11033-023-08631-x
Transcriptome analysis reveals the mechanism of different fruit appearance between apricot (Armeniaca vulgaris Lam.) and its seedling.
Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan, 750021, China.; School of Life Science, Ningxia University, Yinchuan, 750021, China.; Ningxia Facility Horticulture Engineering Technology Center, Yinchuan, 750021, China.; Technological Innovation Center of Horticulture (Ningxia University), Ningxia Hui Autonomous Region, Yinchuan, 750021, China.; Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan, 750021, China. zhangguangdi333909@sina.com.; Ningxia Facility Horticulture Engineering Technology Center, Yinchuan, 750021, China. zhangguangdi333909@sina.com.; Technological Innovation Center of Horticulture (Ningxia University), Ningxia Hui Autonomous Region, Yinchuan, 750021, China. zhangguangdi333909@sina.com.; Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan, 750021, China. fanght@nxu.edu.cn.
BACKGROUND: Apricot fruit has great economic value. In the process of apricot breeding using traditional breeding methods, we obtained a larger seedling (named Us) from the original variety (named U). And Us fruit is larger than U, taste better. Therefore, revealing its mechanism is very important for Apricot breeding. METHODS: In this study, de novo assembly and transcriptome sequencing (RNA-Seq) was used to screen the differently expressed genes (DEGs) between U and Us at three development stages, including young fruits stage, mid-ripening stage and mature fruit stage. RESULTS: The results showed that there were 6,753 DEGs at different sampling time. "Cellulose synthase (UDP-forming) activity" and "cellulose synthase activity" were the key GO terms enriched in GO, of which CESA and CSL family played a key role. "Photosynthesis-antenna proteins" and "Plant hormone signal transduction" were the candidate pathways and lhca, lhcb, Aux/IAA and SAUR were the main regulators. CONCLUSION: The auxin signaling pathway was active in Us, of which Aux/IAAs and SAUR were the key fruit size regulators. The low level of lhca and lhcb in Us could reveal the low demand for exogenous carbon, but they increased at mature stage, which might be due to the role of aux, who was keeping the fruit growing. Aux and photosynthesis maight be the main causes of appearance formation of Us fruits. Interestingly, the higher expression of CESA and CSL proved that Us entered the hardening process earlier than U. The advanced developmental progress might also be due to the role of Aux.
PMID: 37540452
Antonie Van Leeuwenhoek , IF:2.271 , 2023 Sep , V116 (9) : P855-866 doi: 10.1007/s10482-023-01850-z
Ancylobacter radicis sp. nov., a novel aerobic methylotrophic bacteria associated with plants.
G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center <
The two novel bacterial strains, designated as VT(T) and ML, were isolated from roots of cinquefoil (Potentilla sp.) and leaves of meadow-grass (Poa sp.) on the flooded bank of lake, respectively. These isolates were Gram-negative, non-spore-forming, non-motile, rod-shaped cells, utilized methanol, methylamine, and polycarbon compounds as carbon and energy sources. In the whole-cell fatty acid pattern of strains prevailed C(18:1)omega7c and C(19:0cyc). Based on the phylogenetic analysis of 16S rRNA gene sequences, strains VT(T) and ML were closely related to the representatives of the genus Ancylobacter (98.3-98.5%). The assembled genome of strain VT(T) has a total length of 4.22 Mbp, and a G + C content is 67.3%. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strain VT(T) and closely related type strains of genus Ancylobacter were 78.0-80.6%, 73.8-78.3% and 22.1-24.0%, respectively, that clearly lower than proposed thresholds for species. On the basis of the phylogenetic, phenotypic, and chemotaxonomic analysis, isolates VT(T) and ML represent a novel species of the genus Ancylobacter, for which the name Ancylobacter radicis sp. nov. is proposed. The type strain is VT(T) (= VKM B-3255(T) = CCUG 72400(T)). In addition, novel strains were able to dissolve insoluble phosphates, to produce siderophores and plant hormones (auxin biosynthesis). According to genome analysis genes involved in the biosynthesis of siderophores, polyhydroxybutyrate, exopolysaccharides and phosphorus metabolism, as well as the genes involved in the assimilation of C(1)-compounds (natural products of plant metabolism) were found in the genome of type strain VT(T).
PMID: 37270429
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2261744 doi: 10.1080/15592324.2023.2261744
The HOS1-PIF4/5 module controls callus formation in Arabidopsis leaf explants.
Department of Chemistry, Seoul National University, Seoul, Korea.; Research Institute of Basic Sciences, Seoul National University, Seoul, Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul, Korea.
A two-step plant regeneration has been widely exploited to genetic manipulation and genome engineering in plants. Despite technical importance, understanding of molecular mechanism underlying in vitro plant regeneration remains to be fully elucidated. Here, we found that the HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1)-PHYTOCHROME INTERACTING FACTOR 4/5 (PIF4/5) module participates in callus formation. Consistent with the repressive role of HOS1 in PIF transcriptional activation activity, hos1-3 mutant leaf explants exhibited enhanced callus formation, whereas pif4-101 pif5-3 mutant leaf explants showed reduced callus size. The HOS1-PIF4/5 function would be largely dependent on auxin biosynthesis and signaling, which are essential for callus initiation and proliferation. Our findings suggest that the HOS1-PIF4/5 module plays a pivotal role in auxin-dependent callus formation in Arabidopsis.
PMID: 37747842
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2218670 doi: 10.1080/15592324.2023.2218670
ChIFNalpha regulates adventitious root development in Lotus japonicus via an auxin-mediated pathway.
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang, Guizhou Province, China.; Department of Genetics, University of Georgia, Athens, GA, USA.
Adventitious roots (ARs), developing from non-root tissue, play an important role in some plants. Here, the molecular mechanism of AR differentiation in Lotus japonicus L. (L. japonicus) with the transformed chicken interferon alpha gene (ChIFNalpha) encoding cytokine was studied. ChIFNalpha transgenic plants (TP) were identified by GUS staining, PCR, RT-PCR, and ELISA. Up to 0.175 mug/kg rChIFNalpha was detected in TP2 lines. Expressing rChIFNalpha promotes AR development by producing longer roots than controls. We found that the effect was enhanced with the auxin precursor IBA treatment in TP. IAA contents, POD, and PPO activities associated with auxin regulation were higher than wild type (WT) in TP and exogenous ChIFNalpha treatment plants. Transcriptome analysis revealed 48 auxin-related differentially expressed genes (DEGs) (FDR < 0.05), which expression levels were verified by RT-qPCR analysis. GO enrichment analysis of DEGs also highlighted the auxin pathway. Further analysis found that ChIFNalpha significantly enhanced auxin synthesis and signaling mainly with up-regulated genes of ALDH, and GH3. Our study reveals that ChIFNalpha can promote plant AR development by mediating auxin regulation. The findings help explore the role of ChIFNalpha cytokines and expand animal gene sources for the molecular breeding of growth regulation of forage plants.
PMID: 37288791
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2207845 doi: 10.1080/15592324.2023.2207845
Mendel-200: Pea as a model system to analyze hormone-mediated stem elongation.
I- Cultiver, Inc, Manteca, CA 95336 & Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA.
In a recent Review Article on Gregor Mendel's (1822-1884) work with pea (Pisum sativum)-plants, it was proposed that this crop species should be re-vitalized as a model organism for the study of cell- and organ growth. Here, we describe the effect of exogenous gibberellic acid (GA(3)) on the growth of the second internode in 4-day-old light-grown pea seedlings (Pisum sativum, large var. "Senator"). lnjection of glucose into the internode caused a growth-promoting effect similar to that of the hormone GA(3). Imbibition of dry pea seeds in GA(3), or water as control, resulted in a drastic enhancement in organ development in this tall variety. Similar results were reported for dwarf peas. These "classical" experimental protocols are suitable to study the elusive effect of gibberellins (which act in coordination with auxin) on the regulation of plant development at the biochemical and molecular levels.
PMID: 37166004
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163342 doi: 10.1080/15592324.2022.2163342
Cloning and expression study of a high-affinity nitrate transporter gene from Zea mays L.
Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China.; Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China.; Aulin College, Northeast Forestry University, Harbin, Heilongjiang, China.
A nitrate transporter gene, named B46NRT2.1, from salt-tolerant Zea mays L. B46 has been cloned. B46NRT2.1 contained the same domain belonging to the major facilitator superfamily (PLN00028). The results of the phylogenetic tree indicated that B46NRT2.1 exhibits sequence similarity and the closest relationship with those known nitrate transporters of the NRT2 family. Through RT-qPCR, we found that the expression of B46NRT2.1 mainly happens in the root and leaf. Moreover, the treatment with NaCl, Na(2)CO(3), and NaHCO(3) could significantly increase the expression of B46NRT2.1. B46NRT2.1 was located in the plasma membrane. Through the study of yeast and plant salt response brought by B46NRT2.1 overexpression, we have preliminary knowledge that the expression of B46NRT2.1 makes yeast and plants respond to salt shock. There are 10 different kinds of cis-acting regulatory elements (CRES) in the promotor sequences of B46NRT2.1 gene using the PlantCARE web server to analyze. It mainly includes hormone response, abscisic acid, salicylic acid, gibberellin, methyl jasmonate, and auxin. The B46NRT2.1 gene's co-expression network showed that it was co-expressed with a number of other genes in several biological pathways, including regulation of NO(3) long-distance transit, modulation of nitrate sensing and metabolism, nitrate assimilation, and transduction of Jasmonic acid-independent wound signal. The results of this work should serve as a good scientific foundation for further research on the functions of the NRT2 gene family in plants (inbred line B46), and this research adds to our understanding of the molecular mechanisms under salt tolerance.
PMID: 36645908
Biosci Biotechnol Biochem , IF:2.043 , 2023 Sep , V87 (10) : P1145-1154 doi: 10.1093/bbb/zbad089
Molecular and cellular insights into auxin-regulated primary root growth: a comparative study of Arabidopsis and rice.
Kihara Institute for Biological Research, Yokohama City University, Maioka, Totsuka, Yokohama, Kanagawa, Japan.
Auxin regulation of primary root growth in Arabidopsis and rice was compared by analyzing root growth in response to changes in auxin levels. A bell-shaped root-growth curve was identified in both Arabidopsis and rice in response to change in auxin levels. In Arabidopsis, cell division was the main regulator of root growth in response to auxin; in rice, auxin promoted root growth by regulating cell division and cell length. The expression levels of PLETHORA (PLT) genes in response to change in auxin level followed a bell-shaped curve and closely correlated with cell division in Arabidopsis but not in rice, implying that PLT gene expression plays key role to control root growth in Arabidopsis. The level of auxin in Arabidopsis was optimal for primary root elongation, while in rice it was higher than optimal. These differences may explain the species-dependent development of root systems.
PMID: 37385821
Genet Mol Biol , IF:1.771 , 2023 , V46 (3 Suppl 1) : Pe20230100 doi: 10.1590/1678-4685-GMB-2023-0100
Effects on gene expression during maize-Azospirillum interaction in the presence of a plant-specific inhibitor of indole-3-acetic acid production.
Universidade Federal do Rio Grande do Sul (UFRGS), Instituto de Biociencias, Departamento de Genetica, Programa de Pos-Graduacao em Genetica e Biologia Molecular, Porto Alegre, RS, Brazil.; Universidade Federal do Parana (UFPR), Centro Politecnico, Departamento de Bioquimica e Biologia Molecular, Curitiba, PR, Brazil.; Universidade Federal de Ciencias da Saude de Porto Alegre (UFCSPA), Programa de Pos-Graduacao em Biociencias, Porto Alegre, RS, Brazil.; Universidade Federal de Ciencias da Saude de Porto Alegre (UFCSPA), Departamento de Farmacociencias, Programa de Pos-Graduacao em Biociencias, Porto Alegre, Brazil.
Amongst the sustainable alternatives to increase maize production is the use of plant growth-promoting bacteria (PGPB). Azospirillum brasilense is one of the most well-known PGPB being able to fix nitrogen and produce phytohormones, especially indole-3-acetic acid - IAA. This work investigated if there is any contribution of the bacterium to the plant's IAA levels, and how it affects the plant. To inhibit plant IAA production, yucasin, an inhibitor of the TAM/YUC pathway, was applied. Plantlets' IAA concentration was evaluated through HPLC and dual RNA-Seq was used to analyze gene expression. Statistical differences between the group treated with yucasin and the other groups showed that A. brasilense inoculation was able to prevent the phenotype caused by yucasin concerning the number of lateral roots. Genes involved in the auxin and ABA response pathways, auxin efflux transport, and the cell cycle were regulated by the presence of the bacterium, yucasin, or both. Genes involved in the response to biotic/abiotic stress, plant disease resistance, and a D-type cellulose synthase changed their expression pattern among two sets of comparisons in which A. brasilense acted as treatment. The results suggest that A. brasilense interferes with the expression of many maize genes through an IAA-independent pathway.
PMID: 37725833
J Genet Genomics , 2023 Sep doi: 10.1016/j.jgg.2023.09.001
TaACTIN7-D regulates plant height and grain shape in bread wheat.
Frontiers Science Center for Molecular Design Breeding, China Agricultural University, Beijing, 100193, P. R. China.; State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, P. R. China.; Frontiers Science Center for Molecular Design Breeding, China Agricultural University, Beijing, 100193, P. R. China. Electronic address: chaizz901230@163.com.; Frontiers Science Center for Molecular Design Breeding, China Agricultural University, Beijing, 100193, P. R. China. Electronic address: jieliu@cau.edu.cn.
Exploitation of new gene resources and genetic networks contributing to the control of crop yield-related traits, such as plant height and grain size and shape, may enable us to breed modern high-yielding wheat varieties through molecular methods. In this study, via ethylmethanesulfonate (EMS) mutagenesis, we identified a wheat mutant plant, mu-597, that shows semi-dwarf plant architecture and round grain shape. Through bulked segregant RNA-seq and map-based cloning, the causal gene for the semi-dwarf phenotype of mu-597 was located. We found that a single-base mutation in the coding region of TaACTIN7-D (TaACT7-D), leading to a Gly-to-Ser (G65S) amino acid mutation at the 65(th) residue of the deduced TaACT7-D protein, can explain the semi-dwarfism and round grain shape of mu-597. Further evidence shows that the G65S mutation in TaACT7-D hinders the polymerization of actin from monomeric (G-actin) to filamentous (F-actin) status while attenuates wheat responses to multiple phytohormones, including brassinosteroids, auxin, and gibberellin. Together, these findings not only define a new semi-dwarfing gene resource that can be potentially used to design plant height and grain shape of bread wheat but also establish a direct link between actin structure modulation and phytohormone signal transduction.
PMID: 37709194
Quant Plant Biol , 2023 , V4 : Pe10 doi: 10.1017/qpb.2023.9
Quantitative regeneration: Skoog and Miller revisited.
Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
In 1957, Skoog and Miller published their seminal work on the effects of hormones upon plant growth. By varying the concentrations of auxin and cytokinin, they observed dramatic differences in shoot and root growth from tobacco stem cultures. Their finding that quantitative differences in hormone concentrations could dramatically alter the fate of developing organs provided a foundation for understanding organ formation and tissue regeneration. Their in vitro assays established plant propagation techniques that were critical for regenerating transgenic plants. Here, I discuss their original paper, what led to their findings and its impact on our understanding of hormone interactions, how plants regenerate and in vitro tissue culture techniques.
PMID: 37706182
Plant Commun , 2023 Sep , V4 (5) : P100665 doi: 10.1016/j.xplc.2023.100665
Combining single-cell RNA sequencing with spatial transcriptome analysis reveals dynamic molecular maps of cambium differentiation in the primary and secondary growth of trees.
National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China.; National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.; National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: lgli@cemps.ac.cn.
Primary and secondary growth of the tree stem are responsible for corresponding increases in trunk height and diameter. However, our molecular understanding of the biological processes that underlie these two types of growth is incomplete. In this study, we used single-cell RNA sequencing and spatial transcriptome sequencing to reveal the transcriptional landscapes of primary and secondary growth tissues in the Populus stem. Comparison between the cell atlas and differentiation trajectory of primary and secondary growth revealed different regulatory networks involved in cell differentiation from cambium to xylem precursors and phloem precursors. These regulatory networks may be controlled by auxin accumulation and distribution. Analysis of cell differentiation trajectories suggested that vessel and fiber development followed a sequential pattern of progressive transcriptional regulation. This research provides new insights into the processes of cell identity and differentiation that occur throughout primary and secondary growth of tree stems, increasing our understanding of the cellular differentiation dynamics that occur during stem growth in trees.
PMID: 37491818
Plant Commun , 2023 Sep , V4 (5) : P100604 doi: 10.1016/j.xplc.2023.100604
The miR167-OsARF12 module regulates rice grain filling and grain size downstream of miR159.
Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China.; Joint Center for Single Cell Biology/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; Department of Biotechnology, Sharda University, Greater Noida 201306, India.; Institute of Paulownia, Henan Agricultural University, Zhengzhou 450046, China.; Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.; Joint Center for Single Cell Biology/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: hwxue@sjtu.edu.cn.; Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China; College of Agriculture, Guizhou University, Guiyang 550025, China. Electronic address: qzzhaoh@126.com.; Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: lypengting@163.com.
Grain weight and quality are always determined by grain filling. Plant microRNAs have drawn attention as key targets for regulation of grain size and yield. However, the mechanisms that underlie grain size regulation remain largely unclear because of the complex networks that control this trait. Our earlier studies demonstrated that suppressed expression of miR167 (STTM/MIM167) substantially increased grain weight. In a field test, the yield increased up to 12.90%-21.94% because of a significantly enhanced grain filling rate. Here, biochemical and genetic analyses revealed the regulatory effects of miR159 on miR167 expression. Further analysis indicated that OsARF12 is the major mediator by which miR167 regulates rice grain filling. Overexpression of OsARF12 produced grain weight and grain filling phenotypes resembling those of STTM/MIM167 plants. Upon in-depth analysis, we found that OsARF12 activates OsCDKF;2 expression by directly binding to the TGTCGG motif in its promoter region. Flow cytometry analysis of young panicles from OsARF12-overexpressing plants and examination of cell number in cdkf;2 mutants verified that OsARF12 positively regulates grain filling and grain size by targeting OsCDKF;2. Moreover, RNA sequencing results suggested that the miR167-OsARF12 module is involved in the cell development process and hormone pathways. OsARF12-overexpressing plants and cdkf;2 mutants exhibited enhanced and reduced sensitivity to exogenous auxin and brassinosteroid (BR) treatment, confirming that targeting of OsCDKF;2 by OsARF12 mediates auxin and BR signaling. Our results reveal that the miR167-OsARF12 module works downstream of miR159 to regulate rice grain filling and grain size via OsCDKF;2 by controlling cell division and mediating auxin and BR signals.
PMID: 37085993