Trends Plant Sci , IF:18.313 , 2023 Aug 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
Trends Plant Sci , IF:18.313 , 2023 Aug , V28 (8) : P873-875 doi: 10.1016/j.tplants.2023.05.003
A complex signaling trio in seed germination: Auxin-JA-ABA.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland.; Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland. Electronic address: agata.daszkowska@us.edu.pl.
Recently. Mei et al. discovered the molecular mechanism behind the synergistic action of auxins and jasmonates in enhancing the role of abscisic acid (ABA) in seed germination. They found that JASMONATE-ZIM DOMAIN (JAZ) proteins interact with AUXIN RESPONSE FACTOR (ARF)-16 to mediate auxin-jasmonic acid (JA) crosstalk. Furthermore, they revealed that ARF16 interacts with ABSCISIC ACID INSENSITIVE (ABI)-5 and positively modulates ABA responses at seed germination.
PMID: 37208202
Trends Plant Sci , IF:18.313 , 2023 Jul , V28 (7) : P765-775 doi: 10.1016/j.tplants.2023.02.003
The consequences of synthetic auxin herbicide on plant-herbivore interactions.
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: rsbaucom@umich.edu.
Although herbicide drift is a common side effect of herbicide application in agroecosystems, its effects on the ecology and evolution of natural communities are rarely studied. A recent shift to dicamba, a synthetic auxin herbicide known for 'drifting' to nontarget areas, necessitates the examination of drift effects on the plant-insect interactions that drive eco-evo dynamics in weed communities. We review current knowledge of direct effects of synthetic auxin herbicides on plant-insect interactions, focusing on plant herbivory, and discuss potential indirect effects, which are cascading effects on organisms that interact with herbicide-exposed plants. We end by developing a framework for the study of plant-insect interactions given drift, highlighting potential changes to plant developmental timing, resource quantity, quality, and cues.
PMID: 36842859
Nucleic Acids Res , IF:16.971 , 2023 Jun doi: 10.1093/nar/gkad521
Spatially resolved transcriptomic analysis of the germinating barley grain.
Department of Animal, Plant and Soil Science, La Trobe Institute for Sustainable Agriculture and Food, School of Agriculture, Biomedical and Environmental Sciences, La Trobe University, Bundoora, Victoria 3086, Australia.; Australian Research Council Research Hub for Medicinal Agriculture, AgriBio Building, La Trobe University, Bundoora, VIC 3086, Australia.; Research Centre for Engineering Biology, College of Life Science, Zhejiang University, 718 East Haizhou Road, Haining, Jiaxing, Zhejiang 314400, China.
Seeds are a vital source of calories for humans and a unique stage in the life cycle of flowering plants. During seed germination, the embryo undergoes major developmental transitions to become a seedling. Studying gene expression in individual seed cell types has been challenging due to the lack of spatial information or low throughput of existing methods. To overcome these limitations, a spatial transcriptomics workflow was developed for germinating barley grain. This approach enabled high-throughput analysis of spatial gene expression, revealing specific spatial expression patterns of various functional gene categories at a sub-tissue level. This study revealed over 14 000 genes differentially regulated during the first 24 h after imbibition. Individual genes, such as the aquaporin gene family, starch degradation, cell wall modification, transport processes, ribosomal proteins and transcription factors, were found to have specific spatial expression patterns over time. Using spatial autocorrelation algorithms, we identified auxin transport genes that had increasingly focused expression within subdomains of the embryo over time, suggesting their role in establishing the embryo axis. Overall, our study provides an unprecedented spatially resolved cellular map for barley germination and identifies specific functional genomics targets to better understand cellular restricted processes during germination. The data can be viewed at https://spatial.latrobe.edu.au/.
PMID: 37351575
Nat Plants , IF:15.793 , 2023 Aug , V9 (8) : P1306-1317 doi: 10.1038/s41477-023-01485-y
A network of CLAVATA receptors buffers auxin-dependent meristem maintenance.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Biological Sciences, Auburn University, Auburn, AL, USA.; Thermo Fisher Scientific, Raleigh, NC, USA.; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. zackn@email.unc.edu.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. zackn@email.unc.edu.
Plant body plans are elaborated in response to both environmental and endogenous cues. How these inputs intersect to promote growth and development remains poorly understood. During reproductive development, central zone stem cell proliferation in inflorescence meristems is negatively regulated by the CLAVATA3 (CLV3) peptide signalling pathway. In contrast, floral primordia formation on meristem flanks requires the hormone auxin. Here we show that CLV3 signalling is also necessary for auxin-dependent floral primordia generation and that this function is partially masked by both inflorescence fasciation and heat-induced auxin biosynthesis. Stem cell regulation by CLAVATA signalling is separable from primordia formation but is also sensitized to temperature and auxin levels. In addition, we uncover a novel role for the CLV3 receptor CLAVATA1 in auxin-dependent meristem maintenance in cooler environments. As such, CLV3 signalling buffers multiple auxin-dependent shoot processes across divergent thermal environments, with opposing effects on cell proliferation in different meristem regions.
PMID: 37550370
Nat Commun , IF:14.919 , 2023 Jul , V14 (1) : P4441 doi: 10.1038/s41467-023-40176-2
The OsSGS3-tasiRNA-OsARF3 module orchestrates abiotic-biotic stress response trade-off in rice.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032, Shanghai, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.; Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, 650500, Kunming, China.; Department of Rice Breeding, Hunan Yahua Seed Scientific Research Institute, 410119, Changsha, Hunan, China.; National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, 210095, Nanjing, China.; University of Chinese Academy of Sciences, 100039, Beijing, China.; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 100101, Beijing, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China. xwsong@genetics.ac.cn.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032, Shanghai, China. zhhe@cemps.ac.cn.; Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, 650500, Kunming, China. liujunzhong@ynu.edu.cn.
Recurrent heat stress and pathogen invasion seriously threaten crop production, and abiotic stress often antagonizes biotic stress response against pathogens. However, the molecular mechanisms of trade-offs between thermotolerance and defense remain obscure. Here, we identify a rice thermo-sensitive mutant that displays a defect in floret development under high temperature with a mutation in SUPPRESSOR OF GENE SILENCING 3a (OsSGS3a). OsSGS3a interacts with its homolog OsSGS3b and modulates the biogenesis of trans-acting small interfering RNA (tasiRNA) targeting AUXIN RESPONSE FACTORS (ARFs). We find that OsSGS3a/b positively, while OsARF3a/b and OsARF3la/lb negatively modulate thermotolerance. Moreover, OsSGS3a negatively, while OsARF3a/b and OsARF3la/lb positively regulate disease resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) and the fungal pathogen Magnaporthe oryzae (M. oryzae). Taken together, our study uncovers a previously unknown trade-off mechanism that regulates distinct immunity and thermotolerance through the OsSGS3-tasiRNA-OsARF3 module, highlighting the regulation of abiotic-biotic stress response trade-off in plants.
PMID: 37488129
Trends Biochem Sci , IF:13.807 , 2023 Aug doi: 10.1016/j.tibs.2023.07.006
Substrate recognition and transport mechanism of the PIN-FORMED auxin exporters.
Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark.; Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany.; Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NY 10016, USA.; Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark. Electronic address: bpp@mbg.au.dk.
Auxins are pivotal plant hormones that regulate plant growth and transmembrane polar auxin transport (PAT) direct patterns of development. The PIN-FORMED (PIN) family of membrane transporters mediate auxin export from the plant cell and play crucial roles in PAT. Here we describe the recently solved structures of PIN transporters, PIN1, PIN3, and PIN8, and also their mechanisms of substrate recognition and transport of auxin. We compare structures of PINs in both inward- and outward-facing conformations, as well as PINs with different binding configurations for auxin. By this comparative analysis, a model emerges for an elevator transport mechanism. Central structural elements necessary for function are identified, and we show that these are shared with other distantly related protein families.
PMID: 37574372
Mol Plant , IF:13.164 , 2023 Jul , V16 (7) : P1120-1130 doi: 10.1016/j.molp.2023.06.008
The AFB1 auxin receptor controls the cytoplasmic auxin response pathway in Arabidopsis thaliana.
Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Prague, Czech Republic.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.; Plant Molecular and Cellular Biology Laboratory and Integrative Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA.; Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Prague, Czech Republic. Electronic address: matyas.fendrych@natur.cuni.cz.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA. Electronic address: mestelle@ucsd.edu.
The phytohormone auxin triggers root growth inhibition within seconds via a non-transcriptional pathway. Among members of the TIR1/AFB auxin receptor family, AFB1 has a primary role in this rapid response. However, the unique features that confer this specific function have not been identified. Here we show that the N-terminal region of AFB1, including the F-box domain and residues that contribute to auxin binding, is essential and sufficient for its specific role in the rapid response. Substitution of the N-terminal region of AFB1 with that of TIR1 disrupts its distinct cytoplasm-enriched localization and activity in rapid root growth inhibition by auxin. Importantly, the N-terminal region of AFB1 is indispensable for auxin-triggered calcium influx, which is a prerequisite for rapid root growth inhibition. Furthermore, AFB1 negatively regulates lateral root formation and transcription of auxin-induced genes, suggesting that it plays an inhibitory role in canonical auxin signaling. These results suggest that AFB1 may buffer the transcriptional auxin response, whereas it regulates rapid changes in cell growth that contribute to root gravitropism.
PMID: 37391902
Plant Cell , IF:11.277 , 2023 Aug doi: 10.1093/plcell/koad214
The transcription factor ERF108 interacts with AUXIN RESPONSE FACTORs to mediate cotton fiber secondary cell wall biosynthesis.
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.; Maize Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China.; College of Biomedicine and Health & College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Phytohormones play indispensable roles in plant growth and development. However, the molecular mechanisms underlying phytohormone-mediated regulation of fiber secondary cell wall (SCW) formation in cotton (Gossypium hirsutum) remain largely underexplored. Here, we provide mechanistic evidence for functional interplay between the AP2/ERF transcription factor GhERF108 and auxin response factors GhARF7-1 and GhARF7-2 in dictating the ethylene-auxin signaling crosstalk that regulates fiber SCW biosynthesis. Specifically, in vitro cotton ovule culture revealed that ethylene and auxin promote fiber SCW deposition. GhERF108 RNAi cotton displayed remarkably reduced cell wall thickness compared with controls. GhERF108 interacted with GhARF7-1 and GhARF7-2 to enhance the activation of the MYB transcription factor gene GhMYBL1 (MYB domain like protein 1) in fibers. GhARF7-1 and GhARF7-2 respond to auxin signals that promote fiber SCW thickening. GhMYBL1 RNAi and, GhARF7-1 and GhARF7-2 VIGS cotton displayed similar defects in fiber SCW formation as GhERF108 RNAi cotton. Moreover, the ethylene and auxin responses were reduced in GhMYBL1 RNAi plants. GhMYBL1 directly binds to the promoters of GhCesA4-1, GhCesA4-2, and GhCesA8-1 and activates their expression to promote cellulose biosynthesis, thereby boosting fiber SCW formation. Collectively, our findings demonstrate that the collaboration between GhERF108 and GhARF7-1 or GhARF7-2 establishes ethylene-auxin signaling crosstalk to activate GhMYBL1, ultimately leading to the activation of fiber SCW biosynthesis.
PMID: 37542517
Plant Cell , IF:11.277 , 2023 Aug , V35 (8) : P2871-2886 doi: 10.1093/plcell/koad130
The transcriptional hub SHORT INTERNODES1 integrates hormone signals to orchestrate rice growth and development.
State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plants have evolved sophisticated mechanisms to coordinate their growth and stress responses via integrating various phytohormone signaling pathways. However, the precise molecular mechanisms orchestrating integration of the phytohormone signaling pathways remain largely obscure. In this study, we found that the rice (Oryza sativa) short internodes1 (shi1) mutant exhibits typical auxin-deficient root development and gravitropic response, brassinosteroid (BR)-deficient plant architecture and grain size as well as enhanced abscisic acid (ABA)-mediated drought tolerance. Additionally, we found that the shi1 mutant is also hyposensitive to auxin and BR treatment but hypersensitive to ABA. Further, we showed that OsSHI1 promotes the biosynthesis of auxin and BR by activating the expression of OsYUCCAs and D11, meanwhile dampens ABA signaling by inducing the expression of OsNAC2, which encodes a repressor of ABA signaling. Furthermore, we demonstrated that 3 classes of transcription factors, AUXIN RESPONSE FACTOR 19 (OsARF19), LEAF AND TILLER ANGLE INCREASED CONTROLLER (LIC), and OsZIP26 and OsZIP86, directly bind to the promoter of OsSHI1 and regulate its expression in response to auxin, BR, and ABA, respectively. Collectively, our results unravel an OsSHI1-centered transcriptional regulatory hub that orchestrates the integration and self-feedback regulation of multiple phytohormone signaling pathways to coordinate plant growth and stress adaptation.
PMID: 37195873
Plant Cell , IF:11.277 , 2023 Aug , V35 (8) : P2848-2870 doi: 10.1093/plcell/koad125
SHORT ROOT and INDETERMINATE DOMAIN family members govern PIN-FORMED expression to regulate minor vein differentiation in rice.
Biotechnology Research Institute (BRI), Chinese Academy of Agricultural Sciences (CAAS), Beijing 100081, China.; Joint Laboratory for Photosynthesis Enhancement and C4 Rice Development, BRI, CAAS, Beijing 100081, China.; C4 Rice Centre, International Rice Research Institute, Los Banos, Laguna 4030, Philippines.; Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
C3 and C4 grasses directly and indirectly provide the vast majority of calories to the human diet, yet our understanding of the molecular mechanisms driving photosynthetic productivity in grasses is largely unexplored. Ground meristem cells divide to form mesophyll or vascular initial cells early in leaf development in C3 and C4 grasses. Here we define a genetic circuit composed of SHORT ROOT (SHR), INDETERMINATE DOMAIN (IDD), and PIN-FORMED (PIN) family members that specifies vascular identify and ground cell proliferation in leaves of both C3 and C4 grasses. Ectopic expression and loss-of-function mutant studies of SHR paralogs in the C3 plant Oryza sativa (rice) and the C4 plant Setaria viridis (green millet) revealed the roles of these genes in both minor vein formation and ground cell differentiation. Genetic and in vitro studies further suggested that SHR regulates this process through its interactions with IDD12 and 13. We also revealed direct interactions of these IDD proteins with a putative regulatory element within the auxin transporter gene PIN5c. Collectively, these findings indicate that a SHR-IDD regulatory circuit mediates auxin transport by negatively regulating PIN expression to modulate minor vein patterning in the grasses.
PMID: 37154077
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Aug , V120 (31) : Pe2218865120 doi: 10.1073/pnas.2218865120
Endoplasmic reticulum stress controls PIN-LIKES abundance and thereby growth adaptation.
Institute of Biology II, Chair of Molecular Plant Physiology, University of Freiburg, 79104 Freiburg, Germany.; Center for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.; Department of Applied Genetics and Cell Biology, Institute of Molecular Plant Biology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria.; CNRS-University of Bordeaux, UMR 5200 Membrane Biogenesis Laboratory, National Research Institute for Agriculture, Food and the Environment Bordeaux Aquitaine, 33140 Bordeaux, France.
Extreme environmental conditions eventually limit plant growth [J. R. Dinneny, Annu. Rev. Cell Dev. Biol. 35, 1-19 (2019), N. Gigli-Bisceglia, C. Testerink, Curr. Opin. Plant Biol. 64, 102120 (2021)]. Here, we reveal a mechanism that enables multiple external cues to get integrated into auxin-dependent growth programs in Arabidopsis thaliana. Our forward genetics approach on dark-grown hypocotyls uncovered that an imbalance in membrane lipids enhances the protein abundance of PIN-LIKES (PILS) [E. Barbez et al., Nature 485, 119 (2012)] auxin transport facilitators at the endoplasmic reticulum (ER), which thereby limits nuclear auxin signaling and growth rates. We show that this subcellular response relates to ER stress signaling, which directly impacts PILS protein turnover in a tissue-dependent manner. This mechanism allows PILS proteins to integrate environmental input with phytohormone auxin signaling, contributing to stress-induced growth adaptation in plants.
PMID: 37487064
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Jul , V120 (28) : Pe2221606120 doi: 10.1073/pnas.2221606120
Genetic robustness control of auxin output in priming organ initiation.
Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Ministry of Education Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.; Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu 241000, China.; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu 241000, China.
Auxin signaling is essential for organ initiation in plants. How genetic robustness controls auxin output during organ initiation is largely unknown. Here, we identified DORNROSCHEN-LIKE (DRNL) as a target of MONOPTEROS (MP) that plays essential roles in organ initiation. We demonstrate that MP physically interacts with DRNL to inhibit cytokinin accumulation by directly activating ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 and CYTOKININ OXIDASE 6. DRN, the paralogous gene of DRNL, acts redundantly with DRNL but is not coexpressed with DRNL in the organ founder cells in which DRNL is expressed. We demonstrate that DRNL directly inhibits DRN expression in the peripheral zone, whereas DRN transcripts are ectopically activated in drnl mutants and fully restore the functional deficiency of drnl in organ initiation. Our results provide a mechanistic framework for the robust control of auxin signaling in organ initiation through paralogous gene-triggered spatial gene compensation effects.
PMID: 37399382
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Jun , V120 (25) : Pe2221313120 doi: 10.1073/pnas.2221313120
The nitrate transporter NRT2.1 directly antagonizes PIN7-mediated auxin transport for root growth adaptation.
State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, Frontiers Science Center for Molecular Design Breeding (MOE), China Agricultural University, Beijing 100193, China.; Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China.; College of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding 071002, China.; Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.
As a crucial nitrogen source, nitrate (NO(3)(-)) is a key nutrient for plants. Accordingly, root systems adapt to maximize NO(3)(-) availability, a developmental regulation also involving the phytohormone auxin. Nonetheless, the molecular mechanisms underlying this regulation remain poorly understood. Here, we identify low-nitrate-resistant mutant (lonr) in Arabidopsis (Arabidopsis thaliana), whose root growth fails to adapt to low-NO(3)(-) conditions. lonr2 is defective in the high-affinity NO(3)(-) transporter NRT2.1. lonr2 (nrt2.1) mutants exhibit defects in polar auxin transport, and their low-NO(3)(-)-induced root phenotype depends on the PIN7 auxin exporter activity. NRT2.1 directly associates with PIN7 and antagonizes PIN7-mediated auxin efflux depending on NO(3)(-) levels. These results reveal a mechanism by which NRT2.1 in response to NO(3)(-) limitation directly regulates auxin transport activity and, thus, root growth. This adaptive mechanism contributes to the root developmental plasticity to help plants cope with changes in NO(3)(-) availability.
PMID: 37307446
Curr Biol , IF:10.834 , 2023 Aug , V33 (15) : PR805-R808 doi: 10.1016/j.cub.2023.06.065
Plant signaling: The sugar-coated story of root growth.
Plant-Environment Signaling, Department of Biology, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, the Netherlands.; Plant-Environment Signaling, Department of Biology, Science4Life, Utrecht University, Padualaan 8, Utrecht, 3584 CH, the Netherlands. Electronic address: r.pierik@uu.nl.
A new study draws attention to photosynthetically produced sucrose as a major shoot-derived and auxin-dependent regulator of root growth and development in plants.
PMID: 37552945
Curr Biol , IF:10.834 , 2023 Jul , V33 (14) : P2977-2987.e6 doi: 10.1016/j.cub.2023.06.037
Interspersed expression of CUP-SHAPED COTYLEDON2 and REDUCED COMPLEXITY shapes Cardamine hirsuta complex leaf form.
Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829 Cologne, Germany.; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829 Cologne, Germany. Electronic address: tsiantis@mpipz.mpg.de.
How genetically regulated growth shapes organ form is a key problem in developmental biology. Here, we investigate this problem using the leaflet-bearing complex leaves of Cardamine hirsuta as a model. Leaflet development requires the action of two growth-repressing transcription factors: REDUCED COMPLEXITY (RCO), a homeodomain protein, and CUP-SHAPED COTYLEDON2 (CUC2), a NAC-domain protein. However, how their respective growth-repressive actions are integrated in space and time to generate complex leaf forms remains unknown. By using live imaging, we show that CUC2 and RCO are expressed in an interspersed fashion along the leaf margin, creating a distinctive striped pattern. We find that this pattern is functionally important because forcing RCO expression in the CUC2 domain disrupts auxin-based marginal patterning and can abolish leaflet formation. By combining genetic perturbations with time-lapse imaging and cellular growth quantifications, we provide evidence that RCO-mediated growth repression occurs after auxin-based leaflet patterning and in association with the repression of cell proliferation. Additionally, through the use of genetic mosaics, we show that RCO is sufficient to repress both cellular growth and proliferation in a cell-autonomous manner. This mechanism of growth repression is different to that of CUC2, which occurs in proliferating cells. Our findings clarify how the two growth repressors RCO and CUC2 coordinate to subdivide developing leaf primordia into distinct leaflets and generate the complex leaf form. They also indicate different relationships between growth repression and cell proliferation in the patterning and post-patterning stages of organogenesis.
PMID: 37453425
J Hazard Mater , IF:10.588 , 2023 Aug , V455 : P131637 doi: 10.1016/j.jhazmat.2023.131637
Indole-3-acetic acid and zinc synergistically mitigate positively charged nanoplastic-induced damage in rice.
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, PR China.; Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, PR China; National Key Laboratory of Rice Biology, The Advanced Seed Institute, Zhejiang University, Hangzhou 310058, PR China.; National Key Laboratory of Rice Biology, The Advanced Seed Institute, Zhejiang University, Hangzhou 310058, PR China.; Institute of Nuclear Agricultural Sciences, Zhejiang University, Hangzhou 310058, PR China. Electronic address: zhen.yang@zju.edu.cn.; Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, PR China. Electronic address: mengjiang@zju.edu.cn.
Recent research has shown that polystyrene nanoplastics (PS-NPs) can inhibit plant growth and the development of crops, such as rice. In this study, we aimed to investigate the effects of PS-NPs of different particle sizes (80 nm, 200 nm, and 2 microm) and charges (negative, neutral, and positive) on rice growth, and to explore the underlying mechanisms and potential strategies for mitigating their impacts. Two-week-old rice plants were planted in a standard (1/2) Murashige-Skoog liquid medium holding 50 mg/L of different particle sizes and/or charged PS-NPs for 10 days, and the liquid medium without PS-NPs was used as control. The results showed that positively charged PS-NPs (80 nm PS-NH(2)) had the greatest impact on plant growth and greatly reduced the dry biomass, root length, and plant height of rice by 41.04%, 46.34%, and 37.45%, respectively. The positively charged NPs with a size of 80 nm significantly decreased the zinc (Zn) and indole-3-acetic acid (IAA, auxin) contents by 29.54% and 48.00% in roots, and 31.15% and 64.30% in leaves, respectively, and down-regulated the relative expression level of rice IAA response and biosynthesis genes. Moreover, Zn and/or IAA supplements significantly alleviated the adverse effects of 80 nm PS-NH(2) on rice plant growth. Exogenous Zn and/or IAA increased seedlings' growth, decreased PS-NPs distribution, maintained redox homeostasis, and improved tetrapyrrole biosynthesis in rice treated with 80 nm PS-NH(2). Our findings suggest that Zn and IAA synergistically alleviate positively charged NP-induced damage in rice.
PMID: 37210880
New Phytol , IF:10.151 , 2023 Aug 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 Jul 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
New Phytol , IF:10.151 , 2023 Aug , V239 (3) : P964-978 doi: 10.1111/nph.19004
Ethylene controls cambium stem cell activity via promoting local auxin biosynthesis.
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, 100193, China.; College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, Shandong, China.; School of Applied Chemistry and Biotechnology, Shenzhen Polytechnic, Shenzhen, 518055, Guangdong, China.; Core Facilities, College of Life Sciences, Peking University, Beijing, 100871, China.; Faculty of Agriculture, New Valley University, New Valley Governorate, 72511, New Valley, Egypt.; Flower Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.; Crop Pathology and Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA, 95616, USA.; Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA.; Plant Biology Section, School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.
The vascular cambium is the main secondary meristem in plants that produces secondary phloem (outside) and xylem (inside) on opposing sides of the cambium. The phytohormone ethylene has been implicated in vascular cambium activity, but the regulatory network underlying ethylene-mediated cambial activity remains to be elucidated. Here, we found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), an ethylene-inducible HOMEODOMAIN-LEUCINE ZIPPER I transcription factor in woody plant rose (Rosa hybrida), regulates local auxin biosynthesis and auxin transport to maintain cambial activity. Knockdown of RhPMP1 resulted in smaller midveins and reduced auxin content, while RhPMP1 overexpression resulted in larger midveins and increased auxin levels compared with the wild-type plants. Furthermore, we revealed that Indole-3-pyruvate monooxygenase YUCCA 10 (RhYUC10) and Auxin transporter-like protein 2 (RhAUX2), encoding an auxin biosynthetic enzyme and an auxin influx carrier, respectively, are direct downstream targets of RhPMP1. In summary, our results suggest that ethylene promotes an auxin maximum in the cambium adjacent to the xylem to maintain cambial activity.
PMID: 37282811
New Phytol , IF:10.151 , 2023 Aug , V239 (3) : P949-963 doi: 10.1111/nph.18988
SlMYB99-mediated auxin and abscisic acid antagonistically regulate ascorbic acids biosynthesis in tomato.
Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing, 400044, China.
Ascorbic acid (AsA) is a water-soluble antioxidant that plays important roles in plant development and human health. Understanding the regulatory mechanism underlying AsA biosynthesis is imperative to the development of high AsA plants. In this study, we reveal that the auxin response factor SlARF4 transcriptionally inhibits SlMYB99, which subsequently modulates AsA accumulation via transcriptional activation of AsA biosynthesis genes GPP, GLDH, and DHAR. The auxin-dependent transcriptional cascade of SlARF4-SlMYB99-GPP/GLDH/DHAR modulates AsA synthesis, while mitogen-activated protein kinase SlMAPK8 not only phosphorylates SlMYB99, but also activates its transcriptional activity. Both SlMYB99 and SlMYB11 proteins physically interact with each other, thereby synergistically regulating AsA biosynthesis by upregulating the expression of GPP, GLDH, and DHAR genes. Collectively, these results demonstrate that auxin and abscisic acid antagonistically regulate AsA biosynthesis during development and drought tolerance in tomato via the SlMAPK8-SlARF4-SlMYB99/11 module. These findings provide new insights into the mechanism underlying phytohormone regulation of AsA biosynthesis and provide a theoretical basis for the future development of high AsA plants via molecular breeding.
PMID: 37247338
New Phytol , IF:10.151 , 2023 Jul , V239 (2) : P639-659 doi: 10.1111/nph.18947
Disruption of the amino acid transporter CsAAP2 inhibits auxin-mediated root development in cucumber.
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing, 100193, China.
Amino acid transporters are the principal mediators of organic nitrogen distribution within plants and are essential for plant growth and development. Despite this importance, relatively few amino acid transporter genes have been explored and elucidated in cucumber (Cucumis sativus). Here, a total of 86 amino acid transporter genes were identified in the cucumber genome. We further identified Amino Acid Permease (AAP) subfamily members that exhibited distinct expression patterns in different tissues. We found that the CsAAP2 as a candidate gene encoding a functional amino acid transporter is highly expressed in cucumber root vascular cells. CsAAP2 knockout lines exhibited arrested development of root meristem, which then caused the delayed initiation of lateral root and the inhibition of root elongation. What is more, the shoot growth of aap2 mutants was strongly retarded due to defects in cucumber root development. Moreover, aap2 mutants exhibited higher concentrations of amino acids and lignin in roots. We found that the mutant roots had a stronger ability to acidize medium. Furthermore, in the aap2 mutants, polar auxin transport was disrupted in the root tip, leading to high auxin levels in roots. Interestingly, slightly alkaline media rescued their severely reduced root growth by stimulating auxin pathway.
PMID: 37129077
Plant Biotechnol J , IF:9.803 , 2023 Aug 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 Biotechnol J , IF:9.803 , 2023 Jul , V21 (7) : P1479-1495 doi: 10.1111/pbi.14054
A systematic dissection in oilseed rape provides insights into the genetic architecture and molecular mechanism of yield heterosis.
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China.; Zhengzhou Fruit Research Institute of the Chinese Academy of Agricultural Sciences, The Laboratory of Melon Crops, Zhengzhou, China.; Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, China.; Hubei Hongshan Laboratory (HHL), Wuhan, China.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA, Australia.
Heterosis refers to the better performance of cross progeny compared with inbred parents, and its utilization contributes greatly to agricultural production. Several hypotheses have been proposed to explain heterosis mainly including dominance, over-dominance (or pseudo-overdominance) and epistasis. However, systematic dissection and verification of these hypotheses are rarely documented. Here, comparison of heterosis level across different traits showed that the strong heterosis of composite traits (such as yield) could be attributed to the multiplicative effects of moderate heterosis of component traits, whether at the genome or locus level. Yield heterosis was regulated by a complex trait-QTL network that was characterized by obvious centre-periphery structure, hub QTL, complex up/downstream and positive/negative feedback relationships. More importantly, we showed that better-parent heterosis on yield could be produced in a cross of two near-isogenic lines by the pyramiding and complementation of two major heterotic QTL showing partial-dominance on yield components. The causal gene (BnaA9.CYP78A9) of QC14 was identified, and its heterotic effect results from the heterozygous status of a CACTA-like transposable element in its upstream regulatory region, which led to partial dominance at expression and auxin levels, thus resulting in non-additive expression of downstream responsive genes involved in cell cycle and proliferation, eventually leading to the heterosis of cell number. Taken together, the results at the phenotypic, genetic and molecular levels were highly consistent, which demonstrated that the pyramiding effect of heterotic QTL and the multiplicative effect of individual component traits could well explain substantial parts of yield heterosis in oilseed rape. These results provide in-depth insights into the genetic architecture and molecular mechanism of yield heterosis.
PMID: 37170717
Plant Biotechnol J , IF:9.803 , 2023 Jul , V21 (7) : P1408-1425 doi: 10.1111/pbi.14046
Auxin inhibits lignin and cellulose biosynthesis in stone cells of pear fruit via the PbrARF13-PbrNSC-PbrMYB132 transcriptional regulatory cascade.
College of Horticulture, State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing, Jiangsu, China.; The New Zealand Institute for Plant and Food Research Ltd, Mt Albert Research Centre, Auckland, New Zealand.; College of Horticultural Science and Engineering, Shandong Agricultural University, Taian, Shandong, China.
Stone cells are often present in pear fruit, and they can seriously affect the fruit quality when present in large numbers. The plant growth regulator NAA, a synthetic auxin, is known to play an active role in fruit development regulation. However, the genetic mechanisms of NAA regulation of stone cell formation are still unclear. Here, we demonstrated that exogenous application of 200 muM NAA reduced stone cell content and also significantly decreased the expression level of PbrNSC encoding a transcriptional regulator. PbrNSC was shown to bind to an auxin response factor, PbrARF13. Overexpression of PbrARF13 decreased stone cell content in pear fruit and secondary cell wall (SCW) thickness in transgenic Arabidopsis plants. In contrast, knocking down PbrARF13 expression using virus-induced gene silencing had the opposite effect. PbrARF13 was subsequently shown to inhibit PbrNSC expression by directly binding to its promoter, and further to reduce stone cell content. Furthermore, PbrNSC was identified as a positive regulator of PbrMYB132 through analyses of co-expression network of stone cell formation-related genes. PbrMYB132 activated the expression of gene encoding cellulose synthase (PbrCESA4b/7a/8a) and lignin laccase (PbrLAC5) binding to their promotors. As expected, overexpression or knockdown of PbrMYB132 increased or decreased stone cell content in pear fruit and SCW thickness in Arabidopsis transgenic plants. In conclusion, our study shows that the 'PbrARF13-PbrNSC-PbrMYB132' regulatory cascade mediates the biosynthesis of lignin and cellulose in stone cells of pear fruit in response to auxin signals and also provides new insights into plant SCW formation.
PMID: 37031416
Cell Rep , IF:9.423 , 2023 Aug , V42 (8) : P112966 doi: 10.1016/j.celrep.2023.112966
WOX-ARF modules initiate different types of roots.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China. Electronic address: xulin@cemps.ac.cn.
Seed plants have evolved a complex root system consisting of at least three root types, i.e., adventitious roots, lateral roots, and the primary root. Auxin is the key hormone that controls the initiation of different root types. Here, we show that protein complexes with different combinations of intermediate-clade WUSCHEL-RELATED HOMEOBOXs (IC-WOXs) and class-A AUXIN RESPONSE FACTORs (A-ARFs) initiate the three root types in Arabidopsis thaliana. In adventitious root founder cells from detached leaves, the WOX11-ARF6/8 complex activates RGF1 INSENSITIVEs (RGIs) and LATERAL ORGAN BOUNDARIES DOMAIN 16 (LBD16) to initiate the adventitious root primordium. In lateral root founder cells, ARF7/19 activate RGIs and LBD16 without IC-WOX to initiate the lateral root primordium. In the primary root founder cell (i.e., hypophysis of an embryo), the WOX9-ARF5 complex initiates the primary root by activation of RGIs. Overall, the WOX-ARF modules show a division of labor to initiate different type of roots.
PMID: 37556327
Cell Rep , IF:9.423 , 2023 Jul , V42 (7) : P112809 doi: 10.1016/j.celrep.2023.112809
The ABI3-ERF1 module mediates ABA-auxin crosstalk to regulate lateral root emergence.
Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China.; Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China. Electronic address: zhaopingxia2008@163.com.; Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China. Electronic address: xiangcb@ustc.edu.cn.
Abscisic acid (ABA) is involved in lateral root (LR) development, but how ABA signaling interacts with auxin signaling to regulate LR formation is not well understood. Here, we report that ABA-responsive ERF1 mediates the crosstalk between ABA and auxin signaling to regulate Arabidopsis LR emergence. ABI3 is a negative factor in LR emergence and transcriptionally activates ERF1 by binding to its promoter, and reciprocally, ERF1 activates ABI3, which forms a regulatory loop that enables rapid signal amplification. Notably, ABI3 physically interacts with ERF1, reducing the cis element-binding activities of both ERF1 and ABI3 and thus attenuating the expression of ERF1-/ABI3-regulated genes involved in LR emergence and ABA signaling, such as PIN1, AUX1, ARF7, and ABI5, which may provide a molecular rheostat to avoid overamplification of auxin and ABA signaling. Taken together, our findings identify the role of the ABI3-ERF1 module in mediating crosstalk between ABA and auxin signaling in LR emergence.
PMID: 37450369
Cell Rep , IF:9.423 , 2023 Jul , V42 (7) : P112741 doi: 10.1016/j.celrep.2023.112741
RLI2 regulates Arabidopsis female gametophyte and embryo development by facilitating the assembly of the translational machinery.
The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.; Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China.; The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: whlin@sjtu.edu.cn.
Eukaryotic protein translation is a complex process that requires the participation of different proteins. Defects in the translational machinery often result in embryonic lethality or severe growth defects. Here, we report that RNase L inhibitor 2/ATP-BINDING CASSETTE E2 (RLI2/ABCE2) regulates translation in Arabidopsis thaliana. Null mutation of rli2 is gametophytic and embryonic lethal, whereas knockdown of RLI2 causes pleiotropic developmental defects. RLI2 interacts with several translation-related factors. Knockdown of RLI2 affects the translational efficiency of a subset of proteins involved in translation regulation and embryo development, indicating that RLI2 has critical roles in these processes. In particular, RLI2 knockdown mutant exhibits decreased expression of genes involved in auxin signaling and female gametophyte and embryo development. Therefore, our results reveal that RLI2 facilitates assembly of the translational machinery and indirectly modulates auxin signaling to regulate plant growth and development.
PMID: 37421624
Plant Physiol , IF:8.34 , 2023 Aug doi: 10.1093/plphys/kiad431
LIPID TRANSFER PROTEIN4 regulates cotton ceramide content and activates fiber cell elongation.
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China.; Engineering Research Center of Ministry of Education for Cotton Germplasm Enhancement and Application, Nanjing Agricultural University, Nanjing 210095, China.; The Sanya Institute of Nanjing Agricultural University, Sanya, China.
Cell elongation is a fundamental process for plant growth and development. Studies have shown lipid metabolism plays important roles in cell elongation; however, the related functional mechanisms remain largely unknown. Here, we report that cotton (Gossypium hirsutum) LIPID TRANSFER PROTEIN4 (GhLTP4) promotes fiber cell elongation via elevating ceramides (Cers) content and activating auxin-responsive pathways. GhLTP4 was preferentially expressed in elongating fibers. Over-expression and down-regulation of GhLTP4 led to longer and shorter fiber cells, respectively. Cers were greatly enriched in GhLTP4-overexpressing lines and decreased dramatically in GhLTP4-down-regulating lines. Moreover, auxin content and transcript levels of IAA-responsive genes were significantly increased in GhLTP4-overexpressing cotton fibers. Exogenous application of Cers promoted fiber elongation, while NPA (N-1-naphthalic acid, a polar auxin transport inhibitor) counteracted the promoting effect, suggesting that IAA functions downstream of Cers in regulating fiber elongation. Furthermore, we identified a bHLH transcription factor, GhbHLH105, that binds to the E-box element in the GhLTP4 promoter region and promotes the expression of GhLTP4. Suppression of GhbHLH105 in cotton reduced the transcripts level of GhLTP4, resulting in smaller cotton bolls and decreased fiber length. These results provide insights into the complex interactions between lipids and auxin signaling pathways to promote plant cell elongation.
PMID: 37527491
Plant Physiol , IF:8.34 , 2023 Jul doi: 10.1093/plphys/kiad397
FUSCA3-induced AINTEGUMENTA-like 6 manages seed dormancy and lipid metabolism.
College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China.; College of Life sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
FUSCA 3 (FUS3), a seed master regulator, plays critical roles in seed dormancy and oil accumulation. However, its downstream regulation mechanisms remain poorly understood. Here, we explored the roles of AINTEGUMENTA-like 6 (AIL6), a seed transcription factor, in these processes. The activation of AIL6 by FUS3 was demonstrated by dual-LUC assay. Seeds of ail6 mutants showed alterations of fatty acid compositions, and both AtAIL6 (AIL6 from Arabidopsis thaliana) and BnaAIL6 (AIL6 from Brassica napus) rescued the phenotype. Over-expression (OE) of AIL6s reversed changes in seed fatty acid composition. Notably, OE lines showed low seed germination rates down to 12% compared to 100% of wild-type Col-0. Transcriptome analysis of the mutant and an OE line indicated widespread expression changes of genes involved in lipid metabolism and phytohormone pathways. In OE mature seeds, GA4 content decreased more than 15-fold, while ABA and IAA contents clearly increased. Exogenous GA3 treatments did not effectively rescue the low germination rate. Nicking seed coats increased germination rates from 25% to nearly 80% while the wild-type rdr6-11 is 100% and 98% respectively, and elongation of storage time also improved seed germination. Furthermore, dormancy imposed by AIL6 was fully released in the della quintuple mutant. Together, our results indicate AIL6 acts as a manager downstream of FUS3 in seed dormancy and lipid metabolism.
PMID: 37418568
Plant Physiol , IF:8.34 , 2023 Jun 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, 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 , V192 (4) : P2838-2854 doi: 10.1093/plphys/kiad289
miR171-targeted SCARECROW-LIKE genes CsSCL2 and CsSCL3 regulate somatic embryogenesis in citrus.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.; Hubei Hongshan Laboratory, Wuhan 430070, China.
Somatic embryogenesis (SE) is a key regeneration pathway in various biotechnology approaches to crop improvement, especially for economically important perennial woody crops like citrus. However, maintenance of SE capability has long been a challenge and becomes a bottleneck in biotechnology-facilitated plant improvement. In the embryogenic callus (EC) of citrus, we identified 2 csi-miR171c-targeted SCARECROW-LIKE genes CsSCL2 and CsSCL3 (CsSCL2/3), which exert positive feedback regulation on csi-miR171c expression. Suppression of CsSCL2 expression by RNA interference (RNAi) enhanced SE in citrus callus. A thioredoxin superfamily protein CsClot was identified as an interactive protein of CsSCL2/3. Overexpression of CsClot disturbed reactive oxygen species (ROS) homeostasis in EC and enhanced SE. Chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA-Seq identified 660 genes directly suppressed by CsSCL2 that were enriched in biological processes including development-related processes, auxin signaling pathway, and cell wall organization. CsSCL2/3 bound to the promoters of regeneration-related genes, such as WUSCHEL-RELATED HOMEOBOX 2 (CsWOX2), CsWOX13, and Lateral Organ Boundaries Domain 40 (LBD40), and repressed their expression. Overall, CsSCL2/3 modulate ROS homeostasis through the interactive protein CsClot and directly suppress the expression of regeneration-related genes, thus regulating SE in citrus. We uncovered a regulatory pathway of miR171c-targeted CsSCL2/3 in SE, which shed light on the mechanism of SE and regeneration capability maintenance in citrus.
PMID: 37204807
Plant Physiol , IF:8.34 , 2023 Aug , V192 (4) : P3189-3202 doi: 10.1093/plphys/kiad254
Integration of multiple stress signals in plants using synthetic Boolean logic gates.
Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.; BioDiscovery Institute, University of North Texas, Denton, TX 76203, USA.
As photosynthetic organisms, plants have a potential role in the sustainable production of high-value products such as medicines, biofuels, and chemical feedstocks. With effective engineering using synthetic biology approaches, plant-based platforms could conceivably be designed to minimize the costs and waste of production for materials that would otherwise be uneconomical. Additionally, modern agricultural crops could be engineered to be more productive, resilient, or restorative in different or rapidly changing environments and climates. Information-processing genetic devices and circuits containing multiple interacting parts that behave predictably must be developed to achieve these complex goals. A genetic Boolean AND logic gate is a device that computes the presence or absence of 2 inputs (signals and stimuli) and produces an output (response) only when both inputs are present. We optimized individual genetic components and used synthetic protein heterodimerizing domains to rationally assemble genetic AND logic gates that integrate 2 hormonal inputs in transgenic Arabidopsis thaliana plants. These AND gates produce an output only in the presence of both abscisic acid and auxin but not when either or neither hormone is present. The AND logic gate can also integrate signals resulting from 2 plant stresses, cold temperature and bacterial infection, to produce a response. The design principles used here are generalizable, and, therefore, multiple orthogonal AND gates could be assembled and rationally layered to process complex genetic information in plants. These layered logic gates may be used in genetic circuits to probe fundamental questions in plant biology, such as hormonal crosstalk, in addition to plant engineering for bioproduction.
PMID: 37119276
Plant Physiol , IF:8.34 , 2023 Aug , V192 (4) : P2687-2702 doi: 10.1093/plphys/kiad248
WAVE-DAMPENED2-LIKE4 modulates the hyper-elongation of light-grown hypocotyl cells.
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Light, temperature, water, and nutrient availability influence how plants grow to maximize access to resources. Axial growth, the linear extension of tissues by coordinated axial cell expansion, plays a central role in these adaptive morphological responses. Using Arabidopsis (Arabidopsis thaliana) hypocotyl cells to explore axial growth control mechanisms, we investigated WAVE-DAMPENED2-LIKE4 (WDL4), an auxin-induced, microtubule-associated protein and member of the larger WDL gene family shown to modulate hypocotyl growth under changing environmental conditions. Loss-of-function wdl4 seedlings exhibited a hyper-elongation phenotype under light conditions, continuing to elongate when wild-type Col-0 hypocotyls arrested and reaching 150% to 200% of wild-type length before shoot emergence. wdl4 seedling hypocotyls showed dramatic hyper-elongation (500%) in response to temperature elevation, indicating an important role in morphological adaptation to environmental cues. WDL4 was associated with microtubules under both light and dark growth conditions, and no evidence was found for altered microtubule array patterning in loss-of-function wdl4 mutants under various conditions. Examination of hormone responses showed altered sensitivity to ethylene and evidence for changes in the spatial distribution of an auxin-dependent transcriptional reporter. Our data provide evidence that WDL4 regulates hypocotyl cell elongation without substantial changes to microtubule array patterning, suggesting an unconventional role in axial growth control.
PMID: 37096683
Plant Physiol , IF:8.34 , 2023 Jul , V192 (3) : P2336-2355 doi: 10.1093/plphys/kiad205
Modulating auxin response stabilizes tomato fruit set.
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University, PO Box 12, Rehovot 76100, Israel.; Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Halle 06120, Germany.; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, Umea 901 83, Sweden.
Fruit formation depends on successful fertilization and is highly sensitive to weather fluctuations that affect pollination. Auxin promotes fruit initiation and growth following fertilization. Class A auxin response factors (Class A ARFs) repress transcription in the absence of auxin and activate transcription in its presence. Here, we explore how multiple members of the ARF family regulate fruit set and fruit growth in tomato (Solanum lycopersicum) and Arabidopsis thaliana, and test whether reduction of SlARF activity improves yield stability in fluctuating temperatures. We found that several tomato Slarf mutant combinations produced seedless parthenocarpic fruits, most notably mutants deficient in SlARF8A and SlARF8B genes. Arabidopsis Atarf8 mutants deficient in the orthologous gene had less complete parthenocarpy than did tomato Slarf8a Slarf8b mutants. Conversely, Atarf6 Atarf8 double mutants had reduced fruit growth after fertilization. AtARF6 and AtARF8 likely switch from repression to activation of fruit growth in response to a fertilization-induced auxin increase in gynoecia. Tomato plants with reduced SlARF8A and SlARF8B gene dosage had substantially higher yield than the wild type under controlled or ambient hot and cold growth conditions. In field trials, partial reduction in the SlARF8 dose increased yield under extreme temperature with minimal pleiotropic effects. The stable yield of the mutant plants resulted from a combination of early onset of fruit set, more fruit-bearing branches and more flowers setting fruits. Thus, ARF8 proteins mediate the control of fruit set, and relieving this control with Slarf8 mutations may be utilized in breeding to increase yield stability in tomato and other crops.
PMID: 37032117
Plant Physiol , IF:8.34 , 2023 Jul , V192 (3) : P2457-2474 doi: 10.1093/plphys/kiad197
The trans-zeatin-type side-chain modification of cytokinins controls rice growth.
Graduate School of Bioagricultural Sciences, Nagoya University, Furocho, Chikusa-ku, Nagoya 464-8601, Japan.; RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro, Tsurumi, Yokohama 230-0045, Japan.; Biosci. Biotech Center, Nagoya University, Furocho, Chikusa-ku, Nagoya 464-8601, Japan.; Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan.; Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima 770-8503, Japan.
Cytokinins (CKs), a class of phytohormones with vital roles in growth and development, occur naturally with various side-chain structures, including N6-(Delta2-isopentenyl)adenine-, cis-zeatin- and trans-zeatin (tZ)-types. Recent studies in the model dicot plant Arabidopsis (Arabidopsis thaliana) have demonstrated that tZ-type CKs are biosynthesized via cytochrome P450 monooxygenase (P450) CYP735A and have a specific function in shoot growth promotion. Although the function of some of these CKs has been demonstrated in a few dicotyledonous plant species, the importance of these variations and their biosynthetic mechanism and function in monocots and in plants with distinctive side-chain profiles other than Arabidopsis, such as rice (Oryza sativa), remain elusive. In this study, we characterized CYP735A3 and CYP735A4 to investigate the role of tZ-type CKs in rice. Complementation test of the Arabidopsis CYP735A-deficient mutant and CK profiling of loss-of-function rice mutant cyp735a3 cyp735a4 demonstrated that CYP735A3 and CYP735A4 encode P450s required for tZ-type side-chain modification in rice. CYP735As are expressed in both roots and shoots. The cyp735a3 cyp735a4 mutants exhibited growth retardation concomitant with reduction in CK activity in both roots and shoots, indicating that tZ-type CKs function in growth promotion of both organs. Expression analysis revealed that tZ-type CK biosynthesis is negatively regulated by auxin, abscisic acid, and CK and positively by dual nitrogen nutrient signals, namely glutamine-related and nitrate-specific signals. These results suggest that tZ-type CKs control the growth of both roots and shoots in response to internal and environmental cues in rice.
PMID: 36994817
Plant Physiol , IF:8.34 , 2023 Jul , V192 (3) : P1836-1857 doi: 10.1093/plphys/kiad099
MicroRNA156ab regulates apple plant growth and drought tolerance by targeting transcription factor MsSPL13.
Department of Pomology, College of Horticulture, China Agricultural University, Beijing 100193, China.
Drought stress substantially reduces the productivity of apple plants and severely restricts the development of apple industry. Malus sieversii, wild apples with excellent drought resistance, is a valuable wild resource for a rootstock improvement of cultivated apple (Malus domestica). miRNAs and their targets play essential roles in plant growth and stress responses, but their roles in drought stress responses in apple are unknown. Here, we demonstrate that microRNA156ab is upregulated in M. sieversii in response to drought stress. Overexpressing msi-miR156ab promoted auxin accumulation, maintained the growth of apple plants, and increased plant resistance to osmotic stress. Antioxidant enzyme activities and proline contents were also increased in miR156ab-OE transgenic apple lines, which improved drought resistance. The squamosa promoter binding protein-like transcription factor MsSPL13 is the target of msi-miR156ab, as demonstrated by 5'-RACE and dual luciferase assays. Heterologous expression of MsSPL13 decreased auxin contents and inhibited growth in Arabidopsis (Arabidopsis thaliana) under normal and stress conditions. The activities of antioxidant enzymes were also suppressed in MsSPL13-OE transgenic Arabidopsis, reducing drought resistance. We showed that MsSPL13 regulates the expression of the auxin-related genes MsYUCCA5, PIN-FORMED7 (MsPIN7), and Gretchen Hagen3-5 (MsGH3-5) by binding to the GTAC cis-elements in their promoters, thereby regulating auxin metabolism. Finally, we demonstrated that the miR156ab-SPL13 module is involved in mediating the difference in auxin metabolism and stress responses between M. sieversii and M26 (M. domestica) rootstocks. Overall, these findings reveal that the miR156ab-SPL13 module enhances drought stress tolerance in apples by regulating auxin metabolism and antioxidant enzyme activities.
PMID: 36805285
Elife , IF:8.14 , 2023 Jul , V12 doi: 10.7554/eLife.85193
The AUX1-AFB1-CNGC14 module establishes a longitudinal root surface pH profile.
Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.; Institute of Cell and Interaction Biology, Heinrich-Heine-University Dusseldorf, Dusseldorf, Germany.; Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czech Republic.; CEPLAS - Cluster of Excellence on Plant Sciences, Heinrich-Heine-University Dusseldorf, Dusseldorf, Germany.
Plant roots navigate in the soil environment following the gravity vector. Cell divisions in the meristem and rapid cell growth in the elongation zone propel the root tips through the soil. Actively elongating cells acidify their apoplast to enable cell wall extension by the activity of plasma membrane AHA H(+)-ATPases. The phytohormone auxin, central regulator of gravitropic response and root development, inhibits root cell growth, likely by rising the pH of the apoplast. However, the role of auxin in the regulation of the apoplastic pH gradient along the root tip is unclear. Here, we show, by using an improved method for visualization and quantification of root surface pH, that the Arabidopsis thaliana root surface pH shows distinct acidic and alkaline zones, which are not primarily determined by the activity of AHA H(+)-ATPases. Instead, the distinct domain of alkaline pH in the root transition zone is controlled by a rapid auxin response module, consisting of the AUX1 auxin influx carrier, the AFB1 auxin co-receptor, and the CNCG14 calcium channel. We demonstrate that the rapid auxin response pathway is required for an efficient navigation of the root tip.
PMID: 37449525
PLoS Biol , IF:8.029 , 2023 Jul , V21 (7) : Pe3002189 doi: 10.1371/journal.pbio.3002189
Structural and biochemical characterization of the key components of an auxin degradation operon from the rhizosphere bacterium Variovorax.
State Key Laboratory of Experimental Hematology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Haihe Laboratory of Cell Ecosystem, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China.; YDS Pharmatech, Albany, New York, United States of America.; The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Tianjin Medical University; Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, China.; State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, China.
Plant-associated bacteria play important regulatory roles in modulating plant hormone auxin levels, affecting the growth and yields of crops. A conserved auxin degradation (iad) operon was recently identified in the Variovorax genomes, which is responsible for root growth inhibition (RGI) reversion, promoting rhizosphere colonization and root growth. However, the molecular mechanism underlying auxin degradation by Variovorax remains unclear. Here, we systematically screened Variovorax iad operon products and identified 2 proteins, IadK2 and IadD, that directly associate with auxin indole-3-acetic acid (IAA). Further biochemical and structural studies revealed that IadK2 is a highly IAA-specific ATP-binding cassette (ABC) transporter solute-binding protein (SBP), likely involved in IAA uptake. IadD interacts with IadE to form a functional Rieske non-heme dioxygenase, which works in concert with a FMN-type reductase encoded by gene iadC to transform IAA into the biologically inactive 2-oxindole-3-acetic acid (oxIAA), representing a new bacterial pathway for IAA inactivation/degradation. Importantly, incorporation of a minimum set of iadC/D/E genes could enable IAA transformation by Escherichia coli, suggesting a promising strategy for repurposing the iad operon for IAA regulation. Together, our study identifies the key components and underlying mechanisms involved in IAA transformation by Variovorax and brings new insights into the bacterial turnover of plant hormones, which would provide the basis for potential applications in rhizosphere optimization and ecological agriculture.
PMID: 37459330
Sci Total Environ , IF:7.963 , 2023 Jul , 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 Jul , 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 Jul , 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 Jun , 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 Jun , 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
Curr Opin Plant Biol , IF:7.834 , 2023 Aug , V74 : P102377 doi: 10.1016/j.pbi.2023.102377
How do plants reprogramme the fate of differentiated cells?
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan. Electronic address: hatsune.morinaka@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.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology (PRESTO), 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan.; 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.
Being able to change cell fate after differentiation highlights the remarkable developmental plasticity of plant cells. Recent studies show that phytohormones, such as auxin and cytokinin, promote cell cycle reactivation, a critical first step to reprogramme mitotically inactive, differentiated cells into organogenic stem cells. Accumulating evidence suggests that wounding provides an additional cue to convert the identity of differentiated cells by promoting the loss of existing cell fate and/or acquisition of new cell fate. Differentiated cells can also alter cell fate without undergoing cell division and in this case, wounding and phytohormones induce master regulators that can directly assign new cell fate.
PMID: 37167921
Plant Cell Environ , IF:7.228 , 2023 Aug doi: 10.1111/pce.14680
UV-B responses in the spotlight: Dynamic photoreceptor interplay and cell-type specificity.
Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium.; Department of Agricultural Economics, Ghent University, Coupure Links 653 B-9000, Ghent, Belgium.
Plants are constantly exposed to a multitude of external signals, including light. The information contained within the full spectrum of light is perceived by a battery of photoreceptors, each with specific and shared signalling outputs. Recently, it has become clear that UV-B radiation is a vital component of the electromagnetic spectrum, guiding growth and being crucial for plant fitness. However, given the large overlap between UV-B specific signalling pathways and other photoreceptors, understanding how plants can distinguish UV-B specific signals from other light components deserves more scrutiny. With recent evidence, we propose that UV-B signalling and other light signalling pathways occur within distinct tissues and cell-types and that the contribution of each pathway depends on the type of response and the developmental stage of the plant. Elucidating the precise site(s) of action of each molecular player within these signalling pathways is key to fully understand how plants are able to orchestrate coordinated responses to light within the whole plant body. Focusing our efforts on the molecular study of light signal interactions to understand plant growth in natural environments in a cell-type specific manner will be a next step in the field of photobiology.
PMID: 37554043
Plant Cell Environ , IF:7.228 , 2023 Jul doi: 10.1111/pce.14670
The fungal metabolite 4-hydroxyphenylacetic acid from Neofusicoccum parvum modulates defence responses in grapevine.
Department of Molecular Cell Biology, Joseph Gottlieb Kolreuter Institute of Plant Science, Karlsruhe Institute of Technology, Karlsruhe, Germany.; INRAE, SVQV UMR-A 1131, Universite de Strasbourg, Colmar, France.; Institut fur Biotechnologie und Wirkstoff-Forschung gGmbH, Mainz, Germany.; Institute for Biological Interfaces 5, Karlsruhe Institute of Technology, Karlsruhe, Germany.; Department of Horticulture, Faculty of Agriculture, Damanhour University, Damanhour, Egypt.
In a consequence of global warming, grapevine trunk diseases (GTDs) have become a pertinent problem to viticulture, because endophytic fungi can turn necrotrophic upon host stress killing the plant. In Neofusicoccum parvum Bt-67, plant-derived ferulic acid makes the fungus release Fusicoccin aglycone triggering plant cell death. Now, we show that the absence of ferulic acid lets the fungus secrete 4-hydroxyphenylacetic acid (4-HPA), mimicking the effect of auxins on grapevine defence and facilitating fungal spread. Using Vitis suspension cells, we dissected the mode of action of 4-HPA during defence triggered by the bacterial cell-death elicitor, harpin. Early responses (cytoskeletal remodelling and calcium influx) are inhibited, as well as the expression of Stilbene Synthase 27 and phytoalexin accumulation. In contrast to other auxins, 4-HPA quells transcripts for the auxin conjugating GRETCHEN HAGEN 3. We suggest that 4-HPA is a key component of the endophytic phase of N. parvum Bt-67 preventing host cell death. Therefore, our study paves the way to understand how GTDs regulate their latent phase for successful colonisation, before turning necrotrophic and killing the vines.
PMID: 37431974
Microbiol Spectr , IF:7.171 , 2023 Aug , V11 (4) : Pe0151023 doi: 10.1128/spectrum.01510-23
Volatile Organic Compounds Emitted by the Biocontrol Agent Pythium oligandrum Contribute to Ginger Plant Growth and Disease Resistance.
Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China.; School of Biosciences, University of Birmingham, Birmingham, United Kingdom.; Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, China.; Fungal Genomics Laboratory (FungiG), Jiangsu Provincial Key Lab of Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, China.; College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, Henan, China.; Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China.; Jiangsu Coastal Ecological Science and Technology Development Co., Ltd., Nanjing, China.
The oomycete Pythium oligandrum is a potential biocontrol agent to control a wide range of fungal and oomycete-caused diseases, such as Pythium myriotylum-caused rhizome rot in ginger, leading to reduced yields and compromised quality. Previously, P. oligandrum has been studied for its plant growth-promoting potential by auxin production and induction of disease resistance by elicitors such as oligandrin. Volatile organic compounds (VOCs) play beneficial roles in sustainable agriculture by enhancing plant growth and resistance. We investigated the contribution of P. oligandrum-produced VOCs on plant growth and disease suppression by initially using Nicotiana benthamiana plants for screening. P. oligandrum VOCs significantly enhanced tobacco seedling and plant biomass contents. Screening of the individual VOCs showed that 3-octanone and hexadecane promoted the growth of tobacco seedlings. The total VOCs from P. oligandrum also enhanced the shoot and root growth of ginger plants. Transcriptomic analysis showed a higher expression of genes related to plant growth hormones and stress responses in the leaves of ginger plants exposed to P. oligandrum VOCs. The concentrations of plant growth hormones such as auxin, zeatin, and gibberellic acid were higher in the leaves of ginger plants exposed to P. oligandrum VOCs. In a ginger disease biocontrol assay, the VOC-exposed ginger plants infected with P. myriotylum had lower levels of disease severity. We conclude that this study contributes to understanding the growth-promoting mechanisms of P. oligandrum on ginger and tobacco, priming of ginger plants against various stresses, and the mechanisms of action of P. oligandrum as a biocontrol agent. IMPORTANCE Plant growth promotion plays a vital role in enhancing production of agricultural crops, and Pythium oligandrum is known for its plant growth-promoting potential through production of auxins and induction of resistance by elicitors. This study highlights the significance of P. oligandrum-produced VOCs in plant growth promotion and disease resistance. Transcriptomic analyses of leaves of ginger plants exposed to P. oligandrum VOCs revealed the upregulation of genes involved in plant growth hormone signaling and stress responses. Moreover, the concentration of growth hormones significantly increased in P. oligandrum VOC-exposed ginger plants. Additionally, the disease severity was reduced in P. myriotylum-infected ginger plants exposed to P. oligandrum VOCs. In ginger, P. myriotylum-caused rhizome rot disease results in severe losses, and biocontrol has a role as part of an integrated pest management strategy for rhizome rot disease. Overall, growth enhancement and disease reduction in plants exposed to P. oligandrum-produced VOCs contribute to its role as a biocontrol agent.
PMID: 37534988
Chemosphere , IF:7.086 , 2023 Aug : 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 Integr Plant Biol , IF:7.061 , 2023 Aug doi: 10.1111/jipb.13554
The advantages of crosstalk during the evolution of the BZR1-ARF6-PIF4 (BAP) module.
College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
The BAP module, comprising BRASSINAZOLE RESISTANT 1 (BZR1), AUXIN RESPONSE FACTOR 6 (ARF6), and PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), functions as a molecular hub to orchestrate plant growth and development. In Arabidopsis thaliana, components of the BAP module physically interact to form a complex system that integrates light, brassinosteroid (BR), and auxin signals. Little is known about the origin and evolution of the BAP module. Here, we conducted comparative genomic and transcriptomic analyses to investigate the evolution and functional diversification of the BAP module. Our results suggest that the BAP module originated in land plants and that the zeta, epsilon, and gamma whole-genome duplication/triplication events contributed to the expansion of BAP module components in seed plants. Comparative transcriptomic analysis suggested that the prototype BAP module arose in Marchantia polymorpha, experienced stepwise evolution, and became established as a mature regulatory system in seed plants. We developed a formula to calculate the signal transduction productivity of the BAP module and demonstrate that more crosstalk among components enables higher signal transduction efficiency. Our results reveal the evolutionary history of the BAP module and provide insights into the evolution of plant signaling networks and the strategies employed by plants to integrate environmental and endogenous signals. This article is protected by copyright. All rights reserved.
PMID: 37552560
J Integr Plant Biol , IF:7.061 , 2023 Jul , V65 (7) : P1753-1766 doi: 10.1111/jipb.13484
Auxin signaling module OsSK41-OsIAA10-OsARF regulates grain yield traits in rice.
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; College of Agronomy, Anhui Agricultural University, Hefei, 230036, China.; Institute of Crop Breeding and Cultivation, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, China.; Institute of Genetics and Regenerative Biology, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518100, China.
Auxin is an important phytohormone in plants, and auxin signaling pathways in rice play key roles in regulating its growth, development, and productivity. To investigate how rice grain yield traits are regulated by auxin signaling pathways and to facilitate their application in rice improvement, we validated the functional relationships among regulatory genes such as OsIAA10, OsSK41, and OsARF21 that are involved in one of the auxin (OsIAA10) signaling pathways. We assessed the phenotypic effects of these genes on several grain yield traits across two environments using knockout and/or overexpression transgenic lines. Based on the results, we constructed a model that showed how grain yield traits were regulated by OsIAA10 and OsTIR1, OsAFB2, and OsSK41 and OsmiR393 in the OsSK41-OsIAA10-OsARF module and by OsARF21 in the transcriptional regulation of downstream auxin response genes in the OsSK41-OsIAA10-OsARF module. The population genomic analyses revealed rich genetic diversity and the presence of major functional alleles at most of these loci in rice populations. The strong differentiation of many major alleles between Xian/indica and Geng/japonica subspecies and/or among modern varieties and landraces suggested that they contributed to improved productivity during evolution and breeding. We identified several important aspects associated with the genetic and molecular bases of rice grain and yield traits that were regulated by auxin signaling pathways. We also suggested rice auxin response factor (OsARF) activators as candidate target genes for improving specific target traits by overexpression and/or editing subspecies-specific alleles and by searching and pyramiding the 'best' gene allelic combinations at multiple regulatory genes in auxin signaling pathways in rice breeding programs.
PMID: 36939166
J Integr Plant Biol , IF:7.061 , 2023 Jul , V65 (7) : P1767-1781 doi: 10.1111/jipb.13473
An ARF24-ZmArf2 module influences kernel size in different maize haplotypes.
State Key Laboratory of Wheat and Maize Crop Science, Henan Maize Engineering Technology Joint Center, College of Agronomy, and Center for Crop Genome Engineering, Longzi Lake Campus, Henan Agricultural University, Zhengzhou, 450046, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Members of the ADP-ribosylation factor family, which are GTP-binding proteins, are involved in metabolite transport, cell division, and expansion. Although there has been a significant amount of research on small GTP-binding proteins, their roles and functions in regulating maize kernel size remain elusive. Here, we identified ZmArf2 as a maize ADP-ribosylation factor-like family member that is highly conserved during evolution. Maize zmarf2 mutants showed a characteristic smaller kernel size. Conversely, ZmArf2 overexpression increased maize kernel size. Furthermore, heterologous expression of ZmArf2 dramatically elevated Arabidopsis and yeast growth by promoting cell division. Using expression quantitative trait loci (eQTL) analysis, we determined that ZmArf2 expression levels in various lines were mainly associated with variation at the gene locus. The promoters of ZmArf2 genes could be divided into two types, pS and pL, that were significantly associated with both ZmArf2 expression levels and kernel size. In yeast-one-hybrid screening, maize Auxin Response Factor 24 (ARF24) is directly bound to the ZmArf2 promoter region and negatively regulated ZmArf2 expression. Notably, the pS and pL promoter types each contained an ARF24 binding element: an auxin response element (AuxRE) in pS and an auxin response region (AuxRR) in pL, respectively. ARF24 binding affinity to AuxRR was much higher compared with AuxRE. Overall, our results establish that the small G-protein ZmArf2 positively regulates maize kernel size and reveals the mechanism of its expression regulation.
PMID: 36866706
J Exp Bot , IF:6.992 , 2023 Aug doi: 10.1093/jxb/erad325
Auxin and Abiotic Stress Responses.
Department of Biology, Duke University, Durham, NC 27008, USA.
Plants are exposed to a variety of abiotic stresses; these stresses have profound effects on plant growth, survival, and productivity. Tolerance and adaptation to stress require sophisticated stress sensing, signaling, and various regulatory mechanisms. The plant hormone auxin is a key regulator of plant growth and development, playing pivotal roles in the integration of abiotic stress signals and control of downstream stress responses. In this review, we summarize and discuss recent advances in understanding the intersection of auxin and abiotic stress in plants, with a focus on temperature, salt, and drought stresses. We also explore the auxin roles in stress tolerance and arising opportunities for agricultural applications.
PMID: 37591508
J Exp Bot , IF:6.992 , 2023 Aug doi: 10.1093/jxb/erad324
Molecular regulation of apple and grape ripening: exploring common and distinct transcriptional aspects of representative climacteric and non-climacteric fruits.
Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.; Department of Agricultural, Forest and Food Sciences - University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy.; Research and Innovation Centre, Fondazione Edmund Mach, Via Mach 1, 39098 San Michele all'Adige (Trento), Italy.; Center Agriculture Food Environment (C3A), University of Trento, Via Mach 1, 39098 San Michele all'Adige (Trento), Italy.
Fleshy fruits of angiosperms are organs specialized for promoting seed dispersal by attracting herbivores and enticing them to consume the organ and the contained seeds. Ripening can be broadly defined as the processes serving as a plant strategy to make the fleshy fruit appealing to animals and leads to a coordinated series of changes in color, texture, aroma and flavor, as result of an intricate interplay of genetically and epigenetically programmed events. The ripening of fruits can be categorized into two types: climacteric, which is characterized by a rapid increase in respiration rate typically accompanied by a burst of ethylene production, and non-climacteric, where this pronounced peak in respiration is absent. Here we review the most current knowledge on transcriptomic changes taking place in apple (climacteric) and grapevine (non-climacteric) fruit during ripening, with the aim to highlight specific and common hormonal and molecular events governing the process in both species. In this perspective, we found that specific NAC transcription factor members participate in the ripening initiation in grape and are involved in the attempt to restore the normal physiological ripening progression in impaired fruit ripening physiology in apple. These elements suggest the existence of a common regulatory mechanism operated by NAC transcription factors and auxin in the two species.
PMID: 37591311
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad299
The ratio of auxin to cytokinin controls leaf development and meristem initiation in Physcomitrium patens.
School of Integrative Plant Science, Section of Plant Biology, Cornell University, Ithaca, NY.; Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY.; Seeds Research, Syngenta Crop Protection, Research Triangle Park, North Carolina, United States.
Crosstalk between auxin and cytokinin contributes to widespread developmental processes, including root and shoot meristem maintenance, phyllotaxy, and vascular patterning. However, our understanding of crosstalk between these hormones is limited primarily to angiosperms. The moss Physcomitrium patens (formerly Physcomitrella patens) is a powerful system for studying plant hormone function. Auxin and cytokinin play similar roles in regulating moss gametophore (shoot) architecture, as they do in flowering plant shoots. However, auxin-cytokinin crosstalk is poorly understood in moss. Here we find that the ratio of auxin to cytokinin is an important determinant of development in P. patens, especially during leaf development and branch stem cell initiation. Addition of high levels of auxin to P. patens gametophores blocks leaf outgrowth. However, simultaneous addition of high levels of both auxin and cytokinin partially restores leaf outgrowth, suggesting that the ratio of these hormones is the predominant factor. Likewise, during branch initiation and outgrowth, chemical inhibition of auxin synthesis phenocopies cytokinin application. Finally, cytokinin insensitive mutants resemble plants with altered auxin signaling and are hypersensitive to auxin. In summary, our results suggest that the ratio between auxin and cytokinin signaling is the basis for developmental decisions in the moss gametophore.
PMID: 37498739
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad297
Roles of auxin pathways in maize biology.
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA.
Phytohormones play a central role in plant development and environmental responses. Auxin is a classical hormone that is required for organ formation, tissue patterning, and defense responses. Auxin pathways have been extensively studied across numerous land plant lineages, including bryophytes and eudicots. In contrast, our understanding of the roles of auxin in maize morphogenesis and immune responses are limited. Here, we will review evidence for auxin-mediated processes in maize and describe promising areas for future research in the auxin field. Several recent transcriptomic and genetic studies have demonstrated that auxin is a key influencer of both vegetative and reproductive development in maize (namely roots, leaves and kernels). Auxin signaling has been implicated in both maize shoot architecture and immune responses through genetic and molecular analyses of the conserved co-repressor RAMOSA ENHANCER LOCUS2. Polar auxin transport is linked to maize drought responses, root growth, shoot formation, and leaf morphogenesis. Notably, maize has been a key system for delineating auxin biosynthetic pathways and offers many opportunities for future investigations on auxin metabolism. In addition, crosstalk between auxin and other phytohormones has been uncovered through gene expression studies and are important for leaf and root development in maize. Collectively these studies point to auxin as a cornerstone for maize biology that could be leveraged for improved crop resilience and yield.
PMID: 37493143
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad284
A roadmap of haustorium morphogenesis in parasitic plants.
BESE Division, Plant Cell and Developmental Biology, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.; BESE Division, The BioActives Lab, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
Parasitic plants invade their host through their invasive organ, the haustoria. This organ connects to the vasculature of the host roots and hijacks water and nutrients. Although plant parasitism has evolved independently in plants, haustoria formation follows a similar mechanism throughout different plant species, highlighting the developmental plasticity of plant tissues. Here, we compare three types of haustoria formed by root and shoot in the plant parasites Striga and Cuscuta. We discuss mechanisms underlying the interactions with their hosts and how different approaches have contributed to major understanding of haustoria formation and host invasion. We also illustrate the role of auxin and cytokinin in controlling this process.
PMID: 37486862
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad292
StHAB1, a negative regulatory factor in abscisic acid signaling, plays crucial roles in potato drought tolerance and shoot branching.
National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Ministry of Agriculture and Rural Affairs, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.; College of Plant Science, Tarim University, Alar, Xinjiang, 843300, People's Republic of China.; Zhangjiakou Academy of Agriculture Sciences, Zhangjiakou, Hebei 075000, People's Republic of China.
Abscisic acid (ABA) is critical in drought tolerance and plant growth. Group A protein type 2C phosphatases (PP2Cs) are negative regulators of ABA signaling and plant adaptation to stress. However, our knowledge about the functions of potato group A PP2Cs is limited. Here, we report that potato group A PP2C StHAB1 is broadly expressed in potato plants and strongly induced by ABA and drought. Suppression of StHAB1 enhanced potato ABA sensitivity and drought tolerance, whereas overexpression of the dominant mutant StHAB1G276D compromised ABA sensitivity and drought tolerance. StHAB1 interacts with almost all ABA receptors and the Snf1-Related Kinase OST1. Suppressing StHAB1 and overexpressing StHAB1G276D alter potato growth morphology; notably, overexpression of StHAB1G276D causes excessive shoot branching in potato. RNA-seq analyses identified that auxin efflux carrier genes, StPIN3, StPIN5, and StPIN8, were upregulated in StHAB1G276D-overexpressed axillary buds. Correspondingly, auxin concentration was reduced in StHAB1G276D-overexpressed axillary buds, consistent with the repressing role of auxin in lateral branch outgrowth. The expression of BRANCHED1s (StBRC1a and StBRC1b) does not change in StHAB1G276D-overexpressed axillary buds, suggesting that overexpression of StHAB1G276D caused axillary bud outgrowth is not due to regulating BRC1 expression. Our findings demonstrate that StHAB1 is vital in potato drought tolerance and shoot branching.
PMID: 37479226
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad288
Auxins and Grass Shoot Architecture: How the Most Important Hormone Makes the Most Important Plants.
School of Biology, Faculty of Biological Sciences, University of Leeds.
Cereals are a group of grasses cultivated by humans for their grain. It is from these cereal grains that the majority of all human calorie consumption is derived. The production of these grains is the result of the development of a series of hierarchical reproductive structures that form the distinct shoot architecture of the grasses. Being spatiotemporally complex, the coordination of grass shoot development is tightly controlled by a network of genes and signals, including the key phytohormone auxin. Hormonal manipulation has therefore been identified as a promising potential approach to increasing cereal crop yields and therefore ultimately global food security. Recent work translating the substantial body of auxin research from model plants into cereal crop species is revealing the contribution of auxin biosynthesis, transport and signalling to the development of grass shoot architecture. This review discusses this still-maturing knowledge base and examines the possibility that changes in auxin biology could have been a causative agent in the evolution of differences in shoot architecture between key grass species, or could underpin the future selective breeding of cereal crops.
PMID: 37474124
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad272
Game of Thrones among AUXIN RESPONSE FACTORs - over thirty years of MONOPTEROS research.
Mendel Centre for Genomics and Proteomics of Plants Systems, CEITEC MU - Central European Institute of Technology, Masaryk University, Brno, Czech Republic.; Institute of Biology, Biotechnology, and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice, Poland.; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia.
For many years, research has been carried out to understand the mechanism of auxin action, its biosynthesis, catabolism, perception, and transport. One central interest is understanding the auxin-dependent gene expression regulation mechanism involving AUXIN RESPONSE FACTOR (ARF) transcription factors and their repressors, the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins. Numerous studies have been focused on the MONOPTEROS (MP)/ARF5, an activator of auxin-dependent gene expression with a crucial impact on plant development. This review paper summarizes over thirty years of research on MP/ARF5. We indicate the available analytical tools to study MP/ARF5 and point out the known mechanism of MP/ARF5-dependent regulation of gene expression during various developmental processes, i.e., embryogenesis, leaf formation, vascularization, and shoot and root meristem formation. However, many questions remain about the auxin-dose-dependent regulation of gene transcription by MP/ARF5 and its isoforms in plant cells, the composition of the MP/ARF5 protein complex, and finally, the list of genes under its direct control. In addition, the information on post-translational modifications of MP/ARF5 protein is marginal, and knowledge about their consequences on MP/ARF5 function is limited. Moreover, the epigenetic factors and other regulators that act upstream of MP/ARF5 are poorly understood. Their identification will be a challenge in the coming years.
PMID: 37450945
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad259
To bind or not to bind: how Auxin Response Factors select their target genes.
Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, the Netherlands.
Most plant growth and development processes are regulated one way or another by auxin. The best-studied mechanism by which auxin exerts its regulatory effects is through the nuclear auxin pathway (NAP). In this pathway, AUXIN RESPONSE FACTORs (ARFs) are the transcription factors that ultimately determine which genes become auxin-regulated by binding to specific DNA sequences. ARFs have primarily been studied in Arabidopsis thaliana, but recent studies in other species have revealed family-wide DNA-binding specificities for different ARFs and the minimal functional system of the NAP system, consisting in a duo of competing ARFs of the A and B classes. In this review, we provide an overview of key aspects of ARF DNA-binding such as auxin response elements (TGTCNN) and tandem repeat motifs, and consider how structural biology and in vitro studies help us understand ARF DNA preferences. We also highlight some recent aspects related to the regulation of ARF levels inside a cell, which may alter the DNA-binding profile of ARFs in different tissues. We finally emphasize on the need to study minimal NAP systems to understand fundamental aspects of ARF function, the need to characterize algal ARFs to understand how ARFs evolved, how cutting-edge techniques can increase our understanding of ARFs, and which remaining questions can only be answered by structural biology.
PMID: 37431145
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad265
Temperature regulation of auxin-related gene expression and its implications for plant growth.
Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomia, Buenos Aires, Argentina.; Instituto de Fisiologia, Biologia Molecular y Neurociencias (IFIBYNE), CONICET-UBA, Buenos Aires, Argentina.
Twenty-five years ago, a seminal paper demonstrated that warm temperatures increase auxin levels to promote hypocotyl growth in Arabidopsis thaliana. Here we highlight recent advances in auxin-mediated thermomorphogenesis and identify unanswered questions. In the warmth, PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF7 bind the YUCCA 8 gene promoter and, in concert with histone modifications, enhance its expression to increase auxin synthesis in the cotyledons. Once transported to the hypocotyl, auxin promotes cell elongation. The meta-analysis of expression of auxin-related genes in seedlings exposed to temperatures ranging from cold to hot shows complex patterns of response. Changes in auxin only partially account for these responses. The expression of many SMALL AUXIN UP RNA (SAUR) genes reaches a maximum in the warmth, decreasing towards both temperature extremes in correlation with the rate of hypocotyl growth. Warm temperatures enhance primary root growth, the response requires auxin, and the hormone levels increase in the root tip but the impacts on cell division and cell expansion are not clear. A deeper understanding of auxin-mediated temperature control of plant architecture is necessary to face the challenge of global warming.
PMID: 37422862
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad263
Signal communication during microbial modulation of root system architecture.
Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China.; College of Environment and Ecology, Jiangsu Open University, Nanjing 210017, China.; State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
Every living organism on Earth depends on its interactions with other organisms to live. In the rhizosphere, plants and microorganisms constantly exchange signals and influence each other's behavior. Recent studies have shown that many beneficial rhizosphere microbes can produce specific signaling molecules that affect plant root architecture and may therefore have substantial effects on aboveground growth. This review sorts out these chemical signals and summarizes their mechanisms of action, enhancing our understanding of plant-microbe interactions and providing references for the comprehensive development and utilization of these active components in agricultural production. Finally, we have pointed out future research directions and challenges, such as the searching of microbial signals to induce the primary root development.
PMID: 37419655
J Exp Bot , IF:6.992 , 2023 Jul doi: 10.1093/jxb/erad244
Spatial regulation of plant hormone action.
Instituto de Biologia Molecular y Celular de Plantas (CSIC-UPV), 46022-Valencia, Spain.
Although many plant cell types are capable of producing hormones and plant hormones can in most cases act in the same cells in which they are produced, they also act as signaling molecules that coordinate physiological responses between different parts of the plant, indicating that their action is subject to spatial regulation. Numerous publications have reported that all levels of plant hormonal pathways, i.e., metabolism, transport, and perception/signal transduction, can help determine the spatial ranges of hormone action. For example, polar auxin transport or localized auxin biosynthesis contribute to creating a differential hormone accumulation across tissues that is instrumental for specific growth and developmental responses. On the other hand, tissue specificity of cytokinin actions has been proposed to be regulated by mechanisms operating at the signaling stages. Here, we review and discuss current knowledge about the contribution of the three levels mentioned above in providing spatial specificity to plant hormone action. We also explore how new technological developments, such as plant hormone sensors based on FRET or single-cell RNA-seq, can provide an unprecedented level of resolution in defining the spatial domains of plant hormone action and its dynamics.
PMID: 37401809
J Exp Bot , IF:6.992 , 2023 Jun 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, 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, Brazil.
The microRNA156 (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 (SB) by connecting multiple phytohormones with classical genetic pathways regulating both axillary bud (AB) development and outgrowth. MiR156-overexpressing plants (156-OE) displayed high SB, whereas plants overexpressing a miR156-resistant SlSBP15 allele (rSBP15) showed arrested SB. Importantly, the rSBP15 allele was able to partially restore the wild-type SB phenotype in 156-OE background. rSBP15 plants have tiny ABs, 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 ABs, respectively. Genetic and molecular data indicated that SlSBP15 regulates AB development and outgrowth by inhibiting auxin transport and GOBLET (GOB) activity, and by interacting with tomato BRANCHED1b (SlBRC1b) to control ABA levels within ABs. Collectively, our data provide a new mechanism by which the miR156/SPL/SBP hub regulates SB, and suggest that modulating SlSBP15 activity might have potential applications in shaping tomato shoot architecture.
PMID: 37347477
J Exp Bot , IF:6.992 , 2023 Jun doi: 10.1093/jxb/erad232
Hormonal control of the molecular networks guiding vascular tissue development in the primary root meristem of Arabidopsis thaliana.
Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium.; VIB Centre for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; Current Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; and University of Chinese Academy of Sciences, Beijing, China.
Vascular tissues serve a dual function in plants providing both physical support as well as controlling the transport of nutrients, water, hormones and other small signaling molecules. Xylem tissues transport water from root to shoot; phloem tissues transfer photosynthates from shoot to root; while divisions of the (pro)cambium increase the number of xylem and phloem cells. Although vascular development constitutes a continuous process from primary growth in the early embryo and meristem regions to secondary growth in the mature plant organs, it can be artificially separated into distinct processes including cell type specification, proliferation, patterning and differentiation. In this review, we focus our attention to how hormonal signals orchestrate the molecular regulation of vascular development in the Arabidopsis thaliana primary root meristem. Although auxin and cytokinin have taken center stage in this aspect since their discovery, other hormones including brassinosteroids, abscisic acid and jasmonic acid are also taking up leading roles during vascular development. All these hormonal cues synergistically or antagonistically participate in the development of vascular tissues, forming a complex hormonal control network.
PMID: 37343122
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P3951-3960 doi: 10.1093/jxb/erad213
Flowering also has to end: knowns and unknowns of reproductive arrest in monocarpic plants.
Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas - Universidad Politecnica de Valencia, 46022, Valencia, Spain.
All flowering plants adjust their reproductive period for successful reproduction. Flower initiation is controlled by a myriad of intensively studied factors, so it can occur in the most favorable conditions. However, the end of flowering is also a controlled process, required to optimize the size of the offspring and to maximize resource allocation. Reproductive arrest was described and mainly studied in the last century by physiological approaches, but it is much less understood at the genetic or molecular level. In this review, we present an overview of recent progress in this topic, fueled by highly complementary studies that are beginning to provide an integrated view of how the end of flowering is regulated. In this emerging picture, we also highlight key missing aspects that will guide future research and may provide new biotechnological avenues to improve crop yield in annual plants.
PMID: 37280109
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4377-4383 doi: 10.1093/jxb/erad185
PIN structures shed light on their mechanism of auxin efflux.
School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
Polar auxin transport is a quintessential feature of higher plant physiology and it has been known for many years that some of the primary drivers of polar auxin transport are the PIN-formed (PIN) auxin efflux proteins. Formative research established many key biochemical features of the transport system and discovered inhibitors such as 1-naphthylphthalamic acid (NPA), but the mechanism of action of PINs has remained elusive. This changed in 2022 with the publication of high-resolution structures of the membrane-spanning domains of three PIN proteins. The atomic structures and associated activity assays reveal that PINs use an elevator mechanism to transport auxin anions out of the cell. NPA was shown to be a competitive inhibitor that traps PINs in their inward-open conformation. The secrets of the hydrophilic cytoplasmic loop of PIN proteins remain to be discovered.
PMID: 37195878
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4503-4519 doi: 10.1093/jxb/erad178
Deciphering transcriptional mechanisms of maize internodal elongation by regulatory network analysis.
State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China.; North China Key Laboratory for Crop Germplasm Resources, Ministry of Education, State Key Laboratory of North China Crop Improvement and Regulation & College of Agronomy, Hebei Agricultural University, Baoding, Hebei 071001, China.; College of Plant Science and Technology, Beijing University of Agriculture, Beijing, 102206, China.
The lengths of the basal internodes is an important factor for lodging resistance of maize (Zea mays). In this study, foliar application of coronatine (COR) to 10 cultivars at the V8 growth stage had different suppression effects on the length of the eighth internode, with three being categorized as strong-inhibition cultivars (SC), five as moderate (MC), and two as weak (WC). RNA-sequencing of the eighth internode of the cultivars revealed a total of 7895 internode elongation-regulating genes, including 777 transcription factors (TFs). Genes related to the hormones cytokinin, gibberellin, auxin, and ethylene in the SC group were significantly down-regulated compared to WC, and more cell-cycle regulatory factors and cell wall-related genes showed significant changes, which severely inhibited internode elongation. In addition, we used EMSAs to explore the direct regulatory relationship between two important TFs, ZmABI7 and ZmMYB117, which regulate the cell cycle and cell wall modification by directly binding to the promoters of their target genes ZmCYC1, ZmCYC3, ZmCYC7, and ZmCPP1. The transcriptome reported in this study will provide a useful resource for studying maize internode development, with potential use for targeted genetic control of internode length to improve the lodging resistance of maize.
PMID: 37170764
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4489-4502 doi: 10.1093/jxb/erad173
The ARF2-MYB6 module mediates auxin-regulated petal expansion in rose.
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing, 100193, China.
In cut rose (Rosa hybrida), the flower-opening process is closely associated with vase life. Auxin induces the expression of transcription factor genes that function in petal growth via cell expansion. However, the molecular mechanisms underlying the auxin effect during flower opening are not well understood. Here, we identified the auxin-inducible transcription factor gene RhMYB6, whose expression level is high during the early stages of flower opening. Silencing of RhMYB6 delayed flower opening by controlling petal cell expansion through down-regulation of cell expansion-related genes. Furthermore, we demonstrated that the auxin response factor RhARF2 directly interacts with the promoter of RhMYB6 and represses its transcription. Silencing of RhARF2 resulted in larger petal size and delayed petal movement. We also showed that the expression of genes related to ethylene and petal movement showed substantial differences in RhARF2-silenced petals. Our results indicate that auxin-regulated RhARF2 is a critical player that controls flower opening by governing RhMYB6 expression and mediating the crosstalk between auxin and ethylene signaling.
PMID: 37158672
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4324-4348 doi: 10.1093/jxb/erad168
The phenomenon of autonomous endosperm in sexual and apomictic plants.
Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdansk, Gdansk, Poland.; School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.
Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In sexually-reproducing flowering plants, it generally develops after fertilization. However, autonomous endosperm (AE) formation (i.e. independent of fertilization) is also possible. Recent findings of AE loci/ genes and aberrant imprinting in native apomicts, together with a successful initiation of parthenogenesis in rice and lettuce, have enhanced our understanding of the mechanisms bridging sexual and apomictic seed formation. However, the mechanisms driving AE development are not well understood. This review presents novel aspects related to AE development in sexual and asexual plants underlying stress conditions as the primary trigger for AE. Both application of hormones to unfertilized ovules and mutations that impair epigenetic regulation lead to AE development in sexual Arabidopsis thaliana, which may point to a common pathway for both phenomena. Apomictic-like AE development under experimental conditions can take place due to auxin-dependent gene expression and/or DNA methylation.
PMID: 37155961
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4642-4653 doi: 10.1093/jxb/erad163
Local phytochrome signalling limits root growth in light by repressing auxin biosynthesis.
Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands.
In nature, plant shoots are exposed to light whereas the roots grow in relative darkness. Surprisingly, many root studies rely on in vitro systems that leave the roots exposed to light whilst ignoring the possible effects of this light on root development. Here, we investigated how direct root illumination affects root growth and development in Arabidopsis and tomato. Our results show that in light-grown Arabidopsis roots, activation of local phytochrome A and B by far-red or red light inhibits respectively PHYTOCHROME INTERACTING FACTORS 1 or 4, resulting in decreased YUCCA4 and YUCCA6 expression. As a result, auxin levels in the root apex become suboptimal, ultimately resulting in reduced growth of light-grown roots. These findings highlight once more the importance of using in vitro systems where roots are grown in darkness for studies that focus on root system architecture. Moreover, we show that the response and components of this mechanism are conserved in tomato roots, thus indicating its importance for horticulture as well. Our findings open up new research possibilities to investigate the importance of light-induced root growth inhibition for plant development, possibly by exploring putative correlations with responses to other abiotic signals, such as temperature, gravity, touch, or salt stress.
PMID: 37140032
J Exp Bot , IF:6.992 , 2023 Aug , V74 (15) : P4471-4488 doi: 10.1093/jxb/erad159
Cytokinin-inducible response regulator SlRR6 controls plant height through gibberellin and auxin pathways in tomato.
Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.; Institute of Vegetable Science, Zhejiang Academy of Agricultural Sciences, Hangzhou 310022, China.; Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agricultural, Zhejiang University, Hangzhou 310058, China.
Plant height is a key agronomic trait regulated by several phytohormones such as gibberellins (GAs) and auxin. However, little is known about how cytokinin (CK) participates in this process. Here, we report that SlRR6, a type-A response regulator in the CK signaling pathway, positively regulates plant height in tomato. SlRR6 was induced by exogenous kinetin and GA3, but inhibited by indole-3-acetic acid (IAA). Knock out of SlRR6 reduced tomato plant height through shortening internode length, while overexpression of SlRR6 caused taller plants due to increased internode number. Cytological observation of longitudinal stems showed that both knock out and overexpression of SlRR6 generated larger cells, but significantly reduced cell numbers in each internode. Further studies demonstrated that overexpression of SlRR6 enhanced GA accumulation and lowered IAA content, along with expression changes in GA- and IAA-related genes. Exogenous paclobutrazol and IAA treatments restored the increased plant height phenotype in SlRR6-overexpressing lines. Yeast two-hybrid, bimolecular fluorescence complementation, and co-immunoprecipitation assays showed that SlRR6 interacts with a small auxin up RNA protein, SlSAUR58. Moreover, SlSAUR58-overexpressing plants were dwarf with decreased internode length. Overall, our findings establish SlRR6 as a vital component in the CK signaling, GA, and IAA regulatory network that controls plant height.
PMID: 37115725
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P4093-4109 doi: 10.1093/jxb/erad152
The transcription factor GhTCP7 suppresses petal expansion by interacting with the WIP-type zinc finger protein GhWIP2 in Gerbera hybrida.
State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China.; Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, Guangdong 518004, China.; Department of Plant and Soil Sciences, Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY 40546, USA.; Institute of Biomass Engineering; Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs; Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, South China Agricultural University, Guangzhou 510642, China.; Provincial Key Lab of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, Guangdong 510631, China.
Petal size is a critical factor in plant reproduction and horticulture, and is largely determined by cell expansion. Gerbera hybrida is an important horticultural plant and serves as a model for studying petal organogenesis. We have previously characterized GhWIP2, a Trp-Ile-Pro (WIP)-type zinc protein, that constrains petal size by suppressing cell expansion. However, the underlying molecular mechanism remains largely unclear. Using yeast two-hybrid screening, bimolecular fluorescence complementation, and co-immunoprecipitation, we identified a TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family transcription factor, GhTCP7, that interacts with GhWIP2 both in vitro and in vivo. Using reverse genetic approaches, we elucidated the function of the GhTCP7-GhWIP2 complex in controlling petal expansion. GhTCP7 overexpression severely reduced cell expansion and petal size, whereas GhTCP7 silencing resulted in increased cell expansion and petal size. GhTCP7 showed similar expression patterns to GhWIP2 in various types of G. hybrida petals. We further identified GhIAA26, which encodes an auxin signalling regulator, that is activated by the GhTCP7-GhWIP2 complex, leading to the suppression of petal expansion. Our findings reveal a previously unknown transcriptional regulatory mechanism that involves protein-protein interactions between two different transcription factor families to activate a negative regulator of petal organogenesis.
PMID: 37102769
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P3903-3922 doi: 10.1093/jxb/erad137
Lessons from a century of apical dominance research.
ARC Centre of Excellence for Plant Success in Nature and Agriculture, St Lucia, QLD 4072, Australia.; School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.; Universite Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France.
The process of apical dominance by which the apical bud/shoot tip of the plant inhibits the outgrowth of axillary buds located below has been studied for more than a century. Different approaches were used over time, with first the physiology era, the genetic era, and then the multidisciplinary era. During the physiology era, auxin was thought of as the master regulator of apical dominance acting indirectly to inhibit bud outgrowth via unknown secondary messenger(s). Potential candidates were cytokinin (CK) and abscisic acid (ABA). The genetic era with the screening of shoot branching mutants in different species revealed the existence of a novel carotenoid-derived branching inhibitor and led to the significant discovery of strigolactones (SLs) as a novel class of plant hormones. The re-discovery of the major role of sugars in apical dominance emerged from modern physiology experiments and involves ongoing work with genetic material affected in sugar signalling. As crops and natural selection rely on the emergent properties of networks such as this branching network, future work should explore the whole network, the details of which are critical but not individually sufficient to solve the 'wicked problems' of sustainable food supply and climate change.
PMID: 37076257
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P3887-3902 doi: 10.1093/jxb/erad132
A matter of time: auxin signaling dynamics and the regulation of auxin responses during plant development.
Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France.
As auxin is a major regulator of plant development, studying the signaling mechanisms by which auxin influences cellular activities is of primary importance. In this review, we describe current knowledge on the different modalities of signaling, from the well-characterized canonical nuclear auxin pathway, to the more recently discovered or re-discovered non-canonical modes of auxin signaling. In particular, we discuss how both the modularity of the nuclear auxin pathway and the dynamic regulation of its core components allow specific transcriptomic responses to be triggered. We highlight the fact that the diversity of modes of auxin signaling allows for a wide range of time scales of auxin responses, from second-scale cytoplasmic responses to minute-/hour-scale modifications of gene expression. Finally, we question the extent to which the temporality of auxin signaling and responses contributes to development in both the shoot and the root meristems. We conclude by stressing the fact that future investigations should allow an integrative view to be built not only of the spatial control, but also of the temporality of auxin-mediated regulation of plant development, from the cell to the whole organism.
PMID: 37042516
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P4158-4168 doi: 10.1093/jxb/erad131
The dynamics of H2A.Z on SMALL AUXIN UP RNAs regulate abscisic acid-auxin signaling crosstalk in Arabidopsis.
Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200032, China.
Extreme environmental changes threaten plant survival and worldwide food production. In response to osmotic stress, the plant hormone abscisic acid (ABA) activates stress responses and restricts plant growth. However, the epigenetic regulation of ABA signaling and crosstalk between ABA and auxin are not well known. Here, we report that the histone variant H2A.Z-knockdown mutant in Arabidopsis Col-0, h2a.z-kd, has altered ABA signaling and stress responses. RNA-sequencing data showed that a majority of stress-related genes are activated in h2a.z-kd. In addition, we found that ABA directly promotes the deposition of H2A.Z on SMALL AUXIN UP RNAs (SAURs), and that this is involved in ABA-repression of SAUR expression. Moreover, we found that ABA represses the transcription of H2A.Z genes through suppressing the ARF7/19-HB22/25 module. Our results shed light on a dynamic and reciprocal regulation hub through H2A.Z deposition on SAURs and ARF7/19-HB22/25-mediated H2A.Z transcription to integrate ABA/auxin signaling and regulate stress responses in Arabidopsis.
PMID: 37022978
J Exp Bot , IF:6.992 , 2023 Aug , V74 (14) : P4031-4049 doi: 10.1093/jxb/erad123
GOLVEN peptides regulate lateral root spacing as part of a negative feedback loop on the establishment of auxin maxima.
Department of Plant Biotechnology and Bioinformatics, Faculty of Sciences, Ghent University, Ghent 9052, Belgium.; Center for Plant Systems Biology, VIB-UGent, Ghent 9052, Belgium.; Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, 90183 Umea, Sweden.
Lateral root initiation requires the accumulation of auxin in lateral root founder cells, yielding a local auxin maximum. The positioning of auxin maxima along the primary root determines the density and spacing of lateral roots. The GOLVEN6 (GLV6) and GLV10 signaling peptides and their receptors have been established as regulators of lateral root spacing via their inhibitory effect on lateral root initiation in Arabidopsis. However, it was unclear how these GLV peptides interfere with auxin signaling or homeostasis. Here, we show that GLV6/10 signaling regulates the expression of a subset of auxin response genes, downstream of the canonical auxin signaling pathway, while simultaneously inhibiting the establishment of auxin maxima within xylem-pole pericycle cells that neighbor lateral root initiation sites. We present genetic evidence that this inhibitory effect relies on the activity of the PIN3 and PIN7 auxin export proteins. Furthermore, GLV6/10 peptide signaling was found to enhance PIN7 abundance in the plasma membranes of xylem-pole pericycle cells, which likely stimulates auxin efflux from these cells. Based on these findings, we propose a model in which the GLV6/10 signaling pathway serves as a negative feedback mechanism that contributes to the robust patterning of auxin maxima along the primary root.
PMID: 37004244
J Exp Bot , IF:6.992 , 2023 Jun , V74 (12) : P3579-3594 doi: 10.1093/jxb/erad091
Cytokinin signaling promotes root hair growth by directly regulating RSL4 expression.
Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.; School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.; RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.; Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan.; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Root hairs are single-celled tubular structures produced from the epidermis, which play an essential role in water and nutrient uptake from the soil. Therefore, root hair formation and elongation are controlled not only by developmental programs but also by environmental factors, enabling plants to survive under fluctuating conditions. Phytohormones are key signals that link environmental cues to developmental programs; indeed, root hair elongation is known to be controlled by auxin and ethylene. Another phytohormone, cytokinin, also affects root hair growth, while whether cytokinin is actively involved in root hair growth and, if so, how it regulates the signaling pathway governing root hair development have remained unknown. In this study, we show that the two-component system of cytokinin, which involves the B-type response regulators ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12, promotes the elongation process of root hairs. They directly up-regulate ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4) encoding a basic helix-loop-helix (bHLH) transcription factor that plays a central role in root hair growth, whereas the ARR1/12-RSL4 pathway does not crosstalk with auxin or ethylene signaling. These results indicate that cytokinin signaling constitutes another input onto the regulatory module governed by RSL4, making it possible to fine-tune root hair growth in changing environments.
PMID: 36912789
J Exp Bot , IF:6.992 , 2023 Jun , V74 (12) : P3560-3578 doi: 10.1093/jxb/erad088
LONG HYPOCOTYL IN FAR-RED 1 mediates a trade-off between growth and defence under shade in Arabidopsis.
Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore.; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
Plants respond to vegetative shade with developmental and physiological changes that are collectively known as shade avoidance syndrome (SAS). Although LONG HYPOCOTYL IN FAR-RED 1 (HFR1) is known to be a negative regulator of SAS by forming heterodimers with other basic helix-loop-helix (bHLH) transcription factors to inhibit them, its function in genome-wide transcriptional regulation has not been fully elucidated. Here, we performed RNA-sequencing analyses of Arabidopsis thaliana hfr1-5 mutant and HFR1 overexpression line [HFR1(DeltaN)-OE] to comprehensively identify HFR1-regulated genes at different time points of shade treatment. We found that HFR1 mediates the trade-off between shade-induced growth and shade-repressed defence, by regulating the expression of relevant genes in the shade. Genes involved in promoting growth, such as auxin biosynthesis, transport, signalling and response were induced by shade but suppressed by HFR1 under both short and long durations of shade. Likewise, most ethylene-related genes were shade-induced and HFR1-repressed. However, shade suppressed defence-related genes, while HFR1 induced their expression, especially under long durations of shade treatment. We demonstrated that HFR1 confers increased resistance to bacterial infection under shade.
PMID: 36882154
Development , IF:6.868 , 2023 Aug doi: 10.1242/dev.201608
The maize preligule band is subdivided into distinct domains with contrasting cellular properties prior to ligule outgrowth.
Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, CA 92521, USA.; Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA.; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, CA 90095, USA.; California NanoSystems Institute, Los Angeles, CA 90095, USA.
The maize ligule is an epidermis-derived structure that arises from the preligule band (PLB) at a boundary between the blade and sheath. A hinge-like auricle also develops immediately distal to the ligule and contributes to blade angle. Here, we characterize the stages of PLB and early ligule development in terms of topography, cell area, division orientation, cell wall rigidity, and auxin response dynamics. Differential thickening of epidermal cells and localized periclinal divisions contributed to the formation of a ridge within the PLB, which ultimately produces the ligule fringe. Patterns in cell wall rigidity were consistent with the subdivision of the PLB into two regions along a distinct line positioned at the nascent ridge. The proximal region produces the ligule, while the distal region contributes to one epidermal face of the auricles. Whereas the auxin transporter PIN1 accumulated in the PLB, observed differential auxin transcriptional response did not underlie the partitioning of the PLB. Our data demonstrate that two zones with contrasting cellular properties, the preligule and preauricle, are specified within the ligular region prior to ligule outgrowth.
PMID: 37539661
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 Jul , V10 (7) : Puhad108 doi: 10.1093/hr/uhad108
Molecular and genetic regulations of fleshy fruit shape and lessons from Arabidopsis and rice.
College of Horticulture, State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Vegetable Germplasm Innovation and Utilization of Hebei, Collaborative Innovation Center of Vegetable Industry in Hebei, Hebei Agricultural University, Baoding, Hebei 071000, China.; Center for Applied Genetic Technologies, Institute for Plant Breeding, Genetics and Genomics, Department of Horticulture, University of Georgia, Athens, GA, USA.
Fleshy fruit shape is an important external quality trait influencing the usage of fruits and consumer preference. Thus, modification of fruit shape has become one of the major objectives for crop improvement. However, the underlying mechanisms of fruit shape regulation are poorly understood. In this review we summarize recent progress in the genetic basis of fleshy fruit shape regulation using tomato, cucumber, and peach as examples. Comparative analyses suggest that the OFP-TRM (OVATE Family Protein - TONNEAU1 Recruiting Motif) and IQD (IQ67 domain) pathways are probably conserved in regulating fruit shape by primarily modulating cell division patterns across fleshy fruit species. Interestingly, cucumber homologs of FRUITFULL (FUL1), CRABS CLAW (CRC) and 1-aminocyclopropane-1-carboxylate synthase 2 (ACS2) were found to regulate fruit elongation. We also outline the recent progress in fruit shape regulation mediated by OFP-TRM and IQD pathways in Arabidopsis and rice, and propose that the OFP-TRM pathway and IQD pathway coordinate regulate fruit shape through integration of phytohormones, including brassinosteroids, gibberellic acids, and auxin, and microtubule organization. In addition, functional redundancy and divergence of the members of each of the OFP, TRM, and IQD families are also shown. This review provides a general overview of current knowledge in fruit shape regulation and discusses the possible mechanisms that need to be addressed in future studies.
PMID: 37577396
J Environ Manage , IF:6.789 , 2023 Jul , V337 : P117723 doi: 10.1016/j.jenvman.2023.117723
Integrated biochemical and transcriptomic analysis reveals the effects of Burkholderia sp. SRB-1 on cadmium accumulating in Chrysopogon zizanioides L. under Cd stress.
Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.; College of Pharmacy, Chengdu Medical College, Chengdu, Sichuan, China.; Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, China.; Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China; Key Laboratory of Environment Protection, Soil Ecological Protection and Pollution Control, Sichuan University & Department of Ecology and Environment of Sichuan, Chengdu, 610065, Sichuan, PR China. Electronic address: xuheng64@sina.com.
Application of plant growth-promoting rhizobacteria plays a vital role in enhancing phytoremediation efficiency. In this study, multiple approaches were employed to investigate the underlying mechanisms of Burkholderia sp. SRB-1 (SRB-1) on elevating Cd uptake and accumulation. Inoculation experiment indicated that SRB-1 could facilitate plant growth and Cd tolerance, as evidenced by the enhanced plant biomass and antioxidative enzymes activities. Cd content in plant shoots and roots increased about 36.56%-39.66% and 25.97%-130.47% assisted with SRB-1 when compared with control. Transcriptomics analysis revealed that SRB-1 upregulated expression of amiE, AAO1-2 and GA2-ox related to auxin and gibberellin biosynthesis in roots. Auxin and gibberellin, as hormone signals, regulated plant Cd tolerance and growth through activating hormone signal transduction pathways, which might also contribute to 67.94% increase of dry weight. The higher expression levels of ATP-binding cassette transporter subfamilies (ABCB, ABCC, ABCD and ABCG) in Chrysopogon zizanioides roots contributed to higher Cd uptake in Cd15 B (323.83 mg kg(-1)) than Cd15 (136.28 mg kg(-1)). Further, SRB-1 facilitated Cd migration from roots to shoots via upregulating the expression of Nramp, ZIP and HMA families. Our integrative analysis provided a molecular-scale perspective on Burkholderia sp. SRB-1 contributing to C. zizanioides performance.
PMID: 36958280
Environ Res , IF:6.498 , 2023 Jul , V229 : P115966 doi: 10.1016/j.envres.2023.115966
Strigolactones can be a potential tool to fight environmental stresses in arid lands.
Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China. Electronic address: akash.malik786@mails.ucas.ac.cn.; Department of Plant Breeding & Genetics, Gomal University, Dera Ismail Khan, Pakistan.; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193, Barcelona, Catalonia, Spain; CREAF, Cerdanyola Del Valles, 08193, Catalonia, Spain.; Instituto de Fisiologia Vegetal, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Universidad Nacional de La Plata, Buenos Aires, Argentina.; Department of Botanical and Environmental Sciences, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan.; Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China.; Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China. Electronic address: zengfj@ms.xjb.ac.cn.; Key Laboratory of Humid Subtropical Eco-Geographical Process, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China; Institute of Geography, Fujian Normal University, Fuzhou, 350007, China.; Department of Biology, College of Science, University of Tabuk, Tabuk, Saudi Arabia.; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.; State Key Laboratory of Phytochemistry and Plant Resources in West China, Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
BACKGROUND: Environmental stresses pose a significant threat to plant growth and ecosystem productivity, particularly in arid lands that are more susceptible to climate change. Strigolactones (SLs), carotenoid-derived plant hormones, have emerged as a potential tool for mitigating environmental stresses. METHODS: This review aimed to gather information on SLs' role in enhancing plant tolerance to ecological stresses and their possible use in improving the resistance mechanisms of arid land plant species to intense aridity in the face of climate change. RESULTS: Roots exude SLs under different environmental stresses, including macronutrient deficiency, especially phosphorus (P), which facilitates a symbiotic association with arbuscular mycorrhiza fungi (AMF). SLs, in association with AMF, improve root system architecture, nutrient acquisition, water uptake, stomatal conductance, antioxidant mechanisms, morphological traits, and overall stress tolerance in plants. Transcriptomic analysis revealed that SL-mediated acclimatization to abiotic stresses involves multiple hormonal pathways, including abscisic acid (ABA), cytokinins (CK), gibberellic acid (GA), and auxin. However, most of the experiments have been conducted on crops, and little attention has been paid to the dominant vegetation in arid lands that plays a crucial role in reducing soil erosion, desertification, and land degradation. All the environmental gradients (nutrient starvation, drought, salinity, and temperature) that trigger SL biosynthesis/exudation prevail in arid regions. The above-mentioned functions of SLs can potentially be used to improve vegetation restoration and sustainable agriculture. CONCLUSIONS: Present review concluded that knowledge on SL-mediated tolerance in plants is developed, but still in-depth research is needed on downstream signaling components in plants, SL molecular mechanisms and physiological interactions, efficient methods of synthetic SLs production, and their effective application in field conditions. This review also invites researchers to explore the possible application of SLs in improving the survival rate of indigenous vegetation in arid lands, which can potentially help combat land degradation problems.
PMID: 37100368
Plant J , IF:6.417 , 2023 Aug doi: 10.1111/tpj.16394
An enhancer trap system to track developmental dynamics in Marchantia polymorpha.
Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
A combination of streamlined genetics, experimental tractability and relative morphological simplicity compared to vascular plants makes the liverwort Marchantia polymorpha an ideal model system for studying many aspects of plant biology. Here we describe a transformation vector combining a constitutive fluorescent membrane marker with a nuclear marker that is regulated by nearby enhancer elements and use this to produce a library of enhancer trap lines for Marchantia. Screening gemmae from these lines allowed the identification and characterization of novel marker lines, including markers for rhizoids and oil cells. The library allowed the identification of a margin tissue running around the thallus edge, highlighted during thallus development. The expression of this marker is correlated with auxin levels. We generated multiple markers for the meristematic apical notch region, which have different spatial expression patterns, reappear at different times during meristem regeneration following apical notch excision and have varying responses to auxin supplementation or inhibition. This reveals that there are proximodistal substructures within the apical notch that could not be observed otherwise. We employed our markers to study Marchantia sporeling development, observing meristem emergence as defining the protonema-to-prothallus stage transition, and subsequent production of margin tissue during the prothallus stage. Exogenous auxin treatment stalls meristem emergence at the protonema stage but does not inhibit cell division, resulting in callus-like sporelings with many rhizoids, whereas pharmacologically inhibiting auxin synthesis and transport does not prevent meristem emergence. This enhancer trap system presents a useful resource for the community and will contribute to future Marchantia research.
PMID: 37583263
Plant J , IF:6.417 , 2023 Jul doi: 10.1111/tpj.16410
HISTONE DEACETYLASE 9 promotes hypocotyl-specific auxin response under shade.
Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, 117604, Singapore.; Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
Vegetative shade causes an array of morphological changes in plants called shade avoidance syndrome, which includes hypocotyl and petiole elongation, leaf hyponasty, reduced leaf growth, early flowering and rapid senescence. Here, we show that loss-of-function mutations in HISTONE DEACETYLASE 9 (HDA9) attenuated the shade-induced hypocotyl elongation in Arabidopsis. However, the hda9 cotyledons and petioles under shade were not significantly different from those in wild-type, suggesting a specific function of HDA9 in hypocotyl elongation in response to shade. HDA9 expression levels were stable under shade and its protein was ubiquitously detected in cotyledon, hypocotyl and root. Organ-specific transcriptome analysis unraveled that shade induced a set of auxin-responsive genes, such as SMALL AUXIN UPREGULATED RNAs (SAURs) and AUXIN/INDOLE-3-ACETIC ACIDs (AUX/IAAs) and their induction was impaired in hda9-1 hypocotyls. In addition, HDA9 binding to loci of SAUR15/65, IAA5/6/19 and ACS4 was increased under shade. The genetic and organ-specific gene expression analyses further revealed that HDA9 may cooperate with PHYTOCHROME-INTERACTING FACTOR 4/7 in the regulation of shade-induced hypocotyl elongation. Furthermore, HDA9 and PIF7 proteins were found to interact together and thus it is suggested that PIF7 may recruit HDA9 to regulate the shade/auxin responsive genes in response to shade. Overall, our study unravels that HDA9 can work as one component of a hypocotyl-specific transcriptional regulatory machinery that activates the auxin response at the hypocotyl leading to the elongation of this organ under shade.
PMID: 37522556
Plant J , IF:6.417 , 2023 Jul doi: 10.1111/tpj.16403
AXR1 modulates trichome morphogenesis through mediating ROP2 stability in Arabidopsis.
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.; Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA.
Cell differentiation and morphogenesis are crucial for the establishment of diverse cell types and organs in multicellular organisms. Trichome cells offer an excellent paradigm for dissecting the regulatory mechanisms of plant cell differentiation and morphogenesis due to their unique growth characteristics. Here, we report the isolation of an Arabidopsis mutant, aberrantly branched trichome 3-1 (abt3-1), with a reduced trichome branching phenotype. Positional cloning and molecular complementation experiments confirmed that abt3-1 is a new mutant allele of Auxin resistant 1 (AXR1), which encodes the N-terminal half of ubiquitin-activating enzyme E1 and functions in auxin signaling pathway. Meanwhile, we found that transgenic plants expressing constitutively active version of ROP2 (CA-ROP2) caused a reduction of trichome branches, resembling that of abt3-1. ROP2 is a member of Rho GTPase of plants (ROP) family, serving as versatile signaling switches involved in a range of cellular and developmental processes. Our genetic and biochemical analyses showed AXR1 genetically interacted with ROP2 and mediated ROP2 protein stability. The loss of AXR1 aggravated the trichome defects of CA-ROP2 and induced the accumulation of steady-state ROP2. Consistently, elevated AXR1 expression levels suppressed ROP2 expression and partially rescued trichome branching defects in CA-ROP2 plants. Together, our results presented a new mutant allele of AXR1, uncovered the effects of AXR1 and ROP2 during trichome development, and revealed a pathway of ROP2-mediated regulation of plant cell morphogenesis in Arabidopsis.
PMID: 37516999
Plant J , IF:6.417 , 2023 Jul , V115 (1) : P155-174 doi: 10.1111/tpj.16218
Salicylic acid inhibits rice endocytic protein trafficking mediated by OsPIN3t and clathrin to affect root growth.
College of Plant Protection, Yunnan Agricultural University, Kunming, 650201, China.; State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China.; Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, 650201, China.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China.; Shanxi Agricultural University/Shanxi Academy of Agricultural Sciences, The Industrial Crop Institute, Fenyang, 032200, China.; Key Lab of Agricultural Biotechnology of Yunnan Province, Biotechnology and Germplasm Resources Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.; Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.
Salicylic acid (SA) plays important roles in different aspects of plant development, including root growth, where auxin is also a major player by means of its asymmetric distribution. However, the mechanism underlying the effect of SA on the development of rice roots remains poorly understood. Here, we show that SA inhibits rice root growth by interfering with auxin transport associated with the OsPIN3t- and clathrin-mediated gene regulatory network (GRN). SA inhibits root growth as well as Brefeldin A-sensitive trafficking through a non-canonical SA signaling mechanism. Transcriptome analysis of rice seedlings treated with SA revealed that the OsPIN3t auxin transporter is at the center of a GRN involving the coat protein clathrin. The root growth and endocytic trafficking in both the pin3t and clathrin heavy chain mutants were SA insensitivity. SA inhibitory effect on the endocytosis of OsPIN3t was dependent on clathrin; however, the root growth and endocytic trafficking mediated by tyrphostin A23 (TyrA23) were independent of the pin3t mutant under SA treatment. These data reveal that SA affects rice root growth through the convergence of transcriptional and non-SA signaling mechanisms involving OsPIN3t-mediated auxin transport and clathrin-mediated trafficking as key components.
PMID: 37025008
Ecotoxicol Environ Saf , IF:6.291 , 2023 Aug , V262 : P115315 doi: 10.1016/j.ecoenv.2023.115315
Root system architecture and genomic plasticity to salinity provide insights into salt-tolerant traits in tall fescue.
School of Resources and Environmental Engineering, Ludong University, Yantai 264000, PR China.; African Sustainable Agriculture Research Institute, Mohammed VI Polytechnic University, Laayoune 70000, Morocco.; Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Science, Wuhan 430061, PR China.; School of Resources and Environmental Engineering, Ludong University, Yantai 264000, PR China. Electronic address: 38019113@qq.com.; School of Resources and Environmental Engineering, Ludong University, Yantai 264000, PR China. Electronic address: yatingli@ldu.edu.cn.
Salinity is detrimental to soil health, plant growth, and crop productivity. Understanding salt tolerance mechanisms offers the potential to introduce superior crops, especially in coastal regions. Root system architecture (RSA) plasticity is vital for plant salt stress adaptation. Tall fescue is a promising forage grass in saline regions with scarce RSA studies. Here, we used the computer-integrated and -automated programs EZ-Rhizo II and ROOT-Vis II to analyze and identify natural RSA variations and adaptability to high salt stress at physiological and genetic levels in 17 global tall fescue accessions. Total root length rather than the number of lateral roots contribute more to water uptake and could be used to separate salt-tolerant (LS-11) and -sensitive accessions (PI531230). Comparative evaluation of LS-11 and PI531230 demonstrated that the lateral root length rather than the main root contributed more towards the total root length in LS-11. Also, high water uptake was associated with a larger lateral root vector and position while low water intake was associated with an insignificant correlation between root length, vector, and position. To examine candidate gene expression, we performed transcriptome and transcription analyses using high-throughput RNA sequencing and real-time quantitative PCR, respectively of the lateral and main roots. The main root displayed more differentially expressed genes than the lateral root. A Poisson comparison of LS-11 vs PI531230 demonstrated significant upregulation of PLASMA MEMBRANE AQUAPORIN 1 and AUXIN RESPONSE FACTOR 22 in both the main and lateral root, which are associated with transmembrane water transport and the auxin-activated signaling system, respectively. There is also an upregulation of BASIC HELIX-LOOP-HELIX 5 in the main root and a downregulation in the lateral root, which is ascribed to sodium ion transmembrane transport, as well as an upregulation of THE MEDIATOR COMPLEX 1 assigned to water transport in the lateral root and a downregulation in the main root. Gene-protein interaction analysis found that more genes interacting with aquaporins proteins were upregulated in the lateral root than in the main root. We inferred that deeper main roots with longer lateral roots emanating from the bottom of the main root were ideal for tall fescue water uptake and salt tolerance, rather than many shallow roots, and that, while both main lateral roots may play similar roles in salt sensing and water uptake, there are intrinsic genomic differences.
PMID: 37542983
Ecotoxicol Environ Saf , IF:6.291 , 2023 Jul , 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
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (14) doi: 10.3390/ijms241411850
bra-miR167a Targets ARF8 and Negatively Regulates Arabidopsis thaliana Immunity against Plasmodiophora brassicae.
Institute of Horticulture, Henan Academy of Agricultural Sciences, Graduate T&R Base of Zhengzhou University, Zhengzhou 450002, China.; Henan International Joint Laboratory of Crop Gene Resources and Improvement, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.; Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
Clubroot is a soil-borne disease caused by Plasmodiophora brassicae, which can seriously affect the growth and production of cruciferous crops, especially Chinese cabbage crops, worldwide. At present, few studies have been conducted on the molecular mechanism of this disease's resistance response. In this experiment, we analyzed the bioinformation of bra-miR167a, constructed a silencing vector (STTM167a) and an overexpression vector (OE-miR167a), and transformed them to Arabidopsis to confirm the role of miR167a in the clubroot resistance mechanism of Arabidopsis. Afterwards, phenotype analysis and expression level analysis of key genes were conducted on transgenic plants. From the result, we found that the length and number of lateral roots of silence transgenic Arabidopsis STTM167a was higher than that of WT and OE-miR167a. In addition, the STTM167a transgenic Arabidopsis induced up-regulation of disease resistance-related genes (PR1, PR5, MPK3, and MPK6) at 3 days after inoculation. On the other hand, the auxin pathway genes (TIR1, AFB2, and AFB3), which are involved in maintaining the balance of auxin/IAA and auxin response factor (ARF), were down-regulated. These results indicate that bra-miR167a is negative to the development of lateral roots and auxins, but positive to the expression of resistance-related genes. This also means that the STTM167a can improve the resistance of clubroot by promoting lateral root development and the level of auxin, and can induce resistance-related genes by regulating its target genes. We found a positive correlation between miR167a and clubroot disease, which is a new clue for the prevention and treatment of clubroot disease.
PMID: 37511608
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (14) doi: 10.3390/ijms241411789
Transcriptome and Small RNA Sequencing Reveals the Basis of Response to Salinity, Alkalinity and Hypertonia in Quinoa (Chenopodium quinoa Willd.).
College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan 250014, China.; CAS Center for Excellence in Molecular Plant Sciences, Fenglin Road 300, Shanghai 200032, China.
Quinoa (Chenopodium quinoa Willd.) is a dicotyledonous cereal that is rich in nutrients. This important crop has been shown to have significant tolerance to abiotic stresses such as salinization and drought. Understanding the underlying mechanism of stress response in quinoa would be a significant advantage for breeding crops with stress tolerance. Here, we treated the low-altitude quinoa cultivar CM499 with either NaCl (200 mM), Na(2)CO(3)/NaHCO(3) (100 mM, pH 9.0) or PEG6000 (10%) to induce salinity, alkalinity and hypertonia, respectively, and analyzed the subsequent expression of genes and small RNAs via high-throughput sequencing. A list of known/novel genes were identified in quinoa, and the ones responding to different stresses were selected. The known/novel quinoa miRNAs were also identified, and the target genes of the stress response ones were predicted. Both the differently expressed genes and the targets of differently expressed miRNAs were found to be enriched for reactive oxygen species homeostasis, hormone signaling, cell wall synthesis, transcription factors and some other factors. Furthermore, we detected changes in reactive oxygen species accumulation, hormone (auxin and ethylene) responses and hemicellulose synthesis in quinoa seedlings treated with stresses, indicating their important roles in the response to saline, alkaline or hyperosmotic stresses in quinoa. Thus, our work provides useful information for understanding the mechanism of abiotic stress responses in quinoa, which would provide clues for improving breeding for quinoa and other crops.
PMID: 37511549
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (14) doi: 10.3390/ijms241411740
ARF3-Mediated Regulation of SPL in Early Anther Morphogenesis: Maintaining Precise Spatial Distribution and Expression Level.
State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China.
Early anther morphogenesis is a crucial process for male fertility in plants, governed by the transcription factor SPL. While the involvement of AGAMOUS (AG) in SPL activation and microsporogenesis initiation is well established, our understanding of the mechanisms governing the spatial distribution and precise expression of SPL during anther cell fate determination remains limited. Here, we present novel findings on the abnormal phenotypes of two previously unreported SPL mutants, spl-4 and spl-5, during anther morphogenesis. Through comprehensive analysis, we identified ARF3 as a key upstream regulator of SPL. Our cytological experiments demonstrated that ARF3 plays a critical role in restricting SPL expression specifically in microsporocytes. Moreover, we revealed that ARF3 directly binds to two specific auxin response elements on the SPL promoter, effectively suppressing AG-mediated activation of SPL. Notably, the arf3 loss-of-function mutant exhibits phenotypic similarities to the SPL overexpression mutant (spl-5), characterized by defective adaxial anther lobes. Transcriptomic analysis revealed differential expression of the genes involved in the morphogenesis pathway in both arf3 and spl mutants, with ARF3 and SPL exhibited opposing regulatory effects on this pathway. Taken together, our study unveils the precise role of ARF3 in restricting the spatial expression and preventing aberrant SPL levels during early anther morphogenesis, thereby ensuring the fidelity of the critical developmental process in plants.
PMID: 37511499
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (14) doi: 10.3390/ijms241411408
Canonical and Alternative Auxin Signaling Systems in Mono-, Di-, and Tetraploid Potatoes.
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, 127276 Moscow, Russia.
It has long been known that the phytohormone auxin plays a promoting role in tuber formation and stress tolerance in potatoes. Our study aimed to identify and characterize the complete sets of auxin-related genes that presumably constitute the entire auxin signaling system in potato (Solanum tuberosum L.). The corresponding genes were retrieved from sequenced genomes of the doubled monoploid S. tuberosum DM1-3-516-R44 (DM) of the Phureja group, the heterozygous diploid line RH89-039-16 (RH), and the autotetraploid cultivar Otava. Both canonical and noncanonical auxin signaling pathways were considered. Phylogenetic and domain analyses of deduced proteins were supplemented by expression profiling and 3D molecular modeling. The canonical and ABP1-mediated pathways of auxin signaling appeared to be well conserved. The total number of potato genes/proteins presumably involved in canonical auxin signaling is 46 and 108 in monoploid DM and tetraploid Otava, respectively. Among the studied potatoes, spectra of expressed genes obviously associated with auxin signaling were partly cultivar-specific and quite different from analogous spectrum in Arabidopsis. Most of the noncanonical pathways found in Arabidopsis appeared to have low probability in potato. This was equally true for all cultivars used irrespective of their ploidy. Thus, some important features of the (noncanonical) auxin signaling pathways may be variable and species-specific.
PMID: 37511169
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (13) doi: 10.3390/ijms241311177
Opposite Auxin Dynamics Determine the Gametophytic and Embryogenic Fates of the Microspore.
Pollen Biotechnology of Crop Plants Group, Biological Research Center Margarita Salas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.; Department of Genetics, Microbiology and Physiology, Complutense University of Madrid, 28040 Madrid, Spain.; Department of Plant Nutrition, Center for Edaphology and Applied Biology of Segura, CEBAS-CSIC, Campus Universitario de Espinardo, 30100 Murcia, Spain.
The microspore can follow two different developmental pathways. In vivo microspores follow the gametophytic program to produce pollen grains. In vitro, isolated microspores can be reprogrammed by stress treatments and follow the embryogenic program, producing doubled-haploid embryos. In the present study, we analyzed the dynamics and role of endogenous auxin in microspore development during these two different scenarios, in Brassica napus. We analyzed auxin concentration, cellular accumulation, the expression of the TAA1 auxin biosynthesis gene, and the PIN1-like efflux carrier gene, as well as the effects of inhibiting auxin biosynthesis by kynurenine on microspore embryogenesis. During the gametophytic pathway, auxin levels and TAA1 and PIN1-like expression were high at early stages, in tetrads and tapetum, while they progressively decreased during gametogenesis in both pollen and tapetum cells. In contrast, in microspore embryogenesis, TAA1 and PIN1-like genes were upregulated, and auxin concentration increased from the first embryogenic divisions. Kynurenine treatment decreased both embryogenesis induction and embryo production, indicating that auxin biosynthesis is required for microspore embryogenesis initiation and progression. The findings indicate that auxin exhibits two opposite profiles during these two microspore developmental pathways, which determine the different cell fates of the microspore.
PMID: 37446349
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (13) doi: 10.3390/ijms241311006
Genome-Wide Identification and Expression Analysis of Auxin Response Factor Gene Family in Linum usitatissimum.
Institute of Crop, Gansu Academy of Agricultural Sciences, Lanzhou 730070, China.
Auxin response factors (ARFs) are critical components of the auxin signaling pathway, and are involved in diverse plant biological processes. However, ARF genes have not been investigated in flax (Linum usitatissimum L.), an important oilseed and fiber crop. In this study, we comprehensively analyzed the ARF gene family and identified 33 LuARF genes unevenly distributed on the 13 chromosomes of Longya-10, an oil-use flax variety. Detailed analysis revealed wide variation among the ARF family members and predicted nuclear localization for all proteins. Nineteen LuARFs contained a complete ARF structure, including DBD, MR, and CTD, whereas the other fourteen lacked the CTD. Phylogenetic analysis grouped the LuARFs into four (I-V) clades. Combined with sequence analysis, the LuARFs from the same clade showed structural conservation, implying functional redundancy. Duplication analysis identified twenty-seven whole-genome-duplicated LuARF genes and four tandem-duplicated LuARF genes. These duplicated gene pairs' K(a)/K(s) ratios suggested a strong purifying selection pressure on the LuARF genes. Collinearity analysis revealed that about half of the LuARF genes had homologs in other species, indicating a relatively conserved nature of the ARFs. The promoter analysis identified numerous hormone- and stress-related elements, and the qRT-PCR experiment revealed that all LuARF genes were responsive to phytohormone (IAA, GA3, and NAA) and stress (PEG, NaCl, cold, and heat) treatments. Finally, expression profiling of LuARF genes in different tissues by qRT-PCR indicated their specific functions in stem or capsule growth. Thus, our findings suggest the potential functions of LuARFs in flax growth and response to an exogenous stimulus, providing a basis for further functional studies on these genes.
PMID: 37446183
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310906
Comparative Analysis Based on Physiological and Transcriptomic Data between Juvenile and Adult Tree Peony (Paeonia delavayi).
College of Forestry, Shandong Agricultural University, Tai'an 271018, China.; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry Agriculture and Rural Affairs, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
A long juvenile period limits the breeding process of many woody plants including tree peony. To investigate the physiological and transcriptomic differences between juvenile and adult plants of tree peony and to explore the key SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes, which are vital in age-dependent pathways, 1-year-old and 3-year-old Paeonia delavayi plants were used to compare the relevant physiological parameters and transcriptomic profiles of the leaves in two phases of plants. The results of the physiological parameters showed that the starch content in the leaves of adult plants remained unchanged and that the soluble sugar content significantly increased compared with those in the juvenile plants. In terms of plant hormones, the contents of cytokinin-like hormone (N6-isopentenyladenine (iP)) and jasmonic acid (JA) significantly decreased, whereas the contents of auxin (indole-3-acetic acid, IAA), abscisic acid (ABA), cytokinin-like hormone (N6-isopentenyladenenosine (iPR)), and ethylene precursor (1-aminocyclopropane-1-carboxylic acid, ACC) showed no statistic difference. Transcriptome sequencing results showed that there were 194 differentially expressed genes (DEGs) between juvenile and adult plants, including 171 up-regulated DEGs and 23 down-regulated DEGs. Circadian rhythm, plant hormone signal transduction, and sugar metabolism were closely related to the juvenile-to-adult transition in P. delavayi, involving a total of 12 DEGs. In addition, a total of 13 SPL genes were identified in the transcriptome data, but only PdSPL10 (c71307.graph_c0) was differentially expressed. It was further validated via qRT-PCR analysis, indicating that PdSPL10 might be a key gene regulating the process of juvenile-to-adult in P. delavayi. Based on the above results, a hypothetical transcriptional network regulating juvenile-to-adult transition and flowering in P. delavayi was proposed. These findings provide a reference for understanding the mechanism of juvenile-to-adult transition in tree peony.
PMID: 37446082
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310863
Phytohormone Crosstalk of Cytokinin Biosynthesis and Signaling Family Genes in Moso Bamboo (Phyllostachys edulis).
Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, International Center for Bamboo and Rattan, Beijing 100102, China.
Cytokinin is widely involved in the regulation of plant growth, but its pathway-related genes have not been reported in Moso bamboo. In this study, a total of 129 candidate sequences were identified by bioinformatic methods. These included 15 IPT family genes, 19 LOG family genes, 22 HK family genes, 11 HP family genes and 62 RR family genes. Phylogenetic analysis revealed that the cytokinin pathway was closely related to rice, and evolutionary pattern analysis found that most of the genes have syntenic relationship with rice-related genes. The Moso bamboo cytokinin pathway was evolutionarily conservative and mainly underwent purifying selection, and that gene family expansion was mainly due to whole-gene duplication events. Analysis of transcriptome data revealed a tissue-specific expression pattern of Moso bamboo cytokinin family genes, with auxin and gibberellin response patterns. Analysis of co-expression patterns at the developmental stages of Moso bamboo shoots revealed the existence of a phytohormone co-expression pattern centered on cytokinin signaling genes. The auxin signaling factor PheARF52 was identified by yeast one-hybrid assay as regulating the PheRR3 gene through a P-box element in the PheRR3 promoter region. Auxin and cytokinin signaling crosstalk to regulate Moso bamboo growth. Overall, we systematically identified and analyzed key gene families of the cytokinin pathway in Moso bamboo and obtained key factors for auxin and cytokinin crosstalk, laying the foundation for the study of hormone regulation in Moso bamboo.
PMID: 37446040
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310728
BSA-Seq and Transcriptomic Analysis Provide Candidate Genes Associated with Inflorescence Architecture and Kernel Orientation by Phytohormone Homeostasis in Maize.
Specialty Corn Institute, College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China.; College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
The developmental plasticity of the maize inflorescence depends on meristems, which directly affect reproductive potential and yield. However, the molecular roles of upper floral meristem (UFM) and lower floral meristem (LFM) in inflorescence and kernel development have not been fully elucidated. In this study, we characterized the reversed kernel1 (rk1) novel mutant, which contains kernels with giant embryos but shows normal vegetative growth like the wild type (WT). Total RNA was extracted from the inflorescence at three stages for transcriptomic analysis. A total of 250.16-Gb clean reads were generated, and 26,248 unigenes were assembled and annotated. Gene ontology analyses of differentially expressed genes (DEGs) detected in the sexual organ formation stage revealed that cell differentiation, organ development, phytohormonal responses and carbohydrate metabolism were enriched. The DEGs associated with the regulation of phytohormone levels and signaling were mainly expressed, including auxin (IAA), jasmonic acid (JA), gibberellins (GA), and abscisic acid (ABA). The transcriptome, hormone evaluation and immunohistochemistry observation revealed that phytohormone homeostasis were affected in rk1. BSA-Seq and transcriptomic analysis also provide candidate genes to regulate UFM and LFM development. These results provide novel insights for understanding the regulatory mechanism of UFM and LFM development in maize and other plants.
PMID: 37445901
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310666
Molecular Network for Regulation of Seed Size in Plants.
National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou 450046, China.
The size of seeds is particularly important for agricultural development, as it is a key trait that determines yield. It is controlled by the coordinated development of the integument, endosperm, and embryo. Large seeds are an important way of improving the ultimate "sink strength" of crops, providing more nutrients for early plant growth and showing certain tolerance to abiotic stresses. There are several pathways for regulating plant seed size, including the HAIKU (IKU) pathway, ubiquitin-proteasome pathway, G (Guanosine triphosphate) protein regulatory pathway, mitogen-activated protein kinase (MAPK) pathway, transcriptional regulators pathway, and phytohormone regulatory pathways including the auxin, brassinosteroid (BR), gibberellin (GA), jasmonic acid (JA), cytokinin (CK), Abscisic acid (ABA), and microRNA (miRNA) regulatory pathways. This article summarizes the seed size regulatory network and prospective ways of improving yield. We expect that it will provide a valuable reference to researchers in related fields.
PMID: 37445843
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (12) doi: 10.3390/ijms241210410
Integrated Transcriptome and Metabolome Analysis Revealed the Causal Agent of Primary Bud Necrosis in 'Summer Black' Grape.
College of Horticulture, Hunan Agricultural University, Changsha 410128, China.
Primary bud necrosis of grape buds is a physiological disorder that leads to decreased berry yield and has a catastrophic impact on the double cropping system in sub-tropical areas. The pathogenic mechanisms and potential solutions remain unknown. In this study, the progression and irreversibility patterns of primary bud necrosis in 'Summer Black' were examined via staining and transmission electron microscopy observation. Primary bud necrosis was initiated at 60 days after bud break and was characterized by plasmolysis, mitochondrial swelling, and severe damage to other organelles. To reveal the underlying regulatory networks, winter buds were collected during primary bud necrosis progression for integrated transcriptome and metabolome analysis. The accumulation of reactive oxygen species and subsequent signaling cascades disrupted the regulation systems for cellular protein quality. ROS cascade reactions were related to mitochondrial stress that can lead to mitochondrial dysfunction, lipid peroxidation causing damage to membrane structure, and endoplasmic reticulum stress leading to misfolded protein aggregates. All these factors ultimately resulted in primary bud necrosis. Visible tissue browning was associated with the oxidation and decreased levels of flavonoids during primary bud necrosis, while the products of polyunsaturated fatty acids and stilbenes exhibited an increasing trend, leading to a shift in carbon flow from flavonoids to stilbene. Increased ethylene may be closely related to primary bud necrosis, while auxin accelerated cell growth and alleviated necrosis by co-chaperone VvP23-regulated redistribution of auxin in meristem cells. Altogether, this study provides important clues for further study on primary bud necrosis.
PMID: 37373557
J Fungi (Basel) , IF:5.816 , 2023 Jul , V9 (7) doi: 10.3390/jof9070728
Several Characteristics of Oidiodendron maius G.L. Barron Important for Heather Plants' Controlled Mycorrhization.
Department of Biochemistry and Biotechnology, Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Gagarin Avenue 23, 603950 Nizhny Novgorod, Russia.; LLC "Mikofit", Internatsionalnaya 56b, 606440 Bor, Russia.
Oidiodendron maius G.L. Barron is a recognized fungal species capable of forming ericoid mycorrhiza with various positive effects on host plants; therefore, newly found and previously uncharacterized O. maius strains may be valuable for heather plants' controlled mycorrhization. Characteristics of the O. maius F3860 strain were studied, i.e., mycelium growth on various nutrient media and the ability to secrete auxins and enzymes. O. maius F3860 grew rapidly on malt extract agar and potato dextrose agar. It was also able to grow on nutrient media suitable for heather plant cultivation. The presence of the flavonoids rutin and quercetin increased the mycelium growth rate compared to the control, starting from the 8th to the 13th days of cultivation. The ability to secrete auxins was confirmed with bioassay and thin-layer chromatography, and their content, as well as phytase activity, was estimated spectrophotometrically. Both in nutrient media with tryptophan and without it, O. maius F3860 secreted about 6 mug IAA/mL growth medium. O. maius F3860 possessed extracellular phytase, protease, and phenol oxidase activities. The investigation indicates O. maius F3860's promise for heather seedling inoculation as an approach to increase their fitness.
PMID: 37504716
Microb Biotechnol , IF:5.813 , 2023 Aug , V16 (8) : P1611-1615 doi: 10.1111/1751-7915.14235
The emerging role of auxins as bacterial signal molecules: Potential biotechnological applications.
Department of Biotechnology and Environmental Protection, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas, Granada, Spain.; Laboratory of Crystallographic Studies, IACT (CSIC-UGR), Armilla, Spain.; Department of Microbiology, Facultad de Farmacia, Universidad de Granada, Granada, Spain.
Microorganisms are exposed in their natural niches to a wide diversity of signal molecules. Specific detection of these signals results in alterations in microbial metabolism and physiology. Auxins like indole-3-acetic acid are key phytohormones that regulate plant growth and development. Nonetheless, auxin biosynthesis is not restricted to plants but is ubiquitous in all kingdoms of life. This wide phylogenetic distribution of auxins production, together with the diversity of regulated cellular processes, have made auxins key intra- and inter-kingdom signal molecules in life modulating, for example microbial physiology, metabolism and virulence. Despite their increasing importance as global signal molecules, the mechanisms by which auxins perform their regulatory functions in microorganisms are largely unknown. In this article, we outline recent research that has advanced our knowledge of the mechanisms of bacterial auxin perception. We also highlight the potential applications of this research in aspects such as antibiotic production, biosensor design, plant microbiome engineering and antivirulence therapies.
PMID: 37466451
Microb Biotechnol , IF:5.813 , 2023 Aug , V16 (8) : P1671-1689 doi: 10.1111/1751-7915.14296
Regulation of indole-3-acetic acid biosynthesis and consequences of auxin production deficiency in Serratia plymuthica.
Department of Biotechnology and Environmental Protection, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas, Granada, Spain.
Indole-3-acetic acid (IAA) is emerging as a key intra- and inter-kingdom signal molecule that modulates a wide range of processes of importance during plant-microorganism interaction. However, the mechanisms by which IAA carries out its functions in bacteria as well as the regulatory processes by which bacteria modulate auxin production are largely unknown. Here, we found that IAA synthesis deficiency results in important global transcriptional changes in the broad-range antibiotic-producing rhizobacterium Serratia plymuthica A153. Most pronounced transcriptional changes were observed in various gene clusters for aromatic acid metabolism, including auxin catabolism. To delve into the corresponding molecular mechanisms, different regulatory proteins were biochemically characterized. Among them, a TyrR orthologue was essential for IAA production through the activation of the ipdc gene encoding a key enzyme for IAA biosynthesis. We showed that TyrR specifically recognizes different aromatic amino acids which, in turn, alters the interactions of TyrR with the ipdc promoter. Screening of mutants defective in various transcriptional and post-transcriptional regulators allowed the identification of additional regulators of IAA production, including PigP and quorum sensing-related genes. Advancing our knowledge on the mechanisms that control the IAA biosynthesis in beneficial phytobacteria is of biotechnological interest for improving agricultural productivity and sustainable agricultural development.
PMID: 37345981
Front Plant Sci , IF:5.753 , 2023 , V14 : P1198160 doi: 10.3389/fpls.2023.1198160
Comparative sequence analysis of pPATH pathogenicity plasmids in Pantoea agglomerans gall-forming bacteria.
School of Plant Sciences and Food Security, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.; The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
Acquisition of the pathogenicity plasmid pPATH that encodes a type III secretion system (T3SS) and effectors (T3Es) has likely led to the transition of a non-pathogenic bacterium into the tumorigenic pathogen Pantoea agglomerans. P. agglomerans pv. gypsophilae (Pag) forms galls on gypsophila (Gypsophila paniculata) and triggers immunity on sugar beet (Beta vulgaris), while P. agglomerans pv. betae (Pab) causes galls on both gypsophila and sugar beet. Draft sequences of the Pag and Pab genomes were previously generated using the MiSeq Illumina technology and used to determine partial T3E inventories of Pab and Pag. Here, we fully assembled the Pab and Pag genomes following sequencing with PacBio technology and carried out a comparative sequence analysis of the Pab and Pag pathogenicity plasmids pPATH(pag) and pPATH(pab). Assembly of Pab and Pag genomes revealed a ~4 Mbp chromosome with a 55% GC content, and three and four plasmids in Pab and Pag, respectively. pPATH(pag) and pPATH(pab) share 97% identity within a 74% coverage, and a similar GC content (51%); they are ~156 kb and ~131 kb in size and consist of 198 and 155 coding sequences (CDSs), respectively. In both plasmids, we confirmed the presence of highly similar gene clusters encoding a T3SS, as well as auxin and cytokinins biosynthetic enzymes. Three putative novel T3Es were identified in Pab and one in Pag. Among T3SS-associated proteins encoded by Pag and Pab, we identified two novel chaperons of the ShcV and CesT families that are present in both pathovars with high similarity. We also identified insertion sequences (ISs) and transposons (Tns) that may have contributed to the evolution of the two pathovars. These include seven shared IS elements, and three ISs and two transposons unique to Pab. Finally, comparative sequence analysis revealed plasmid regions and CDSs that are present only in pPATH(pab) or in pPATH(pag). The high similarity and common features of the pPATH plasmids support the hypothesis that the two strains recently evolved into host-specific pathogens.
PMID: 37583594
Front Plant Sci , IF:5.753 , 2023 , V14 : P1228902 doi: 10.3389/fpls.2023.1228902
A mulberry 9-cis-epoxycarotenoid dioxygenase gene MaNCED1 is involved in plant growth regulation and confers salt and drought tolerance in transgenic tobacco.
State Key Laboratory of Resource Insects, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.; Resource Institute for Chinese & Ethnic Materia Medica, Guizhou University of Traditional Chinese Medicine, Guiyang, China.; The National Engineering Laboratory of Crop Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, China.
The phytohormone abscisic acid (ABA) is vital in regulating root elongation, seed germination, and abiotic stress responses in plants. Conversely, the mechanisms of ABA in mulberry root growth, seed germination, and abiotic stress responses are poorly understood. Here, we reported that exogenous ABA and drought treatment inhibited the growth of mulberry seedlings but significantly increased the ratio of root/stem. Inhibition of ABA synthesis by fluridone and sodium tungstate resulted in the decrease of root/stem ratio. We also showed that the expression of MaNCED1 in the root was strongly induced by drought and salt stress. Increasing the expression of MaNCED1 in tobacco using overexpression leads to increased root elongation and reduced seed germination. Compared with the wild type, the accumulation of H(2)O(2) and MDA was reduced, while the POD activity and proline content was increased in the transgenic plants after drought and salt treatment. Further studies revealed increased resistance to drought and salt stress in MaNCED1 overexpressed tobaccos. Meanwhile, the auxin and ethylene signal pathway-related gene expression levels increased in MaNCED1 overexpressed tobaccos. This study demonstrated the roles of mulberry MaNCED1 in regulating plant development and abiotic stress responses. It gave further insights into the coordinated regulation of ABA, auxin, and ethylene in seed growth and germination.
PMID: 37575921
Front Plant Sci , IF:5.753 , 2023 , V14 : P1143853 doi: 10.3389/fpls.2023.1143853
Genome-wide association studies in rice germplasm reveal significant genomic regions for root and yield-related traits under aerobic and irrigated conditions.
Indian Council of Agricultural Research (ICAR)-Indian Institute of Rice Research (IIRR), Hyderabad, India.; University of Agricultural Sciences (UAS), Raichur, India.; Chaudhary Charan Singh University, Meerut, India.; Agricultural Research Station (ARS) Dhadesugur, University of Agricultural Sciences (UAS), Raichur, India.
The development of nutrient-use efficient rice lines is a priority amidst the changing climate and depleting resources viz., water, land, and labor for achieving sustainability in rice cultivation. Along with the traditional transplanted irrigated system of cultivation, the dry direct-seeded aerobic system is gaining ground nationwide. The root-related traits play a crucial role in nutrient acquisition, adaptation and need to be concentrated along with the yield-attributing traits. We phenotyped an association panel of 118 rice lines for seedling vigour index (SVI) traits at 14 and 21 days after sowing (DAS), root-related traits at panicle initiation (PI) stage in polythene bags under controlled aerobic condition, yield and yield-related traits under the irrigated condition at ICAR-IIRR, Hyderabad, Telangana; irrigated and aerobic conditions at ARS, Dhadesugur, Raichur, Karnataka. The panel was genotyped using simple sequence repeats (SSR) markers and genome-wide association studies were conducted for identifying marker-trait associations (MTAs). Significant correlations were recorded for root length, root dry weight with SVI, root volume at the PI stage, number of productive tillers per plant, spikelet fertility, the total number of grains per panicle with grain yield per plant under irrigated conditions, and the total number of grains per panicle with grain yield per plant under aerobic condition. The panel was divided into three sub-groups (K = 3) and correlated with the principal component analysis. The maximum number of MTAs were found on chromosomes 2, 3, and 12 with considerable phenotypic variability. Consistent MTAs were recorded for SVI traits at 14 and 21 DAS (RM25310, RM80, RM22961, RM1385), yield traits under irrigated conditions (RM2584, RM5179, RM410, RM20698, RM14753) across years at ICAR-IIRR, grain yield per plant (RM22961, RM1146) under the aerobic condition, grain yield per plant at irrigated ICAR-IIRR and SVI (RM5501), root traits at PI stage (RM2584, RM80, RM410, RM1146, RM18472). Functionally relevant genes near the MTAs through in-silico expression analysis in root and panicle tissues viz., HBF2 bZIP transcription factor, WD40 repeat-like domain, OsPILS6a auxin efflux carrier, WRKY108, OsSCP42, OsMADS80, nodulin-like domain-containing protein, amino acid transporter using various rice expression databases were identified. The identified MTAs and rice lines having high SVI traits (Langphou, TI-128, Mouli, TI-124, JBB-631-1), high yield under aerobic (Phouren, NPK-43, JBB-684, Ratnamudi, TI-112), irrigated conditions (KR-209, KR-262, Phouren, Keibi-Phou, TI-17), robust root traits like root length (MoirangPhou-Angouba, Wangoo-Phou, JBB-661, Dissi, NPK-45), root volume (Ratnachudi, KJ-221, Mow, Heimang-Phou, PUP-229) can be further employed in breeding programs for the targeted environments aimed at improving seedling vigour, yield-related traits under irrigated condition, aerobic condition as adaptability to water-saving technology.
PMID: 37538056
Front Plant Sci , IF:5.753 , 2023 , V14 : P1217421 doi: 10.3389/fpls.2023.1217421
Metabolic profiles of 2-oxindole-3-acetyl-amino acid conjugates differ in various plant species.
Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences & Faculty of Science, Palacky University, Olomouc, Czechia.; Department of Chemical Biology, Faculty of Science, Palacky University, Olomouc, Czechia.
Auxins are a group of phytohormones that play a key role in plant growth and development, mainly presented by the major member of the family - indole-3-acetic acid (IAA). The levels of free IAA are regulated, in addition to de novo biosynthesis, by irreversible oxidative catabolism and reversible conjugation with sugars and amino acids. These conjugates, which serve as inactive storage forms of auxin and/or degradation intermediates, can also be oxidized to form 2-oxindole-3-acetyl-1-O-ss-d-glucose (oxIAA-glc) and oxIAA-amino acids (oxIAA-AAs). Until now, only oxIAA conjugates with aspartate and glutamate have been identified in plants. However, detailed information on the endogenous levels of these and other putative oxIAA-amino acid conjugates in various plant species and their spatial distribution is still not well understood but is finally getting more attention. Herein, we identified and characterized two novel naturally occurring auxin metabolites in plants, namely oxIAA-leucine (oxIAA-Leu) and oxIAA-phenylalanine (oxIAA-Phe). Subsequently, a new liquid chromatography-tandem mass spectrometry method was developed for the determination of a wide range of IAA metabolites. Using this methodology, the quantitative determination of IAA metabolites including newly characterized oxIAA conjugates in roots, shoots and cotyledons of four selected plant models - Arabidopsis thaliana, pea (Pisum sativum L.), wheat (Triticum aestivum L.) and maize (Zea mays L.) was performed to compare auxin metabolite profiles. The distribution of various groups of auxin metabolites differed notably among the studied species as well as their sections. For example, oxIAA-AA conjugates were the major metabolites found in pea, while oxIAA-glc dominated in Arabidopsis. We further compared IAA metabolite levels in plants harvested at different growth stages to monitor the dynamics of IAA metabolite profiles during early seedling development. In general, our results show a great diversity of auxin inactivation pathways among angiosperm plants. We believe that our findings will greatly contribute to a better understanding of IAA homeostasis.
PMID: 37534287
Front Plant Sci , IF:5.753 , 2023 , V14 : P1141692 doi: 10.3389/fpls.2023.1141692
Comparative transcriptome profiling provides insights into the growth promotion activity of Pseudomonas fluorescens strain SLU99 in tomato and potato plants.
Department of Plant Breeding, Horticum, Swedish University of Agricultural Sciences, Lomma, Sweden.; Agrobiodiversity and Environment Research Centre, Malaysian Agricultural Research and Development Institute (MARDI), Serdang, Selangor, Malaysia.; Cell and Molecular Sciences, James Hutton Institute, Dundee, United Kingdom.
The use of biocontrol agents with plant growth-promoting activity has emerged as an approach to support sustainable agriculture. During our field evaluation of potato plants treated with biocontrol rhizobacteria, four bacteria were associated with increased plant height. Using two important solanaceous crop plants, tomato and potato, we carried out a comparative analysis of the growth-promoting activity of the four bacterial strains: Pseudomonas fluorescens SLU99, Serratia plymuthica S412, S. rubidaea AV10, and S. rubidaea EV23. Greenhouse and in vitro experiments showed that P. fluorescens SLU99 promoted plant height, biomass accumulation, and yield of potato and tomato plants, while EV23 promoted growth in potato but not in tomato plants. SLU99 induced the expression of plant hormone-related genes in potato and tomato, especially those involved in maintaining homeostasis of auxin, cytokinin, gibberellic acid and ethylene. Our results reveal potential mechanisms underlying the growth promotion and biocontrol effects of these rhizobacteria and suggest which strains may be best deployed for sustainably improving crop yield.
PMID: 37534284
Front Plant Sci , IF:5.753 , 2023 , V14 : P1164534 doi: 10.3389/fpls.2023.1164534
CdWRKY2 transcription factor modulates salt oversensitivity in bermudagrass [Cynodon dactylon (L.) Pers.].
Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, Shandong, China.
Common bermudagrass [Cynodon dactylon (L.) Pers.] has higher utilization potential on saline soil due to its high yield potential and excellent stress tolerance. However, key functional genes have not been well studied partly due to its hard transformation. Here, bermudagrass "Wrangler" successfully overexpressing CdWRKY2 exhibited significantly enhanced salt and ABA sensitivity with severe inhibition of shoot and root growth compared to the transgenic negative line. The reduced auxin accumulation and higher ABA sensitivity of the lateral roots (LR) under salt stress were observed in CdWRKY2 overexpression Arabidopsis lines. IAA application could rescue or partially rescue the salt hypersensitivity of root growth inhibition in CdWRKY2-overexpressing Arabidopsis and bermudagrass, respectively. Subsequent experiments in Arabidopsis indicated that CdWRKY2 could directly bind to the promoter region of AtWRKY46 and downregulated its expression to further upregulate the expression of ABA and auxin pathway-related genes. Moreover, CdWRKY2 overexpression in mapk3 background Arabidopsis could partly rescue the salt-inhibited LR growth caused by CdWRKY2 overexpression. These results indicated that CdWRKY2 could negatively regulate LR growth under salt stress via the regulation of ABA signaling and auxin homeostasis, which partly rely on AtMAPK3 function. CdWRKY2 and its homologue genes could also be useful targets for genetic engineering of salinity-tolerance plants.
PMID: 37528987
Front Plant Sci , IF:5.753 , 2023 , V14 : P1190061 doi: 10.3389/fpls.2023.1190061
Comparative physiological and transcriptomic analyses provide insights into fruit softening in Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don].
College of Horticulture, Sichuan Agricultural University, Chengdu, Sichuan, China.; Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu, Sichuan, China.; Key Laboratory of Agricultural Bioinformatics, Ministry of Education, Chengdu, Sichuan, China.
Fruit softening is a complex, genetically programmed and environmentally regulated process, which undergoes biochemical and physiological changes during fruit development. The molecular mechanisms that determine these changes in Chinese cherry [Cerasus peseudocerasus (Lindl.) G.Don] fruits are still unknown. In the present study, fruits of hard-fleshed 'Hongfei' and soft-fleshed 'Pengzhoubai' varieties of Chinese cherry were selected to illustrate the fruit softening at different developmental stages. We analyzed physiological characteristics and transcriptome profiles to identify key cell wall components and candidate genes related to fruit softening and construct the co-expression networks. The dynamic changes of cell wall components (cellulose, hemicellulose, pectin, and lignin), the degrading enzyme activities, and the microstructure were closely related to the fruit firmness during fruit softening. A total of 6,757 and 3,998 differentially expressed genes (DEGs) were screened between stages and varieties, respectively. Comprehensive functional enrichment analysis supported that cell wall metabolism and plant hormone signal transduction pathways were involved in fruit softening. The majority of structural genes were significantly increased with fruit ripening in both varieties, but mainly down-regulated in Hongfei fruits compared with Pengzhoubai, especially DEGs related to cellulose and hemicellulose metabolism. The expression levels of genes involving lignin biosynthesis were decreased with fruit ripening, while mainly up-regulated in Hongfei fruits at red stage. These obvious differences might delay the cell all degrading and loosening, and enhance the cell wall stiffing in Hongfei fruits, which maintained a higher level of fruit firmness than Pengzhoubai. Co-expressed network analysis showed that the key structural genes were correlated with plant hormone signal genes (such as abscisic acid, auxin, and jasmonic acid) and transcription factors (MADS, bHLH, MYB, ERF, NAC, and WRKY). The RNA-seq results were supported using RT-qPCR by 25 selected DEGs that involved in cell wall metabolism, hormone signal pathways and TF genes. These results provide important basis for the molecular mechanism of fruit softening in Chinese cherry.
PMID: 37528967
Front Plant Sci , IF:5.753 , 2023 , V14 : P1163228 doi: 10.3389/fpls.2023.1163228
ZmmiR169q/ZmNF-YA8 is a module that homeostatically regulates primary root growth and salt tolerance in maize.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences (CAAS), Hainan, China.
In response to salt stress, plants alter the expression of manifold gene networks, enabling them to survive and thrive in the face of adversity. As a result, the growth and development of plant roots could be drastically altered, with significant inhibition of the growth of root meristematic zones. Although it is known that root growth is primarily regulated by auxins and cytokinins, the molecular regulatory mechanism by which salt stress stunts root meristems remains obscure. In this study, we found that the ZmmiR169q/ZmNF-YA8 module regulates the growth of maize taproots in response to salt stress. Salt stress downregulates ZmmiR169q expression, allowing for significant upregulation of ZmNF-YA8, which, in turn, activates ZmERF1B, triggering the upregulation of ASA1 and ASA2, two rate-limiting enzymes in the biosynthesis of tryptophan (Trp), leading to the accumulation of auxin in the root tip, thereby inhibiting root growth. The development of the maize root is stymied as meristem cell division and meristematic zone expansion are both stifled. This study reveals the ZmmiR169q/ZmNF-YA8 module's involvement in maintaining an equilibrium in bestowing plant salt tolerance and root growth and development under salt stress, providing new insights into the molecular mechanism underlying the homeostatic regulation of plant development in response to salt stress.
PMID: 37457348
Front Plant Sci , IF:5.753 , 2023 , V14 : P1142748 doi: 10.3389/fpls.2023.1142748
The origin and early evolution of cytokinin signaling.
Department of Research and Development, Garden City, NY, United States.
Angiosperms, especially Arabidopsis and rice, have long been at the center of plant research. However, technological advances in sequencing have led to a dramatic increase in genome and transcriptome data availability across land plants and, more recently, among green algae. These data allowed for an in-depth study of the evolution of different protein families - including those involved in the metabolism and signaling of phytohormones. While most early studies on phytohormone evolution were phylogenetic, those studies have started to be complemented by genetic and biochemical studies in recent years. Examples of such functional analyses focused on ethylene, jasmonic acid, abscisic acid, and auxin. These data have been summarized recently. In this review, we will focus on the progress in our understanding of cytokinin biology. We will use these data to synthesize key points about the evolution of cytokinin metabolism and signaling, which might apply to the evolution of other phytohormones as well.
PMID: 37457338
Front Plant Sci , IF:5.753 , 2023 , V14 : P1201486 doi: 10.3389/fpls.2023.1201486
An integrated transcriptome and metabolome analysis reveals the gene network regulating flower development in Pogostemon cablin.
Sanya Nanfan Research Institute of Hainan University, College of Tropical Crops, Hainan University, Sanya, China.; Guangdong VTR BioTech Co., Ltd., Zhuhai, China.
Pogostemon cablin is a well-known protected species widely used in medicine and spices, however the underlying molecular mechanisms and metabolite dynamics of P. cablin flower development remain unclear due to the difficulty in achieving flowering in this species. A comparison of the transcriptome and widely targeted metabolome during P. cablin flower development was first performed in this study. Results showed that a total of 13,469 differentially expressed unigenes (DEGs) and 371 differentially accumulated metabolites (DAMs) were identified. Transcriptomic analysis revealed that the DEGs were associated with starch and sucrose metabolism, terpenoid biosynthesis and phenylpropanoid biosynthesis. Among these DEGs, 75 MIKC-MADS unigenes were associated with the development of floral organs. Gibberellins (GAs), auxin, and aging signaling might form a cross-regulatory network to regulate flower development in P. cablin. According to the metabolic profile, the predominant DAMs were amino acids, flavonoids, terpenes, phenols, and their derivatives. The accumulation patterns of these predominant DAMs were closely associated with the flower developmental stage. The integration analysis of DEGs and DAMs indicated that phenylpropanoids, flavonoids, and amino acids might be accumulated due to the activation of starch and sucrose metabolism. Our results provide some important insights for elucidating the reproductive process, floral organ, and color formation of P. cablin flowers at the molecular level. These results will improve our understanding of the molecular and genetic mechanisms involved in the floral development of P. cablin.
PMID: 37457333
Front Plant Sci , IF:5.753 , 2023 , V14 : P1197776 doi: 10.3389/fpls.2023.1197776
Hormonal regulation of ethylene response factors in tomato during storage and distribution.
Postharvest Research Division, National Institute of Horticultural and Herbal Science, Wanju, Republic of Korea.
INTRODUCTION: Ethylene response factors (ERFs) play a critical role in regulating hormone interactions that affect the shelf life of tomatoes. Understanding their regulation during storage and distribution can be highly beneficial. METHODS: This study examined the effects of treatment with ethylene (ET), brassinosteroid (BR), auxin (AUX), and gibberellin (GA) on fruit ripening and the expression of 18 ripening-associated ERFs in tomato stored at 20 degrees C (room temperature) for 10 d or 4 degrees C (cold storage) for 14 d followed by 2 d at 20 degrees C (retailer conditions). RESULTS: The results showed that ripening was accelerated by ET and BR but was delayed by AUX and GA at room temperature. Cold storage delayed ripening in all groups, with ET and GA treatments showing the highest and lowest a* values, respectively. The effects of hormone treatment were consistent with room temperature when the fruits were transferred from cold storage to retail conditions. At room temperature, ERFs responsive to ET (ERF.B1, B2, B6, E2, and F1) and BR (ERF.E5, F2, and F3) were inhibited by AUX. ET-induced genes (ERF.C1, E1, F4, and H7) could be co-regulated by other hormones at cold storage. When the fruits were transferred from cold storage to retailer conditions, ERFs responsive to ET and BR were inhibited by GA. Additionally, ET-responsive ERFs could be inhibited by BR at room temperature, whereas ET could inhibit BR-responsive ERFs at retailer conditions. The same ERFs that were regulated by ET at room temperature were instead regulated by BR under retailer conditions, and vice versa. DISCUSSION: These findings can help provide a better understanding of the complex hormone interactions regulating the postharvest physiology of tomato and in maintaining its quality and shelf life during storage and distribution.
PMID: 37448864
Front Plant Sci , IF:5.753 , 2023 , V14 : P1190373 doi: 10.3389/fpls.2023.1190373
How do you build a nectar spur? A transcriptomic comparison of nectar spur development in Linaria vulgaris and gibba development in Antirrhinum majus.
Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom.; Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Koln, Germany.
Nectar spurs (tubular outgrowths of floral organs) have long fascinated biologists. However, given that no model species possess nectar spurs, there is still much to learn about their development. In this study we combined morphological analysis with comparative transcriptomics to gain a global insight into the morphological and molecular basis of spur outgrowth in Linaria. Whole transcriptome sequencing was performed on two related species at three key developmental stages (identified by our morphological analysis), one with a spur (Linaria vulgaris), and one without a spur (Antirrhinum majus). A list of spur-specific genes was selected, on which we performed a gene enrichment analysis. Results from our RNA-seq analysis agreed with our morphological observations. We describe gene activity during spur development and provide a catalogue of spur-specific genes. Our list of spur-specific genes was enriched for genes connected to the plant hormones cytokinin, auxin and gibberellin. We present a global view of the genes involved in spur development in L. vulgaris, and define a suite of genes which are specific to spur development. This work provides candidate genes for spur outgrowth and development in L. vulgaris which can be investigated in future studies.
PMID: 37426957
Front Plant Sci , IF:5.753 , 2023 , V14 : P1184058 doi: 10.3389/fpls.2023.1184058
Overexpression of peanut (Arachis hypogaea L.) AhGRFi gene enhanced root growth inhibition under exogenous NAA treatment in Arabidopsis thaliana.
Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.; Department of Plant Pathology, University of Georgia, Tifton, GA, United States.; Department of Agriculture Biotechnology, National Agri-food Biotechnology Institute (NABI), Mohali, India.; Crops Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
The 14-3-3 protein is a kind of evolutionary ubiquitous protein family highly conserved in eukaryotes. Initially, 14-3-3 proteins were reported in mammalian nervous tissues, but in the last decade, their role in various metabolic pathways in plants established the importance of 14-3-3 proteins. In the present study, a total of 22 14-3-3 genes, also called general regulatory factors (GRF), were identified in the peanut (Arachis hypogaea) genome, out of which 12 belonged to the epsilon group, whereas 10 of them belonged to the non- epsilon-group. Tissue-specific expression of identified 14-3-3 genes were studied using transcriptome analysis. The peanut AhGRFi gene was cloned and transformed into Arabidopsis thaliana. The investigation of subcellular localization indicated that AhGRFi is localized in the cytoplasm. Overexpression of the AhGRFi gene in transgenic Arabidopsis showed that under exogenous 1-naphthaleneacetic acid (NAA) treatment, root growth inhibition in transgenic plants was enhanced. Further analysis indicated that the expression of auxin-responsive genes IAA3, IAA7, IAA17, and SAUR-AC1 was upregulated and GH3.2 and GH3.3 were downregulated in transgenic plants, but the expression of GH3.2, GH3.3, and SAUR-AC1 showed opposite trends of change under NAA treatment. These results suggest that AhGRFi may be involved in auxin signaling during seedling root development. An in-depth study of the molecular mechanism of this process remains to be further explored.
PMID: 37416889
Theor Appl Genet , IF:5.699 , 2023 Aug , V136 (9) : P182 doi: 10.1007/s00122-023-04434-7
The genetic architecture of prolificacy in maize revealed by association mapping and bulk segregant analysis.
National Key Laboratory of Wheat and Maize Crop Science, Department of Agronomy, College of Agronomy, Henan Agricultural University, No. 218 Ping'an Avenue, Zhengdong New District, Zhengzhou, 450046, People's Republic of China.; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, People's Republic of China.; Zhucheng Mingjue Tender Company Limited, Weifang, People's Republic of China.; National Key Laboratory of Wheat and Maize Crop Science, Department of Agronomy, College of Agronomy, Henan Agricultural University, No. 218 Ping'an Avenue, Zhengdong New District, Zhengzhou, 450046, People's Republic of China. xuehai85@126.com.; National Key Laboratory of Wheat and Maize Crop Science, Department of Agronomy, College of Agronomy, Henan Agricultural University, No. 218 Ping'an Avenue, Zhengdong New District, Zhengzhou, 450046, People's Republic of China. tangjihua1@163.com.; The Shennong Laboratory, Zhengzhou, People's Republic of China. tangjihua1@163.com.
Here, we revealed maize prolificacy highly correlated with domestication and identified a causal gene ZmEN1 located in one novel QTL qGEN261 that regulating maize prolificacy by using multiple-mapping methods. The development of maize prolificacy (EN) is crucial for enhancing yield and breeding specialty varieties. To achieve this goal, we employed a genome-wide association study (GWAS) to analyze the genetic architecture of EN in maize. Using 492 inbred lines with a wide range of EN variability, our results demonstrated significant differences in genetic, environmental, and interaction effects. The broad-sense heritability (H(2)) of EN was 0.60. Through GWAS, we identified 527 significant single nucleotide polymorphisms (SNPs), involved 290 quantitative trait loci (QTL) and 806 genes. Of these SNPs, 18 and 509 were classified as major effect loci and minor loci, respectively. In addition, we performed a bulk segregant analysis (BSA) in an F(2) population constructed by a few-ears line Zheng58 and a multi-ears line 647. Our BSA results identified one significant QTL, qBEN1. Importantly, combining the GWAS and BSA, four co-located QTL, involving six genes, were identified. Three of them were expressed in vegetative meristem, shoot tip, internode and tip of ear primordium, with ZmEN1, encodes an unknown auxin-like protein, having the highest expression level in these tissues. It suggested that ZmEN1 plays a crucial role in promoting axillary bud and tillering to encourage the formation of prolificacy. Haplotype analysis of ZmEN1 revealed significant differences between different haplotypes, with inbred lines carrying hap6 having more EN. Overall, this is the first report about using GWAS and BSA to dissect the genetic architecture of EN in maize, which can be valuable for breeding specialty maize varieties and improving maize yield.
PMID: 37555969
Theor Appl Genet , IF:5.699 , 2023 Jun , V136 (7) : P160 doi: 10.1007/s00122-023-04404-z
Photoperiod and gravistimulation-associated Tiller Angle Control 1 modulates dynamic changes in rice plant architecture.
State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China.; Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. caoliyong@caas.cn.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. zhangyingxin@caas.cn.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. chengshihua@caas.cn.
TAC1 is involved in photoperiodic and gravitropic responses to modulate rice dynamic plant architecture likely by affecting endogenous auxin distribution, which could explain TAC1 widespread distribution in indica rice. Plants experience a changing environment throughout their growth, which requires dynamic adjustments of plant architecture in response to these environmental cues. Our previous study demonstrated that Tiller Angle Control 1 (TAC1) modulates dynamic changes in plant architecture in rice; however, the underlying regulatory mechanisms remain largely unknown. In this study, we show that TAC1 regulates plant architecture in an expression dose-dependent manner, is highly expressed in stems, and exhibits dynamic expression in tiller bases during the growth period. Photoperiodic treatments revealed that TAC1 expression shows circadian rhythm and is more abundant during the dark period than during the light period and under short-day conditions than under long-day conditions. Therefore, it contributes to dynamic plant architecture under long-day conditions and loose plant architecture under short-day conditions. Gravity treatments showed that TAC1 is induced by gravistimulation and negatively regulates shoot gravitropism, likely by affecting auxin distribution. Notably, the tested indica rice containing TAC1 displayed dynamic plant architecture under natural long-day conditions, likely explaining the widespread distribution of TAC1 in indica rice. Our results provide new insights into TAC1-mediated regulatory mechanisms for dynamic changes in rice plant architecture.
PMID: 37347301
Plant Cell Physiol , IF:4.927 , 2023 Jul doi: 10.1093/pcp/pcad077
KAI2 can do: Karrikin Receptor Function in Plant Development and Response to Abiotic and Biotic Factors.
Max-Planck-Institute of Molecular Plant Physiology, Potsdam Science Park, Am Muhlenberg 1, 14476 Potsdam-Golm, 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 signalling 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-signalling is being linked to an elaborate cross-talk with other phytohormone pathways such as auxin, gibberellin, abscisic acid, ethylene, and salicylic acid signalling, in addition to light and nutrient starvation signalling. Further connections will likely be revealed in the future. This article summarizes recent advances in unravelling the function of KAI2-mediated signalling and its interaction with other signalling pathways.
PMID: 37548562
Plant Cell Physiol , IF:4.927 , 2023 Jul doi: 10.1093/pcp/pcad078
PINOID and PIN-FORMED Paralogous Genes Are Required for Leaf Morphogenesis in Rice.
College of Agriculture, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, People's Republic of China.; Rice Research Institute, Jiangxi Academy of Agricultural Sciences, No. 602 Nanlian Road, Nanchang 330200, People's Republic of China.; Key Laboratory of Crop Physiology, Ecology and Production Management, Ministry of Agriculture, No. 1 Weigang, Nanjing 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry, Nanjing Agricultural University, No. 1 Weigang, Nanjing 210095, People's Republic of China.
Auxin plays an essential role in modulating leaf development. However, its role in leaf development in rice (Oryza sativa L.) remains largely unknown. In this study, we found that PINOID (OsPID) and two Sister-of-PIN1s, termed PIN-FORMED1c (OsPIN1c) and OsPIN1d, are necessary for rice leaf development. The ospin1c ospin1d null mutant lines presented severe defects in leaf morphogenesis, including drooping and semi-drooping blades, an abnormally thickened sheath and lamina joint, and fused leaves with absent ligules and auricles. Loss-of-function ospid mutants displayed generally similar leaf morphology but lacked leaf fusion. Interestingly, misshaped leaf genesis displayed a preference for being ipsilateral. In addition, OsPIN1c and OsPID were commonly localized in the initiating leaf primordia. Furthermore, accompanied by the more severe organ morphogenesis in the ospin1c ospin1d ospid triple mutant, RNA sequencing analysis revealed that many genes essential for leaf development have an altered expression level. Together, this study furthers our understanding of the role auxin transport plays during leaf development in monocot rice.
PMID: 37540575
Plant Cell Physiol , IF:4.927 , 2023 Jul doi: 10.1093/pcp/pcad084
Genetic Interaction between Arabidopsis SUR2/CYP83B1 and GNOM Indicates the Importance of Stabilizing Local Auxin Accumulation in Lateral Root Initiation.
Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Kobe 657-8501, Japan.; Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Japan.; Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu 183-8509, Japan.; RIKEN Center for Sustainable Resource Science, Riken, Yokohama, Kanagawa 230-0045, Japan.; Graduate School of Integrated Science for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.; Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-Ku, Tokyo 113-8657, Japan.; College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
Lateral root (LR) formation is an important developmental event for the establishment of the root system in most vascular plants. In Arabidopsis thaliana, the fewer roots (fwr) mutation in the GNOM gene, encoding an Arf GTPase guanine nucleotide exchange factor that regulates vesicle trafficking, severely inhibits LR formation. Local accumulation of auxin response for LR initiation is severely affected in fwr. To better understand how local accumulation of auxin response for LR initiation is regulated, we identified a mutation, fewer roots suppressor1 (fsp1), that partially restores LR formation in fwr. The gene responsible for fsp1 was identified as SUPERROOT2 (SUR2), encoding CYP83B1 that positions at the metabolic branch point in the biosynthesis of auxin/indole-3-acetic acid (IAA) and indole glucosinolate. The fsp1 mutation increases both endogenous IAA levels and the number of the sites where auxin response locally accumulates prior to LR formation in fwr. SUR2 is expressed in the pericycle of the differentiation zone and in the apical meristem in roots. Time-lapse imaging of the auxin response revealed that local accumulation of auxin response is more stable in fsp1. These results suggest that SUR2/CYP83B1 affects LR founder cell formation at the xylem pole pericycle cells where auxin accumulates. Analysis of the genetic interaction between SUR2 and GNOM indicates the importance of stabilization of local auxin accumulation sites for LR initiation.
PMID: 37522618
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
Rice (N Y) , IF:4.783 , 2023 Jun , V16 (1) : P28 doi: 10.1186/s12284-023-00645-0
Pan-transcriptomic Profiling Demarcates Serendipita Indica-Phosphorus Mediated Tolerance Mechanisms in Rice Exposed to Arsenic Toxicity.
Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.; Dow International Medical College, Dow University of Health Sciences, Karachi, 74200, Pakistan.; Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China. drimran@zju.edu.cn.
Inadvertent accumulation of arsenic (As) in rice (Oryza sativa L.) is a concern for people depending on it for their subsistence, as it verily causes epigenetic alterations across the genome as well as in specific cells. To ensure food safety, certain attempts have been made to nullify this highest health hazard encompassing physiological, chemical and biological methods. Albeit, the use of mycorrhizal association along with nutrient reinforcement strategy has not been explored yet. Mechanisms of response and resistance of two rice genotypes to As with or without phosphorus (P) nutrition and Serendipita indica (S. indica; S.i) colonization were explored by root transcriptome profiling in the present study. Results revealed that the resistant genotype had higher auxin content and root plasticity, which helped in keeping the As accumulation and P starvation response to a minimum under alone As stress. However, sufficient P supply and symbiotic relationship switched the energy resources towards plant's developmental aspects rather than excessive root proliferation. Higher As accumulating genotype (GD-6) displayed upregulation of ethylene signaling/biosynthesis, root stunting and senescence related genes under As toxicity. Antioxidant defense system and cytokinin biosynthesis/signaling of both genotypes were strengthened under As + S.i + P, while the upregulation of potassium (K) and zinc (Zn) transporters depicted underlying cross-talk with iron (Fe) and P. Differential expression of phosphate transporters, peroxidases and GSTs, metal detoxification/transport proteins, as well as phytohormonal metabolism were responsible for As detoxification. Taken together, S. indica symbiosis fortified with adequate P-fertilizer can prove to be effective in minimizing As acquisition and accumulation in rice plants.
PMID: 37354226
Plant Sci , IF:4.729 , 2023 Aug , 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 Aug , 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 Aug , 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 Jul , 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
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111726 doi: 10.1016/j.plantsci.2023.111726
Short-term exposition to acute cadmium toxicity induces the loss of root gravitropic stimuli perception through PIN2-mediated auxin redistribution in Arabidopsis thaliana (L.) Heynh.
Department of Agricultural and Environmental Sciences, University of Milano, Milan 20133, Italy.; Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Arcavacata of Rende, CS 87036, Italy.; Universidade de Vigo, Departamento de Bioloxia Vexetal e Ciencias do Solo, Facultade de Bioloxia, Campus Lagoas-Marcosende s/n, 36310 Vigo, Spain.; Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Arcavacata of Rende, CS 87036, Italy. Electronic address: leonardo.bruno@unical.it.
Cadmium (Cd), one of the most widespread and water-soluble polluting heavy metals, has been widely studied on plants, even if the mechanisms underlying its phytotoxicity remain elusive. Indeed, most experiments are performed using extensive exposure time to the toxicants, not observing the primary targets affected. The present work studied Cd effects on Arabidopsis thaliana (L.) Heynh's root apical meristem (RAM) exposed for short periods (24 h and 48 h) to acute phytotoxic concentrations (100 and 150 microM). The effects were studied through integrated morpho-histological, molecular, pharmacological and metabolomic analyses, highlighting that Cd inhibited primary root elongation by affecting the meristem zone via altering cell expansion. Moreover, Cd altered Auxin accumulation in RAM and affected PINs polar transporters, particularly PIN2. In addition, we observed that high Cd concentration induced accumulation of reactive oxygen species (ROS) in roots, which resulted in an altered organization of cortical microtubules and the starch and sucrose metabolism, altering the statolith formation and, consequently, the gravitropic root response. Our results demonstrated that short Cd exposition (24 h) affected cell expansion preferentially, altering auxin distribution and inducing ROS accumulation, which resulted in an alteration of gravitropic response and microtubules orientation pattern.
PMID: 37149227
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111718 doi: 10.1016/j.plantsci.2023.111718
Indole-3-acetaldoxime delays root iron-deficiency responses and modify auxin homeostasis in Medicago truncatula.
Department of Pomology, Aula Dei Experimental Station, Consejo Superior de Investigaciones Cientificas (CSIC), Avda. de Montanana 1005, E-50059 Zaragoza, Spain.; Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, E-31192 Mutilva, Spain.; Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA), Campus de Arrosadia, E-31006 Pamplona, Spain.; Department of Pomology, Aula Dei Experimental Station, Consejo Superior de Investigaciones Cientificas (CSIC), Avda. de Montanana 1005, E-50059 Zaragoza, Spain. Electronic address: aoiz@eead.csic.es.
Iron (Fe) is an essential plant micronutrient, being a major limiting growth factor in calcareous soils. To increase Fe uptake, plants induce lateral roots growth, the expression of a Fe(III)-chelate reductase (FCR), a Fe(II)-transporter and a H(+)-ATPase and the secretion of flavins. Furthermore, auxin hormone family is involved in the Fe-deficiency responses but the action mechanism remains elusive. In this work, we evaluated the effect of the auxin-precursor indole-3-acetaldoxime (IAOx) on hydroponically grown Medicago truncatula plants under different Fe conditions. Upon 4-days of Fe starvation, the pH of the nutrient solution decreased, while both the FCR activity and the presence of flavins increased. Exogenous IAOx increased lateral roots growth contributing to superroot phenotype, decreased chlorosis, and delayed up to 3-days the pH-decrease, the FCR-activity increase, and the presence of flavins, compared to Fe-deficient plants. Gene expression levels were in concordance with the physiological responses. RESULTS: showed that IAOx was immediately transformed to IAN in roots and shoots to maintain auxin homeostasis. IAOx plays an active role in iron homeostasis delaying symptoms and responses in Fe-deficient plants. We may speculate that IAOx or its derivatives remobilize Fe from root cells to alleviate Fe-deficiency. Overall, these results point out that the IAOx-derived phenotype may have advantages to overcome nutritional stresses.
PMID: 37105378
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111699 doi: 10.1016/j.plantsci.2023.111699
Role of EIN2-mediated ethylene signaling in regulating petal senescence, abscission, reproductive development, and hormonal crosstalk in tobacco.
Department of Biology, University of Texas Rio Grande Valley, 1201 W. University Dr, Edinburg, TX 78539, USA. Electronic address: manohar.chakrabarti@utrgv.edu.; Department of Biology, University of Texas Rio Grande Valley, 1201 W. University Dr, Edinburg, TX 78539, USA.
Ethylene plays a pivotal role in a wide range of developmental, physiological, and defense processes in plants. EIN2 (ETHYLENE INSENSITIVE2) is a key player in the ethylene signaling pathway. To characterize the role of EIN2 in processes, such as petal senescence, where it has been found to play important roles along with various other developmental and physiological processes, the tobacco (Nicotiana tabacum) ortholog of EIN2 (NtEIN2) was isolated and NtEIN2 silenced transgenic lines were generated using RNA interference (RNAi). Silencing of NtEIN2 compromised plant defense against pathogens. NtEIN2 silenced lines displayed significant delays in petal senescence, and pod maturation, and adversely affected pod and seed development. This study further dissected the petal senescence in ethylene insensitive lines, that displayed alteration in the pattern of petal senescence and floral organ abscission. Delay in petal senescence was possibly because of delayed aging processes within petal tissues. Possible crosstalk between EIN2 and AUXIN RESPONSE FACTOR 2 (ARF2) in regulating the petal senescence process was also investigated. Overall, these experiments indicated a crucial role for NtEIN2 in controlling diverse developmental and physiological processes, especially in petal senescence.
PMID: 37028457
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 Aug , V42 (8) : P1279-1290 doi: 10.1007/s00299-023-03030-9
The SMC5/6 complex subunit MMS21 regulates stem cell proliferation in rice.
College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, China.; Jiangsu Collaborative Innovation Centre for Modern Crop Production, Nanjing, 210095, China.; College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China. dingcq@njau.edu.cn.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, China. dingcq@njau.edu.cn.; Jiangsu Collaborative Innovation Centre for Modern Crop Production, Nanjing, 210095, China. dingcq@njau.edu.cn.
SMC5/6 complex subunit OsMMS21 is involved in cell cycle and hormone signaling and required for stem cell proliferation during shoot and root development in rice. The structural maintenance of chromosome (SMC)5/6 complex is required for nucleolar integrity and DNA metabolism. Moreover, METHYL METHANESULFONATE SENSITIVITY GENE 21 (MMS21), a SUMO E3 ligase that is part of the SMC5/6 complex, is essential for the root stem cell niche and cell cycle transition in Arabidopsis. However, its specific role in rice remains unclear. Here, OsSMC5 and OsSMC6 single heterozygous mutants were generated using CRISPR/Cas9 technology to elucidate the function of SMC5/6 subunits, including OsSMC5, OsSMC6, and OsMMS21, in cell proliferation in rice. ossmc5/ + and ossmc6/ + heterozygous single mutants did not yield homozygous mutants in their progeny, indicating that OsSMC5 and OsSMC6 both play necessary roles during embryo formation. Loss of OsMMS21 caused severe defects in both the shoot and roots in rice. Transcriptome analysis showed a significant decrease in the expression of genes involved in auxin signaling in the roots of osmms21 mutants. Moreover, the expression levels of the cycB2-1 and MCM genes, which are involved the cell cycle, were significantly lower in the shoots of the mutants, indicating that OsMMS21 was involved in both hormone signaling pathways and the cell cycle. Overall, these findings indicate that the SUMO E3 ligase OsMMS21 is required for both shoot and root stem cell niches, improving the understanding of the function of the SMC5/6 complex in rice.
PMID: 37178216
Plant Cell Rep , IF:4.57 , 2023 Jul , V42 (7) : P1217-1231 doi: 10.1007/s00299-023-03025-6
Transcription elongation factors OsSPT4 and OsSPT5 are essential for rice growth and development and act with APO2.
College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry, Nanjing, 210095, People's Republic of China.; College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.; Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.
The transcription elongation factor SPT4/SPT5 complex is essential for rice vegetative and reproductive growth and that OsSPT5-1, with its interactor APO2, is involved in multiple phytohormone pathways. The SPT4/SPT5 complex is a transcription elongation factor that regulates the processivity of transcription elongation. However, our understanding of the role of SPT4/SPT5 complex in developmental regulation remains limited. Here, we identified three SPT4/SPT5 genes (OsSPT4, OsSPT5-1, and OsSPT5-2) in rice, and investigated their roles in vegetative and reproductive growth. These genes are highly conserved with their orthologs in other species. OsSPT4 and OsSPT5-1 are widely expressed in various tissues. By contrast, OsSPT5-2 is expressed at a relatively low level, which could cause osspt5-2 null mutants have no phenotypes. Loss-of-function mutants of OsSPT4 and OsSPT5-1 could not be obtained; their heterozygotes showed severe reproductive growth defects. An incomplete mutant line (osspt5-1#12) displayed gibberellin-related dwarfed defects and a weak root system at an early vegetative phase, and a short life cycle in different planting environments. Furthermore, OsSPT5-1 interacts with the transcription factor ABERRANT PANICLE ORGANIZATION 2 (APO2) and plays a similar role in regulating the growth of rice shoots. RNA sequencing analysis verified that OsSPT5-1 is involved in multiple phytohormone pathways, including gibberellin, auxin, and cytokinin. Therefore, the SPT4/SPT5 complex is essential for both vegetative and reproductive growth in rice.
PMID: 37148321
Plant Cell Rep , IF:4.57 , 2023 Jul , V42 (7) : P1163-1177 doi: 10.1007/s00299-023-03019-4
A methane-cGMP module positively influences adventitious rooting.
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China.; College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China. wbshenh@njau.edu.cn.
Endogenous cGMP operates downstream of CH(4) control of adventitious rooting, following by the regulation in the expression of cell cycle regulatory and auxin signaling-related genes. Methane (CH(4)) is a natural product from plants and microorganisms. Although exogenously applied CH(4) and cyclic guanosine monophosphate (cGMP) are separately confirmed to be involved in the control of adventitious root (AR) formation, the possible interaction still remains elusive. Here, we observed that exogenous CH(4) not only rapidly promoted cGMP synthesis through increasing the activity of guanosine cyclase (GC), but also induced cucumber AR development. These responses were obviously impaired by the removal of endogenous cGMP with two GC inhibitors. Anatomical evidence showed that the emerged stage (V) among AR primordia development might be the main target of CH(4)-cGMP module. Genetic evidence revealed that the transgenic Arabidopsis that overexpressed the methyl-coenzyme M reductase gene (MtMCR) from Methanobacterium thermoautotrophicum not only increased-cGMP production, but also resulted in a pronounced AR development compared to wild-type (WT), especially with the addition of CH(4) or the cell-permeable cGMP derivative 8-Br-cGMP. qPCR analysis confirmed that some marker genes associated with cell cycle regulatory and auxin signaling were closely related to the brand-new CH(4)-cGMP module in AR development. Overall, our results clearly revealed an important function of cGMP in CH(4) governing AR formation by modulating auxin-dependent pathway and cell cycle regulation.
PMID: 37084115
Genetics , IF:4.562 , 2023 Aug , V224 (4) doi: 10.1093/genetics/iyad102
How flower development genes were identified using forward genetic screens in Arabidopsis thaliana.
School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
In the later part of the 1980s, the time was ripe for identifying genes controlling flower development. In that pregenomic era, the easiest way to do this was to induce random mutations in seeds by chemical mutagens (or irradiation) and to screen thousands of plants for those with phenotypes specifically defective in floral morphogenesis. Here, we discuss the results of premolecular screens for flower development mutants in Arabidopsis thaliana, carried out at Caltech and Monash University, emphasizing the usefulness of saturation mutagenesis, multiple alleles to identify full loss-of-function, conclusions based on multiple mutant analyses, and from screens for enhancer and suppressor modifiers of original mutant phenotypes. One outcome was a series of mutants that led to the ABC floral organ identity model (AP1, AP2, AP3, PI, and AG). In addition, genes controlling flower meristem identity (AP1, CAL, and LFY), floral meristem size (CLV1 and CLV3), development of individual floral organ types (CRC, SPT, and PTL), and inflorescence meristem properties (TFL1, PIN1, and PID) were defined. These occurrences formed targets for cloning that eventually helped lead to an understanding of transcriptional control of the identity of floral organs and flower meristems, signaling within meristems, and the role of auxin in initiating floral organogenesis. These findings in Arabidopsis are now being applied to investigate how orthologous and paralogous genes act in other flowering plants, allowing us to wander in the fertile fields of evo-devo.
PMID: 37294732
Microb Ecol , IF:4.552 , 2023 Jul , V86 (1) : P431-445 doi: 10.1007/s00248-022-02080-y
Screening of Phosphate Solubilization Identifies Six Pseudomonas Species with Contrasting Phytostimulation Properties in Arabidopsis Seedlings.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Catedratico CONACYT-Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Catedratico CONACYT-Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico. jbucio@umich.mx.
The interaction of plants with bacteria and the long-term success of their adaptation to challenging environments depend upon critical traits that include nutrient solubilization, remodeling of root architecture, and modulation of host hormonal status. To examine whether bacterial promotion of phosphate solubilization, root branching and the host auxin response may account for plant growth, we isolated and characterized ten bacterial strains based on their high capability to solubilize calcium phosphate. All strains could be grouped into six Pseudomonas species, namely P. brassicae, P. baetica, P. laurylsulfatiphila, P. chlororaphis, P. lurida, and P. extremorientalis via 16S rRNA molecular analyses. A Solibacillus isronensis strain was also identified, which remained neutral when interacting with Arabidopsis roots, and thus could be used as inoculation control. The interaction of Arabidopsis seedlings with bacterial streaks from pure cultures in vitro indicated that their phytostimulation properties largely differ, since P. brassicae and P. laurylsulfatiphila strongly increased shoot and root biomass, whereas the other species did not. Most bacterial isolates, except P. chlororaphis promoted lateral root formation, and P. lurida and P. chlororaphis strongly enhanced expression of the auxin-inducible gene construct DR5:GUS in roots, but the most bioactive probiotic bacterium P. brassicae could not enhance the auxin response. Inoculation with P. brassicae and P. lurida improved shoot and root growth in medium supplemented with calcium phosphate as the sole Pi source. Collectively, our data indicate the differential responses of Arabidopsis seedlings to inoculation with several Pseudomonas species and highlight the potential of P. brassicae to manage phosphate nutrition and plant growth in a more eco-friendly manner.
PMID: 35867140
Physiol Plant , IF:4.5 , 2023 Jul : Pe13973 doi: 10.1111/ppl.13973
Casein as protein and hydrolysate: biostimulant or nitrogen source for Nicotiana tabacum plants grown in vitro?
Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, CZ-128 43 Praha 2, Czech Republic.; Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemedelska 1, CZ-613 00, Brno, Czech Republic.; Institute of Experimental Botany, Academy of Sciences of the CR, Rozvojova 263, CZ-165 02 Praha 6, Czech Republic.; Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Agoralaan building D, 3590, Diepenbeek, Belgium.; Department of Analytical Chemistry, Faculty of Science, Charles University, Hlavova 2030, CZ-128 43 Praha 2, Czech Republic.
In contrast to inorganic nitrogen (N) assimilation, the role of organic N forms, such as proteins and peptides, as sources of N and their impact on plant metabolism remains unclear. Simultaneously, organic biostimulants are used as priming agents to improve plant defense response. Here, we analyzed the metabolic response of tobacco plants grown in vitro with casein hydrolysate or protein. As the sole source of N, casein hydrolysate enabled tobacco growth, while protein casein was used only to a limited extent. Free amino acids were detected in the roots of tobacco plants grown with protein casein but not in the plants grown with no source of N. Combining hydrolysate with inorganic N had beneficial effects on growth, root N uptake and protein content. The metabolism of casein-supplemented plants shifted to aromatic (Trp), branched-chain (Ile, Leu, Val) and basic (Arg, His, Lys) amino acids, suggesting their preferential uptake and/or alterations in their metabolic pathways. Complementarily, proteomic analysis of tobacco roots identified peptidase C1A and peptidase S10 families as potential key players in casein degradation and response to N starvation. Moreover, amidases were significantly upregulated, most likely for their role in ammonia release and impact on auxin synthesis. In phytohormonal analysis, both forms of casein influenced phenylacetic acid and cytokinin contents, suggesting a root system response to scarce N availability. In turn, metabolomics highlighted the stimulation of some plant defense mechanisms under such growth conditions, i.e., the high concentrations of secondary metabolites (e.g. ferulic acid) and heat shock proteins. This article is protected by copyright. All rights reserved.
PMID: 37402155
Bioessays , IF:4.345 , 2023 Aug : Pe2300018 doi: 10.1002/bies.202300018
AUXIN RESPONSE FACTOR protein accumulation and function.
Department of Biology, Duke University, Durham, North Carolina, USA.
Auxin is a key regulator of plant developmental processes. Its effects on transcription are mediated by the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARFs tightly control specific auxin responses necessary for proper plant growth and development. Recent research has revealed that regulated ARF protein accumulation and ARF nucleo-cytoplasmic partitioning can determine auxin transcriptional outputs. In this review, we explore these recent findings and consider the potential for regulated ARF accumulation in driving auxin responses in plants.
PMID: 37584215
Plant Physiol Biochem , IF:4.27 , 2023 Aug , 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
Plant Physiol Biochem , IF:4.27 , 2023 Aug , V201 : P107827 doi: 10.1016/j.plaphy.2023.107827
Mutant IAA21 genes from Dendrocalamus sinicus Chia et J. L. Sun inhibit stem and root growth in transgenic tobacco by interacting with ARF5.
College of Life Science, Xinjiang Normal University, Xinyi Road, Shayibake District, Urumqi, 830054, PR China; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China.; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China.; College of Life Science, Xinjiang Normal University, Xinyi Road, Shayibake District, Urumqi, 830054, PR China; Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, Xinyi Road, Shayibake District, Urumqi, 830054, PR China.; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China. Electronic address: yanghanqikm@aliyun.com.
Woody bamboos are important resource of industrial fibres. Auxin signaling plays a key role in multiple plant developmental processes, as yet the role of auxin/indole acetic acid (Aux/IAA) in culm development of woody bamboos has not been previously characterized. Dendrocalamus sinicus Chia et J. L. Sun is the largest woody bamboo documented in the world. Here, we identified two alleles of DsIAA21 gene (sIAA21 and bIAA21) from the straight- and bent-culm variants of D. sinicus, respectively, and studied how the domains I, i, and II of DsIAA21 affect the gene transcriptional repression. The results showed that bIAA21 expression was rapidly induced by exogenous auxin in D. sinicus. In transgenic tobacco, sIAA21 and bIAA21 mutated in domains i, and II significantly regulated plant architecture and root development. Stem cross sections revealed that parenchyma cells were smaller in transgenic plants than that in wild type plants. Domain i mutation changed the leucine and proline at position 45 to proline and leucine (siaa21(L45P) and biaa21(P45L)) strongly repressed cell expansion and root elongation by reducing the gravitropic response. Substitution of isoleucine with valine in domain II of the full length DsIAA21 resulted in dwarf stature in transgenic tobacco plants. Furthermore, the DsIAA21 interacted with auxin response factor 5 (ARF5) in transgenic tobacco plants, suggesting that DsIAA21 might inhibit stem and root elongation via interacting with ARF5. Taken together, our data indicated that DsIAA21 was a negative regulator of plant development and suggested that amino acid differences in domain i of sIAA21 versus bIAA21 affected their response to auxin, and might play a key role in the formation of the bent culm variant in D. sinicus. Our results not only shed a light on the morphogenetic mechanism in D. sinicus, but also provided new insights into versatile function of Aux/IAAs in plants.
PMID: 37329689
Plant Physiol Biochem , IF:4.27 , 2023 Aug , V201 : P107832 doi: 10.1016/j.plaphy.2023.107832
Wheat type one protein phosphatase promotes salt and osmotic stress tolerance in arabidopsis via auxin-mediated remodelling of the root system.
Plant Physiology and Functional Genomics Research Unit, Higher Institute of Biotechnology, University of Sfax, BP "1175", 3038, Sfax, Tunisia.; Plant Physiology and Functional Genomics Research Unit, Higher Institute of Biotechnology, University of Sfax, BP "1175", 3038, Sfax, Tunisia. Electronic address: chantal.ebel@isbs.usf.tn.
The control of optimal root growth and plant stress responses depends largely on a variety of phytohormones among which auxin and brassinosteroids (BRs) are the most influential. We have previously reported that the durum wheat type 1 protein phosphatase TdPP1 participates in the control of root growth by modulating BR signaling. In this study, we pursue our understanding of how TdPP1 fulfills this regulatory function on root growth by evaluating the physiological and molecular responses of Arabidopsis TdPP1 over-expressing lines to abiotic stresses. Our results showed that when exposed to 300 mM Mannitol or 100 mM NaCl, the seedlings of TdPP1 over-expressors exhibit modified root architecture with higher lateral root density, and longer root hairs concomitant with a lower inhibition of the primary root growth. These lines also exhibit faster gravitropic response and a decrease in primary root growth inhibition when exposed to high concentrations of exogenous IAA. On another hand, a cross between TdPP1 overexpressors and DR5:GUS marker line was performed to monitor auxin accumulation in roots. Remarkably, the TdPP1 overexpression resulted in an enhanced auxin gradient under salt stress with a higher accumulation in primary and lateral root tips. Moreover, TdPP1 transgenics exhibit a significant induction of a subset of auxin-responsive genes under salt stress conditions. Therefore, our results reveal a role of PP1 in enhancing auxin signaling to help shape greater root plasticity thus improving plant stress resilience.
PMID: 37327648
Plant Physiol Biochem , IF:4.27 , 2023 Aug , V201 : P107808 doi: 10.1016/j.plaphy.2023.107808
Advances in nanoparticle and organic formulations for prolonged controlled release of auxins.
Southern Federal University, ul. Bolshaya Sadovaya 105/42, Rostov-on-Don, 344006, Russian Federation; Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia, 1113, Bulgaria. Electronic address: vbutova@sfedu.ru.; Southern Federal University, ul. Bolshaya Sadovaya 105/42, Rostov-on-Don, 344006, Russian Federation.
Plant hormones have been well known since Charles Darwin as signaling molecules directing plant metabolism. Their action and transport pathways are at the top of scientific interest and were reviewed in many research articles. Modern agriculture applies phytohormones as supplements to achieve desired physiological plant response. Auxins are a class of plant hormones extensively used for crop management. Auxins stimulate the formation of lateral roots and shoots, seed germination, while extensively high concentrations of these chemicals act as herbicides. Natural auxins are unstable; light or enzyme action leads to their degradation. Moreover, the concentration dependant action of phytohormones denier one-shot injection of these chemicals and require constant slow additive of supplement. It obstructs the direct introduction of auxins. On the other hand, delivery systems can protect phytohormones from degradation and provide a slow release of loaded drugs. Moreover, this release can be managed by external stimuli like pH, enzymes, or temperature. The present review is focused on three auxins: indole-3-acetic, indole-3-butyric, and 1-naphthaleneacetic acids. We collected some examples of inorganic (oxides, Ag, layered double hydroxides) and organic (chitosan, organic formulations) delivery systems. The action of carriers can enhance auxin effects via protection and targeted delivery of loaded molecules. Moreover, nanoparticles can act as nano fertilizers, intensifying the phytohormone effect, providing slow controlled release. So delivery systems for auxins are extremely attractive for modern agriculture opening sustainable management of plant metabolism and morphogenesis.
PMID: 37290135
Environ Sci Pollut Res Int , IF:4.223 , 2023 Aug , V30 (37) : P87102-87117 doi: 10.1007/s11356-023-28029-3
The changes in the maize root cell walls after exogenous application of auxin in the presence of cadmium.
Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 38, Bratislava, Slovakia.; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 38, Bratislava, Slovakia. zuzana.vivodova@savba.sk.
Cadmium (Cd) is a transition metal and hazardous pollutant that has many toxic effects on plants. This heavy metal poses a health risk for both humans and animals. The cell wall is the first structure of a plant cell that is in contact with Cd; therefore, it can change its composition and/or ratio of wall components accordingly. This paper investigates the changes in the anatomy and cell wall architecture of maize (Zea mays L.) roots grown for 10 days in the presence of auxin indole-3-butyric acid (IBA) and Cd. The application of IBA in the concentration 10(-9) M delayed the development of apoplastic barriers, decreased the content of lignin in the cell wall, increased the content of Ca(2+) and phenols, and influenced the composition of monosaccharides in polysaccharide fractions when compared to the Cd treatment. Application of IBA improved the Cd(2+) fixation to the cell wall and increased the endogenous concentration of auxin depleted by Cd treatment. The proposed scheme from obtained results may explain the possible mechanisms of the exogenously applied IBA and its effects on the changes in the binding of Cd(2+) within the cell wall, and on the stimulation of growth that resulted in the amelioration of Cd stress.
PMID: 37418187
BMC Plant Biol , IF:4.215 , 2023 Jul , V23 (1) : P371 doi: 10.1186/s12870-023-04382-w
The determination of peanut (Arachis hypogaea L.) pod-sizes during the rapid-growth stage by phytohormones.
College of Agronomy, Peanut Research Institute, Shenyang Agricultural University, Shenyang, China.; College of Agronomy, Peanut Research Institute, Shenyang Agricultural University, Shenyang, China. yuhaiqiu@syau.edu.cn.; Shandong Peanut Research Institute, Qingdao, China. chinapeanut@126.com.
BACKGROUND: Pod size is an important yield target trait for peanut breeding. However, the molecular mechanism underlying the determination of peanut pod size still remains unclear. RESULTS: In this study, two peanut varieties with contrasting pod sizes were used for comparison of differences on the transcriptomic and endogenous hormonal levels. Developing peanut pods were sampled at 10, 15, 20, 25 and 30 days after pegging (DAP). Our results showed that the process of peanut pod-expansion could be divided into three stages: the gradual-growth stage, the rapid-growth stage and the slow-growth stage. Cytological analysis confirmed that the faster increase of cell-number during the rapid-growth stage was the main reason for the formation of larger pod size in Lps. Transcriptomic analyses showed that the expression of key genes related to the auxin, the cytokinin (CK) and the gibberellin (GA) were mostly up-regulated during the rapid-growth stage. Meanwhile, the cell division-related differentially expressed genes (DEGs) were mostly up-regulated at 10DAP which was consistent with the cytological-observation. Additionally, the absolute quantification of phytohormones were carried out by liquid-chromatography coupled with the tandem-mass-spectrometry (LC-MS/MS), and results supported the findings from comparative transcriptomic studies. CONCLUSIONS: It was speculated that the differential expression levels of TAA1 and ARF (auxin-related), IPT and B-ARR (CK-related), KAO, GA20ox and GA3ox (GA-related), and certain cell division-related genes (gene-LOC112747313 and gene-LOC112754661) were important participating factors of the determination-mechanism of peanut pod sizes. These results were informative for the elucidation of the underlying regulatory network in peanut pod-growth and would facilitate further identification of valuable target genes.
PMID: 37491223
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P342 doi: 10.1186/s12870-023-04356-y
Genome-wide identification and expression analysis of the AUX/IAA gene family in turnip (Brassica rapa ssp. rapa).
College of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China.; Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China.; Wenzhou Key Laboratory of Resource Plant Innovation and Utilization, Zhejiang Institute of Subtropical Crops, Zhejiang Academy of Agricultural Sciences, Wenzhou, Zhejiang, 325005, China.; Wenzhou Lucheng District Agricultural Industry Institute, Wenzhou, Zhejiang, 325000, China.; College of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China. sunji@wzvcst.edu.cn.; Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China. sunji@wzvcst.edu.cn.
BACKGROUND: Auxin/indoleacetic acid (AUX/IAA) genes encoding short-lived proteins participate in AUX signaling transduction and play crucial roles in plant growth and development. Although the AUX/IAA gene family has been identified in many plants, a systematic analysis of AUX/IAA genes in Brassica rapa ssp. rapa has not yet been reported. RESULTS: We performed a comprehensive genome-wide analysis and found 89 AUX/IAA genes in turnip based on the conserved AUX/IAA domain (pfam02309). Phylogenetic analysis of AUX/IAA genes from turnip, Arabidopsis, and cabbage revealed that these genes cluster into six subgroups (A1, A2, A3, A4, B1, and B2). The motif distribution was also conservative among the internal members of the clade. Enhanced yellow fluorescent protein (EYFP) signals of BrrIAA-EYFPs showed that BrrIAA members functioned as nucleoproteins. Moreover, transcriptional analysis revealed that the expression patterns of AUX/IAA genes in turnip were tissue-dependent. Because orthologs have similar biological functions and interaction networks in plant growth and development, BrrIAA66 in turnip possibly played a role in embryo axis formation, vascular development, lateral root formation, and floral organ development by interacting with BrrARF19 and BrrTIR1. CONCLUSION: These results provide a theoretical basis for further investigation of BrrAUX/IAA genes and lay the foundation for functional analysis of BrrIAA66 in turnip.
PMID: 37370022
Tree Physiol , IF:4.196 , 2023 Jul doi: 10.1093/treephys/tpad089
Transcriptomic and physiological comparison of Shatangju (Citrus reticulata) and its late-maturing mutant provides insights into auxin regulation of citrus fruit maturation.
Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences/Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs/Guangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, No.80, Dafeng No.2 street, Tianhe District, Guangzhou 510650, China.; Department of Plant Sciences, University of California, Davis, CA, 95616, USA.
Previous studies have shown that abscisic acid and ethylene are involved in pulp maturation and peel coloration in the nonclimacteric citrus fruits. There are also signs indicating that other plant hormones may play some roles in citrus fruit ripening. In this study, we compared profiles of genome-wide gene expression, and changes in hormones and peel pigments between fruits of Shatangju mandarin (Citrus reticulata Blanco, designated WT) and its natural mutant, Yuenongwanju (designated MT). The MT fruit mature approximately two months later than the WT fruit. Significant differences in fruit diameter, total soluble solids, titratable acid content, chlorophylls and carotenoids were detected between the fruits of the two genotypes at the sampled time points. Genome-wide transcriptome profiling showed that many genes involved in auxin and ABA metabolism and/or signaling pathways were differentially expressed between the MT and the WT fruits. Importantly, the expression of CrYUCCA8 was significantly lower and the expression of CrNCED5 was significantly higher in WT than in MT fruits at 230 and 250 DPA, respectively. In addition, the IAA level in the MT fruit was significantly higher than that in the WT counterpart, whereas a significantly lower level of ABA was detected in the mutant. Treatment of the WT fruit with exogenous IAA significantly delayed fruit maturation. Our results provide experimental evidence supporting the notion that auxin is a negative regulator of fruit maturation in citrus.
PMID: 37462512
Tree Physiol , IF:4.196 , 2023 Jul doi: 10.1093/treephys/tpad085
Heritable epigenetic modification of BpPIN1 is associated with leaf shapes in Betula pendula.
State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, Heilongjiang 150040, China.; Citrus Research and Education Center (University of Florida), Lake Alfred, FL 33580, United States.; Department of Plant Pathology (Kansas State University), Throckmorton Center, Manhattan, KS 66506-5502, United States.; College of Life Science (Northeast Forestry University), Harbin, Heilongjiang 150040, China.; College of Forest Resources and Environmental Science (Michigan Technological University), Houghton, MI 49931, United States.
The new variety Betula pendula 'Dalecarlica' selected from Betula pendula, shows high ornamental values owing to its lobed leaf shape. In this study, to identify the genetic components of leaf shape formation, we performed bulked-segregant analysis (BSA) and molecular marker-based fine mapping to identify causal gene responsible for lobed leaves in B. pendula 'Dalecarlica'. The most significant variations associated with leaf shape were identified within the gene BpPIN1 encoding a member of PIN-FORMED family, responsible for the auxin efflux carrier. We further confirmed the hypomethylation at the promoter region promoting the expression level of BpPIN1, which cause stronger and longer veins and lobed leaf shape in B. pendula 'Dalecarlica'. These results indicated that DNA methylation at the BpPIN1 promoter region is associated with leaf shapes in Betula pendula. Our findings revealed an epigenetic mechanism of BpPIN1 in the regulation of leaf shape in birch, which could help in molecular breeding of ornamental traits.
PMID: 37406032
Tree Physiol , IF:4.196 , 2023 Aug , V43 (8) : P1416-1431 doi: 10.1093/treephys/tpad055
Effects of different phosphorus levels on tiller bud development in hydroponic Phyllostachys edulis seedlings.
The State Key Laboratory of Subtropical Silviculture, Bamboo Industry Institute, Zhejiang A&F University, Hangzhou, 311300 Zhejiang, China.
An appropriate amount of phosphate fertilizer can improve the germination rate of bamboo buds and increase the bamboo shoot output. However, the underlying biological mechanisms of phosphate fertilizer in bamboo shoot development have not been systematically reported. Herein, the effects of low (LP, 1 muM), normal (NP, 50 muM) and high (HP, 1000 muM) phosphorus (P) on the growth and development of moso bamboo (Phyllostachys edulis) tiller buds were first investigated. Phenotypically, the seedling biomass, average number of tiller buds and bud height growth rate under the LP and HP treatments were significantly lower than those under the NP treatment. Next, the microstructure difference of tiller buds in the late development stage (S4) at three P levels was analyzed. The number of internode cells and vascular bundles were significantly lower in the LP treatments than in the NP treatments. The relative expression levels of eight P transport genes, eight hormone-related genes and four bud development genes at the tiller bud developmental stage (S2-S4) and the tiller bud re-tillering stage were analyzed with real-time polymerase chain reaction. The results showed that the expression trends for most P transport genes, hormone-related genes and bud development genes from S2 to S4 were diversified at different P levels, and the expression levels were also different at different P levels. In the tiller bud re-tillering stage, the expression levels of seven P transport genes and six hormone-related genes showed a downward trend with increasing P level. REV expression level decreased under LP and HP conditions. TB1 expression level increased under HP condition. Therefore, we conclude that P deficiency inhibits tiller bud development and re-tillering, and that P depends on the expression of REV and TB1 genes and auxin, cytokinin and strigolactones synthesis and transporter genes to mediate tiller bud development and re-tillering.
PMID: 37099799
Microorganisms , IF:4.128 , 2023 Jul , V11 (7) doi: 10.3390/microorganisms11071821
Characterization of Growth-Promoting Activities of Consortia of Chlorpyrifos Mineralizing Endophytic Bacteria Naturally Harboring in Rice Plants-A Potential Bio-Stimulant to Develop a Safe and Sustainable Agriculture.
Department of Biochemistry and Molecular Biology, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh.; Department of Biomedical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia.; Institute of National Analytical Research and Services (INARS), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka 1205, Bangladesh.; Department of Biological Sciences, College of Arts and Sciences, Carlow University, 3333 Fifth Avenue, Pittsburgh, PA 15213, USA.; Department of Chemistry, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Bangladesh.; Department of Green Bio Science and Agri-Food Bio Convergence Institute, Gyeongsang National University, Jinju 52725, Republic of Korea.
Eighteen pesticide-degrading endophytic bacteria were isolated from the roots, stems, and leaves of healthy rice plants and identified through 16S rRNA gene sequencing. Furthermore, biochemical properties, including enzyme production, dye degradation, anti-bacterial activities, plant-growth-promoting traits, including N-fixation, P-solubilization, auxin production, and ACC-deaminase activities of these naturally occurring endophytic bacteria along with their four consortia, were characterized. Enterobacter cloacae HSTU-ABk39 and Enterobacter sp. HSTU-ABk36 displayed inhibition zones of 41.5 +/- 1.5 mm, and 29 +/- 09 mm against multidrug-resistant human pathogenic bacteria Staphylococcus aureus and Staphylococcus epidermidis, respectively. FT-IR analysis revealed that all eighteen isolates were able to degrade chlorpyrifos pesticide. Our study confirms that pesticide-degrading endophytic bacteria from rice plants play a key role in enhancing plant growth. Notably, rice plants grown in pots containing reduced urea (30%) mixed with either endophytic bacterial consortium-1, consortium-2, consortium-3, or consortia-4 demonstrated an increase of 17.3%, 38.6%, 18.2%, and 39.1% yields, respectively, compared to the control plants grown in pots containing 100% fertilizer. GC-MS/MS analysis confirmed that consortia treatment caused the degradation of chlorpyrifos into different non-toxic metabolites, including 2-Hydroxy-3,5,6 trichloropyridine, Diethyl methane phosphonate, Phorate sulfoxide, and Carbonochloridic. Thus, these isolates could be deployed as bio-stimulants to improve crop production by creating a sustainable biological system.
PMID: 37512993
Microorganisms , IF:4.128 , 2023 Jun , V11 (7) doi: 10.3390/microorganisms11071727
Studies Using Mutant Strains of Azospirillum brasilense Reveal That Atmospheric Nitrogen Fixation and Auxin Production Are Light Dependent Processes.
Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA.; Chemistry Department, University of Missouri, Columbia, MO 65211, USA.; Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA.; Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA.; School of Natural Resources, University of Missouri, Columbia, MO 65211, USA.; Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.
As the use of microbial inoculants in agriculture rises, it becomes important to understand how the environment may influence microbial ability to promote plant growth. This work examines whether there are light dependencies in the biological functions of Azospirillum brasilense, a commercialized prolific grass-root colonizer. Though classically defined as non-phototrophic, A. brasilense possesses photoreceptors that could perceive light conducted through its host's roots. Here, we examined the light dependency of atmospheric biological nitrogen fixation (BNF) and auxin biosynthesis along with supporting processes including ATP biosynthesis, and iron and manganese uptake. Functional mutants of A. brasilense were studied in light and dark environments: HM053 (high BNF and auxin production), ipdC (capable of BNF, deficient in auxin production), and FP10 (capable of auxin production, deficient in BNF). HM053 exhibited the highest rate of nitrogenase activity with the greatest light dependency comparing iterations in light and dark environments. The ipdC mutant showed similar behavior with relatively lower nitrogenase activity observed, while FP10 did not show a light dependency. Auxin biosynthesis showed strong light dependencies in HM053 and FP10 strains, but not for ipdC. Ferrous iron is involved in BNF, and a light dependency was observed for microbial (59)Fe(2+) uptake in HM053 and ipdC, but not FP10. Surprisingly, a light dependency for (52)Mn(2+) uptake was only observed in ipdC. Finally, ATP biosynthesis was sensitive to light across all three mutants favoring blue light over red light compared to darkness with observed ATP levels in descending order for HM053 > ipdC > FP10.
PMID: 37512900
Planta , IF:4.116 , 2023 Jul , V258 (3) : P52 doi: 10.1007/s00425-023-04210-3
Spatially activated conserved auxin-transcription factor regulatory module controls de novo root organogenesis in rice.
Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India.; Department of Plant Biology, University of California, Davis, CA, USA.; Department of Biochemistry, All India Institute of Medical Sciences, Raebareli, Uttar Pradesh, India.; School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India.; Center for Organismal Studies, University of Heidelberg, 69120, Heidelberg, Germany.; Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India. shri.yadav@bt.iitr.ac.in.
This study reveals that the process of crown root development and auxin-induced de novo root organogenesis during in vitro plantlet regeneration share a common auxin-OsWOX10 regulatory module in rice. In the fibrous-type root system of rice, the crown roots (CR) are developed naturally from the shoot tissues. Generation of robust auxin response, followed by activation of downstream cell fate determinants and signaling pathways at the onset of crown root primordia (CRP) establishment is essential for new root initiation. During rice tissue culture, embryonic calli are induced to regenerate shoots in vitro which undergo de novo root organogenesis on an exogenous auxin-supplemented medium, but the mechanism underlying spatially restricted root organogenesis remains unknown. Here, we reveal the dynamics of progressive activation of genes involved in auxin homeostasis and signaling during initiation and outgrowth of rice crown root primordia. By comparative global dataset analysis, we identify the crown root primordia-expressed genes whose expression is also regulated by auxin signaling. In-depth spatio-temporal expression pattern analysis shows that the exogenous application of auxin induces a set of key transcription factors exclusively in the spatially positioned CRP. Further, functional analysis of rice WUSCHEL-RELATED HOMEOBOX 10 (OsWOX10) during in vitro plantlet regeneration from embryogenic calli shows that it promotes de novo root organogenesis from regenerated shoots. Expression of rice OsWOX10 also induces adventitious roots (AR) in Arabidopsis, independent of homologous endogenous Arabidopsis genes. Together, our findings reveal that a common auxin-transcription factor regulatory module is involved in root organogenesis under different conditions.
PMID: 37491477
Planta , IF:4.116 , 2023 Jul , V258 (2) : P37 doi: 10.1007/s00425-023-04182-4
Differential expression of genes during recovery of Nicotiana tabacum from tomato leaf curl Gujarat virus infection.
Laboratory of Plant Breeding and Biometry, Department of Crop Science, Agricultural University of Athens, Athens, 11855, Greece.; Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.; Laboratory of Plant Molecular Biology, National Institute of Plant Genome Research, New Delhi, 110067, India.; Laboratory of Plant Breeding and Biometry, Department of Crop Science, Agricultural University of Athens, Athens, 11855, Greece. avoloud@aua.gr.; Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India. supriyachakrasls@yahoo.com.
Nicotiana tabacum exhibits recovery response towards tomato leaf curl Gujarat virus. Transcriptome analysis revealed the differential expression of defense-related genes. Genes encoding for cysteine protease inhibitor, hormonal- and stress-related to DNA repair mechanism are found to be involved in the recovery process. Elucidating the role of host factors in response to viral infection is crucial in understanding the plant host-virus interaction. Begomovirus, a genus in the family Geminiviridae, is reported throughout the globe and is known to cause serious crop diseases. Tomato leaf curl Gujarat virus (ToLCGV) infection in Nicotiana tabacum resulted in initial symptom expression followed by a quick recovery in the systemic leaves. Transcriptome analysis using next-generation sequencing (NGS) revealed a large number of differentially expressed genes both in symptomatic as well as recovered leaves when compared to mock-inoculated plants. The virus infected N. tabacum results in alteration of various metabolic pathways, phytohormone signaling pathway, defense related protein, protease inhibitor, and DNA repair pathway. RT-qPCR results indicated that Germin-like protein subfamily T member 2 (NtGLPST), Cysteine protease inhibitor 1-like (NtCPI), Thaumatin-like protein (NtTLP), Kirola-like (NtKL), and Ethylene-responsive transcription factor ERF109-like (NtERTFL) were down-regulated in symptomatic leaves when compared to recovered leaves of ToLCGV-infected plants. In contrast, the Auxin-responsive protein SAUR71-like (NtARPSL) was found to be differentially down-regulated in recovered leaves when compared to symptomatic leaves and the mock-inoculated plants. Lastly, Histone 2X protein like (NtHH2L) gene was found to be down-regulated, whereas Uncharacterized (NtUNCD) was up-regulated in both symptomatic as well as recovered leaves compared to the mock-inoculated plants. Taken together, the present study suggests potential roles of the differentially expressed genes that might govern tobacco's susceptibility and/or recovery response towards ToLCGV infection.
PMID: 37405593
Planta , IF:4.116 , 2023 Jun , V258 (2) : P33 doi: 10.1007/s00425-023-04193-1
Comparative transcriptome analysis reveals the regulatory effects of exogenous auxin on lateral root development and tanshinone accumulation in Salvia miltiorrhiza.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China. zhangsc@yzu.edu.cn.; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China.; Shaanxi Origin Agricultural Science and Technology Co., Ltd, Tongchuan, 727000, People's Republic of China.; Key Laboratory of Plant Secondary Metabolism and Regulation of Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, People's Republic of China. ydf807@sina.com.
The physiological and transcriptome analysis revealed that auxin was a positive regulator of lateral root development and tanshinone accumulation in Salvia miltiorrhiza. Roots of S. miltiorrhiza are widely used as medicinal materials in China, and the root morphology and content of bioactive compounds [such as phenolic acids and diterpenoid quinones (tanshinones)] are the main factors to determine the quality of this herb. Auxin regulates root development and secondary metabolism in many plant species, but little is known about its function in S. miltiorrhiza. In this study, S. miltiorrhiza seedlings were treated (exogenous application) with the auxin indole-3-acetic acid (IAA) and the polar auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) to investigate the regulatory roles of auxin in S. miltiorrhiza. The results indicated that exogenous IAA promoted both lateral root development and tanshinones biosynthesis in S. miltiorrhiza. The NPA application suppressed the lateral root development but showed no obvious effects on tanshinones accumulation. Based on the RNA-seq analysis, expressions of genes related to auxin biosynthesis and signaling transduction were altered in both treated groups. Coincidental with the enhanced content of tanshinones, transcripts of several key enzyme genes in the tanshinones biosynthetic pathway were stimulated after the exogenous IAA application. The expression profiles of seven common transcription factor domain-containing gene families were analyzed, and the results implied that some AP2/ERF genes were probably responsible for the auxin-induced lateral root development in S. miltiorrhiza. These findings shed new light on the regulatory roles of auxin on root development and bioactive compounds biosynthesis in S. miltiorrhiza, and lay the groundwork for future research into the detailed molecular mechanism underlying these biological functions.
PMID: 37378716
Planta , IF:4.116 , 2023 Jun , V258 (2) : P26 doi: 10.1007/s00425-023-04183-3
LBD18 and IAA14 antagonistically interact with ARF7 via the invariant Lys and acidic residues of the OPCA motif in the PB1 domain.
Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea.; Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea. jungmkim@jnu.ac.kr.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea. jungmkim@jnu.ac.kr.; Kumho Life Science Laboratory, Chonnam National University, Buk-Gu, Gwangju, 500-757, South Korea. jungmkim@jnu.ac.kr.
LBD18 and IAA14 antagonistically interact with ARF7 through the electrostatic faces in the ARF7PB1 domain, modulating ARF7 transcriptional activity. Auxin Response Factor 7 (ARF7)/ARF19 control lateral root development by directly activating Lateral Organ Boundaries Domain 16 (LBD16)/LBD18 genes in Arabidopsis. LBD18 upregulates ARF19 expression by binding to the ARF19 promoter. It also interacts with ARF7 through the Phox and Bem1 (PB1) domain to enhance the ARF7 transcriptional activity, forming a dual mode of positive feedback loop. LBD18 competes with the repressor indole-3-acetic acid 14 (IAA14) for ARF7 binding through the PB1 domain. In this study, we examined the molecular determinant of the ARF7 PB1 domain for interacting with LBD18 and showed that the electronic faces in the ARF7 PB1 domain are critical for interacting with LBD18 and IAA14/17. We used a luminescence complementation imaging assay to determine protein-protein interactions. The results showed that mutation of the invariant lysine residue and the OPCA motif in the PB1 domain in ARF7 significantly reduces the protein interaction between ARF7 and LBD18. Transient gene expression assays with Arabidopsis protoplasts showed that IAA14 suppressed transcription-enhancing activity of LBD18 on the LUC reporter gene fused to the ARF19 promoter harboring an auxin response element, but mutation of the invariant lysine residue and OPCA motif in the PB1 domain of IAA14 reduced the repression capability of IAA14 for transcription-enhancing activity of LBD18. We further showed that the same mutation in the PB1 domain of IAA14 reduces its repression capability, thereby increasing the LUC activity induced by both ARF7 and LBD18 compared with IAA14. These results suggest that LBD18 competes with IAA14 for ARF7 binding via the electrostatic faces of the ARF7 PB1 domain to modulate ARF7 transcriptional activity.
PMID: 37354348
Genes (Basel) , IF:4.096 , 2023 Jul , V14 (7) doi: 10.3390/genes14071390
Comparative Genome-Wide Analysis of MicroRNAs and Their Target Genes in Roots of Contrasting Indica Rice Cultivars under Reproductive-Stage Drought.
Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.; Department of Plants, Soils, and Climate, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.; Bioinformatics Facility, Center for Integrated BioSystems, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.; Indian Council of Agricultural Research, New Delhi 110012, India.
Recurrent occurrence of drought stress in varying intensity has become a common phenomenon in the present era of global climate change, which not only causes severe yield losses but also challenges the cultivation of rice. This raises serious concerns for sustainable food production and global food security. The root of a plant is primarily responsible to perceive drought stress and acquire sufficient water for the survival/optimal growth of the plant under extreme climatic conditions. Earlier studies reported the involvement/important roles of microRNAs (miRNAs) in plants' responses to environmental/abiotic stresses. A number (738) of miRNAs is known to be expressed in different tissues under varying environmental conditions in rice, but our understanding of the role, mode of action, and target genes of the miRNAs are still elusive. Using contrasting rice [IR-64 (reproductive-stage drought sensitive) and N-22 (drought-tolerant)] cultivars, imposed with terminal (reproductive-stage) drought stress, we demonstrate differential expression of 270 known and 91 novel miRNAs in roots of the contrasting rice cultivars in response to the stress. Among the known miRNAs, osamiR812, osamiR166, osamiR156, osamiR167, and osamiR396 were the most differentially expressed miRNAs between the rice cultivars. In the root of N-22, 18 known and 12 novel miRNAs were observed to be exclusively expressed, while only two known (zero novels) miRNAs were exclusively expressed in the roots of IR-64. The majority of the target gene(s) of the miRNAs were drought-responsive transcription factors playing important roles in flower, grain development, auxin signaling, root development, and phytohormone-crosstalk. The novel miRNAs identified in this study may serve as good candidates for the genetic improvement of rice for terminal drought stress towards developing climate-smart rice for sustainable food production.
PMID: 37510295
Plant Mol Biol , IF:4.076 , 2023 Aug doi: 10.1007/s11103-023-01373-1
Ethylene response factor ERF022 is involved in regulating Arabidopsis root growth.
School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China. jiangli@ustc.edu.cn.; School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.
Ethylene response factors (ERFs) are involved in the regulation of plant development processes and stress responses. In this study, we provide evidence for the role of ERF022, a member of the ERF transcription factor group III, in regulating Arabidopsis root growth. We found that ERF022-loss-of-function mutants exhibited increased primary root length and lateral root numbers, and also morphological growth advantages compared to wild-type. Further studies showed that mutants had enhanced cell size in length in the root elongation zones. These results were accompanied by significant increase in the expression of cell elongation and cell wall expansion related genes SAUR10, GASA14, LRX2, XTH19 in mutants. Moreover, ERF022-mediated root growth was associated with the enhanced endogenous auxin and gibberellins levels. Our results suggest that loss-of-function of ERF022 up-regulated the expression of cell elongation and cell wall related genes through auxin and gibberellins signal in the regulation of root growth. Unexpectedly, ERF022 overexpression lines also showed longer primary roots and more lateral roots compared to wild-type, and had longer root apical meristematic zone with increased cell numbers. Overexpression of ERF022 significantly up-regulated cell proliferation, organ growth and auxin biosynthesis genes EXO, HB2, GALK2, LBD26, YUC5, which contribute to enhanced root growth. Altogether, our results provide genetic evidence that ERF022 plays an important role in regulating root growth in Arabidopsis thaliana.
PMID: 37553544
Plant Mol Biol , IF:4.076 , 2023 Jul , V112 (4-5) : P225-243 doi: 10.1007/s11103-023-01355-3
Ectopic overexpression of TaHsfA5 promotes thermomorphogenesis in Arabidopsis thaliana and thermotolerance in Oryza sativa.
Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.; Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. param@genomeindia.org.
Heat stress transcription factors (Hsfs) play an important role in regulating the heat stress response in plants. Among the Hsf family members, the group A members act upstream in initiating the response upon sensing heat stress and thus, impart thermotolerance to the plants. In the present study, wheat HsfA5 (TaHsfA5) was found to be one of the Hsfs, which was upregulated both in heat stress and during the recovery period after the stress. TaHsfA5 was found to interact with TaHsfA3 and TaHsfA4, both of which are known to positively regulate the heat stress-responsive genes. Apart from these, TaHsfA5 also interacted with TaHSBP2 protein, whose role has been implicated in attenuating the heat stress response. Further, its heterologous overexpression in Arabidopsis and Oryza sativa promoted thermotolerance in these plants. This indicated that TaHsfA5 positively regulated the heat stress response. Interestingly, the TaHsfA5 overexpression Arabidopsis plants when grown at warm temperatures showed a hyper-thermomorphogenic response in comparison to the wild-type plants. This was found to be consistent with the higher expression of PIF4 and its target auxin-responsive genes in these transgenics in contrast to the wild-type plants. Thus, these results suggest the involvement of TaHsfA5 both in the heat stress response as well as in the thermomorphogenic response in plants.
PMID: 37166615
BMC Genomics , IF:3.969 , 2023 Jul , V24 (1) : P380 doi: 10.1186/s12864-023-09483-2
Exogenous spraying of IAA improved the efficiency of microspore embryogenesis in Wucai (Brassica campestris L.) by affecting the balance of endogenous hormones, energy metabolism, and cell wall degradation.
College of Horticulture, Vegetable Genetics and Breeding Laboratory, Anhui Agricultural University, 130 West Changjiang Road, Hefei, 230036, Anhui, China.; Provincial Engineering Laboratory for Horticultural Crop Breeding of Anhui, 130 West of Changjiang Road, Hefei, 230036, Anhui, China.; Wanjiang Vegetable Industrial Technology Institute, Maanshan, 238200, Anhui, China.; College of Horticulture, Vegetable Genetics and Breeding Laboratory, Anhui Agricultural University, 130 West Changjiang Road, Hefei, 230036, Anhui, China. yitangxy@126.com.; Provincial Engineering Laboratory for Horticultural Crop Breeding of Anhui, 130 West of Changjiang Road, Hefei, 230036, Anhui, China. yitangxy@126.com.; Wanjiang Vegetable Industrial Technology Institute, Maanshan, 238200, Anhui, China. yitangxy@126.com.
BACKGROUND: Microspore embryogenesis is an extraordinarily complicated process, comprehensively regulated by a composite network of physiological and molecular factors, among which hormone is one of the most crucial factors. Auxin is required for stress-induced microspore reprogramming, however, the mechanism of its regulation of microspore embryogenesis is still unclear. RESULTS: In this study, we found exogenously spraying 100 mg.L(- 1) IAA on the buds of Wucai significantly increased the rate of microspore embryogenesis, and moreover accelerated the process of embryogenesis. Physiological and biochemical tests showed that the contents of amino acids, soluble total sugar, soluble protein, and starch were significantly increased after IAA treatment. Furthermore, exogenously spraying 100 mg.L(- 1) IAA significantly enhanced IAA, GA(4), and GA(9) content, increased catalase (CAT) and malondialdehyde (MDA) activity, and reduced abscisic acid (ABA), MDA and soluble protopectin content, H(2)O(2) and O(2).(-) production rate in the bud with the largest population of late-uninucleate-stage microspores. Transcriptome sequencing was performed on buds respectively treated with 100 mg.L(- 1) IAA and fresh water. A total of 2004 DEGs were identified, of which 79 were involved in micropores development, embryonic development and cell wall formation and modification, most of which were upregulated. KEGG and GO analysis revealed that 9.52% of DEGs were enriched in plant hormone synthesis and signal transduction pathways, pentose and glucuronic acid exchange pathways, and oxidative phosphorylation pathways. CONCLUSIONS: These findings indicated that exogenous IAA altered the contents of endogenous hormone content, total soluble sugar, amino acid, starch, soluble protein, MDA and protopectin, the activities of CAT and peroxidase (POD), and the production rate of H(2)O(2) and O(2).(-). Combined with transcriptome analysis, it was found that most genes related to gibberellin (GA) and Auxin (IAA) synthesis and signal transduction, pectin methylase (PME) and polygalacturonase (PGs) genes and genes related to ATP synthesis and electron transport chain were upregulated, and genes related to ABA synthesis and signal transduction were downregulated. These results indicated that exogenous IAA treatment could change the balance of endogenous hormones, accelerate cell wall degradation, promote ATP synthesis and nutrient accumulation, inhibit ROS accumulation, which ultimately promote microspore embryogenesis.
PMID: 37415142
BMC Genomics , IF:3.969 , 2023 Jul , V24 (1) : P377 doi: 10.1186/s12864-023-09492-1
The role of walnut bZIP genes in explant browning.
College of Life Sciences, Hebei Agricultural University, Baoding, 071001, China.; College of Horticulture, Hebei Agricultural University, Baoding, 071001, China.; College of Life Sciences, Hebei Agricultural University, Baoding, 071001, China. zshug@hebau.edu.cn.
BACKGROUND: Basic leucine zipper (bZIP) proteins are important transcription factors in plants. To study the role of bZIP transcription factors in walnut explant browning, this study used bioinformatics software to analyze walnut bZIP gene family members, along with their transcript levels in different walnut tissues, to evaluate the transcriptional expression of this gene family during the primary culture of walnut explants and to reveal the mechanism of action of walnut bZIP genes in walnut explant browning. RESULTS: The results identified 65 JrbZIP genes in the walnut genome, which were divided into 8 subfamilies and distributed on 16 chromosomes. The results of transcriptome data analysis showed that there were significant differences in the expression of four genes, namely, JrbZIP55, JrbZIP70, JrbZIP72, and JrbZIP88, under both vermiculite and agar culture conditions. There were multiple hormone (salicylic acid, abscisic acid, auxin, and gibberellin) signaling and regulatory elements that are responsive to stress (low temperature, stress, and defense) located in the promoter regions of JrbZIP55, JrbZIP70, JrbZIP72, and JrbZIP88. The walnut JrbZIP55 protein and Arabidopsis bZIP42 protein are highly homologous, and the proteins interacting with Arabidopsis bZIP42 include the AT2G19940 oxidoreductases, which act on aldehyde or oxygen-containing donors. CONCLUSION: It is speculated that JrbZIP55 may participate in the regulation of browning in walnut explants.
PMID: 37407925
Plants (Basel) , IF:3.935 , 2023 Aug , V12 (15) doi: 10.3390/plants12152877
Development of a New Micropropagation Protocol and Transfer of In Vitro Plants to In Vivo Conditions for Cascade Hop.
Department of Agricultural, Food and Forest Sciences, Universita Degli Studi di Palermo, Viale delle Scienze 13, Building 4, 90128 Palermo, Italy.
The vegetative propagation of hops, despite being a reliable method, is not very common due to the unavailability of the plant material. In this study, the technique of in vitro propagation was applied to the Cascade variety of Humulus lupulus L. The plant material was collected from a private field in Sicily; the explants were subjected to sterilization before in vitro culture. Single-node explants were placed in in vitro culture in nine different culture media for multiplication. Thidiazuron (TDZ), Benzyladenine (BAP) and meta-Topoline (mT) were tested for multiplication phase. For the rooting phase, five types of different culture media were evaluated. Binodal cuttings coming from the previous multiplication test were placed in the culture. The rooting media differ from each other in the concentration and ratio of two auxin hormones: Indolo-3-acetic acid (IAA) and Indole-3-butyric acid (IBA). In vitro rooted plants obtained from the rooting phase were transferred to ex vitro conditions in a microbox with agri-perlite and a solution containing Murashige and Skoog (MS) basal medium at half concentration. With a culture medium containing the highest TDZ doses (H6) and combination with cytokinin (H8 and H9), the highest shoot percentage was obtained. After 3 months of in vitro culture, the highest shoot percentage was observed in the culture medium with 2 mL L(-1) of BAP. The highest rooting percentage, roots numbers and root length were found when the culture medium was supplemented with 1 mL L(-1) of IAA. The usage of agri-perlite and MS at half concentration, without PGR, allowed us to obtain a 99.1% survival rate. This micropropagation protocol is useful for obtaining virus-free plants and for the development of the brewery industry.
PMID: 37571031
Plants (Basel) , IF:3.935 , 2023 Aug , V12 (15) doi: 10.3390/plants12152842
GA20ox Family Genes Mediate Gibberellin and Auxin Crosstalk in Moso bamboo (Phyllostachys edulis).
Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, International Center for Bamboo and Rattan, Beijing 100102, China.
Moso bamboo (Phyllostachys edulis) is one of the fastest growing plants. Gibberellin (GA) is a key phytohormone regulating growth, but there are few studies on the growth of Moso bamboo regulated by GA. The gibberellin 20 oxidase (GA20ox) gene family was targeted in this study. Chromosomal distribution and collinearity analysis identified 10 GA20ox genes evenly distributed on chromosomes, and the family genes were relatively conservative in evolution. The genetic relationship of GA20ox genes had been confirmed to be closest in different genera of plants in a phylogenetic and selective pressure analysis between Moso bamboo and rice. About 1/3 GA20ox genes experienced positive selective pressure with segmental duplication being the main driver of gene family expansion. Analysis of expression patterns revealed that only six PheGA20ox genes were expressed in different organs of shoot development and flowers, that there was redundancy in gene function. Underground organs were not the main site of GA synthesis in Moso bamboo, and floral organs are involved in the GA biosynthesis process. The auxin signaling factor PheARF47 was located upstream of PheGA20ox3 and PheGA20ox6 genes, where PheARF47 regulated PheGA20ox3 through cis-P box elements and cis-AuxRR elements, based on the result that promoter analysis combined with yeast one-hybrid and dual luciferase detection analysis identified. Overall, we identified the evolutionary pattern of PheGA20ox genes in Moso bamboo and the possible major synthesis sites of GA, screened for key genes in the crosstalk between auxin and GA, and laid the foundation for further exploration of the synergistic regulation of growth by GA and auxin in Moso bamboo.
PMID: 37570996
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (15) doi: 10.3390/plants12152817
Enhancing the Adaptability of Tea Plants (Camellia sinensis L.) to High-Temperature Stress with Small Peptides and Biosurfactants.
Tea Research Institute, Qingdao Agricultural University, Qingdao 266000, China.; Tea Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Tea plants are highly susceptible to the adverse effects of a high-temperature climate, which can cause reduced yield and quality and even lead to plant death in severe cases. Therefore, reducing the damage caused by high-temperature stress and maintaining the photosynthetic capacity of tea plants is a critical technical challenge. In this study, we investigated the impact of small oligopeptides (small peptides) and surfactants on the high-temperature-stress tolerance of tea plants. Our findings demonstrated that the use of small peptides and surfactants enhances the antioxidant capacity of tea plants and protects their photosynthetic system. They also induce an increase in gibberellin (GA) content and a decrease in jasmonic acid (JA), strigolactone (SL), auxin (IAA), and cytokinin (CTK) content. At the same time, small peptides regulate the metabolic pathways of diterpenoid biosynthesis. Additionally, small peptides and surfactants induce an increase in L-Carnosine and N-Glycyl-L-Leucine content and a decrease in (5-L-Glutamyl)-L-Amino Acid content, and they also regulate the metabolic pathways of Beta-Alanine metabolism, Thiamine metabolism, and Glutathione metabolism. In summary, small peptides and surfactants enhance the ability of tea plants to resist high-temperature stress.
PMID: 37570970
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (15) doi: 10.3390/plants12152809
Overexpression of OsPIN9 Impairs Chilling Tolerance via Disturbing ROS Homeostasis in Rice.
College of Agriculture, Henan University of Science and Technology, Luoyang 471000, China.
The auxin efflux transporter PIN-FORMED (PIN) family is one of the major protein families that facilitates polar auxin transport in plants. Here, we report that overexpression of OsPIN9 leads to altered plant architecture and chilling tolerance in rice. The expression profile analysis indicated that OsPIN9 was gradually suppressed by chilling stress. The shoot height and adventitious root number of OsPIN9-overexpressing (OE) plants were significantly reduced at the seedling stage. The roots of OE plants were more tolerant to N-1-naphthylphthalamic acid (NPA) treatment than WT plants, indicating the disturbance of auxin homeostasis in OE lines. The chilling tolerance assay showed that the survival rate of OE plants was markedly lower than that of wild-type (WT) plants. Consistently, more dead cells, increased electrolyte leakage, and increased malondialdehyde (MDA) content were observed in OE plants compared to those in WT plants under chilling conditions. Notably, OE plants accumulated more hydrogen peroxide (H(2)O(2)) and less superoxide anion radicals (O2-) than WT plants under chilling conditions. In contrast, catalase (CAT) and superoxide dismutase (SOD) activities in OE lines decreased significantly compared to those in WT plants at the early chilling stage, implying that the impaired chilling tolerance of transgenic plants is probably attributed to the sharp induction of H(2)O(2) and the delayed induction of antioxidant enzyme activities at this stage. In addition, several OsRboh genes, which play a crucial role in ROS production under abiotic stress, showed an obvious increase after chilling stress in OE plants compared to that in WT plants, which probably at least in part contributes to the production of ROS under chilling stress in OE plants. Together, our results reveal that OsPIN9 plays a vital role in regulating plant architecture and, more importantly, is involved in regulating rice chilling tolerance by influencing auxin and ROS homeostasis.
PMID: 37570963
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (15) doi: 10.3390/plants12152804
The Knockdown of AUXIN RESPONSE FACTOR 2 Confers Enhanced Tolerance to Salt and Drought Stresses in Tomato (Solanum lycopersicum L.).
Laboratoire de Biotechnologie et de Physiologie Vegetales, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Rabat 10000, Morocco.; Laboratoire de Recherche en Sciences Vegetales, UMR5546, Universite de Toulouse, Centre National de la Recherche Scientifique (CNRS), Universite Toulouse Paul Sabatier (UPS), Toulouse-INP, 31320 Auzeville-Tolosane, France.; Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Rabat 10000, Morocco.
Auxin response factors (ARFs) act as key elements of the auxin-signaling pathway and play important roles in the process of a plant's growth, development, and response to environmental conditions. We studied the implication of the SlARF2 gene in the tomato response to salt (150 mM of NaCl) and drought (15% PEG 20000) stresses. The functional characterization of SlARF2 knockdown tomato mutants revealed that the downregulation of this gene enhanced primary root length and root branching and reduced plant wilting. At the physiological level, the arf2 mutant line displayed higher chlorophyll, soluble sugars, proline, and relative water contents as well as lower stomatal conductance and a decreased malondialdehyde content. Moreover, SlARF2 knockdown tomato mutants demonstrated higher activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) under salt and drought stresses than the wild type. Indeed, the stress tolerance of the arf2 mutant was also reflected by the upregulation of stress-related genes involved in ROS scavenging and plant defense, including SOD, CAT, dehydration-responsive element-binding protein, and early responsive to dehydration, which can ultimately result in a better resistance to salt and drought stresses. Furthermore, the transcriptional levels of the Delta1-pyrroline-5-carboxylate synthase (P5CS) gene were upregulated in the arf2 mutant after stress, in correlation with the higher levels of proline. Taken together, our findings reveal that SlARF2 is implicated in salt and drought tolerance in tomato and provides some considerable elements for improving the abiotic stress tolerance and increasing the crop yields of tomato.
PMID: 37570958
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (14) doi: 10.3390/plants12142719
Integrating Full-Length Transcriptome and RNA Sequencing of Siberian Wildrye (Elymus sibiricus) to Reveal Molecular Mechanisms in Response to Drought Stress.
College of Grassland Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.; Sichuan Academy of Grassland Science, Chengdu 610097, China.
Drought is one of the most significant limiting factors affecting plant growth and development on the Qinghai-Tibet Plateau (QTP). Mining the drought-tolerant genes of the endemic perennial grass of the QTP, Siberian wildrye (Elymus sibiricus), is of great significance to creating new drought-resistant varieties which can be used in the development of grassland livestock and restoring natural grassland projects in the QTP. To investigate the transcriptomic responsiveness of E. sibiricus to drought stress, PEG-induced short- and long-term drought stress was applied to two Siberian wildrye genotypes (drought-tolerant and drought-sensitive accessions), followed by third- and second-generation transcriptome sequencing analysis. A total of 40,708 isoforms were detected, of which 10,659 differentially expressed genes (DEGs) were common to both genotypes. There were 2107 and 2498 unique DEGs in the drought-tolerant and drought-sensitive genotypes, respectively. Additionally, 2798 and 1850 DEGs were identified in the drought-tolerant genotype only under short- and long-term conditions, respectively. DEGs numbering 1641 and 1330 were identified in the drought-sensitive genotype only under short- and long-term conditions, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that all the DEGs responding to drought stress in E. sibiricus were mainly associated with the mitogen-activated protein kinase (MAKP) signaling pathway, plant hormone signal transduction, the linoleic acid metabolism pathway, the ribosome pathway, and plant circadian rhythms. In addition, Nitrate transporter 1/Peptide transporter family protein 3.1 (NPF3.1) and Auxin/Indole-3-Acetic Acid (Aux/IAA) family protein 31(IAA31) also played an important role in helping E. sibiricus resist drought. This study used transcriptomics to investigate how E. sibiricus responds to drought stress, and may provide genetic resources and references for research into the molecular mechanisms of drought resistance in native perennial grasses and for breeding drought-tolerant varieties.
PMID: 37514333
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (14) doi: 10.3390/plants12142663
Lanthanum Supplementation Alleviates Tomato Root Growth Suppression under Low Light Stress.
College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.; School of Agriculture, Meiji University, Kawasaki 214-8571, Japan.; Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
Supplementation with rare earth elements (REEs) such as lanthanum and cerium has been shown to promote plant elongation and/or increase crop yields. On the other hand, there are reports that REE supplementation of plants has no such effect. The appropriate modes for REE utilization and the underlying mechanism are not fully understood. In this study, we investigated how REE supplementation of plants under low light stress affects plant growth and gene expression. Under low light stress conditions, tomato root elongation was observed to be reduced by about half. This suppression of root elongation was found to be considerably alleviated by 20 mM lanthanum ion supplementation. This effect was plant-species-dependent and nutrient-condition-dependent. Under low light stress, the expression of the genes for phytochrome-interacting factor, which induces auxin synthesis, and several auxin-synthesis-related proteins were markedly upregulated by lanthanum ion supplementation. Thus, we speculate that REE supplementation of plants results in auxin-induced cell elongation and alleviates growth suppression under stress conditions.
PMID: 37514277
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (14) doi: 10.3390/plants12142657
Expression of CsSCL1 and Rooting Response in Chestnut Leaves Are Dependent on the Auxin Polar Transport and the Ontogenetic Origin of the Tissues.
Mision Biologica de Galicia Sede Santiago de Compostela, Consejo Superior de Investigaciones Cientificas, Apdo 122, 15780 Santiago de Compostela, Spain.; Fundacion Promiva, Ctra M-501, Km 5.4, Villaviciosa de Odon, 28670 Madrid, Spain.; Agromillora Iberia, C/El Rebato, s/n, 08379 Barcelona, Spain.
The mechanisms underlying the de novo regeneration of adventitious roots are still poorly understood, particularly in trees. We developed a system for studying adventitious rooting (AR) at physiological and molecular levels using leaves excised from chestnut microshoots of the same genotype but with two distinct ontogenetic origins that differ in rooting competence. Leaves were treated with auxin and N-1-naphthyl-phthalamic acid (NPA), an inhibitor of auxin polar transport (PAT). The physiological effects were investigated by recording rooting rates and the number and quality of the roots. Molecular responses were examined by localizing and monitoring the changes in the expression of CsSCL1, an auxin-inducible gene in juvenile and mature shoots during AR. The rooting response of leaves was ontogenetic-stage dependent and similar to that of the donor microshoots. Initiation of root primordia and root development were inhibited by application of NPA, although its effect depended on the timing of application. CsSCL1 was upregulated by auxin only in rooting-competent leaves during the novo root organogenesis, and the expression was reduced by NPA. The inhibitory effect on gene expression was detected during the reprograming of rooting competent cells towards root initials in response to auxin, indicating that PAT-mediated upregulation of CsSCL1 is required in the initial steps of AR in chestnut leaves. The localized expression of CsSCL1 in the quiescent center (QC) also suggests a role for this gene in the maintenance of meristematic competence and root radial patterning.
PMID: 37514273
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (14) doi: 10.3390/plants12142604
Plant-Derived Smoke Mitigates the Inhibitory Effects of the Auxin Inhibitor 2,3,5-Triiodo Benzoic Acid (TIBA) by Enhancing Root Architecture and Biochemical Parameters in Maize.
Department of Botany, Kohat University of Science and Technology, Kohat 2600, Pakistan.; Department of Biology, The University of Haripur, Haripur 2262, Pakistan.; Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.; Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
The present study was designed to investigate and compare the effects of plant-derived smoke (PDS) and auxin (IAA and IBA) on maize growth under the application of 2,3,5-triiodo benzoic acid (TIBA). For this purpose, indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), each at a concentration of 10 ppm, along with PDS at a ratio of 1:500 (v/v) were used alone and in combination with 10 ppm of TIBA. The results indicate that the germination percentage (%) of maize seeds was enhanced under IAA, IBA and PDS treatment. However, IAA and IBA resulted in reduced germination when applied in combination with TIBA. Importantly, the germination percentage (%) was improved by PDS under TIBA treatment. The analysis of seedling height, length of leaves, and number of primary, seminal and secondary/lateral roots showed improvement under individual treatments of IAA and IBA, PDS and PDS + TIBA treatment, while these values were reduced under IAA + TIBA and IBA + TIBA application. Chlorophyll content, total soluble sugars and antioxidative enzymatic activity including POD and SOD increased in seedlings treated with PDS alone or both PDS and TIBA, while in seedlings treated with IAA and TIBA or IBA and TIBA, their levels were decreased. APX and CAT responded in the opposite way-under IAA, IBA and PDS treatment, their levels were found to be lower than the control (simple water treatment), while TIBA treatment with either IAA, IBA or PDS enhanced their levels as compared to the control. These results reveal that PDS has the potential to alleviate the inhibitory effects of TIBA. This study highlights the role of PDS in preventing TIBA from blocking the auxin entry sites.
PMID: 37514219
Plants (Basel) , IF:3.935 , 2023 Jul , V12 (13) doi: 10.3390/plants12132531
The Growth Oscillator and Plant Stomata: An Open and Shut Case.
School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
Since Darwin's "Power of Movement in Plants" the precise mechanism of oscillatory plant growth remains elusive. Hence the search continues for the hypothetical growth oscillator that regulates a huge range of growth phenomena ranging from circumnutation to pollen tube tip growth and stomatal movements. Oscillators are essentially simple devices with few components. A universal growth oscillator with only four major components became apparent recently with the discovery of a missing component, notably arabinogalactan glycoproteins (AGPs) that store dynamic Ca(2+) at the cell surface. Demonstrably, auxin-activated proton pumps, AGPs, Ca(2+) channels, and auxin efflux "PIN" proteins, embedded in the plasma membrane, combine to generate cytosolic Ca(2+) oscillations that ultimately regulate oscillatory growth: Hechtian adhesion of the plasma membrane to the cell wall and auxin-activated proton pumps trigger the release of dynamic Ca(2+) stored in periplasmic AGP monolayers. These four major components represent a molecular PINball machine a strong visual metaphor that also recognises auxin efflux "PIN" proteins as an essential component. Proton "pinballs" dissociate Ca(2+) ions bound by paired glucuronic acid residues of AGP glycomodules, hence reassessing the role of proton pumps. It shifts the prevalent paradigm away from the recalcitrant "acid growth" theory that proposes direct action on cell wall properties, with an alternative explanation that connects proton pumps to Ca(2+) signalling with dynamic Ca(2+) storage by AGPs, auxin transport by auxin-efflux PIN proteins and Ca(2+) channels. The extensive Ca(2+) signalling literature of plants ignores arabinogalactan proteins (AGPs). Such scepticism leads us to reconsider the validity of the universal growth oscillator proposed here with some exceptions that involve marine plants and perhaps the most complex stress test, stomatal regulation.
PMID: 37447091
IUBMB Life , IF:3.885 , 2023 Jul 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
Life (Basel) , IF:3.817 , 2023 Jun , V13 (7) doi: 10.3390/life13071454
Salt Stress-Related Mechanisms in Leaves of the Wild Barley Hordeum spontaneum Generated from RNA-Seq Datasets.
Department of Chemistry, Al-Leith University College, Umm Al-Qura University, Makkah 28434, Saudi Arabia.; Biological Sciences Department, College of Science & Arts, King Abdulaziz University, Rabigh 21911, Saudi Arabia.
This study aims to detect salt stress-related genes and mechanisms of the wild barley Hordeum spontaneum. Among the generated RNA-Seq datasets, several regulated transcripts are influenced by levels of cellular carbon, nitrogen and oxygen. Some of the regulated genes act on photorespiration and ubiquitination processes, as well as promoting plant growth and development under salt stress. One of the genes, encoding alanine:glyoxylate aminotransferase (AGT), participates in signaling transduction and proline biosynthesis, while the gene encoding asparagine synthetase (ASN) influences nitrogen storage and transport in plants under stress. Meanwhile, the gene encoding glutamate dehydrogenase (GDH) promotes shoot and root biomass production as well as nitrate assimilation. The upregulated genes encoding alpha-aminoadipic semialdehyde synthase (AASAS) and small auxin-up RNA 40 (SAUR40) participate in the production of proline and signaling compounds, respectively, while the gene encoding E3 ubiquitin-protein ligase regulates the carbon/nitrogen-nutrient response and pathogen resistance, in addition to some physiological processes under biotic and abiotic stresses via signal transduction. The gene encoding the tetratricopeptide repeat (TPR)-domain suppressor of STIMPY (TSS) negatively regulates the carbon level in the cell. In conclusion, this study sheds light on possible molecular mechanisms underlying salt stress tolerance in wild barley that can be utilized further in genomics-based breeding programs of cultivated species.
PMID: 37511829
Gene , IF:3.688 , 2023 Jun , V871 : P147434 doi: 10.1016/j.gene.2023.147434
Comparative transcriptome analysis reveals hormone, transcriptional and epigenetic regulation involved in prickle formation in Zanthoxylum armatum.
Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: sabrina-0810@hotmail.com.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China. Electronic address: Caozhengyan1998@163.com.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China. Electronic address: wupeiyin718@163.com.; College of Biology and Food Engineering, Chongqing Three Georges University, Chongqing 404100, China. Electronic address: liuyn9523@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: loujuan1981@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: 18580561843@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: sunxiaofan2022@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: ztmysishuo@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: chenzexiong1979@163.com.
Zanthoxylum armatum is an evergreen plant with high economical and medicinal values. The presence of prickles on stems and leaves is undesirable for them make picking difficult. To date, little is known of prickle formation in Z. armatum. Herein, the morphological and molecular features of prickle initiation in prickless (WC) and three types of prickly Z. armatum were characterized. Compared to WC, the levels of cytokinin and auxin were increased, while GA and JA declined in prickly Z. armatum. Transcriptome analysis identified 6258 differentially expressed genes (DEGs) between prickless and prickly Z. armatum. Among them, several DEGs related to hormone metabolism and signaling, including LOG7, CKX3, AHK1, three DELLAs, six JAZs and TIR1, were candidate genes involved in prickle formation. Transcription factors associated with prickle formation were screened, including MYB6-1/MYB6-2, WER, GL3-2, SPL4/5, SOC1, and SCL32. Of them, MYB6-1 and WER might negatively regulate prickles initiation via interacting with GL3-2. Additionally, the histone acetylation and DNA methylation levels, the transcripts of histone acetyltransferase/deacetylase and DNA methyltransferases showed significant differences between prickless and prickly plants, indicating their involvements in prickle initiation. These findings illustrate the regulation of prickle formation might be mediated by phytohormones (especially cytokinin), transcription factors and epigenetic modifications in Z. armatum.
PMID: 37068692
J Plant Physiol , IF:3.549 , 2023 Aug , V287 : P154054 doi: 10.1016/j.jplph.2023.154054
Ginkgo biloba GbbZIP08 transcription factor is involved in the regulation of flavonoid biosynthesis.
College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, China.; College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, China. Electronic address: yejiabao@yangtzeu.edu.cn.; College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, China. Electronic address: xufeng@yangtzeu.edu.cn.
Ginkgo biloba is the oldest relict plant on Earth and an economic plant resource derived from China. Flavonoids extracted from G. biloba are beneficial to the prevention and treatment of cardiovascular and cerebrovascular diseases. Basic leucine zipper (bZIP) transcription factors (TFs) have been recognized to play important roles in plant secondary metabolism. In this study, GbbZIP08 was isolated and characterized. It encodes a protein containing 154 amino acids, which belongs to hypocotyl 5 in group H of the bZIP family. Tobacco transient expression assay indicated that GbbZIP08 was localized in the plant nucleus. GbbZIP08 overexpression showed that the contents of total flavonoids, kaempferol, and anthocyanin in transgenic tobacco were significantly higher than those in the wild type. Transcriptome sequencing analysis revealed significant upregulation of structural genes in the flavonoid biosynthesis pathway. In addition, phytohormone signal transduction pathways, such as the abscisic acid, salicylic acid, auxin, and jasmonic acid pathways, were enriched with a large number of differentially expressed genes. TFs such as MYB, AP2, WRKY, NAC, bZIP, and bHLH, were also differentially expressed. The above results indicated that GbbZIP08 overexpression promoted flavonoid accumulation and increased the transcription levels of flavonoid-synthesis-related genes in plants.
PMID: 37487356
J Plant Physiol , IF:3.549 , 2023 Aug , V287 : P154003 doi: 10.1016/j.jplph.2023.154003
Comparison of two contrasting Leymus chinensis accessions reveals the roles of the cell wall and auxin in rhizome development.
Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China.; Grassland Work Station of East Ujimqin Banner of Xilin Gol League of Inner Mongolia, East Ujimqin Banner, 026300, China.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: 111986015@imu.edu.cn.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: kangyan105@imu.edu.cn.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: qizhi@imu.edu.cn.
Leymus chinensis, a perennial native forage grass, is widely distributed in the steppes of Inner Mongolia as the dominant species. The main reproductive strategy of this grass is clonal propagation, which occurs via the proliferation of subterranean horizontal stems known as rhizomes. To elucidate the mechanism underlying rhizome development in this grass, we collected 60 accessions of L. chinensis and evaluated their rhizome development. One accession, which we named SR-74 (Strong Rhizomes), had significantly better rhizome development capacity than the accession WR-16 (Weak Rhizomes) in terms of rhizome number, total and primary rhizome length, and number of rhizome seedlings. Rhizome elongation was positively correlated with the number of internodes in the rhizome, which affected plant biomass. Compared to WR-16, SR-74 had higher rhizome tip hardness, higher abundance of transcripts participating in the biosynthesis of cell wall components, and higher levels of the metabolites L-phenylalanine, trans-cinnamic acid, 3-coumaric acid, ferulic acid, and coniferin. These metabolites in the phenylpropanoid biosynthesis pathway are precursors of lignin. In addition, SR-74 rhizomes contained higher amounts of auxin and auxin metabolites, including L-Trp, IPA, IBA, IAA and IAA-Asp, as well as upregulated expression of the auxin biosynthesis and signaling genes YUCCA6, YUCCA8, YUCCA10, YUCCA11, PIN1, PIN2, UGT1, UGT2, UGT4, UGT10, GH3, IAA7, IAA23, and IAA30. We propose a network between auxin signaling and the cell wall underlying rhizome development in L. chinensis.
PMID: 37301035
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
Protoplasma , IF:3.356 , 2023 Jul , V260 (4) : P1233-1251 doi: 10.1007/s00709-023-01844-8
Light intensity-mediated auxin homeostasis in spikelets links carbohydrate metabolism enzymes with grain filling rate in rice.
Crop Physiology and Biochemistry Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India.; Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India.; Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India. lambodarjamujhadi@gmail.com.
Low light (LL) stress during the grain-filling stage acutely impairs the quality and quantity of starch accumulation in rice grains. Here, we observed that LL-induced poor starch biosynthesis is modulated by auxin homeostasis, which regulates the activities of major carbohydrate metabolism enzymes such as starch synthase (SS) and ADP-glucose pyrophosphorylase (AGPase) in rice. Further, during the grain-filling period under LL, the starch/sucrose ratio increased in leaves but significantly decreased in the developing spikelets. This suggests poor sucrose biosynthesis in leaves and starch in the grains of the rice under LL. A lower grain starch was found to be correlated with the depleted AGPase and SS activities in the developing rice grains under LL. Further, under LL, the endogenous auxin (IAA) level in the spikelets was found to be synchronized with the expression of a heteromeric G protein gene, RGB1. Interestingly, under LL, the expression of OsYUC11 was significantly downregulated, which subsequently resulted in reduced IAA in the developing rice spikelets, followed by poor activation of grain-filling enzymes. This resulted in lowered grain starch accumulation, grain weight, panicle number, spikelet fertility, and eventually grain yield, which was notably higher in the LL-susceptible (GR4, IR8) than in the LL-tolerant (Purnendu, Swarnaprabha) rice genotypes. Therefore, we hypothesize that depletion in auxin biosynthesis under LL stress is associated with the downregulation of RBG1, which discourages the expression and activities of grain-filling enzymes, resulting in lower starch production, panicle formation, and grain yield in rice.
PMID: 36847862
Protoplasma , IF:3.356 , 2023 Jul , V260 (4) : P1109-1133 doi: 10.1007/s00709-022-01833-3
Auxin- and pH-induced guttation in Phycomyces sporangiophores: relation between guttation and diminished elongation growth.
Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030, Belgrade, Serbia. vunduk@imsi.bg.ac.rs.; Max Planck Institute for Evolutionary Biology, Department of Evolutionary Biology, August Thienemann Str. 2, 24306, Plon, Germany.; Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030, Belgrade, Serbia.; Singidunum University, Danijelova 32, 11010, Belgrade, Serbia.; Faculty of Biology, Philipps-University Marburg, Karl-Von-Frisch Str. 8, 35032, Marburg, Germany.
Guttation, the formation of exudation water, is widespread among plants and fungi, yet the underlying mechanisms remain largely unknown. We describe the conditions for inducing guttation in sporangiophores of the mucoracean fungus, Phycomyces blakesleeanus. Cultivation on peptone-enriched potato dextrose agar elicits vigorous guttation mainly below the apical growing zone, while sporangiophores raised on a glucose-mineral medium manifest only moderate guttation. Mycelia do not guttate irrespective of the employed media. The topology of guttation droplets allows identifying the non-growing part of the sporangiophore as a guttation zone, which responds to humidity and medium composition in ways that become relevant for turgor homeostasis and thus the sensor physiology of the growing zone. Apparently, the entire sporangiophore, rather than exclusively the growing zone, participates in signal reception and integration to generate a common growth output. Exogenous auxin applied to the growing zones elicits two correlated responses: (i) formation of guttation droplets in the growing and transition zones below the sporangium and (ii) a diminution of the growth rate. In sporangiophore populations, guttation-induction by exogenous control buffer occurs at low frequencies; the bias for guttation increases with increasing auxin concentration. Synthetic auxins and the transport inhibitor NPA suppress guttation completely, but leave growth rates largely unaffected. Mutants C2 carA and C148 carA madC display higher sensitivities for auxin-induced guttation compared to wild type. A working model for guttation includes aquaporins and mechanosensitive ion channels that we identified in Phycomyces by sequence domain searches.
PMID: 36622433
AoB Plants , IF:3.276 , 2023 Jul , V15 (4) : Pplad040 doi: 10.1093/aobpla/plad040
Integrating stay-green and PIN-FORMED genes: PIN-FORMED genes as potential targets for designing climate-resilient cereal ideotypes.
Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, 306 Carmody Road, Brisbane, Queensland 4072, Australia.; Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Hermitage Research Facility, 604 Yangan Road, Warwick, Queensland 4370, Australia.
Plant architecture modification (e.g. short-stature crops) is one of the key outcomes of modern crop breeding for high-yielding crop varieties. In cereals, delayed senescence, or stay-green, is an important trait that enables post-anthesis drought stress adaptation. Stay-green crops can prolong photosynthetic capacity during grain-filling period under post-anthesis drought stress, which is essential to ensure grain yield is not impacted under drought stress conditions. Although various stay-green quantitative trait loci have been identified in cereals, the underlying molecular mechanisms regulating stay-green remain elusive. Recent advances in various gene-editing technologies have provided avenues to fast-track crop improvement, such as the breeding of climate-resilient crops in the face of climate change. We present in this viewpoint the focus on using sorghum as the model cereal crop, to study PIN-FORMED (PIN) auxin efflux carriers as means to modulate plant architecture, and the potential to employ it as an adaptive strategy to address the environmental challenges posed by climate uncertainties.
PMID: 37448862
AoB Plants , IF:3.276 , 2023 Jul , V15 (4) : Pplad043 doi: 10.1093/aobpla/plad043
Transcriptomic profile of lettuce seedlings (Lactuca sativa) response to microalgae extracts used as biostimulant agents.
Department of Agriculture, Food and Environment, University of Catania, via Santa Sofia 98, 95123 Catania, Italy.
To reduce the use of chemical fertilizers and maximize agricultural yields, the use of microalgae extracts as biostimulants has recently attracted significant attention due to their favourable impact on both plant growth and their ability to induce tolerance towards environmental stressors. Lettuce (Lactuca sativa) is one of the most important fresh vegetables that often requires applications of chemical fertilizers to increase quality and productivity. Accordingly, the purpose of this study was to analyse the transcriptome reprogramming of lettuce (L. sativa) seedlings in response to either Chlorella vulgaris or Scenedesmus quadricauda extracts by applying an RNAseq approach. Differential gene expression analysis revealed that the core gene set that responded to microalgal treatments in a species-independent manner includes 1330 clusters, 1184 of which were down-regulated and 146 up-regulated, clearly suggesting that the repression of gene expression is the main effect of algal treatments. The deregulation of 7197 transcripts in the C. vulgaris treated seedlings compared to control samples (LsCv vs. LsCK) and 7118 transcripts in the S. quadricauda treated seedlings compared to control samples (LsSq vs. LsCK) were counted. Although the number of deregulated genes turned out to be similar between the algal treatments, the level of deregulation was higher in LsCv versus LsCK than in LsSq versus LsCK. In addition, 2439 deregulated transcripts were observed in the C. vulgaris treated seedlings compared to S. quadricauda treated samples (LsCv vs. LsSq comparison) suggesting that a specific transcriptomic profile was induced by the single algal extracts. 'Plant hormone signal transduction' category includes a very elevated number of DEGs, many of them specifically indicating that C. vulgaris actives both genes involved in the auxin biosynthesis and transduction pathways, whereas S. quadricauda up-regulates genes implicated in the cytokinin biosynthesis pathway. Finally, algal treatments induced the deregulation of genes encoding small hormone-like molecules that are known to act alone or by interacting with major plant hormones. In conclusion, this study offers the groundwork to draw up a list of putative gene targets with the aim of lettuce genetic improvement that will allow a limited or even null use of synthetic fertilizers and pesticides in the management of this crop.
PMID: 37434759
Environ Technol , IF:3.247 , 2023 Jul : P1-14 doi: 10.1080/09593330.2023.2238928
Isolation of bacteria with plant growth-promoting properties from microalgae-bacterial flocs produced in high-rate oxidation ponds.
Institute for Environmental Biotechnology, Rhodes University (EBRU), Makhanda, South Africa.
Exploring plant growth-promoting (PGP) bacterial activity of microbial components aggregated by wastewater treatment can reduce dependence on fossil fuel-derived fertilisers. This study describes the isolation and identification of bacteria from microalgae-bacteria flocs (MaB-flocs) generated in high-rate algal oxidation ponds (HRAOP) of an integrated algal pond system (IAPS) remediating municipal wastewater. Amplified 16S rRNA gene sequence analysis determined the molecular identity of the individual strains. Genetic relatedness to known PGP rhizobacteria in the NCBI GenBank database was by metagenomics. Isolated strains were screened for the production of indoles (measured as indole-3-acetic acid; IAA) and an ability to mineralise NH4+, PO43-, and K (+) . Of the twelve bacterial strains isolated from HRAOP MaB-flocs, four produced indoles, nine mineralised NH4+, seven solubilised P, and one K. Potential of isolated strains for PGP activity according to one-way ANOVA on ranks was: ECCN 7b > ECCN 4b > ECCN 6b > ECCN 3b = ECCN 10b > ECCN 1b = ECCN 5b > ECCN 8b > ECCN 2b > ECCN 12b > ECCN 9b = ECCN 11b. Further study revealed that cell-free filtrate from indole-producing cultures of Aeromonas strain ECCN 4b, Enterobacter strain ECCN 7b, and Arthrobacter strain ECCN 6b promoted mung bean adventitious root formation suggestive of the presence of auxin-like biological activity.
PMID: 37469005
PLoS One , IF:3.24 , 2023 , V18 (8) : Pe0287452 doi: 10.1371/journal.pone.0287452
GWAS of adventitious root formation in roses identifies a putative phosphoinositide phosphatase (SAC9) for marker-assisted selection.
Institute of Horticultural Production Systems, Section Woody Plant and Propagation Physiology, Leibniz Universitat Hannover, Hannover, Germany.; Institute of Plant Genetics, Section Molecular Plant Breeding, Leibniz Universitat Hannover, Hannover, Germany.
Rose propagation by cuttings is limited by substantial genotypic differences in adventitious root formation. To identify possible genetic factors causing these differences and to develop a marker for marker-assisted selection for high rooting ability, we phenotyped 95 cut and 95 garden rose genotypes in a hydroponic rooting system over 6 weeks. Data on rooting percentage after 3 to 6 weeks, root number, and root fresh mass were highly variable among genotypes and used in association mappings performed on genotypic information from the WagRhSNP 68 K Axiom SNP array for roses. GWAS analyses revealed only one significantly associated SNP for rooting percentage after 3 weeks. Nevertheless, prominent genomic regions/peaks were observed and further analysed for rooting percentage after 6 weeks, root number and root fresh mass. Some of the SNPs in these peak regions were associated with large effects on adventitious root formation traits. Very prominent were ten SNPs, which were all located in a putative phosphoinositide phosphatase SAC9 on chromosome 2 and showed very high effects on rooting percentage after 6 weeks of more than 40% difference between nulliplex and quadruplex genotypes. SAC9 was reported to be involved in the regulation of endocytosis and in combination with other members of the SAC gene family to regulate the translocation of auxin-efflux PIN proteins via the dephosphorylation of phosphoinositides. For one SNP within SAC9, a KASP marker was successfully derived and used to select genotypes with a homozygous allele configuration. Phenotyping these homozygous genotypes for adventitious root formation verified the SNP allele dosage effect on rooting. Hence, the presented KASP derived from a SNP located in SAC9 can be used for marker-assisted selection in breeding programs for high rooting ability in the future.
PMID: 37595005
PLoS One , IF:3.24 , 2023 , V18 (7) : Pe0287969 doi: 10.1371/journal.pone.0287969
Dynamic transcriptome profiling provides insights into rhizome enlargement in ginger (Zingiber officinale Rosc.).
Chongqing Key Laboratory of Economic Plant Biotechnology, Collaborative Innovation Center of Special Plant Industry in Chongqing, Institute of Special Plants, Chongqing University of Arts and Sciences, Yongchuan, Chongqing, China.; School of Advanced Agriculture and Bioengineering, Yangtze Normal University, Fuling, Chongqing, China.
The rhizome is an economically important part of ginger (Zingiber officinale Rosc.). However, the mechanism of ginger rhizome enlargement remains unclear. In this study, we performed an integrated analysis of the hormone content and transcriptome of ginger at three rhizome enlargement stages: initial enlargement (S1), middle enlargement (S2), and peak enlargement (S3). With rhizome enlargement, the levels of the hormones zeatin (ZT), gibberellic acid (GA), indole acetic acid (IAA), and jasmonic acid (JA) were significantly increased, and this increase was positively correlated with rhizome diameter. Transcriptomic analysis identified a large number of differentially expressed genes (DEGs); the number of DEGs were 2,206 in the transition from S1 to S2, and 1,151 in the transition from S2 to S3. The expression of several genes related to hormone biosynthesis and signalling and cell division or expansion, and transcription factors was significantly altered, which suggests that these genes play essential roles in rhizome enlargement. The results of correlation analysis suggested that the process of ginger rhizome enlargement may be primarily related to the regulation of endogenous cytokinin, GA3, auxin, and JA biosynthesis pathways and signal transduction; GRAS, HB, MYB, MYB122, bZIP60, ARF1, ARF2, E2FB1, and E2FB2, which may regulate the expression of rhizome formation-related genes; and CYC2, CDKB1, CDKB2, EXPA1, and XTH7, which may mediate cell division and expansion. These results provide gene resources and information that will be useful for the molecular breeding in ginger.
PMID: 37450442
Plant Biol (Stuttg) , IF:3.081 , 2023 Aug 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
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
Int Microbiol , IF:2.479 , 2023 Jul doi: 10.1007/s10123-023-00394-6
Rhizobacteria isolated from xerophyte Haloxylon ammodendron manipulate root system architecture and enhance drought and salt tolerance in Arabidopsis thaliana.
Department of Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.; Department of Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. arseifi@um.ac.ir.
The objective of this study was to identify bacteria from the rhizosphere of the black saxaul (Haloxylon ammodendron) and test the possibility of using the bacteria for enhancement of drought and/or salt tolerance in the model plant, Arabidopsis thaliana. We collected rhizosphere and bulk soil samples from a natural habitat of H. ammodendron in Iran and identified 58 morphotypes of bacteria that were enriched in the rhizosphere. From this collection, we focused our further experiments on eight isolates. Microbiological analyses showed that these isolates have different levels of tolerance to heat, salt, and drought stresses, and showed different capabilities of auxin production and phosphorous solubilization. We first tested the effects of these bacteria on the salt tolerance of Arabidopsis on agar plate assays. The bacteria substantially influenced the root system architecture, but they were not effective in increasing salt tolerance significantly. Pot assays were then conducted to evaluate the effects of the bacteria on salt or drought tolerance of Arabidopsis on peat moss. Results showed that three of these bacteria (Pseudomonas spp. and Peribacillus sp.) effectively enhanced drought tolerance in Arabidopsis, so that while none of the mock-inoculated plants survived after 19 days of water withholding, the survival rate was 50-100% for the plants that were inoculated with these bacteria. The positive effects of the rhizobacteria on a phylogenetically-distant plant species imply that the desert rhizobacteria may be used to enhance abiotic stress in crops.
PMID: 37392309
3 Biotech , IF:2.406 , 2023 Sep , V13 (9) : P290 doi: 10.1007/s13205-023-03709-6
Recent advances in auxin biosynthesis and homeostasis.
Kalapet, Pondicherry, 605014 India Department of Biotechnology, School of Life Sciences, Pondicherry University. 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 Aug 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
Mol Biol Rep , IF:2.316 , 2023 Aug , V50 (8) : P6691-6701 doi: 10.1007/s11033-023-08563-6
Transcriptome analysis provides insights into the stress response in cultivated peanut (Arachis hypogaea L.) subjected to drought-stress.
Department of Biosciences, Saurashtra University Rajkot, Christ Campus, 360005, Vidya Niketan, Gujarat, India.; Christ Campus, Saurashtra University, 360005, Vidya Niketan, Rajkot, Gujarat, India.; Bionivid Technology Private Limited, Bengaluru, Karnataka, India.; Department of Biotechnology and Biochemistry, Junagadh Agricultural University, 362001, Junagadh, Gujarat, India.; Department of Biotechnology and Biochemistry, Junagadh Agricultural University, 362001, Junagadh, Gujarat, India. rukam@jau.in.
BACKGROUND: Peanut (Arachis hypogaea L.) is one of the valuable oilseed crops grown in drought-prone areas worldwide. Drought severely limits peanut production and productivity significantly. METHOD AND RESULTS: In order to decipher the drought tolerance mechanism in peanut under drought stress, RNA sequencing was performed in TAG - 24 (drought tolerant genotype) and JL-24 (drought susceptible genotype). Approximately 51 million raw reads were generated from four different libraries of two genotypes subjected to drought stress exerted by 20% PEG 6000 stress and control conditions, of which ~ 41 million (80.87%) filtered reads were mapped to the Arachis hypogaea L. reference genome. The transcriptome analysis detected 1,629 differentially expressed genes (DEGs), 186 genes encoding transcription factors (TFs) and 30,199 SSR among the identified DEGs. Among the differentially expressed TF encoding genes, the highest number of genes were WRKY followed by bZIP, C2H2, and MYB during drought stress. The comparative analysis between the two genotypes revealed that TAG-24 exhibits activation of certain key genes and transcriptional factors that are involved in essential biological processes. Specifically, TAG-24 showed activation of genes involved in the plant hormone signaling pathway such as PYL9, Auxin response receptor gene, and ABA. Additionally, genes related to water deprivation such as LEA protein and those involved in combating oxidative damage such as Glutathione reductase were also found to be activated in TAG-24. CONCLUSION: This genome-wide transcription map, therefore, provides a valuable tool for future transcript profiling under drought stress and enriches the genetic resources available for this important oilseed crop.
PMID: 37378750
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
Antonie Van Leeuwenhoek , IF:2.271 , 2023 Jul , V116 (7) : P615-630 doi: 10.1007/s10482-023-01828-x
Lysinibacillus spp.: an IAA-producing endospore forming-bacteria that promotes plant growth.
Universidad de Antioquia, Instituto de Biologia, Medellin, Colombia. manuel.pantojag@udea.edu.co.; Facultad de Ciencias Agropecuarias, Unilasallista Corporacion Universitaria, Caldas - Antioquia, Colombia. manuel.pantojag@udea.edu.co.; Plant Response Biotech, Plant City, FL, USA.; United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Crop Bioprotection Research Unit, 1815 N University, Peoria, IL, USA.; Universidad de Antioquia, Instituto de Biologia, Medellin, Colombia.
Lysinibacillus is a bacterial genus that has generated recent interest for its biotechnological potential in agriculture. Strains belonging to this group are recognized for their mosquitocidal and bioremediation activity. However, in recent years some reports indicate its importance as plant growth promoting rhizobacteria (PGPR). This research sought to provide evidence of the PGP activity of Lysinibacillus spp. and the role of the indole-3-acetic acid (IAA) production associated with this activity. Twelve Lysinibacillus spp. strains were evaluated under greenhouse conditions, six of which increased the biomass and root architecture of corn plants. In most cases, growth stimulation was evident at 10(8) CFU/mL inoculum concentration. All strains produced IAA with high variation between them (20-70 microg/mL). The bioinformatic identification of predicted genes associated with IAA production allowed the detection of the indole pyruvic acid pathway to synthesize IAA in all strains; additionally, genes for a tryptamine pathway were detected in two strains. Extracellular filtrates from all strain's cultures increased the corn coleoptile length in an IAA-similar concentration pattern, which demonstrates the filtrates had an auxin-like effect on plant tissue. Five of the six strains that previously showed PGPR activity in corn also promoted the growth of Arabidopsis thaliana (col 0). These strains induced changes in root architecture of Arabidopsis mutant plants (aux1-7/axr4-2), the partial reversion of mutant phenotype indicated the role of IAA on plant growth. This work provided solid evidence of the association of Lysinibacillus spp. IAA production with their PGP activity, which constitutes a new approach for this genus. These elements contribute to the biotechnological exploration of this bacterial genus for agricultural biotechnology.
PMID: 37138159
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
Curr Microbiol , IF:2.188 , 2023 Jul , V80 (9) : P306 doi: 10.1007/s00284-023-03411-z
Mechanisms of Epichloe bromicola to Promote Plant Growth and Its Potential Application for Coix lacryma-jobi L. Cultivation.
Department of Pharmacognosy, School of Pharmacy, Naval Medical University, Shanghai, 200433, China.; Department of Pharmacognosy, School of Pharmacy, Naval Medical University, Shanghai, 200433, China. cjzheng1984@126.com.; Department of Pharmacognosy, School of Pharmacy, Naval Medical University, Shanghai, 200433, China. hanting@smmu.edu.cn.; Department of Pharmacognosy, School of Pharmacy, Naval Medical University, Shanghai, 200433, China. lpqin@zcmu.edu.cn.; School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, 310053, China. lpqin@zcmu.edu.cn.
Endophytic fungi play important roles in regulating plant growth and development and usually used as a promising strategy to enhance the biosynthesis of host valuable secondary metabolite, but the underlying growth-promoting mechanisms are only partly understood. In this study, the wild-type Arabidopsis thaliana seedlings co-cultured with fungal endophyte Epichloe bromicola showed auxin (IAA)-stimulated phenotypes, and the growth-promoting effects caused by E. bromicola were further verified by the experiments of spatially separated co-culture and fungal extract treatment. IAA was detected and identified in the extract of E. bromicola culture by LC-HRMS/MS, whereas 2,3-butanediol was confirmed to be the predominant volatile active compound in the diethyl ether and ethyl acetate extracts by GC-MS. Further study observed that IAA-related genes including synthesis key enzyme genes (CYP79B2, CYP79B3, NIT1, TAA1 and YUCCA1) and controlling polar transport genes (AUX1, BIG, EIR1, AXR3 and ARF1), were highly expressed at different periods after E. bromicola inoculation. More importantly, the introduction of fungal endophyte E. bromicola could effectively promote the growth and accumulation of coixol in Coix under soil conditions. Our study showed that endophytic fungus E. bromicola might be considered as a potential inoculant for improving medicinal plant growth.
PMID: 37501023
Genes Genomics , IF:1.839 , 2023 Aug , V45 (8) : P1073-1083 doi: 10.1007/s13258-023-01385-7
Genome-wide identification of auxin-responsive microRNAs in the poplar stem.
College of Life Science, Inner Mongolia Agricultural University, Hohhot, 010018, China.; College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.; Grass and Science Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, China.; Academy of Dongying Efficient Agricultural Technology and Industry on Saline and Alkaline Land in Collaboration with Qingdao Agricultural University, Dongying, 257000, China.; Forestry College, Inner Mongolia Agricultural University, Huhhot, 010018, China. baiyue@imau.edu.cn.; Forestry College, Inner Mongolia Agricultural University, Huhhot, 010018, China. chenyan@qau.edu.cn.; College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, 266109, China. chenyan@qau.edu.cn.
BACKGROUND: Wood (secondary xylem) of forests is a material of great economic importance. Wood development is strictly controlled by both the phytohormone auxin and microRNAs (miRNAs). Currently, the regulatory mechanisms underlying wood formation by auxin-associated miRNAs remain unclear. OBJECTIVE: This report was designed to identify auxin-responsive miRNAs during wood formation. METHODS: Morphological observation of wood development in the poplar stems was performed under the treatment of different concentrations (0 mg/L, CK; 5 mg/L, Low; 10 mg/L, High) of indol-3-butyric acid (IBA). Using a small RNA sequencing strategy, the effect of IBA treatment on miRNAs expression was genome-widely analyzed. RESULTS: In this study, we found that wood development of poplar was promoted by low concentration of IBA treatment but inhibited by high concentration of IBA treatment. Stringent bioinformatic analysis led to identification of 118 known and 134 novel miRNAs candidates. Sixty-nine unique developmental-related miRNAs, corresponding to 269 target genes, exhibited specific expression patterns in response to auxin, as was consistent with the influence of auxin application on wood formation. Three novel miRNAs had the most number (>/= 9) of target genes, belonging to SPL, GRF and ARF gene families. The evolutionary relationships and tissue expression patterns of 41 SPL, GRF and ARF genes in poplar were thus analyzed. Of them, four representative members and corresponding miRNAs were confirmed using RT-qPCR. CONCLUSIONS: Our results may be helpful for a better understanding of auxin-induced regulation of wood formation in tree species.
PMID: 37336805
STAR Protoc , 2023 Aug , V4 (3) : P102514 doi: 10.1016/j.xpro.2023.102514
Hormone immunolabeling in resin-embedded Arabidopsis tissues.
Unidad de Genomica Avanzada (UGA-LANGEBIO), Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36824, Mexico.; Departamento de Biotecnologia y Bioquimica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36824, Mexico.; Unidad de Genomica Avanzada (UGA-LANGEBIO), Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Irapuato, Guanajuato 36824, Mexico. Electronic address: stefan.defolter@cinvestav.mx.
Here, we present a protocol for immunolabeling of molecules in Arabidopsis tissues. We describe steps for tissue fixation and embedding in resin of microtome-derived sections, immunolabeling using fluorescent and non-fluorescent secondary antibodies, and visualization of cytokinin and auxin molecules. This protocol is suitable to study reproductive structures such as inflorescences, flowers, fruits, and tissue-culture-derived samples. This protocol is useful for studying the distribution of a wide range of molecules including hormones and cell wall components. For complete details on the use and execution of this protocol, please refer to Herrera-Ubaldo et al. (2019).(1).
PMID: 37573503
Open Life Sci , 2023 , V18 (1) : P20220612 doi: 10.1515/biol-2022-0612
Chlorate-induced molecular floral transition revealed by transcriptomes.
Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, Hainan, China.; College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
Flowering in off-season longan (Dimocarpus longan L.) can be induced effectively by the application of potassium chlorate (KClO(3)), but the mechanism of the physiological induction is largely unknown to decipher its mechanism and identify genes potentially regulating the process, and comparative analysis via RNA-Seq was performed between vegetative and KClO(3)-induced floral buds. A total of 18,649 differentially expressed genes (DEGs) were identified between control and treated samples. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that DEGs related to plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling pathway, starch and sucrose metabolism, and phenylpropanoid biosynthesis were enriched in our data. A total of 29 flowering-related DEGs were identified in our study, such as APETALA1 (AP1), APETALA2 (AP2), AUXIN RESPONSE FACTOR 3/ETTIN (ARF3), SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 8 (SPL8), AGAMOUS (AG), and others. The upregulation of AP2 and SPL genes indicates that the age-related pathway is activated and influences the floral induction in KClO(3)-induced longan floral buds by coordinated regulation of genes related to AP1, AG, and ARF3. This study provides a valuable resource for studying molecular mechanisms underlying chlorate-induced floral transition in off-season longan, which may benefit the development and production of off-season tropical/subtropical fruit trees.
PMID: 37528883
Plant Commun , 2023 Jul : P100669 doi: 10.1016/j.xplc.2023.100669
Divergence of trafficking and polarization mechanisms for PIN auxin transporters during land plant evolution.
Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria.; Graduate Institute of Biotechnology, National Chung Hsing University, No. 145, Xingda Rd., South Dist., Taichung 40227, Taiwan, R.O.C.; College of Life Sciences, Northwest A&F University, Shaanxi, Yangling, China.; Institute of Plant and Microbial Biology, Academia Sinica, 128 Sec. 2, Academia Rd, Nankang, Taipei 11529, Taiwan, R.O.C.; Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria. Electronic address: jiri.friml@ist.ac.at.
The phytohormone auxin and its directional transport through tissues play a fundamental role in development of higher plants. This polar auxin transport predominantly relies on PIN-FORMED (PIN) auxin exporters. Hence, PIN polarization is crucial for development, but its evolution during the rise of morphological complexity in land plants remains unclear. Here, we performed a cross-species investigation by observing the trafficking and localization of endogenous and exogenous PINs in two bryophytes, Physcomitrium patens and Marchantia polymorpha, and in the flowering plant Arabidopsis thaliana. We confirmed that the GFP fusion did not compromise the auxin export function of all examined PINs by using radioactive auxin export assay and by observing the phenotypic changes in transgenic bryophytes. Endogenous PINs polarize to filamentous apices, while exogenous Arabidopsis PINs distribute symmetrically on the membrane in both bryophytes. In Arabidopsis root epidermis, bryophytic PINs show no defined polarity. Pharmacological interference revealed a strong cytoskeleton dependence of bryophytic but not Arabidopsis PIN polarization. The divergence of PIN polarization and trafficking is also observed within the bryophyte clade and between tissues of individual species. These results collectively reveal a divergence of PIN trafficking and polarity mechanisms throughout land plant evolution and a co-evolution of PIN sequence-based and cell-based polarity mechanisms.
PMID: 37528584
Mol Breed , 2023 Aug , V43 (8) : P62 doi: 10.1007/s11032-023-01409-w
Small Auxin Up RNA 56 (SAUR56) regulates heading date in rice.
Guangzhou, 510642 People's Republic of China National Plant Space Breeding Engineering Technology Research Center, South China Agricultural University. GRID: grid.20561.30. ISNI: 0000 0000 9546 5767; Guangzhou, 510642 China Guangdong Provincial Key Laboratory of Plant Molecular Breeding, South China Agricultural University. GRID: grid.20561.30. ISNI: 0000 0000 9546 5767; Heyuan Branch Center of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Heyuan, 517000 Guangdong China.
Heading date is a critical agronomic trait that determines crop yield. Although numerous genes associated with heading date have been identified in rice, the mechanisms involving Small Auxin Up RNA (SAUR) family have not been elucidated. In this study, the biological function of several SAUR genes was initially investigated using the CRISPR-Cas9 technology in the Japonica cultivar Zhonghua11 (ZH11) background. Further analysis revealed that the loss-of-function of OsSAUR56 affected heading date in both NLD (natural long-day) and ASD (artificial short-day). OsSAUR56 exhibited predominant expression in the anther, with its protein localized in both the cytoplasm and nucleus. OsSAUR56 regulated flowering time and heading date by modulating the expression of the clock gene OsGI, as well as two repressors Ghd7 and DTH8. Furthermore, haplotype-phenotype association analysis revealed a strong correlation between OsSAUR56 and heading date, suggesting its role in selection during the domestication of rice. In summary, these findings highlights the importance of OsSAUR56 in the regulation of heading date for further potential facilitating genetic engineering for flowering time during rice breeding. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-023-01409-w.
PMID: 37521314
Bio Protoc , 2023 Jul , V13 (14) : Pe4778 doi: 10.21769/BioProtoc.4778
Relative Membrane Potential Measurements Using DISBAC(2)(3) Fluorescence in Arabidopsis thaliana Primary Roots.
Department of Experimental Plant Biology, Charles University, Prague, Czech Republic.; Laboratoire Reproduction et Developpement des Plantes, Universite de Lyon, Ecole normale superieure de Lyon, Centre national de la recherche scientifique (CNRS), Institut National de la Recherche Agronomique (INRAE), Lyon, France.
In vivo microscopy of plants with high-frequency imaging allows observation and characterization of the dynamic responses of plants to stimuli. It provides access to responses that could not be observed by imaging at a given time point. Such methods are particularly suitable for the observation of fast cellular events such as membrane potential changes. Classical measurement of membrane potential by probe impaling gives quantitative and precise measurements. However, it is invasive, requires specialized equipment, and only allows measurement of one cell at a time. To circumvent some of these limitations, we developed a method to relatively quantify membrane potential variations in Arabidopsis thaliana roots using the fluorescence of the voltage reporter DISBAC(2)(3). In this protocol, we describe how to prepare experiments for agar media and microfluidics, and we detail the image analysis. We take an example of the rapid plasma membrane depolarization induced by the phytohormone auxin to illustrate the method. Relative membrane potential measurements using DISBAC(2)(3) fluorescence increase the spatio-temporal resolution of the measurements and are non-invasive and suitable for live imaging of growing roots. Studying membrane potential with a more flexible method allows to efficiently combine mature electrophysiology literature and new molecular knowledge to achieve a better understanding of plant behaviors. Key features Non-invasive method to relatively quantify membrane potential in plant roots. Method suitable for imaging seedlings root in agar or liquid medium. Straightforward quantification.
PMID: 37497461
Plant Commun , 2023 Jul : 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. Electronic address: lgli@cemps.ac.cn.
The primary and secondary growth of a tree stem is responsible for the corresponding increases in height and diameter in the trunk. However, our molecular understanding of the biological processes underlying the two growth events is not yet complete. In this study, we used single-cell RNA sequencing (scRNA-seq) and spatial transcriptome sequencing (ST-seq) to get the transcription landscapes of the stem primary and secondary growth tissues in the Populus tree. The results of a comparison between the cell atlas and the differentiation trajectory in primary and secondary growth revealed different regulatory networks in cell differentiation from cambium to xylem precursors and phloem precursors. These regulatory networks may be controlled through the accumulation and distribution of auxin. The cell differentiation trajectory analysis suggests that vessel and fiber development followed a sequential pattern of progressive transcriptional regulation. The research gives new insights into the processes of cell identity and differentiation that occur throughout the primary and secondary growth of tree stems, which would help in the understanding of the cellular differentiation dynamics that occur during the stem growth of perennial trees.
PMID: 37491818
J Genet Genomics , 2023 Jul doi: 10.1016/j.jgg.2023.07.002
Protein post-translational modifications in auxin signaling.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China.; Shandong Academy of Grape, Jinan, Shandong 250100, China.; College of Horticulture, Qingdao Agricultural University, Qingdao, Shandong 266109, China. Electronic address: lvbingsheng@qau.edu.cn.; The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China. Electronic address: bkhou@sdu.edu.cn.; The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China. Electronic address: dingzhaojun@sdu.edu.cn.
Protein post-translational modifications (PTMs), such as ubiquitination, phosphorylation, and small ubiquitin-like modifier (SUMO)ylation, are crucial for regulating protein stability, activity, subcellular localization, and binding with cofactors. Such modifications remarkably increase the variety and complexity of proteomes, which are essential for regulating numerous cellular and physiological processes. The regulation of auxin signaling is finely tuned in time and space to guide various plant growth and development. Accumulating evidence indicates that PTMs play critical roles in auxin signaling regulations. Thus, a thorough and systematic review of the functions of PTMs in auxin signal transduction will improve our profound comprehension of the regulation mechanism of auxin signaling and auxin-mediated various processes. This review discusses the progress of protein ubiquitination, phosphorylation, histone acetylation and methylation, SUMOylation, and S-nitrosylation in the regulation of auxin signaling.
PMID: 37451336
J Genet Genomics , 2023 Jul , V50 (7) : P473-485 doi: 10.1016/j.jgg.2023.05.001
Nitric oxide-mediated S-nitrosylation of IAA17 protein in intrinsically disordered region represses auxin signaling.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Biology, Duke University, Durham, NC 27008, USA. Electronic address: hongwei.jing@duke.edu.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO 63130, USA.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Department of Biology, Duke University, Durham, NC 27008, USA.; Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA.; Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA; The Translational Plant Sciences Center (TPSC), Virginia Tech, Blacksburg, VA 24061, USA.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: jrzuo@genetics.ac.cn.
The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. Auxin signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) family of transcriptional repressors. Notably, many auxin-modulated physiological processes are also regulated by nitric oxide (NO) that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine residues. However, little is known about the molecular mechanisms in regulating the interactive NO and auxin networks. Here, we show that NO represses auxin signaling by inhibiting IAA17 protein degradation. NO induces the S-nitrosylation of Cys-70 located in the intrinsically disordered region of IAA17, which inhibits the TIR1-IAA17 interaction and consequently the proteasomal degradation of IAA17. The accumulation of a higher level of IAA17 attenuates auxin response. Moreover, an IAA17(C70W) nitrosomimetic mutation renders the accumulation of a higher level of the mutated protein, thereby causing partial resistance to auxin and defective lateral root development. Taken together, these results suggest that S-nitrosylation of IAA17 at Cys-70 inhibits its interaction with TIR1, thereby negatively regulating auxin signaling. This study provides unique molecular insights into the redox-based auxin signaling in regulating plant growth and development.
PMID: 37187411
Plant Commun , 2023 Jul , V4 (4) : P100596 doi: 10.1016/j.xplc.2023.100596
Synthetic dual hormone-responsive promoters enable engineering of plants with broad-spectrum resistance.
Chongqing Key Laboratory of Application and Safety Control of Genetically Modified Crops, Beibei, Chongqing 400716, China; Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China.; Chongqing Key Laboratory of Application and Safety Control of Genetically Modified Crops, Beibei, Chongqing 400716, China; Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China. Electronic address: peiyan3@swu.edu.cn.
In plant immunity, the mutually antagonistic hormones salicylic acid (SA) and jasmonic acid (JA) are implicated in resistance to biotrophic and necrotrophic pathogens, respectively. Promoters that can respond to both SA and JA signals are urgently needed to engineer plants with enhanced resistance to a broad spectrum of pathogens. However, few natural pathogen-inducible promoters are available for this purpose. To address this problem, we have developed a strategy to synthesize dual SA- and JA-responsive promoters by combining SA- and JA-responsive cis elements based on the interaction between their cognate trans-acting factors. The resulting promoters respond rapidly and strongly to both SA and Methyl Jasmonate (MeJA), as well as different types of phytopathogens. When such a synthetic promoter was used to control expression of an antimicrobial peptide, transgenic plants displayed enhanced resistance to a diverse range of biotrophic, necrotrophic, and hemi-biotrophic pathogens. A dual-inducible promoter responsive to the antagonistic signals auxin and cytokinin was generated in a similar manner, confirming that our strategy can be used for the design of other biotically or abiotically inducible systems.
PMID: 36998212
Plant Commun , 2023 Jul , V4 (4) : P100590 doi: 10.1016/j.xplc.2023.100590
The TaTCP4/10-B1 cascade regulates awn elongation in wheat (Triticum aestivum L.).
Frontiers Science Center for Molecular Design Breeding, Key Laboratory of Crop Heterosis and Utilization (MOE), Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.; Frontiers Science Center for Molecular Design Breeding, Key Laboratory of Crop Heterosis and Utilization (MOE), Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China. Electronic address: nizf@cau.edu.cn.
Awns are important morphological markers for wheat and exert a strong physiological effect on wheat yield. The awn elongation suppressor B1 has recently been cloned through association and linkage analysis in wheat. However, the mechanism of awn inhibition centered around B1 remains to be clarified. Here, we identified an allelic variant in the coding region of B1 through analysis of re-sequencing data; this variant causes an amino acid substitution and premature termination, resulting in a long-awn phenotype. Transcriptome analysis indicated that B1 inhibited awn elongation by impeding cytokinin- and auxin-promoted cell division. Moreover, B1 directly repressed the expression of TaRAE2 and TaLks2, whose orthologs have been reported to promote awn development in rice or barley. More importantly, we found that TaTCP4 and TaTCP10 synergistically inhibited the expression of B1, and a G-to-A mutation in the B1 promoter attenuated its inhibition by TaTCP4/10. Taken together, our results reveal novel mechanisms of awn development and provide genetic resources for trait improvement in wheat.
PMID: 36919240