J Extracell Vesicles , IF:25.841 , 2023 Jan , V12 (1) : Pe12285 doi: 10.1002/jev2.12285
Bacterial outer membrane vesicles induce a transcriptional shift in arabidopsis towards immune system activation leading to suppression of pathogen growth in planta.
Department of Plant Pathology and Weed Research, Agricultural Research Organization - Volcani Institute, Rishon LeZion, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Gram-negative bacteria form spherical blebs on their cell periphery, which later dissociate from the bacterial cell wall to form extracellular vesicles. These nano scale structures, known as outer membrane vesicles (OMVs), have been shown to promote infection and disease and can induce typical immune outputs in both mammal and plant hosts. To better understand the broad transcriptional change plants undergo following exposure to OMVs, we treated Arabidopsis thaliana (Arabidopsis) seedlings with OMVs purified from the Gram-negative plant pathogenic bacterium Xanthomonas campestris pv. campestris and performed RNA-seq analysis on OMV- and mock-treated plants at 2, 6 and 24 h post challenge. The most pronounced transcriptional shift occurred at the first two time points tested, as reflected by the number of differentially expressed genes and the average fold change. OMVs induce a major transcriptional shift towards immune system activation, upregulating a multitude of immune-related pathways including a variety of immune receptors. Comparing the response of Arabidopsis to OMVs and to purified elicitors, revealed that OMVs induce a similar suite of genes and pathways as single elicitors, however, pathways activated by OMVs and not by other elicitors were detected. Pretreating Arabidopsis plants with OMVs and subsequently infecting with a bacterial pathogen led to a significant reduction in pathogen growth. Mutations in the plant elongation factor receptor (EFR), flagellin receptor (FLS2), or the brassinosteroid-insensitive 1-associated kinase (BAK1) co-receptor, did not significantly affect the immune priming effect of OMVs. All together these results show that OMVs induce a broad transcriptional shift in Arabidopsis leading to upregulation of multiple immune pathways, and that this transcriptional change may facilitate resistance to bacterial infection.
PMID: 36645092
Trends Plant Sci , IF:18.313 , 2022 Dec doi: 10.1016/j.tplants.2022.12.006
Mass spectrometric exploration of phytohormone profiles and signaling networks.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, 100193, Beijing, China. Electronic address: chenym@cau.edu.cn.; State Key Laboratory of Wheat and Maize Crop Science, College of Resources and Environment, Henan Agricultural University, 450002, Zhengzhou, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, 100193, Beijing, China.; Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria; Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
Phytohormones have crucial roles in plant growth, development, and acclimation to environmental stress; however, measuring phytohormone levels and unraveling their complex signaling networks and interactions remains challenging. Mass spectrometry (MS) has revolutionized the study of complex biological systems, enabling the comprehensive identification and quantification of phytohormones and their related targets. Here, we review recent advances in MS technologies and highlight studies that have used MS to discover and analyze phytohormone-mediated molecular events. In particular, we focus on the application of MS for profiling phytohormones, elucidating phosphorylation signaling, and mapping protein interactions in plants.
PMID: 36585336
EMBO J , IF:11.598 , 2023 Feb , V42 (4) : Pe111883 doi: 10.15252/embj.2022111883
Brassinosteroid signals cooperate with katanin-mediated microtubule severing to control stamen filament elongation.
State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.; University of Chinese Academy of Sciences, Beijing, China.; Houji Laboratory of Shanxi Province, Academy of Agronomy, Shanxi Agricultural University, Taiyuan, China.; Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China.; Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, School of Life Sciences, Guangzhou University, Guangzhou, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.
Proper stamen filament elongation is essential for pollination and plant reproduction. Plant hormones are extensively involved in every stage of stamen development; however, the cellular mechanisms by which phytohormone signals couple with microtubule dynamics to control filament elongation remain unclear. Here, we screened a series of Arabidopsis thaliana mutants showing different microtubule defects and revealed that only those unable to sever microtubules, lue1 and ktn80.1234, displayed differential floral organ elongation with less elongated stamen filaments. Prompted by short stamen filaments and severe decrease in KTN1 and KTN80s expression in qui-2 lacking five BZR1-family transcription factors (BFTFs), we investigated the crosstalk between microtubule severing and brassinosteroid (BR) signaling. The BFTFs transcriptionally activate katanin-encoding genes, and the microtubule-severing frequency was severely reduced in qui-2. Taken together, our findings reveal how BRs can regulate cytoskeletal dynamics to coordinate the proper development of reproductive organs.
PMID: 36546550
Plant Cell , IF:11.277 , 2023 Feb doi: 10.1093/plcell/koad040
Don't be blue: Pure green light spurs brassinosteroid signaling.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Botany and Plant Sciences, University of California Riverside, CA.
PMID: 36808293
Plant Cell , IF:11.277 , 2023 Feb doi: 10.1093/plcell/koad032
Signaling by the EPFL-ERECTA family coordinates female germline specification through the BZR1 family in Arabidopsis.
College of Life Sciences, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany.; Tea Research Institute, Guangdong Academy of Agricultural Sciences & Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Dafeng Road 6, Tianhe District, Guangzhou 510640.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China.
In most flowering plants, the female germline is initiated in the subepidermal L2 layer of ovule primordia forming a single megaspore mother cell (MMC). How signaling from the L1 (epidermal) layer could contribute to the gene regulatory network restricting MMC formation to a single cell is unclear. We show that EPIDERMAL PATTERNING FACTOR-like (EPFL) peptide ligands are expressed in the L1 layer, together with their ERECTA family (ERf) receptor kinases, to control female germline specification in Arabidopsis thaliana. EPFL-ERf dependent signaling restricts multiple subepidermal cells from acquiring MMC-like cell identity by activating the expression of the major brassinosteroid (BR) receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1) and the BR-responsive transcription factor BRASSINOZOLE RESISTANT 1 (BZR1). Additionally, BZR1 coordinates female germline specification by directly activating the expression of a nucleolar GTP-binding protein, NUCLEOSTEMIN-LIKE 1 (NSN1), which is expressed in early-stage ovules excluding the MMC. Mutants defective in this gene regulatory network form multiple MMCs resulting in a strong reduction of seed set. In conclusion, we uncovered a ligand/receptor-like kinase-mediated signaling pathway acting upstream and coordinating BR signaling via NSN1 to restrict MMC differentiation to a single subepidermal cell.
PMID: 36748257
Plant Cell , IF:11.277 , 2023 Feb doi: 10.1093/plcell/koad022
Green means go: Green light promotes hypocotyl elongation via brassinosteroid signaling.
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, 200031 Shanghai, P. R.China.; University of Chinese Academy of Sciences, Shanghai 200031, P. R.China.; Department of Light Source and Illuminating Engineering, Fudan University, 2005 Songhu Rd, Shanghai 200433, P. R.China.
Although many studies have elucidated the mechanisms by which different wavelengths of light (blue, red, far-red or ultraviolet-B [UV-B]) regulate plant development, whether and how green light regulates plant development remains largely unknown. Previous studies reported that green light participates in regulating growth and development in land plants, but these studies have reported conflicting results, likely due to technical problems. For example, commercial green LED light sources emit a little blue or red light. Here, using a pure green light source, we determined that unlike blue, red, far-red or UV-B light, which inhibit hypocotyl elongation, green light promotes hypocotyl elongation in Arabidopsis thaliana and several other plants during first the 2-3 days after planting. Phytochromes, cryptochromes, and other known photoreceptors do not mediate green light-promoted hypocotyl elongation, but the brassinosteroid signaling pathway is involved in this process. Green light promotes the DNA binding activity of BRI1-EMS-SUPPRESSOR 1 (BES1), a master transcription factor of the brassinosteroid pathway, thus regulating gene transcription to promote hypocotyl elongation. Our results indicate that pure green light promotes elongation via brassinosteroid signaling and acts as a shade signal to enable plants to adapt their development to a green-light-dominant environment under a canopy.
PMID: 36724050
Plant Cell , IF:11.277 , 2023 Jan doi: 10.1093/plcell/koad013
Mapping the signaling network of BIN2 kinase using TurboID-mediated biotin labeling and phosphoproteomics.
Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.; Department of Life Science, Hanyang University, Seoul 04763, South Korea.; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, South Korea.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan.; Departments of Genetics, Biology, and Chemistry, Stanford University, Stanford, CA 94305, USA.; Department of Biology, Stanford University, Stanford, CA 94305, USA.; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA.; Department of Cell & Systems Biology/Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario M5S 3B2, Canada.; Chan Zuckerberg Biohub, San Francisco, CA, USA.
Elucidating enzyme-substrate relationships in posttranslational modification (PTM) networks is crucial for understanding signal transduction pathways but is technically difficult because enzyme-substrate interactions tend to be transient. Here we demonstrate that TurboID-based proximity labeling (TbPL) effectively and specifically captures the substrates of kinases and phosphatases. TbPL-mass spectrometry (TbPL-MS) identified over four hundred proximal proteins of Arabidopsis thaliana BRASSINOSTEROID-INSENSITIVE2 (BIN2), a member of the GLYCOGEN SYNTHASE KINASE 3 (GSK3) family that integrates signaling pathways controlling diverse developmental and acclimation processes. A large portion of the BIN2 proximal proteins showed BIN2-dependent phosphorylation in vivo or in vitro, suggesting that these are BIN2 substrates. Protein-protein interaction network analysis showed that the BIN2 proximal proteins include interactors of BIN2 substrates, revealing a high level of interactions among the BIN2 proximal proteins. Our proteomic analysis establishes the BIN2 signaling network and uncovers BIN2 functions in regulating key cellular processes such as transcription, RNA processing, translation initiation, vesicle trafficking, and cytoskeleton organization. We further discovered significant overlap between the GSK3 phosphorylome and the O-GlcNAcylome, suggesting an evolutionarily ancient relationship between GSK3 and the nutrient-sensing O-glycosylation pathway. Our work presents a powerful method for mapping PTM networks, a large dataset of GSK3 kinase substrates, and important insights into the signaling network that controls key cellular functions underlying plant growth and acclimation.
PMID: 36660928
Plant Cell , IF:11.277 , 2023 Jan doi: 10.1093/plcell/koad007
Spatiotemporal formation of the large vacuole regulated by the BIN2-VLG module is required for female gametophyte development in Arabidopsis.
School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, 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, Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200240, China.
In Arabidopsis thaliana, female gametophyte (FG) development is accompanied by the formation and expansion of the large vacuole in the FG; this is essential for FG expansion, nuclear polar localization, and cell fate determination. Arabidopsis VACUOLELESS GAMETOPHYTES (VLG) facilitates vesicular fusion to form large vacuole in the FG, but the regulation of VLG remains largely unknown. Here we found that gain-of-function mutation of BRASSINOSTEROID INSENSITIVE2 (BIN2) (bin2-1) increases VLG abundance to induce the vacuole formation at stage FG1, and leads to abortion of FG. Loss-of-function mutation of BIN2 and its homologs (bin2-3 bil1 bil2) reduced VLG abundance and mimicked vlg/VLG phenotypes. Knocking down VLG in bin2-1 decreased the ratio of aberrant vacuole formation at stage FG1, whereas FG1-specific overexpression of VLG mimicked the bin2-1 phenotype. VLG partially rescued the bin2-3 bil1 bil2 phenotype, demonstrating that VLG acts downstream of BIN2. Mutation of VLG residues that are phosphorylated by BIN2 altered VLG stability and a phosphorylation mimic of VLG causes similar defects as did bin2-1. Therefore, BIN2 may function by interacting with and phosphorylating VLG in the FG to enhance its stability and abundance, thus facilitating vacuole formation. Our findings provide mechanistic insight into how the BIN2-VLG module regulates the spatiotemporal formation of the large vacuole in FG development.
PMID: 36648110
Plant Cell , IF:11.277 , 2023 Jan , V35 (1) : P340-342 doi: 10.1093/plcell/koac326
Crosstalk between ethylene, light, and brassinosteroid signaling in the control of apical hook formation.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
PMID: 36377974
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Jan , V120 (4) : Pe2217255120 doi: 10.1073/pnas.2217255120
SUMO/deSUMOylation of the BRI1 brassinosteroid receptor modulates plant growth responses to temperature.
Plant Science Research Laboratory, Unite Mixte de Recherche 5546 Centre National de la Recherche Scientifique/Universite Toulouse 3, 31320 Auzeville Tolosane, France.; Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom.
Brassinosteroids (BRs) are a class of steroid molecules perceived at the cell surface that act as plant hormones. The BR receptor BRASSINOSTEROID INSENSITIVE1 (BRI1) offers a model to understand receptor-mediated signaling in plants and the role of post-translational modifications. Here we identify SUMOylation as a new modification targeting BRI1 to regulate its activity. BRI1 is SUMOylated in planta on two lysine residues, and the levels of BRI1 SUMO conjugates are controlled by the Desi3a SUMO protease. Loss of Desi3a leads to hypersensitivity to BRs, indicating that Desi3a acts as a negative regulator of BR signaling. Besides, we demonstrate that BRI1 is deSUMOylated at elevated temperature by Desi3a, leading to increased BRI1 interaction with the negative regulator of BR signaling BIK1 and to enhanced BRI1 endocytosis. Loss of Desi3a or BIK1 results in increased response to temperature elevation, indicating that BRI1 deSUMOylation acts as a safety mechanism necessary to keep temperature responses in check. Altogether, our work establishes BRI1 deSUMOylation as a molecular crosstalk mechanism between temperature and BR signaling, allowing plants to translate environmental inputs into growth response.
PMID: 36652487
Curr Biol , IF:10.834 , 2023 Jan doi: 10.1016/j.cub.2023.01.013
Hydathode immunity protects the Arabidopsis leaf vasculature against colonization by bacterial pathogens.
Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.; Wageningen Electron Microscopy Centre, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands.; Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. Electronic address: h.a.vandenburg@uva.nl.
Plants prevent disease by passively and actively protecting potential entry routes against invading microbes. For example, the plant immune system actively guards roots, wounds, and stomata. How plants prevent vascular disease upon bacterial entry via guttation fluids excreted from specialized glands at the leaf margin remains largely unknown. These so-called hydathodes release xylem sap when root pressure is too high. By studying hydathode colonization by both hydathode-adapted (Xanthomonas campestris pv. campestris) and non-adapted pathogenic bacteria (Pseudomonas syringae pv. tomato) in immunocompromised Arabidopsis mutants, we show that the immune hubs BAK1 and EDS1-PAD4-ADR1 restrict bacterial multiplication in hydathodes. Both immune hubs effectively confine bacterial pathogens to hydathodes and lower the number of successful escape events of an hydathode-adapted pathogen toward the xylem. A second layer of defense, which is dependent on the plant hormones' pipecolic acid and to a lesser extent on salicylic acid, reduces the vascular spread of the pathogen. Thus, besides glands, hydathodes represent a potent first line of defense against leaf-invading microbes.
PMID: 36731466
New Phytol , IF:10.151 , 2023 Jan doi: 10.1111/nph.18779
The regulatory module MdBZR1-MdCOL6 mediates brassinosteroid- and light-regulated anthocyanin synthesis in apple.
College of Horticulture, Shandong Agricultural University, Taian, 271000, Shandong, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
* The anthocyanin content is an important indicator of the nutritional value of most fruits, including apple (Malus domestica). Anthocyanin synthesis is coordinately regulated by light and various phytohormones. In this study on apple, we revealed the antagonistic relationship between light and brassinosteroid (BR) signaling pathways, which is mediated by BRASSINAZOLE-RESISTANT 1 (MdBZR1) and the B-box protein MdCOL6. * The exogenous application of brassinolide inhibited the high light-induced anthocyanin accumulation in red-fleshed apple seedlings, whereas increases in the light intensity decreased the endogenous BR content. The overexpression of MdBZR1 inhibited the anthocyanin synthesis in apple plants. An exposure to a high light intensity induced the degradation of dephosphorylated MdBZR1, resulting in functional impairment. * MdBZR1 was identified as an upstream repressor of MdCOL6, which promotes anthocyanin synthesis in apple plants. Furthermore, MdBZR1 interacts with MdCOL6 to attenuate its ability to activate MdUFGT and MdANS transcription. Thus, MdBZR1 negatively regulates MdCOL6-mediated anthocyanin accumulation. * Our study findings have clarified the molecular basis of the integration of light and BR signals during the regulation of anthocyanin biosynthesis, which is an important process influencing fruit quality.
PMID: 36710519
New Phytol , IF:10.151 , 2023 Jan , V237 (2) : P497-514 doi: 10.1111/nph.18560
Molecular evidence for adaptive evolution of drought tolerance in wild cereals.
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.; Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.; Central Laboratory, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.; Collaborative Innovation Centre for Grain Industry, College of Agriculture, Yangtze University, Jingzhou, 434025, China.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China.; School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China.; Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK.; Institute of Evolution, University of Haifa, Mount Carmel, 34988384, Haifa, Israel.; Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS, 7004, Australia.; School of Biological Science, University of Western Australia, Crawley, WA, 6009, Australia.; School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia.; School of Science, Western Sydney University, Penrith, NSW, 2751, Australia.; Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia.
The considerable drought tolerance of wild cereal crop progenitors has diminished during domestication in the pursuit of higher productivity. Regaining this trait in cereal crops is essential for global food security but requires novel genetic insight. Here, we assessed the molecular evidence for natural variation of drought tolerance in wild barley (Hordeum spontaneum), wild emmer wheat (Triticum dicoccoides), and Brachypodium species collected from dry and moist habitats at Evolution Canyon, Israel (ECI). We report that prevailing moist vs dry conditions have differentially shaped the stomatal and photosynthetic traits of these wild cereals in their respective habitats. We present the genomic and transcriptomic evidence accounting for differences, including co-expression gene modules, correlated with physiological traits, and selective sweeps, driven by the xeric site conditions on the African Slope (AS) at ECI. Co-expression gene module 'circadian rhythm' was linked to significant drought-induced delay in flowering time in Brachypodium stacei genotypes. African Slope-specific differentially expressed genes are important in barley drought tolerance, verified by silencing Disease-Related Nonspecific Lipid Transfer 1 (DRN1), Nonphotochemical Quenching 4 (NPQ4), and Brassinosteroid-Responsive Ring-H1 (BRH1). Our results provide new genetic information for the breeding of resilient wheat and barley in a changing global climate with increasingly frequent drought events.
PMID: 36266957
New Phytol , IF:10.151 , 2023 Jan , V237 (2) : P684-697 doi: 10.1111/nph.18557
Engineered ATG8-binding motif-based selective autophagy to degrade proteins and organelles in planta.
College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China.; Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.; WIMI Biotechnology Co. Ltd, Changzhou, 213000, China.; Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou, 510642, China.
Protein-targeting technologies represent essential approaches in biological research. Protein knockdown tools developed recently in mammalian cells by exploiting natural degradation mechanisms allow for precise determination of protein function and discovery of degrader-type drugs. However, no method to directly target endogenous proteins for degradation is currently available in plants. Here, we describe a novel method for targeted protein clearance by engineering an autophagy receptor with a binder to provide target specificity and an ATG8-binding motif (AIM) to link the targets to nascent autophagosomes, thus harnessing the autophagy machinery for degradation. We demonstrate its specificity and broad potentials by degrading various fluorescence-tagged proteins, including cytosolic mCherry, the nucleus-localized bZIP transcription factor TGA5, and the plasma membrane-anchored brassinosteroid receptor BRI1, as well as fluorescence-coated peroxisomes, using a tobacco-based transient expression system. Stable expression of AIM-based autophagy receptors in Arabidopsis further confirms the feasibility of this approach in selective autophagy of endogenous proteins. With its wide substrate scope and its specificity, our concept of engineered AIM-based selective autophagy could provide a convenient and robust research tool for manipulating endogenous proteins in plants and may open an avenue toward degradation of cytoplasmic components other than proteins in plant research.
PMID: 36263708
Plant Biotechnol J , IF:9.803 , 2023 Jan doi: 10.1111/pbi.14005
GhPRE1A promotes cotton fibre elongation by activating the DNA-binding bHLH factor GhPAS1.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, 450000, Zhengzhou, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, 455000, Anyang, China.; College of Life Sciences and Agronomy, Zhoukou Normal University, 466000, Zhoukou, China.; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, 831100, Changji, China.
PMID: 36609789
Plant Physiol , IF:8.34 , 2023 Feb doi: 10.1093/plphys/kiad117
Armadillo Repeat Only protein GS10 negatively regulates brassinosteroid signaling to control rice grain size.
National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China.; School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, 230027, China.; State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, 611130, China.; College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China.; School of Life Science and Technology, Shanghai Tech University, Shanghai, 201210, China.; College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.
Grain yield and grain quality are major determinants in modern breeding controlled by many quantitative traits loci (QTLs) in rice (Oryza sativa). However, the mechanisms underlying grain shape and quality are poorly understood. Here, we characterize a QTL for grain size and grain quality via map-based cloning from wild rice (W1943), GS10 (Grain Size on Chromosome 10), which encodes a protein with six tandem armadillo (ARM) repeats. The null mutant gs10 shows slender and narrow grains with altered cell size, which has a pleiotropic effect on other agronomical traits. Functional analysis reveals that GS10 interacts with TUD1 (Taihu Dwarf1) and is epistatic to OsGSK2 (glycogen synthase kinase 2) through regulating grain shape and lamina joint inclination, indicating it is negatively involved in brassinosteroid (BR) signaling. Pyramiding gs10 and the grain size gene GW5 into cultivar GLA4 substantially improved grain shape and appearance quality. Natural variation analysis revealed that gs10 from the wild rice Oryza rufipogon W1943 is a rare allele across the rice population. Collectively, these findings advance our understanding of the underlying mechanism of grain shape and provide the beneficial allele of gs10 for future rice breeding and genetic improvement.
PMID: 36822628
Plant Physiol , IF:8.34 , 2023 Feb doi: 10.1093/plphys/kiad082
Another tool in the receptor endocytosis kit: Ligand-insensitive BRASSINOSTEROID INSENSITIVE1.
Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305.
PMID: 36782385
Plant Physiol , IF:8.34 , 2023 Jan doi: 10.1093/plphys/kiad005
BRASSINOSTEROID INSENSITIVE1 internalization can occur independent of ligand binding.
Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland.; College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, 710062, P.R. China.; Center for Plant Molecular Biology (ZMBP), University of Tubingen, 72076 Tubingen, Germany.; Laboratoire Reproduction et Developpement des Plantes (RDP), Universite de Lyon, Ecole Normale Superieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), 69342 Lyon, France.
The brassinosteroid (BR) hormone and its plasma membrane receptor BR INSENSITIVE1 (BRI1) is one of the best-studied receptor-ligand pairs for understanding the interplay between receptor endocytosis and signaling in plants. BR signaling is mainly determined by the plasma membrane pool of BRI1, whereas BRI1 endocytosis ensures signal attenuation. Since BRs are ubiquitously distributed in the plant, the tools available to study BRI1 function without interference from endogenous BRs are limited. Here, we designed a BR-binding-deficient Arabidopsis (Arabidopsis thaliana) mutant based on protein sequence-structure analysis and homology modeling of members of BRI1 family. This tool allowed us to re-examine the BRI1 endocytosis and signal attenuation model. We showed that despite impaired phosphorylation and ubiquitination, BR-binding-deficient BRI1 internalizes similarly to the wild-type form. Our data indicate that BRI1 internalization relies on different endocytic machinery. In addition, the BR-binding-deficient mutant provides opportunities to study non-canonical ligand-independent BRI1 functions.
PMID: 36617237
Plant Physiol , IF:8.34 , 2023 Feb , V191 (2) : P1167-1185 doi: 10.1093/plphys/kiac568
Kinase regulators evolved into two families by gain and loss of ability to bind plant steroid receptors.
College of Life Sciences, Shaanxi Normal University, Xi'an 710119, Shaanxi Province, P.R. China.
All biological functions evolve by fixing beneficial mutations and removing deleterious ones. Therefore, continuously fixing and removing the same essential function to separately diverge monophyletic gene families sounds improbable. Yet, here we report that brassinosteroid insensitive1 kinase inhibitor1 (BKI1)/membrane-associated kinase regulators (MAKRs) regulating a diverse function evolved into BKI1 and MAKR families from a common ancestor by respectively enhancing and losing ability to bind brassinosteroid receptor brassinosteroid insensitive1 (BRI1). The BKI1 family includes BKI1, MAKR1/BKI1-like (BKL) 1, and BKL2, while the MAKR family contains MAKR2-6. Seedless plants contain only BKL2. In seed plants, MAKR1/BKL1 and MAKR3, duplicates of BKL2, gained and lost the ability to bind BRI1, respectively. In angiosperms, BKL2 lost the ability to bind BRI1 to generate MAKR2, while BKI1 and MAKR6 were duplicates of MAKR1/BKL1 and MAKR3, respectively. In dicots, MAKR4 and MAKR5 were duplicates of MAKR3 and MAKR2, respectively. Importantly, BKI1 localized in the plasma membrane, but BKL2 localized to the nuclei while MAKR1/BKL1 localized throughout the whole cell. Importantly, BKI1 strongly and MAKR1/BKL1 weakly inhibited plant growth, but BKL2 and the MAKR family did not inhibit plant growth. Functional study of the chimeras of their N- and C-termini showed that only the BKI1 family was partially reconstructable, supporting stepwise evolution by a seesaw mechanism between their C- and N-termini to alternately gain an ability to bind and inhibit BRI1, respectively. Nevertheless, the C-terminal BRI1-interacting motif best defines the divergence of BKI1/MAKRs. Therefore, BKI1 and MAKR families evolved by gradually gaining and losing the same function, respectively, extremizing divergent evolution and adding insights into gene (BKI1/MAKR) duplication and divergence.
PMID: 36494097
Comput Struct Biotechnol J , IF:7.271 , 2023 , V21 : P1092-1101 doi: 10.1016/j.csbj.2023.01.032
On the human health benefits of microalgal phytohormones: An explorative in silico analysis.
Stazione zoologica Anton Dohrn, sede Molosiglio Marina Acton, via ammiraglio F. Acton, 55, 80133 Napoli, Italy.
Phytohormones represent a group of secondary metabolites with different chemical structures, in which belong auxins, cytokinins, gibberellins, or brassinosteroids. In higher plants, they cover active roles in growth or defense function, while their potential benefits for human health protection were noted for some phytohormones and little explored for many others. In this study, we developed a target fishing strategy on fifty-three selected naturally occurring phytohormones covering different families towards proteins involved in key cellular functions related to human metabolism and health protection/disease. This in silico analysis strategy aims to screen the potential human health-driven bioactivity of more than fifty phytohormones through the analysis of their interactions with specific targets. From this analysis, twenty-eight human targets were recovered. Some targets e.g., the proteins mitochondrial glutamate dehydrogenase (GLUD1) or nerve growth factor (NGF) bound many phytohormones, highlighting their involvement in amino acid metabolism and/or in the maintenance or survival of neurons. Conversely, some phytohormones specifically interacted with some proteins, e.g., SPRY domain-containing SOCS box protein 2 (SPSB2) or Inosine-5'-monophosphate dehydrogenase 1 (IMPDH1), both involved in human immune response. They were then investigated with a molecular docking analysis approach. Our bioprospecting study indicated that many phytohormones may endow human health benefits, with potential functional role in multiple cellular processes including immune response and cell cycle progression.
PMID: 36789263
Microbiol Spectr , IF:7.171 , 2023 Feb , V11 (1) : Pe0362122 doi: 10.1128/spectrum.03621-22
Duplicated Flagellins in Pseudomonas Divergently Contribute to Motility and Plant Immune Elicitation.
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.; Department of Plant Pathology, China Agricultural University, Beijing, China.
Flagellins are the main constituents of the flagellar filaments that provide bacterial motility, chemotactic ability, and host immune elicitation ability. Although the functions of flagellins have been extensively studied in bacteria with a single flagellin-encoding gene, the function of multiple flagellin-encoding genes in a single bacterial species is largely unknown. Here, the model plant-growth-promoting bacterium Pseudomonas kilonensis F113 was used to decipher the divergent functions of duplicated flagellins. We demonstrate that the two flagellins (FliC-1 and FliC-2) in 12 Pseudomonas strains, including F113, are evolutionarily distinct. Only the fliC-1 gene but not the fliC-2 gene in strain F113 is responsible for flagellar biogenesis, motility, and plant immune elicitation. The transcriptional expression of fliC-2 was significantly lower than that of fliC-1 in medium and in planta, most likely due to variations in promoter activity. In silico prediction revealed that all fliC-2 genes in the 12 Pseudomonas strains have a poorly conserved promoter motif. Compared to the Flg22-2 epitope (relative to FliC-2), Flg22-1 (relative to FliC-1) induced stronger FLAGELLIN SENSING 2 (FLS2)-mediated microbe-associated molecular pattern-triggered immunity and significantly inhibited plant root growth. A change in the 19th amino acid in Flg22-2 reduced its binding affinity to the FLS2/brassinosteroid insensitive 1-associated kinase 1 complex. Also, Flg22-2 epitopes in the other 11 Pseudomonas strains were presumed to have low binding affinity due to the same change in the 19th amino acid. These findings suggest that Pseudomonas has evolved duplicate flagellins, with only FliC-1 contributing to motility and plant immune elicitation. IMPORTANCE Flagellins have emerged as important microbial patterns. This work focuses on flagellin duplication in some plant-associated Pseudomonas. Our findings on the divergence of duplicated flagellins provide a conceptual framework for better understanding the functional determinant flagellin and its peptide in multiple-flagellin plant-growth-promoting rhizobacteria.
PMID: 36629446
J Integr Plant Biol , IF:7.061 , 2023 Jan doi: 10.1111/jipb.13458
A Nicotiana benthamiana receptor-like kinase regulates Phytophthora resistance by coupling with BAK1 to enhance elicitin-triggered immunity.
College of Plant Protection, China Agricultural University, Beijing, 100094, China.; College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.; Department of Plant Pathology, Washington State University, Pullman, Washington, 99164, USA.
Cell-surface-localized leucine-rich-repeat receptor-like kinases (LRR-RLKs) are crucial for plant immunity. Most LRR-RLKs that act as receptors directly recognize ligands via a large extracellular domain (ECD), whereas LRR-RLK that serve as regulators are relatively small and contain fewer LRRs. Here, we identified LRR-RLK regulators using high-throughput tobacco rattle virus (TRV)-based gene silencing in the model plant Nicotiana benthamiana. We used the cell-death phenotype caused by INF1, an oomycete elicitin that induces pattern-triggered immunity, as an indicator. By screening 33 small LRR-RLKs (
PMID: 36661038
J Integr Plant Biol , IF:7.061 , 2022 Dec doi: 10.1111/jipb.13443
Brassinosteroid signaling regulates phosphate starvation-induced malate secretion in plants.
Microelement Research Center, College of Resources & Environment, Huazhong Agricultural University, Wuhan, 430070, China.; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China.
Inorganic phosphate (Pi) is often limited in soils due to precipitation with iron (Fe) and aluminum (Al). To scavenge heterogeneously distributed phosphorus (P) resources, plants have evolved a local Pi signaling pathway that induces malate secretion to solubilize the occluded Fe-P or Al-P oxides. In this study, we show that Pi limitation impaired brassinosteroid signaling and downregulated BRASSINAZOLE-RESISTANT 1 (BZR1) expression in Arabidopsis thaliana. Exogenous 2,4-epibrassinolide treatment or constitutive activation of BZR1 (in the bzr1-D mutant) significantly reduced primary root growth inhibition under Pi-starvation conditions by downregulating ALUMINUM-ACTIVATED MALATE TRANSPORTER 1 (ALMT1) expression and malate secretion. Furthermore, AtBZR1 competitively suppressed the activator effect of SENSITIVITY TO PROTON RHIZOTOXICITY 1 (STOP1) on ALMT1 expression and malate secretion in Nicotiana benthamiana leaves and Arabidopsis. The ratio of nuclear-localized STOP1 and BZR1 determined ALMT1 expression and malate secretion in Arabidopsis. In addition, BZR1-inhibited malate secretion is conserved in rice (Oryza sativa). Our findings provide insight into plant mechanisms for optimizing the secretion of malate, an important carbon resource, to adapt to Pi-deficiency stress.
PMID: 36579777
J Integr Plant Biol , IF:7.061 , 2023 Jan , V65 (1) : P64-81 doi: 10.1111/jipb.13397
CKL2 mediates the crosstalk between abscisic acid and brassinosteroid signaling to promote swift growth recovery after stress in Arabidopsis.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Key Laboratory of Plant Stress, Life Science College, Shandong Normal University, Jinan, 250014, China.
Plants must adapt to the constantly changing environment. Adverse environmental conditions trigger various defensive responses, including growth inhibition mediated by phytohormone abscisic acid (ABA). When the stress recedes, plants must transit rapidly from stress defense to growth recovery, but the underlying mechanisms by which plants switch promptly and accurately between stress resistance and growth are poorly understood. Here, using quantitative phosphoproteomics strategy, we discovered that early ABA signaling activates upstream components of brassinosteroid (BR) signaling through CASEIN KINASE 1-LIKE PROTEIN 2 (CKL2). Further investigations showed that CKL2 interacts with and phosphorylates BRASSINOSTEROID INSENSITIVE1 (BRI1), the main BR receptor, to maintain the basal activity of the upstream of BR pathway in plants exposed to continuous stress conditions. When stress recedes, the elevated phosphorylation of BRI1 by CKL2 contributes to the swift reactivation of BR signaling, which results in quick growth recovery. These results suggest that CKL2 plays a critical regulatory role in the rapid switch between growth and stress resistance. Our evidence expands the understanding of how plants modulate stress defense and growth by integrating ABA and BR signaling cascades.
PMID: 36282494
J Integr Plant Biol , IF:7.061 , 2023 Jan , V65 (1) : P10-24 doi: 10.1111/jipb.13356
Brassinosteroid signaling positively regulates abscisic acid biosynthesis in response to chilling stress in tomato.
Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.; Hainan Institute, Zhejiang University, Sanya, 572025, China.; Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, 310058, China.
Brassinosteroids (BRs) and abscisic acid (ABA) are essential regulators of plant growth and stress tolerance. Although the antagonistic interaction of BRs and ABA is proposed to ensure the balance between growth and defense in model plants, the crosstalk between BRs and ABA in response to chilling in tomato (Solanum lycopersicum), a warm-climate horticultural crop, is unclear. Here, we determined that overexpression of the BR biosynthesis gene DWARF (DWF) or the key BR signaling gene BRASSINAZOLE-RESISTANT1 (BZR1) increases ABA levels in response to chilling stress via positively regulating the expression of the ABA biosynthesis gene 9-CIS-EPOXYCAROTENOID DIOXYGENASE1 (NCED1). BR-induced chilling tolerance was mostly dependent on ABA biosynthesis. Chilling stress or high BR levels decreased the abundance of BRASSINOSTEROID-INSENSITIVE2 (BIN2), a negative regulator of BR signaling. Moreover, we observed that chilling stress increases BR levels and results in the accumulation of BZR1. BIN2 negatively regulated both the accumulation of BZR1 protein and chilling tolerance by suppressing ABA biosynthesis. Our results demonstrate that BR signaling positively regulates chilling tolerance via ABA biosynthesis in tomato. The study has implications in production of warm-climate crops in horticulture.
PMID: 36053143
J Exp Bot , IF:6.992 , 2023 Jan , V74 (1) : P283-295 doi: 10.1093/jxb/erac429
BRASSINOSTEROID-SIGNALING KINASE1-1, a positive regulator of brassinosteroid signalling, modulates plant architecture and grain size in rice.
Biotechnology Research Institute, Chinese Academy of Agriculture Sciences, Beijing 100081, China.; College of Life Sciences, Shandong Agricultural University, Taian 271018, China.; Key Laboratory of Crop Genetics and Germplasm Enhancement/Jiangsu Provincial Center of Plant Gene Engineering, Nanjing Agricultural University, Nanjing 210095, China.; College of Life Sciences, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.
Brassinosteroids (BRs) are a crucial class of plant hormones that regulate plant growth and development, thus affecting many important agronomic traits in crops. However, there are still significant gaps in our understanding of the BR signalling pathway in rice. In this study, we provide multiple lines of evidence to indicate that BR-SIGNALING KINASE1-1 (OsBSK1-1) likely represents a missing component in the BR signalling pathway in rice. We showed that knockout mutants of OsBSK1-1 are less sensitive to BR and exhibit a pleiotropic phenotype, including lower plant height, less tiller number and shortened grain length, whereas transgenic plants overexpressing a gain-of-function dominant mutant form of OsBSK1-1 (OsBSK1-1A295V) are hypersensitive to BR, and exhibit some enhanced BR-responsive phenotypes. We found that OsBSK1-1 physically interacts with the BR receptor BRASSINOSTEROID INSENSITIVE1 (OsBRI1), and GLYCOGEN SYNTHASE KINASE2 (OsGSK2), a downstream component crucial for BR signalling. Moreover, we showed that OsBSK1-1 can be phosphorylated by OsBRI1 and can inhibit OsGSK2-mediated phosphorylation of BRASSINOSTEROID RESISTANT1 (OsBZR1). We further demonstrated that OsBSK1-1 genetically acts downstream of OsBRI1, but upstream of OsGSK2. Together, our results suggest that OsBSK1-1 may serve as a scaffold protein directly bridging OsBRI1 and OsGSK2 to positively regulate BR signalling, thus affecting plant architecture and grain size in rice.
PMID: 36346128
Plant J , IF:6.417 , 2023 Feb , V113 (3) : P460-477 doi: 10.1111/tpj.16058
Altered expression levels of long non-coding natural antisense transcripts overlapping the UGT73C6 gene affect rosette size in Arabidopsis thaliana.
Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Halle/Saale, D-06120, Germany.; Section Microbial Biotechnology, Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, D-06120, Germany.
Natural antisense long non-coding RNAs (lncNATs) are involved in the regulation of gene expression in plants, modulating different relevant developmental processes and responses to various stimuli. We have identified and characterized two lncNATs (NAT1(UGT73C6) and NAT2(UGT73C6) , collectively NATs(UGT73C6) ) from Arabidopsis thaliana that are transcribed from a gene fully overlapping UGT73C6, a member of the UGT73C subfamily of genes encoding UDP-glycosyltransferases (UGTs). Expression of both NATs(UGT73C6) is developmentally controlled and occurs independently of the transcription of UGT73C6 in cis. Downregulation of NATs(UGT73C6) levels through artificial microRNAs results in a reduction of the rosette area, while constitutive overexpression of NAT1(UGT73C6) or NAT2(UGT73C6) leads to the opposite phenotype, an increase in rosette size. This activity of NATs(UGT73C6) relies on its RNA sequence and, although modulation of UGT73C6 in cis cannot be excluded, the observed phenotypes are not a consequence of the regulation of UGT73C6 in trans. The NATs(UGT73C6) levels were shown to affect cell proliferation and thus individual leaf size. Consistent with this concept, our data suggest that the NATs(UGT73C6) influence the expression levels of key transcription factors involved in regulating leaf growth by modulating cell proliferation. These findings thus reveal an additional regulatory layer on the process of leaf growth. In this work, we characterized at the molecular level two long non-coding RNAs (NATs(UGT73C6) ) that are transcribed in the opposite direction to UGT73C6, a gene encoding a glucosyltransferase involved in brassinosteroid homeostasis in A. thaliana. Our results indicate that NATs(UGT73C6) expression influences leaf growth by acting in trans and by modulating the levels of transcription factors that are involved in the regulation of cell proliferation.
PMID: 36495314
Plant J , IF:6.417 , 2023 Jan , V113 (1) : P92-105 doi: 10.1111/tpj.16036
CRISPR/Cas9 genome-editing applied to MdPGT1 in apple results in reduced foliar phloridzin without impacting plant growth.
Research and Innovation Centre, Edmund Mach Foundation, Via Edmund Mach 1, San Michele all'Adige, 38098, Italy.; C3A Center Agriculture Food Environment, University of Trento, Via Edmund Mach 1, San Michele all'Adige, 38098, Italy.; The New Zealand Institute for Plant and Food Research Limited, 120 Mt Albert Road, Auckland, 1025, New Zealand.; Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Hans-Knoll-Strasse 8, Jena, 07745, Germany.; Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences and Palacky University, Slechtitelu 19, Olomouc, CZ-783 71, Czech Republic.
Phloridzin is the most abundant polyphenolic compound in apple (Malus x domestica Borkh.), which results from the action of a key phloretin-specific UDP-2'-O-glucosyltransferase (MdPGT1). Here, we simultaneously assessed the effects of targeting MdPGT1 by conventional transgenesis and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome editing. To this end, we conducted transcriptomic and metabolic analyses of MdPGT1 RNA interference knockdown and genome-edited lines. Knockdown lines exhibited characteristic impairment of plant growth and leaf morphology, whereas genome-edited lines exhibited normal growth despite reduced foliar phloridzin. RNA-sequencing analysis identified a common core of regulated genes, involved in phenylpropanoid and flavonoid pathways. However, we identified genes and processes differentially modulated in stunted and genome-edited lines, including key transcription factors and genes involved in phytohormone signalling. Therefore, we conducted a phytohormone profiling to obtain insight into their role in the phenotypes observed. We found that salicylic and jasmonic acid were increased in dwarf lines, whereas auxin and ABA showed no correlation with the growth phenotype. Furthermore, bioactive brassinosteroids were commonly up-regulated, whereas gibberellin GA(4) was distinctively altered, showing a sharp decrease in RNA interference knockdown lines. Expression analysis by reverse transcriptase-quantitative polymerase chain reaction expression analysis further confirmed transcriptional regulation of key factors involved in brassinosteroid and gibberellin interaction. These findings suggest that a differential modulation of phytohormones may be involved in the contrasting effects on growth following phloridzin reduction. The present study also illustrates how CRISPR/Cas9 genome editing can be applied to dissect the contribution of genes involved in phloridzin biosynthesis in apple.
PMID: 36401738
Ecotoxicol Environ Saf , IF:6.291 , 2023 Feb , V251 : P114534 doi: 10.1016/j.ecoenv.2023.114534
Exogenous brassinosteroid alleviates calcium deficiency induced tip-burn by regulating calcium transport in Brassica rapa L. ssp. pekinensis.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.; College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China; State Key Laboratory of Arid-land Crop Science, Gansu Agricultural University, Lanzhou 730070, China. Electronic address: hull@gsau.edu.cn.; College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China; State Key Laboratory of Arid-land Crop Science, Gansu Agricultural University, Lanzhou 730070, China. Electronic address: yujihuagg@163.com.
Mini Chinese cabbage (Brassica rapa L. ssp. Pekinensis) plays an important role in the supply of summer vegetables on the plateau in western China. In recent years, tip-burn has seriously affected the yield, quality and commodity value of mini Chinese cabbage. Calcium (Ca(2+)) deficiency is a key inducer of tip-burn. As a new type plant hormone, brassinolide (BR) is involved in regulating a variety of biotic and abiotic stresses. To explore the alleviation role of BR in tip-burn caused by Ca(2+) deficiency, a hydroponic experiment was conducted to study the relationship between BR and Ca(2+) absorption and transport. The results showed that foliar spraying with 0.5 microM BR significantly reduced tip-burn incidence rate and disease index of mini Chinese cabbage caused by Ca(2+) deficiency. Moreover, the dynamic monitoring results of tip-burn incidence rate showed that the value reached the highest on the ninth day after treatment. BR promoted the Ca(2+) transport from roots to shoots and from outer leaves to inner leaves by increasing the activities of Ca(2+)-ATPase and H(+)-ATPase as well as the total ATP content, which provided power for Ca(2+) transport. In addition, exogenous BR upregulated the relative expression levels of BrACA4, BrACA11, BrECA1, BrECA3, BrECA4, BrCAX1, BrCAS and BrCRT2, whereas Ca(2+) deficiency induced down-regulation. In conclusion, exogenous BR can alleviate the Ca(2+)-deficiency induced tip-burn of mini Chinese cabbage by promoting the transport and distribution of Ca(2+).
PMID: 36646009
Commun Biol , IF:6.268 , 2023 Jan , V6 (1) : P45 doi: 10.1038/s42003-023-04440-x
Shaping transcriptional responses to a phytohormone.
Communications Biology, . david.favero@us.nature.com.
The BIL1/BZR1 transcription factor is known to regulate transcriptional responses to the brassinosteroid class of phytohormones by directly recognizing short cis regulatory elements in promoters. A new study by Shohei Nosaki, Nobutaka Mitsuda, and colleagues published in Nature Plants indicates that binding of this transcription factor is additionally affected by nucleobases that influence DNA shape but are not directly contacted by BIL1/BZR1.
PMID: 36639703
Int J Mol Sci , IF:5.923 , 2023 Feb , V24 (4) doi: 10.3390/ijms24043631
Insights on Phytohormonal Crosstalk in Plant Response to Nitrogen Stress: A Focus on Plant Root Growth and Development.
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Sugarcane Biology, Guangxi University, Nanning 530004, China.; Department of Horticulture, Institute of Vegetable Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.; National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China.
Nitrogen (N) is a vital mineral component that can restrict the growth and development of plants if supplied inappropriately. In order to benefit their growth and development, plants have complex physiological and structural responses to changes in their nitrogen supply. As higher plants have multiple organs with varying functions and nutritional requirements, they coordinate their responses at the whole-plant level based on local and long-distance signaling pathways. It has been suggested that phytohormones are signaling substances in such pathways. The nitrogen signaling pathway is closely associated with phytohormones such as auxin (AUX), abscisic acid (ABA), cytokinins (CKs), ethylene (ETH), brassinosteroid (BR), strigolactones (SLs), jasmonic acid (JA), and salicylic acid (SA). Recent research has shed light on how nitrogen and phytohormones interact to modulate physiology and morphology. This review provides a summary of the research on how phytohormone signaling affects root system architecture (RSA) in response to nitrogen availability. Overall, this review contributes to identifying recent developments in the interaction between phytohormones and N, as well as serving as a foundation for further study.
PMID: 36835044
Int J Mol Sci , IF:5.923 , 2023 Feb , V24 (3) doi: 10.3390/ijms24032819
A Revised View of the LSU Gene Family: New Functions in Plant Stress Responses and Phytohormone Signaling.
Instituto de Bioquimica y Microbiologia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5110566, Chile.; ANID-Millennium Science Initiative Program-Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile.; Centro de Biotecnologia y Genomica de Plantas, INIA-CSIC-Universidad Politecnica de Madrid, 28223 Madrid, Spain.; Centro de Genomica y Bioinformatica, Facultad de Ciencias, Universidad Mayor, Santiago 8580745, Chile.; Escuela de Biotecnologia, Facultad de Ciencias, Universidad Mayor, Santiago 8580745, Chile.
LSUs (RESPONSE TO LOW SULFUR) are plant-specific proteins of unknown function that were initially identified during transcriptomic studies of the sulfur deficiency response in Arabidopsis. Recent functional studies have shown that LSUs are important hubs of protein interaction networks with potential roles in plant stress responses. In particular, LSU proteins have been reported to interact with members of the brassinosteroid, jasmonate signaling, and ethylene biosynthetic pathways, suggesting that LSUs may be involved in response to plant stress through modulation of phytohormones. Furthermore, in silico analysis of the promoter regions of LSU genes in Arabidopsis has revealed the presence of cis-regulatory elements that are potentially responsive to phytohormones such as ABA, auxin, and jasmonic acid, suggesting crosstalk between LSU proteins and phytohormones. In this review, we summarize current knowledge about the LSU gene family in plants and its potential role in phytohormone responses.
PMID: 36769138
Int J Mol Sci , IF:5.923 , 2023 Jan , V24 (3) doi: 10.3390/ijms24032287
Genome-Wide Identification of BES1 Gene Family in Six Cucurbitaceae Species and Its Expression Analysis in Cucurbita moschata.
National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
The BES1 (BRI1-EMSSUPPRESSOR1) gene family play a vital role in the BR (brassinosteroid) signaling pathway, which is involved in the growth and development, biotic, abiotic, and hormone stress response in many plants. However, there are few reports of BES1 in Cucurbita moschata. In this study, 50 BES1 genes were identified in six Cucurbitaceae species by genome-wide analysis, which could be classified into 3 groups according to their gene structural features and motif compositions, and 13 CmoBES1 genes in Cucurbita moschata were mapped on 10 chromosomes. Quantitative real-time PCR analysis showed that the CmoBES1 genes displayed differential expression under different abiotic stress and hormone treatments. Subcellular localization showed that the most of CmoBES1 proteins localized in nucleus and cytoplasm, and transactivation assay indicated 9 CmoBES1 proteins played roles as transcription factors. Our analysis of BES1s diversity, localization, and expression in Curcubitaceae contributes to the better understanding of the essential roles of these transcription factors in plants.
PMID: 36768611
J Agric Food Chem , IF:5.279 , 2022 Dec , V70 (51) : P16229-16240 doi: 10.1021/acs.jafc.2c07072
Novel Plant Growth Regulator Guvermectin from Plant Growth-Promoting Rhizobacteria Boosts Biomass and Grain Yield in Rice.
Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China.; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.; Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Science, Huzhou University, Huzhou 313000, China.; Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China.
Food is a fundamental human right, and global food security is threatened by crop production. Plant growth regulators (PGRs) play an essential role in improving crop yield and quality, and this study reports on a novel PGR, termed guvermectin (GV), isolated from plant growth-promoting rhizobacteria, which can promote root and coleoptile growth, tillering, and early maturing in rice. GV is a nucleoside analogue like cytokinin (CK), but it was found that GV significantly promoted root and hypocotyl growth, which is different from the function of CK in Arabidopsis. The Arabidopsis CK receptor triple mutant ahk2-2 ahk3-3 cre1-12 still showed a GV response. Moreover, GV led different growth-promoting traits from auxin, gibberellin (GA), and brassinosteroid (BR) in Arabidopsis and rice. The results from a four-year field trial involving 28 rice varieties showed that seed-soaking treatment with GV increased the yields by 6.2 to 19.6%, outperforming the 4.0 to 10.8% for CK, 1.6 to 16.9% for BR, and 2.2 to 7.1% for GA-auxin-BR mixture. Transcriptome analysis demonstrated that GV induced different transcriptome patterns from CK, auxin, BR, and GA, and SAUR genes may regulate GV-mediated plant growth and development. This study suggests that GV represents a novel PGR with a unique signal perception and transduction pathway in plants.
PMID: 36515163
Plant Cell Physiol , IF:4.927 , 2023 Jan , V63 (12) : P1848-1856 doi: 10.1093/pcp/pcac149
Integration of Auxin, Brassinosteroid and Cytokinin in the Regulation of Rice Yield.
Department of Life Sciences, POSTECH Biotech Center, Pohang University of Science and Technology, 77 Cheongam-Ro, Namgu, Pohang-si 37673, South Korea.; Department of Botany, Hindu Girls College, Maharshi Dayanand University, Sonipat 131001, India.; Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang, TX 79409, Vietnam.; Department of Plant and Soil Science, Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX 79409, USA.
Crop varieties with a high yield are most desirable in the present context of the ever-growing human population. Mostly, the yield traits are governed by a complex of numerous molecular and genetic facets modulated by various quantitative trait loci (QTLs). With the identification and molecular characterizations of yield-associated QTLs over recent years, the central role of phytohormones in regulating plant yield is becoming more apparent. Most often, different groups of phytohormones work in close association to orchestrate yield attributes. Understanding this cross talk would thus provide new venues for phytohormone pyramiding by editing a single gene or QTL(s) for yield improvement. Here, we review a few important findings to integrate the knowledge on the roles of auxin, brassinosteroid and cytokinin and how a single gene or a QTL could govern cross talk among multiple phytohormones to determine the yield traits.
PMID: 36255097
Plant Cell Rep , IF:4.57 , 2023 Jan doi: 10.1007/s00299-023-02981-3
Propiconazole-induced brassinosteroid deficiency reduces female fertility by inhibiting female gametophyte development in woodland strawberry.
Yokohama City University, Kihara Institute for Biological Research, Maioka 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan.; Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi, 321-8505, Japan.; Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi, 321-8505, Japan.; Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi, 320-8551, Japan.; Yokohama City University, Kihara Institute for Biological Research, Maioka 641-12, Totsuka, Yokohama, Kanagawa, 244-0813, Japan. aynakamu@yokohama-cu.ac.jp.
In woodland strawberry, a brassinosteroid biosynthesis inhibitor propiconazole induced typical brassinosteroid-deficient phenotypes and decreased female fertility due to attenuated female gametophyte development. Brassinosteroids (BRs) play roles in various aspects of plant development. We investigated the physiological roles of BRs in the woodland strawberry, Fragaria vesca. BR-level-dependent phenotypes were observed using a BR biosynthetic inhibitor, propiconazole (PCZ), and the most active natural BR, brassinolide (BL). Endogenous BL and castasterone, the active BRs, were below detectable levels in PCZ-treated woodland strawberry. The plants were typical BR-deficient phenotypes, and all phenotypes were restored by treatment with BL. These observations indicate that PCZ is an effective inhibitor of BR in woodland strawberry. Only one gene for each major step of BR biosynthesis in Arabidopsis is encoded in the woodland strawberry genome. BR biosynthetic genes are highly expressed during the early stage of fruit development. Emasculated flowers treated with BL failed to develop fruit, implying that BR is not involved in parthenocarpic fruit development. Similar to BR-deficient and BR-insensitive Arabidopsis mutants, female fertility was lower in PCZ-treated plants than in mock-treated plants due to failed attraction of the pollen tube to the ovule. In PCZ-treated plants, expression of FveMYB98, the homologous gene for Arabidopsis MYB98 (a marker for synergid cells), was downregulated. Ovules were smaller in PCZ-treated plants than in mock-treated plants, and histological analysis implied that the development of more than half of female gametophytes was arrested at the early stage in PCZ-treated plants. Our findings explain how BRs function during female gametophyte development in woodland strawberry.
PMID: 36629883
Physiol Plant , IF:4.5 , 2023 Feb : Pe13875 doi: 10.1111/ppl.13875
Transcriptome analysis of drought-responsive and drought-tolerant mechanisms in maize leaves under drought stress.
Jilin Engineering Research Center for Crop Biotechnology Breeding, College of Plant Science, Jilin University, Changchun, China.
Maize is a major crop essential for food and feed, but its production is threatened by various biotic and abiotic stresses. Drought is one of the most common abiotic stresses, causing severe crop yield reduction. Although several studies have been devoted to selecting drought-tolerant maize lines and detecting the drought-responsive mechanism of maize, the transcriptomic differences between drought-tolerant and drought-susceptible maize lines are still largely unknown. In our study, RNA-seq was performed on leaves of the drought-tolerant line W9706 and the drought-susceptible line B73 after drought treatment. We identified 3147 differentially expressed genes (DEGs) between these two lines. The up-regulated DEGs in W9706 were enriched in specific processes, including ABA signaling, wax biosynthesis, CHO metabolism, signal transduction and brassinosteroid biosynthesis-related processes, while the downregulated DEGs were enriched in specific processes, such as stomatal movement. Altogether, transcriptomic analysis suggests that the different drought resistances were correlated with the differential expression of genes, while the drought tolerance of W9706 is due to the more rapid response to stimulus, higher water retention capacity and stable cellular environment under water deficit conditions. This article is protected by copyright. All rights reserved.
PMID: 36775906
Plant Physiol Biochem , IF:4.27 , 2023 Jan , V196 : P281-290 doi: 10.1016/j.plaphy.2023.01.056
Cadmium treatment induces endoplasmic reticulum stress and unfolded protein response in Arabidopsisthaliana.
Institute of Sciences of Food Production, C.N.R., Unit of Lecce, Lecce, Italy.; Laboratory of General and Inorganic Chemistry, Di.S.Te.B.A. (Dipartimento di Scienze e Technologie Biologic e Ambientali), University of Salento, Lecce, Italy.; Institute of Agricultural Biology and Biotechnology, C.N.R., Unit of Milan, Milano, Italy; Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK.; Institute of Sciences of Food Production, C.N.R., Unit of Lecce, Lecce, Italy. Electronic address: angelo.santino@ispa.cnr.it.
We report about the response of Arabidopsis thaliana to chronic and temporary Cd(2+) stress, and the Cd(2+) induced activation of ER stress and unfolded protein response (UPR). Cd(2+)-induced UPR proceeds mainly through the bZIP60 arm, which in turn activates relevant ER stress marker genes such as BiP3, CNX, PDI5 and ERdj3B in a concentration- (chronic stress) or time- (temporary stress) dependent manner. A more severe Cd-stress triggers programmed cell death (PCD) through the activation of the NAC089 transcription factor. Toxic effects of Cd(2+) exposure are reduced in the Atbzip28/bzip60 double mutant in terms of primary root length and fresh shoot weight, likely due to reduced UPR and PCD activation. We also hypothesised that the enhanced Cd(2+) tolerance of the Atbzip28/bzip60 double mutant is due to an increase in brassinosteroids signaling, since the amount of the brassinosteroid insensitive1 receptor (BRI1) protein decreases under Cd(2+) stress only in Wt plants. These data highlight the complexity of the UPR pathway, since the ER stress response is strictly related to the type of the treatment applied and the multifaceted connections of ER signaling. The reduced sensing of Cd(2+) stress in plants with UPR defects can be used as a novel strategy for phytoremediation.
PMID: 36736010
Plant Physiol Biochem , IF:4.27 , 2023 Feb , V195 : P163-169 doi: 10.1016/j.plaphy.2023.01.007
Light induction of somatic embryogenesis in Arabidopsis is regulated by PHYTOCHROME E.
Department of Plant Science, University of Manitoba, Winnipeg, R3T2N2, Canada.; Department of Plant Science, University of Manitoba, Winnipeg, R3T2N2, Canada. Electronic address: Claudio.stasolla@umanitoba.ca.
The requirement of light on somatic embryogenesis (SE) has been documented in many species; however, no mechanism of action has been elucidated. Using Arabidopsis SE as a model, the effect of red light (660 nm) during the induction phase corresponding to the formation of the embryogenic tissue was examined. Analyses of several phytochrome mutants revealed that red light signaling, conducive to SE, was mediated by PHYTOCHROME E (PHYE). Both phyE and darkness were sufficient to repress the formation of somatic embryos and reduced the expression of CONSTITUTIVE PHOTOMORPHIC DWARF 3 (CPD3), a rate limiting step in brassinosteroid (BR) biosynthesis, as well as AGAMOUS LIKE 15 (AGL15), a key inducer of many SE genes. We further integrated BR signaling and nitric oxide (NO) with PHYE by demonstrating that applications of both compounds to phyE explants and WT explants cultured in the dark partially restored AGL15 expression. These results demonstrate that SE induction by red light operates via PHYE through BR signaling and NO required to induce AGL15.
PMID: 36640683
BMC Plant Biol , IF:4.215 , 2023 Feb , V23 (1) : P64 doi: 10.1186/s12870-023-04050-z
Transcriptome analysis reveals the key pathways and candidate genes involved in salt stress responses in Cymbidium ensifolium leaves.
The First Affiliated Hospital of Yunnan University of Traditional Chinese Medicine, 650021, Kunming, China.; Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, 650224, Kunming, China.; Yunnan Key Laboratory of Plateau Wetland Conservation, Restoration and Ecological Services, Southwest Forestry University, 650224, Kunming, China.; Department of Life Technology Teaching and Research, School of Life Science, Southwest Forestry University, 650224, Kunming, China.; Faculty of Mathematics and Physics, Southwest Forestry University, 650224, Kunming, China.; CIRAD, UMR AGAP Institute, F-34398, Montpellier, France.; The First Affiliated Hospital of Yunnan University of Traditional Chinese Medicine, 650021, Kunming, China. 1820059756@qq.com.; Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, 650224, Kunming, China. 1820059756@qq.com.
BACKGROUND: Cymbidium ensifolium L. is known for its ornamental value and is frequently used in cosmetics. Information about the salt stress response of C. ensifolium is scarce. In this study, we reported the physiological and transcriptomic responses of C. ensifolium leaves under the influence of 100 mM NaCl stress for 48 (T48) and 96 (T96) hours. RESULTS: Leaf Na(+) content, activities of the antioxidant enzymes i.e., superoxide dismutase, glutathione S-transferase, and ascorbate peroxidase, and malondialdehyde content were increased in salt-stressed leaves of C. ensifolium. Transcriptome analysis revealed that a relatively high number of genes were differentially expressed in CKvsT48 (17,249) compared to CKvsT96 (5,376). Several genes related to salt stress sensing (calcium signaling, stomata closure, cell-wall remodeling, and ROS scavenging), ion balance (Na(+) and H(+)), ion homeostasis (Na(+)/K(+) ratios), and phytohormone signaling (abscisic acid and brassinosteroid) were differentially expressed in CKvsT48, CKvsT96, and T48vsT96. In general, the expression of genes enriched in these pathways was increased in T48 compared to CK while reduced in T96 compared to T48. Transcription factors (TFs) belonging to more than 70 families were differentially expressed; the major families of differentially expressed TFs included bHLH, NAC, MYB, WRKY, MYB-related, and C3H. A Myb-like gene (CenREV3) was further characterized by overexpressing it in Arabidopsis thaliana. CenREV3's expression was decreased with the prolongation of salt stress. As a result, the CenREV3-overexpression lines showed reduced root length, germination %, and survival % suggesting that this TF is a negative regulator of salt stress tolerance. CONCLUSION: These results provide the basis for future studies to explore the salt stress response-related pathways in C. ensifolium.
PMID: 36721093
Planta , IF:4.116 , 2023 Feb , V257 (3) : P48 doi: 10.1007/s00425-023-04086-3
Insights on the stem elongation of spur-type bud sport mutant of 'Red Delicious' apple.
College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China.; College of Bioengineering and Biotechnology, Tianshui Normal University, Tianshui, 741000, China.; College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China. bhch@gsau.edu.cn.
The decreased capacity of auxin-, CTK-, and BR-mediated cell division and cell enlargement pathways, combined with the enhanced capacity of GA and ETH-, JA-, ABA-, SA-mediated stress-resistant pathways were presumed to be the crucial reasons for the formation of spur-type 'Red Delicious' mutants. Vallee Spur', which exhibit short internodes and compact tree shape, is the fourth generation of the spur-type bud sport mutant of 'Red Delicious'. However, the underlying molecular mechanism of these properties remains unclear. Here, comparative phenotypic, full-length transcriptome and phytohormone analyses were performed between 'Red Delicious' (NSP) and 'Vallee Spur' (SP). The new shoot internode length of NSP was > 1.53-fold higher than that of the SP mutant. Cytological analysis showed that the stem cells of the SP mutant were smaller and more tightly arranged relative to the NSP. By Iso-Seq, a total of 1426 differentially expressed genes (DEGs) were detected, including 808 upregulated and 618 downregulated genes in new shoot apex with 2 leaves of the SP mutant. Gene expressions involved in auxin, cytokinin (CTK), and brassinosteroid (BR) signal transduction were mostly downregulated in the SP mutant, whereas those involved in gibberellin (GA), ethylene (ETH), jasmonate (JA), ABA, and salicylic acid (SA) signal transduction were mostly upregulated. The overall thermogram analysis of hormone levels in the shoot apex carrying two leaves detected by LC-MS/MS absolute quantification showed that the levels of IAA-Asp, IAA, iP7G, OPDA, and 6-deoxyCS were significantly upregulated in the SP mutant, while the remaining 28 hormones were significantly downregulated. It is speculated that the decreased capacity of auxin, CTK, and BR-mediated cell division and cell enlargement pathways is crucial for the formation of the SP mutant. GA and stress-resistant pathways of ETH, JA, ABA, and SA also play vital roles in stem elongation. These results highlight the involvement of phytohormones in the formation of stem elongation occurring in 'Red Delicious' spur-type bud sport mutants and provide information for exploring its biological mechanism.
PMID: 36740622
Plant Mol Biol , IF:4.076 , 2023 Jan , V111 (1-2) : P89-106 doi: 10.1007/s11103-022-01313-5
GhBES1 mediates brassinosteroid regulation of leaf size by activating expression of GhEXO2 in cotton (Gossypium hirsutum).
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Henan, 450001, Zhengzhou, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China.; State Key Laboratory of Cotton Biology (Hebei Base), Hebei Agricultural University, Baoding, 071001, Hebei, China.; College of Chemistry, Zhengzhou University, Henan, 450001, Zhengzhou, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Henan, 450001, Zhengzhou, China. liuzhaocaas@163.com.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Henan, 450001, Zhengzhou, China. yangzuoren@caas.cn.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China. yangzuoren@caas.cn.
We proposed a working model of BR to promote leaf size through cell expansion. In the BR signaling pathway, GhBES1 affects cotton leaf size by binding to and activating the expression of the E-box element in the GhEXO2 promoter region. Brassinosteroid (BR) is an essential phytohormone that controls plant growth. However, the mechanisms of BR regulation of leaf size remain to be determined. Here, we found that the BR deficient cotton mutant pagoda1 (pag1) had a smaller leaf size than wild-type CRI24. The expression of EXORDIUM (GhEXO2) gene, was significantly downregulated in pag1. Silencing of BRI1-EMS-SUPPRESSOR 1 (GhBES1), inhibited leaf cell expansion and reduced leaf size. Overexpression of GhBES1.4 promoted leaf cell expansion and enlarged leaf size. Expression analysis showed GhEXO2 expression positively correlated with GhBES1 expression. In plants, altered expression of GhEXO2 promoted leaf cell expansion affecting leaf size. Furthermore, GhBES1.4 specifically binds to the E-box elements in the GhEXO2 promoter, inducing its expression. RNA-seq data revealed many down-regulated genes related to cell expansion in GhEXO2 silenced plants. In summary, we discovered a novel mechanism of BR regulation of leaf size through GhBES1 directly activating the expression of GhEXO2.
PMID: 36271986
BMC Genomics , IF:3.969 , 2023 Feb , V24 (1) : P65 doi: 10.1186/s12864-023-09151-5
Transcriptome analysis of Citrus limon infected with Citrus yellow vein clearing virus.
Citrus Research Institute, Southwest University, Beibei, Chongqing, 400712, China.; Citrus Research Institute, Southwest University, Beibei, Chongqing, 400712, China. songzhen@cric.cn.; Citrus Research Institute, Southwest University, Beibei, Chongqing, 400712, China. zhoucy@cric.cn.
BACKGROUND: Citrus yellow vein clearing virus (CYVCV) is the causative agent of citrus yellow vein clearing disease, and poses a serious threat to the lemon industry in Asia. The common symptoms of CYVCV-infected lemon plants are leaf crinkling, leaf chlorotic mottling, and yellow vein clearing. However, the molecular mechanisms underlying CYVCV-citrus interaction that responsible for symptom occurrence is still unclarified. In this study, RNA-seq was performed to analyze the gene expression patterns of 'Eureka' lemon (Citrus limon Burm. f.) plants in response to CYVCV infection. RESULTS: There were 3691 differentially expressed genes (DEGs) identified by comparison between mock and CYVCV-infected lemon plants through RNA-seq. Bioinformatics analyses revealed that these DEGs were components of different pathways involved in phenylpropanoid biosynthesis, brassinosteroid biosynthesis, flavonoid biosynthesis and photosynthesis. Among these, the DEGs related to phytohormone metabolism and photosynthesis pathways were further enriched and analyzed. This study showed that different phytohormone-related genes had different responses toward CYVCV infection, however almost all of the photosynthesis-related DEGs were down-regulated in the CYVCV-infected lemon plants. The obtained RNA-seq data were validated by RT-qPCR using 12 randomly chosen genes, and the results of mRNA expression analysis were consistent with those of RNA-seq. CONCLUSIONS: The phytohormone biosynthesis, signaling and photosynthesis-related genes of lemon plants were probably involved in systemic infection and symptom occurrence of CYVCV. Notably, CYVCV infection had regulatory effects on the biosynthesis and signaling of phytohormone, which likely improve systemic infection of CYVCV. Additionally, CYVCV infection could cause structural changes in chloroplast and inhibition of photosynthesis pathway, which probably contribute to the appearance of leaf chlorotic mottling and yellow vein clearing in CYVCV-infected lemon plants. This study illustrates the dynamic nature of the citrus-CYVCV interaction at the transcriptome level and provides new insights into the molecular mechanism underlying the pathogenesis of CYVCV in lemon plants.
PMID: 36750773
Plants (Basel) , IF:3.935 , 2023 Jan , V12 (2) doi: 10.3390/plants12020409
Auxin Transporter OsPIN1b, a Novel Regulator of Leaf Inclination in Rice (Oryza sativa L.).
Key Laboratory of Herbage & Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010030, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.; College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China.
Leaf inclination is one of the most important components of the ideal architecture, which effects yield gain. Leaf inclination was shown that is mainly regulated by brassinosteroid (BR) and auxin signaling. Here, we reveal a novel regulator of leaf inclination, auxin transporter OsPIN1b. Two CRISPR-Cas9 homozygous mutants, ospin1b-1 and ospin1b-2, with smaller leaf inclination compared to the wild-type, Nipponbare (WT/NIP), while overexpression lines, OE-OsPIN1b-1 and OE-OsPIN1b-2 have opposite phenotype. Further cell biological observation showed that in the adaxial region, OE-OsPIN1b-1 has significant bulge compared to WT/NIP and ospin1b-1, indicating that the increase in the adaxial cell division results in the enlarging of the leaf inclination in OE-OsPIN1b-1. The OsPIN1b was localized on the plasma membrane, and the free IAA contents in the lamina joint of ospin1b mutants were significantly increased while they were decreased in OE-OsPIN1b lines, suggesting that OsPIN1b might action an auxin transporter such as AtPIN1 to alter IAA content and leaf inclination. Furthermore, the OsPIN1b expression was induced by exogenous epibrassinolide (24-eBL) and IAA, and ospin1b mutants are insensitive to BR or IAA treatment, indicating that the effecting leaf inclination is regulated by OsPIN1b. This study contributes a new gene resource for molecular design breeding of rice architecture.
PMID: 36679122
Life (Basel) , IF:3.817 , 2023 Feb , V13 (2) doi: 10.3390/life13020498
Interplay Impact of Exogenous Application of Abscisic Acid (ABA) and Brassinosteroids (BRs) in Rice Growth, Physiology, and Resistance under Sodium Chloride Stress.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.; Soil and Water Testing Laboratory, Marketing Division, Pak Arab Fertilizer Limited, Multan 66000, Pakistan.; MS Swaminathan School of Agriculture, Centurion University of Technology and Management, Paralakhemundi 761211, India.; Department of Soil Science, Bahauddin Zakariya University, Multan 60700, Pakistan.; Department of Soil Science, Faculty of Agricultural Sciences, Quid-E-Azam Campus, University of the Punjab, Lahore 54590, Pakistan.; Department of Plant Pathology, Agricultural College, Guizhou University, Guiyang 550001, China.
The hormonal imbalances, including abscisic acid (ABA) and brassinosteroid (BR) levels, caused by salinity constitute a key factor in hindering spikelet development in rice and in reducing rice yield. However, the effects of ABA and BRs on spikelet development in plants subjected to salinity stress have been explored to only a limited extent. In this research, the effect of ABA and BRs on rice growth characteristics and the development of spikelets under different salinity levels were investigated. The rice seedlings were subjected to three different salt stress levels: 0.0875 dS m(-1) (Control, CK), low salt stress (1.878 dS m(-1), LS), and heavy salt stress (4.09 dS m(-1), HS). Additionally, independent (ABA or BR) and combined (ABA+BR) exogenous treatments of ABA (at 0 and 25 muM concentration) and BR (at 0 and 5 muM concentration) onto the rice seedlings were performed. The results showed that the exogenous application of ABA, BRs, and ABA+BRs triggered changes in physiological and agronomic characteristics, including photosynthesis rate (Pn), SPAD value, pollen viability, 1000-grain weight (g), and rice grain yield per plant. In addition, spikelet sterility under different salt stress levels (CK, LS, and HS) was decreased significantly through the use of both the single phytohormone and the cocktail, as compared to the controls. The outcome of this study reveals new insights about rice spikelet development in plants subjected to salt stress and the effects on this of ABA and BR. Additionally, it provides information on the use of plant hormones to improve rice yield under salt stress and on the enhancement of effective utilization of salt-affected soils.
PMID: 36836855
Gene , IF:3.688 , 2023 Feb , V854 : P147059 doi: 10.1016/j.gene.2022.147059
Grape BES1 transcription factor gene VvBES1-3 confers salt tolerance in transgenic Arabidopsis.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.; College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China. Electronic address: bhch@gsau.edu.cn.
BRI1-EMS-Suppressor 1 (BES1) regulates plant growth, development, and stress resistance, and plays a pivotal role in the brassinosteroid (BR) signal transduction pathway. In this study, a total of 12 BES1 genes were identified in the grape (Vitis vinifera) genome. Phylogenetic, structure, and motif sequence analyses of these genes provided insights into their evolutionary characteristics. Hormone-, stress-, and light-responsive and organ-specific cis-acting elements were identified in VvBES1 gene promoters. Microarray data analysis showed that VvBES1 family members exhibit diverse expression patterns in different organs. Quantitative real-time PCR (qRT-PCR) analysis showed that the expression levels of VvBES1 genes differed in response to BR, methyl jasmonate (MeJA), cold (4 degrees C), NaCl, and polyethylene glycol (PEG) treatments. The expression of VvBES1-3 was 29-fold higher under salt stress than control at 12 h. Moreover, VvBES1-3-overexpessing Arabidopsis thaliana plants showed lower malondialdehyde content, higher proline content, enhanced antioxidant enzyme (catalase, superoxide dismutase, peroxidase) activities, and higher salt-responsive gene expression levels than wild-type plants under salt stress, indicating that VvBES1-3 overexpression enhances salt stress tolerance in transgenic Arabidopsis. These results will contribute to further understanding the functions of BES1 transcription factors in the abiotic stress response.
PMID: 36535462
J Plant Physiol , IF:3.549 , 2023 Jan , V280 : P153905 doi: 10.1016/j.jplph.2022.153905
Rice miR168a-5p regulates seed length, nitrogen allocation and salt tolerance by targeting OsOFP3, OsNPF2.4 and OsAGO1a, respectively.
Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, Guangdong, China.; Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, Guangdong, China; University of Chinese Academy of Sciences, Beijing, 100049, China.; Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, Guangdong, China. Electronic address: zhangmy@scbg.ac.cn.
Rice microRNA168a (osa-miR168a) plays important roles in mediating flowering time, grain yield and vigor, seeding growth, and immunity by targeting the RNA-induced silencing complex component Argonaute 1 (AGO1). However, the functions of miR168a exerted by targeting other genes require further clarification before it could be used in rice molecular breeding. In this study, we identified a new target gene of osa-miR168a-5p (miR168a-5p) in rice called OsOFP3 (ovate family protein 3) and investigated the roles of miR168a-5p in response to brassinosteroids (BRs), salt stress, and nitrogen allocation. Up- and downregulated miR168a-5p expression respectively decreased and increased the expression of the BR-negative regulator OsOPF3. The results of RNA ligase-mediated rapid amplification of cDNA ends (5'RLM-RACE) revealed cleavage sites in OsOPF3 and OsNPF2.4 mRNAs. The phenotype of miR168a-5p transgenic rice was BR-associated and included the lamina bending response to BR, short seeds, and low 1000-grain weight. MicroRNA 168a-5p also regulated the expression of the nitrate transporter, OsNPF2.4, which affected nitrogen allocation, and regulated OsAGO1a expression in response to salt stress. Taken together, rice miR168a-5p regulates BR-associated pathways, nitrogen transport, and stress by targeting OsOFP3, OsNPF2.4, and OsAGO1a, respectively, resulting in a series of important agronomic traits for rice breeding.
PMID: 36580705
Plant Biol (Stuttg) , IF:3.081 , 2023 Feb doi: 10.1111/plb.13511
Nitric oxide, calmodulin and calcium protein kinase interactions in the response of Brassica napus to salinity stress.
Department of Plant Biology, Faculty of basic sciences, Tarbiat Modares University, Tehran, Iran.
Involvement of nitric oxide (NO) in plant metabolism and its connection with phytohormones has not been fully described, thus information about the role of this molecule in signaling pathways remains fragmented. Therefore, in this study, the effects of NO on calmodulin (CAM), calcium protein kinase (CPK), the content of phytohormones and secondary metabolites in canola plants under salinity stress conditions were investigated. 100 muM sodium nitroprusside as an NO source were applied to canola plants grown under saline (100 mM NaCl) and non-saline conditions at vegetative stage. Plant growth was negatively affected by salinity conditions but exogenous NO treatment improved this parameter. NO caused a significant increase in activities of catalase (CAT), superoxide dismutase (SOD) and peroxidases (POX) due to enhancing CAT, SOD and POX expression in stressed-canola plants. Salinity-responsive genes, namely CAM and CPK, were induced by NO in plants grown under salinity conditions. NO application enhanced phenolic compounds such as gallic acid and coumaric acid and flavonoid compounds included catechin, diadzein and kaempferol in plants subjected to salinity. NO treatment enhanced abscisic acid and brassinosteroid, but declined auxin and gibberellin in stressed-canola plants. The impacts of NO on improving tolerance stress in canola were dependent on prompting CAM and CPK. Also, NO-signaling role re-established the phytohormones balance and resulted enhancement in plants tolerance to the salt stress. Too, NO improved salinity tolerance in canola plant by increasing enzymatic and non-enzymatic antioxidants.
PMID: 36779525
Mol Biotechnol , IF:2.695 , 2023 Jan , V65 (1) : P52-60 doi: 10.1007/s12033-022-00525-w
Target Metabolome and Transcriptome Analysis Reveal Molecular Mechanism Associated with Changes of Tea Quality at Different Development Stages.
Resources & Environment College, Tibet Agricultural and Animal Husbandry University, Nyingchi, 860000, China.; School of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, China. guoqiang2008@163.com.; School of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
This study aimed to explore the molecular mechanisms underlying the differential quality of tea made from leaves at different development stages. Fresh Camellia sinensis (L.) O. Kuntze "Sichuan Colonial" leaves of various development stages, from buds to old leaves, were subjected to transcriptome sequencing and metabolome analysis, and the DESeq package was used for differential expression analysis, followed by functional enrichment analyses and protein interaction analysis. Target metabolome analysis indicated that the contents of most compounds, including theobromine and epicatechin gallate, were lowest in old leaves, and transcriptome analysis revealed that DEGs were significantly involved in extracellular regions and phenylpropanoid biosynthesis, photosynthesis-related pathways, and the oleuropein steroid biosynthesis pathway. Protein-protein interaction analysis identified LOC114256852 as a hub gene. Caffeine, theobromine, L-theanine, and catechins were the main metabolites of the tea leaves, and the contents of all four main metabolites were the lowest in old leaves. Phenylpropanoid biosynthesis, photosynthesis, and brassinosteroid biosynthesis may be important targets for breeding efforts to improve tea quality.
PMID: 35780278
Steroids , IF:2.668 , 2023 Feb , V190 : P109153 doi: 10.1016/j.steroids.2022.109153
Cancer and brassinosteroids: Mechanisms of action, SAR and future perspectives.
Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: marcos.lorcac@alumnos.uv.cl.; Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: david.cabezas@postgrado.uv.cl.; Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: ileana.araque@postgrado.uv.cl.; Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: andres.teran@postgrado.uv.cl.; Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: santiago.hernandez@postgrado.uv.cl.; Instituto de Investigacion y Postgrado, Facultad de Ciencias de la Salud, Universidad Central de Chile, Santiago 8330507, Chile. Electronic address: marco.mellado@ucentral.cl.; Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Av. Espana No. 1680, Valparaiso 2340000, Chile. Electronic address: luis.espinozac@usm.cl.; Instituto de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile; Centro de Investigacion Farmacopea Chilena (CIFAR), Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso 2360102, Chile. Electronic address: jaime.mella@uv.cl.
Brassinosteroids are plant hormones whose main function is to stimulate plant growth. However, they have been studied for their biological applications in humans. Brassinosteroid compounds have displayed an important role in the study of cancer pathology and show potential for developing novel anticancer drugs. In this review we describe the relationship of brassinosteroids with cancer with focus on the last decade, the mechanisms of cytotoxic activity described to date, and a structure-activity relationship based on the available information.
PMID: 36481216
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163337 doi: 10.1080/15592324.2022.2163337
Arabidopsis clathrin adaptor EPSIN1 but not MODIFIED TRANSPORT TO THE VACOULE1 contributes to effective plant immunity against pathogenic Pseudomonas bacteria.
University of Missouri-Columbia, Division of Biochemistry, Interdisciplinary Plant Group (IPG), Columbia, MO, USA.; Department of Plant Physiology, University of Potsdam, Potsdam, Germany.
In eukaryotes, EPSINs are Epsin N-terminal Homology (ENTH) domain-containing proteins that serve as monomeric clathrin adaptors at the plasma membrane (PM) or the trans-Golgi Network (TGN)/early endosomes (EE). The model plant Arabidopsis thaliana encodes for seven ENTH proteins, of which so far, only AtEPSIN1 (AtEPS1) and MODIFIED TRANSPORT TO THE VACUOLE1 (AtMTV1) localize to the TGN/EE and contribute to cargo trafficking to both the cell surface and the vacuole. However, relatively little is known about role(s) of any plant EPSIN in governing physiological responses. We have recently shown that AtEPS1 is a positive modulator of plant immune signaling and pattern-triggered immunity against flagellated Pseudomonas syringae pv. tomato (Pto) DC3000 bacteria. In eps1 mutants, impaired immune responses correlate with reduced accumulation of the receptor FLAGELLIN SENSING2 (AtFLS2) and the convergent immune co-receptor BRASSINOSTEROID INSENTIVE1-ASSOCIATED RECEPTOR KINASE1 (AtBAK1) in the PM. Here, we report that in contrast to AtEPS1, the TGN/EE-localized AtMTV1 did not contribute significantly to immunity against pathogenic Pto DC3000 bacteria. We also compared the amino acid sequences, peptide motif structures and in silico tertiary structures of the ENTH domains of AtEPS1 and AtMTV1 in more detail. We conclude that despite sharing the classical tertiary alpha helical ENTH-domain structure and clathrin-binding motifs, the overall low amino acid identity and differences in peptide motifs may explain their role(s) in trafficking of some of the same as well as distinct cargo components to their site of function, with the latter potentially contributing to differences in physiological responses.
PMID: 36603596
Plant Signal Behav , IF:2.247 , 2022 Dec : P1-5 doi: 10.1080/15592324.2022.2153209
MYB3R-SCL28-SMR module with a role in cell size control negatively regulates G2 progression in Arabidopsis.
School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.; RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan.; Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.; Graduate School of Biostudies, Kyoto University, Kyoto, Japan.; Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Japan.; Department of Biological Sciences, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.; School of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar, Mongolia.
Cell size control is one of the prerequisites for plant growth and development. Recently, a GRAS family transcription factor, SCARECROW-LIKE28 (SCL28), was identified as a critical regulator for both mitotic and postmitotic cell-size control. Here, we show that SCL28 is specifically expressed in proliferating cells and exerts its function to delay G2 progression during mitotic cell cycle in Arabidopsis thaliana. Overexpression of SCL28 provokes a significant enlargement of cells in various organs and tissues, such as leaves, flowers and seeds, to different extents depending on the type of cells. The increased cell size is most likely due to a delayed G2 progression and accelerated onset of endoreplication, an atypical cell cycle repeating DNA replication without cytokinesis or mitosis. Unlike DWARF AND LOW-TILLERING, a rice ortholog of SCL28, SCL28 may not have a role in brassinosteroid (BR) signaling because sensitivity against brassinazole, a BR biosynthesis inhibitor, was not dramatically altered in scl28 mutant and SCL28-overexpressing plants. Collectively, our findings strengthen a recently proposed model of cell size control by SCL28 and suggest the presence of diversified evolutionary mechanisms for the regulation and action of SCL28.
PMID: 36576149
Plant Signal Behav , IF:2.247 , 2022 Dec , V17 (1) : P2084277 doi: 10.1080/15592324.2022.2084277
Behavior and possible function of Arabidopsis BES1/BZR1 homolog 2 in brassinosteroid signaling.
The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan.; Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan.; Department of Japanese Food Culture, Faculty of Letters, Kyoto Prefectural University, Kyoto, Japan.
Two key transcription factors (TFs) in brassinosteroid (BR) signaling BRASSINOSTEROID INSENSITIVE 1-EMS-SUPPRESSOR 1 (BES1) and BRASSINAZOLE RESISTANT 1 (BZR1), belong to a small family with four BES1/BZR1 homologs (BEH1-4). To date, in contrast to the wealth of knowledge regarding BES1 and BZR1, little is known about BEH1-4. Here, we show that BEH2 was expressed preferentially in the roots and leaf margins including serrations, which was quite different from another member BEH4, and that BRs downregulated BEH2 through a module containing GSK3-like kinases and BES1/BZR1 TFs, among which BES1, rather than BZR1, contributed to this process. In addition, BEH2 consistently existed in the nucleus, suggesting that its subcellular localization is not under BR-dependent nuclear-cytoplasmic shuttling control. Furthermore, gene ontology analysis on RNA-seq data indicated that BEH2 may be implicated in stress response and photosynthesis. These findings might assist in the future elucidation of the molecular mechanisms underlying BR signaling.
PMID: 35695417