Mol Plant , IF:13.164 , 2022 Oct , V15 (10) : P1543-1557 doi: 10.1016/j.molp.2022.08.008
The regeneration factors ERF114 and ERF115 regulate auxin-mediated lateral root development in response to mechanical cues.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium.; Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas alle 5, 756 51 Uppsala, Sweden.; Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), University of Tubingen, 72076 Tubingen, Germany.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium. Electronic address: lieven.deveylder@psb.vib-ugent.be.
Plants show an unparalleled regenerative capacity, allowing them to survive severe stress conditions, such as injury, herbivory attack, and harsh weather conditions. This potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant bodies. Despite the intertwined nature of development and regeneration, common upstream cues and signaling mechanisms are largely unknown. Here, we demonstrate that in addition to being activators of regeneration, ETHYLENE RESPONSE FACTOR 114 (ERF114) and ERF115 govern developmental growth in the absence of wounding or injury. Increased ERF114 and ERF115 activity enhances auxin sensitivity, which is correlated with enhanced xylem maturation and lateral root formation, whereas their knockout results in a decrease in lateral roots. Moreover, we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions. Antagonistically, cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions. Taken together, our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114- and ERF115-mediated auxin signaling.
PMID: 36030378
EMBO J , IF:11.598 , 2022 Oct , V41 (19) : Pe110682 doi: 10.15252/embj.2022110682
Salicylic acid-activated BIN2 phosphorylation of TGA3 promotes Arabidopsis PR gene expression and disease resistance.
Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, China.; School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China.
The plant defense hormone, salicylic acid (SA), plays essential roles in immunity and systemic acquired resistance. Salicylic acid induced by the pathogen is perceived by the receptor nonexpressor of pathogenesis-related genes 1 (NPR1), which is recruited by TGA transcription factors to induce the expression of pathogenesis-related (PR) genes. However, the mechanism by which post-translational modifications affect TGA's transcriptional activity by salicylic acid signaling/pathogen infection is not well-established. Here, we report that the loss-of-function mutant of brassinosteroid insensitive2 (BIN2) and its homologs, bin2-3 bil1 bil2, causes impaired pathogen resistance and insensitivity to SA-induced PR gene expression, whereas the gain-of-function mutant, bin2-1, exhibited enhanced SA signaling and immunity against the pathogen. Our results demonstrate that salicylic acid activates BIN2 kinase, which in turn phosphorylates TGA3 at Ser33 to enhance TGA3 DNA binding ability and NPR1-TGA3 complex formation, leading to the activation of PR gene expression. These findings implicate BIN2 as a new component of salicylic acid signaling, functioning as a key node in balancing brassinosteroid-mediated plant growth and SA-induced immunity.
PMID: 35950443
Plant Cell , IF:11.277 , 2022 Nov 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
Plant Cell , IF:11.277 , 2022 Oct , V34 (11) : P4516-4530 doi: 10.1093/plcell/koac245
The deubiquitinating enzymes UBP12 and UBP13 positively regulate recovery after carbon starvation by modulating BES1 stability in Arabidopsis thaliana.
Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China.; Department of Genetics, Development, and Cell Biology, Plant Sciences Institute, Iowa State University, Ames, Iowa 50011, USA.
BRI1-EMS-SUPPRESSOR1 (BES1), a core transcription factor in the brassinosteroid (BR) signaling pathway, primarily regulates plant growth and development by influencing BR-regulated gene expression. Several E3 ubiquitin (Ub) ligases regulate BES1 stability, but little is known about BES1 deubiquitination, which antagonizes E3 ligase-mediated ubiquitination to maintain BES1 homeostasis. Here, we report that two Arabidopsis thaliana deubiquitinating enzymes, Ub-SPECIFIC PROTEASE (UBP) 12 and UBP13, interact with BES1. UBP12 and UBP13 removed Ub from polyubiquitinated BES1 to stabilize both phosphorylated and dephosphorylated forms of BES1. A double mutant, ubp12-2w ubp13-3, lacking UBP12 and UBP13 function showed both BR-deficient and BR-insensitive phenotypes, whereas transgenic plants overexpressing UBP12 or UBP13 exhibited an increased BR response. Expression of UBP12 and UPB13 was induced during recovery after carbon starvation, which led to BES1 accumulation and quick recovery of stressed plants. Our work thus establishes a mechanism by which UBP12 and UBP13 regulate BES1 protein abundance to enhance BR-regulated growth during recovery after carbon starvation.
PMID: 35944221
New Phytol , IF:10.151 , 2022 Oct 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 , 2022 Oct 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
New Phytol , IF:10.151 , 2022 Nov , V236 (3) : P893-910 doi: 10.1111/nph.18404
Integration of multi-omics data reveals interplay between brassinosteroid and Target of Rapamycin Complex signaling in Arabidopsis.
Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.; Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA.; Department of Biology, Duke University, Durham, NC, 27708, USA.; USDA-ARS Cereal Disease Laboratory, University of Minnesota, St Paul, MN, 55108, USA.; Plant Sciences Institute, Iowa State University, Ames, IA, 50011, USA.
Brassinosteroids (BRs) and Target of Rapamycin Complex (TORC) are two major actors coordinating plant growth and stress responses. Brassinosteroids function through a signaling pathway to extensively regulate gene expression and TORC is known to regulate translation and autophagy. Recent studies have revealed connections between these two pathways, but a system-wide view of their interplay is still missing. We quantified the level of 23 975 transcripts, 11 183 proteins, and 27 887 phosphorylation sites in wild-type Arabidopsis thaliana and in mutants with altered levels of either BRASSINOSTEROID INSENSITIVE 2 (BIN2) or REGULATORY ASSOCIATED PROTEIN OF TOR 1B (RAPTOR1B), two key players in BR and TORC signaling, respectively. We found that perturbation of BIN2 or RAPTOR1B levels affects a common set of gene-products involved in growth and stress responses. Furthermore, we used the multi-omic data to reconstruct an integrated signaling network. We screened 41 candidate genes identified from the reconstructed network and found that loss of function mutants of many of these proteins led to an altered BR response and/or modulated autophagy activity. Altogether, these results establish a predictive network that defines different layers of molecular interactions between BR- or TORC-regulated growth and autophagy.
PMID: 35892179
Plant Physiol , IF:8.34 , 2022 Nov , V190 (4) : P2350-2365 doi: 10.1093/plphys/kiac374
Identification of growth regulators using cross-species network analysis in plants.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; Institute of Biosciences and Bioresources, National Research Council (CNR), Via Amendola 165/A, 70126 Bari, Italy.; Department of Plant Physiology, Umea Plant Science Centre (UPSC), Umea University, 90187 Umea, Sweden.; SweTree Technologies AB, Skogsmarksgrand 7, SE-907 36 Umea, Sweden.; Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432 As, Norway.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences, 90183 Umea, Sweden.; Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.
With the need to increase plant productivity, one of the challenges plant scientists are facing is to identify genes that play a role in beneficial plant traits. Moreover, even when such genes are found, it is generally not trivial to transfer this knowledge about gene function across species to identify functional orthologs. Here, we focused on the leaf to study plant growth. First, we built leaf growth transcriptional networks in Arabidopsis (Arabidopsis thaliana), maize (Zea mays), and aspen (Populus tremula). Next, known growth regulators, here defined as genes that when mutated or ectopically expressed alter plant growth, together with cross-species conserved networks, were used as guides to predict novel Arabidopsis growth regulators. Using an in-depth literature screening, 34 out of 100 top predicted growth regulators were confirmed to affect leaf phenotype when mutated or overexpressed and thus represent novel potential growth regulators. Globally, these growth regulators were involved in cell cycle, plant defense responses, gibberellin, auxin, and brassinosteroid signaling. Phenotypic characterization of loss-of-function lines confirmed two predicted growth regulators to be involved in leaf growth (NPF6.4 and LATE MERISTEM IDENTITY2). In conclusion, the presented network approach offers an integrative cross-species strategy to identify genes involved in plant growth and development.
PMID: 35984294
Plant Physiol , IF:8.34 , 2022 Oct , V190 (3) : P1978-1996 doi: 10.1093/plphys/kiac354
DIACYLGLYCEROL KINASE 5 participates in flagellin-induced signaling in Arabidopsis.
Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 263, 16502 Prague, Czech Republic.; Department of Experimental Plant Biology, Charles University, Vinicna 5, Prague 12844, Czech Republic.; Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Universite Paris-Sud, Universite Evry, Universite Paris-Saclay, Batiment 630, 91405 Orsay, France.; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cite, Batiment 630, 91405 Orsay, France.; Laboratoire de Physiologie Cellulaire et Moleculaire des Plantes, Sorbonne Universite, F-75005 Paris, France.; CNRS Enzyme and Cell Engineering Laboratory, Universite de Technologie de Compiegne, Rue du Docteur Schweitzer, 60203 Compiegne, France.
Flagellin perception is a keystone of pattern-triggered immunity in plants. The recognition of this protein by a plasma membrane (PM) receptor complex is the beginning of a signaling cascade that includes protein phosphorylation and the production of reactive oxygen species (ROS). In both Arabidopsis (Arabidopsis thaliana) seedlings and suspension cells, we found that treatment with flg22, a peptide corresponding to the most conserved domain of bacterial flagellin, caused a rapid and transient decrease in the level of phosphatidylinositol (PI) 4,5-bisphosphate along with a parallel increase in phosphatidic acid (PA). In suspension cells, inhibitors of either phosphoinositide-dependent phospholipases C (PLC) or diacylglycerol kinases (DGKs) inhibited flg22-triggered PA production and the oxidative burst. In response to flg22, receptor-like kinase-deficient fls2, bak1, and bik1 mutants (FLAGELLIN SENSITIVE 2, BRASSINOSTEROID INSENSITIVE 1-associated kinase 1, and BOTRYTIS-INDUCED KINASE 1, respectively) produced less PA than wild-type (WT) plants, whereas this response did not differ in NADPH oxidase-deficient rbohD (RESPIRATORY BURST OXIDASE HOMOLOG D) plants. Among the DGK-deficient lines tested, the dgk5.1 mutant produced less PA and less ROS after flg22 treatment compared with WT seedlings. In response to flg22, dgk5.1 plants showed lower callose accumulation and impaired resistance to Pseudomonas syringae pv. tomato DC3000 hrcC-. Transcriptomics revealed that the basal expression of defense-related genes was altered in dgk5.1 seedlings compared with the WT. A GFP-DGK5 fusion protein localized to the PM, where RBOHD and PLC2 (proteins involved in plant immunity) are also located. The role of DGK5 and its enzymatic activity in flagellin signaling and fine-tuning of early immune responses in plant-microbe interactions is discussed.
PMID: 35900211
BMC Biol , IF:7.431 , 2022 Nov , V20 (1) : P254 doi: 10.1186/s12915-022-01455-4
ERF49 mediates brassinosteroid regulation of heat stress tolerance in Arabidopsis thaliana.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China.; School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.; College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China.; College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.; College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China. guanghuix@snnu.edu.cn.; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China. zhusw@ibcas.ac.cn.
BACKGROUND: Heat stress is a major abiotic stress affecting the growth and development of plants, including crop species. Plants have evolved various adaptive strategies to help them survive heat stress, including maintaining membrane stability, encoding heat shock proteins (HSPs) and ROS-scavenging enzymes, and inducing molecular chaperone signaling. Brassinosteroids (BRs) are phytohormones that regulate various aspects of plant development, which have been implicated also in plant responses to heat stress, and resistance to heat in Arabidopsis thaliana is enhanced by adding exogenous BR. Brassinazole resistant 1 (BZR1), a transcription factor and positive regulator of BR signal, controls plant growth and development by directly regulating downstream target genes. However, the molecular mechanism at the basis of BR-mediated heat stress response is poorly understood. Here, we report the identification of a new factor critical for BR-regulated heat stress tolerance. RESULTS: We identified ERF49 in a genetic screen for proteins required for BR-regulated gene expression. We found that ERF49 is the direct target gene of BZR1 and that overexpressing ERF49 enhanced sensitivity of transgenic plants to heat stress. The transcription levels of heat shock factor HSFA2, heat stress-inducible gene DREB2A, and three heat shock protein (HSP) were significantly reduced under heat stress in ERF49-overexpressed transgenic plants. Transcriptional activity analysis in protoplast revealed that BZR1 inhibits ERF49 expression by binding to the promoter of ERF49. Our genetic analysis showed that dominant gain-of-function brassinazole resistant 1-1D mutant (bzr1-1D) exhibited lower sensitivity to heat stress compared with wild-type. Expressing ERF49-SRDX (a dominant repressor reporter of ERF49) in bzr1-1D significantly decreased the sensitivity of ERF49-SRDX/bzr1-1D transgenic plants to heat stress compared to bzr1-1D. CONCLUSIONS: Our data provide clear evidence that BR increases thermotolerance of plants by repressing the expression of ERF49 through BZR1, and this process is dependent on the expression of downstream heat stress-inducible genes. Taken together, our work reveals a novel molecular mechanism mediating plant response to high temperature stress.
PMID: 36357887
Plant Cell Environ , IF:7.228 , 2022 Dec , V45 (12) : P3551-3565 doi: 10.1111/pce.14441
HOP1 and HOP2 are involved in salt tolerance by facilitating the brassinosteroid-related nucleo-cytoplasmic partitioning of the HSP90-BIN2 complex.
College of Life Science, Shandong Normal University, Jinan, China.
The co-chaperone heat shock protein (HSP)70-HSP90 organizing protein (HOP) is involved in plant thermotolerance. However, its function in plant salinity tolerance was not yet studied. We found that Arabidopsis HOP1 and HOP2 play critical roles in salt tolerance by affecting the nucleo-cytoplasmic partitioning of HSP90 and brassinosteroid-insensitive 2 (BIN2). A hop1/2 double mutant was hypersensitive to salt-stress. Interestingly, this sensitivity was remedied by exogenous brassinolide application, while the application of brassinazole impeded growth of both wild-type (WT) and hop1/2 plants under normal and salt stress conditions. This suggested that the insufficient brassinosteroid (BR) content was responsible for the salt-sensitivity of hop1/2. After WT was transferred to salt stress conditions, HOP1/2, BIN2 and HSP90 accumulated in the nucleus, brassinazole-resistant 1 (BZR1) was phosphorylated and accumulated in the cytoplasm, and BR content significantly increased. This initial response resulted in dephosphorylation of BZR1 and BR response. This dynamic regulation of BR content was impeded in salt-stressed hop1/2. Thus, we propose that HOP1 and HOP2 are involved in salt tolerance by affecting BR signalling.
PMID: 36123951
J Integr Plant Biol , IF:7.061 , 2022 Oct 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 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 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. This article is protected by copyright. All rights reserved.
PMID: 36282494
J Integr Plant Biol , IF:7.061 , 2022 Oct , V64 (10) : P1883-1900 doi: 10.1111/jipb.13333
Ribonuclease H-like gene SMALL GRAIN2 regulates grain size in rice through brassinosteroid signaling pathway.
State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Nanjing National Field Scientific Observation and Research Station for Rice Germplasm, Nanjing Agricultural University, Nanjing, 210095, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Grain size is a key agronomic trait that determines the yield in plants. Regulation of grain size by brassinosteroids (BRs) in rice has been widely reported. However, the relationship between the BR signaling pathway and grain size still requires further study. Here, we isolated a rice mutant, named small grain2 (sg2), which displayed smaller grain and a semi-dwarf phenotype. The decreased grain size was caused by repressed cell expansion in spikelet hulls of the sg2 mutant. Using map-based cloning combined with a MutMap approach, we cloned SG2, which encodes a plant-specific protein with a ribonuclease H-like domain. SG2 is a positive regulator downstream of GLYCOGEN SYNTHASE KINASE2 (GSK2) in response to BR signaling, and its mutation causes insensitivity to exogenous BR treatment. Genetical and biochemical analysis showed that GSK2 interacts with and phosphorylates SG2. We further found that BRs enhance the accumulation of SG2 in the nucleus, and subcellular distribution of SG2 is regulated by GSK2 kinase activity. In addition, Oryza sativa OVATE family protein 19 (OsOFP19), a negative regulator of grain shape, interacts with SG2 and plays an antagonistic role with SG2 in controlling gene expression and grain size. Our results indicated that SG2 is a new component of GSK2-related BR signaling response and regulates grain size by interacting with OsOFP19.
PMID: 35904032
J Exp Bot , IF:6.992 , 2022 Nov doi: 10.1093/jxb/erac429
OsBSK1-1, a positive regulator of brassinosteroid signaling, 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, Shandong 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 regulates plant growth and development, thus imparting on many important agronomic traits in crops. However, there are still significant gaps in our understanding of the BR signaling pathway in rice. In this study, we collected multiple lines of evidence to indicate that OsBSK1-1 likely represents a missing component in the BR signaling 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 (OsBSK1-1 A295V) are hypersensitive to BR and exhibit some enhanced BR-responsive phenotypes. We found that OsBSK1-1 physically interacts with the BR receptor OsBRI1, and OsGSK2, a downstream component crucial for BR signaling. Moreover, we showed that OsBSK1-1 can be phosphorylated by OsBRI1 and can inhibit OsGSK2-mediated phosphorylation of OsBZR1. We further demonstrated that OsBSK1-1 genetically acts downstream of OsBRI1, but upstream of OsGSK2. Together, our results suggest that OsBSK1-1 likely serves as a scaffold protein directly bridging OsBRI1 and OsGSK2 to positively regulate BR signaling, thus affecting plant architecture and grain size in rice.
PMID: 36346128
Cells , IF:6.6 , 2022 Oct , V11 (21) doi: 10.3390/cells11213341
BRI1 and BAK1 Canonical Distribution in Plasma Membrane Is HSP90 Dependent.
Biotechnology Department, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.; Department of Plant Sciences, University of California, Davis, CA 95616, USA.; Biology Department, National and Kapodistrian University of Athens, 15701 Athens, Greece.
The activation of BRASSINOSTEROID INSENSITIVE1 (BRI1) and its association with the BRI1 ASSOCIATED RECEPTOR KINASE1 (BAK1) are key steps for the initiation of the BR signaling cascade mediating hypocotyl elongation. Heat shock protein 90 (HSP90) is crucial in the regulation of signaling processes and the activation of hormonal receptors. We report that HSP90 is required for the maintenance of the BRI1 receptor at the plasma membrane (PM) and its association with the BAK1 co-receptor during BL-ligand stimulation. HSP90 mediates BR perception and signal transduction through physical interactions with BRI1 and BAK1, while chaperone depletion resulted in lower levels of BRI1 and BAK1 receptors at the PM and affected the spatial partitioning and organization of BRI1/BAK1 heterocomplexes at the PM. The BRI1/BAK1 interaction relies on the HSP90-dependent activation of the kinase domain of BRI1 which leads to the confinement of the spatial dynamics of the membrane resident BRI1 and the attenuation of the downstream signaling. This is evident by the impaired activation and transcriptional activity of BRI1 EMS SUPPRESSOR 1 (BES1) upon HSP90 depletion. Our findings provide conclusive evidence that further expands the commitment of HSP90 in BR signaling through the HSP90-mediated activation of BRI1 in the control of the BR signaling cascade in plants.
PMID: 36359737
Plant J , IF:6.417 , 2022 Nov , V112 (4) : P946-965 doi: 10.1111/tpj.15980
The Arabidopsis TETRATRICOPEPTIDE-REPEAT THIOREDOXIN-LIKE (TTL) family members are involved in root system formation via their interaction with cytoskeleton and cell wall remodeling.
Department of Experimental Plant Biology, Faculty of Science, Charles University, Vinicna 5, 128 44, Prague 2, Czech Republic.; Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico (UNAM), Av. Universidad, 2001, Cuernavaca, 62250, Morelos, Mexico.; Group of Reproductive Development and Apomixis, UGA Laboratorio Nacional de Genomica para la Biodiversidad, CINVESTAV Irapuato, Guanajuato, 36821, Mexico.
Lateral roots (LR) are essential components of the plant edaphic interface; contributing to water and nutrient uptake, biotic and abiotic interactions, stress survival, and plant anchorage. We have identified the TETRATRICOPEPTIDE-REPEAT THIOREDOXIN-LIKE 3 (TTL3) gene as being related to LR emergence and later development. Loss of function of TTL3 leads to a reduced number of emerged LR due to delayed development of lateral root primordia (LRP). This trait is further enhanced in the triple mutant ttl1ttl3ttl4. TTL3 interacts with microtubules and endomembranes, and is known to participate in the brassinosteroid (BR) signaling pathway. Both ttl3 and ttl1ttl3ttl4 mutants are less sensitive to BR treatment in terms of LR formation and primary root growth. The ability of TTL3 to modulate biophysical properties of the cell wall was established under restrictive conditions of hyperosmotic stress and loss of root growth recovery, which was enhanced in ttl1ttl3ttl4. Timing and spatial distribution of TTL3 expression is consistent with its role in development of LRP before their emergence and subsequent growth of LR. TTL3 emerged as a component of the root system morphogenesis regulatory network.
PMID: 36270031
Plant J , IF:6.417 , 2022 Oct , V112 (2) : P493-517 doi: 10.1111/tpj.15961
Transcriptional responses to gibberellin in the maize tassel and control by DELLA domain proteins.
USDA, Agriculture Research Service, Plant Genetics Research Unit, Columbia, Missouri, 65211, USA.; Department of Biochemistry, Purdue University; West Lafayette, Indiana, 47907, USA.; Center for Plant Biology, Purdue University, West Lafayette, Indiana, 47907, USA.
The plant hormone gibberellin (GA) impacts plant growth and development differently depending on the developmental context. In the maize (Zea mays) tassel, application of GA alters floral development, resulting in the persistence of pistils. GA signaling is achieved by the GA-dependent turnover of DELLA domain transcription factors, encoded by dwarf8 (d8) and dwarf9 (d9) in maize. The D8-Mpl and D9-1 alleles disrupt GA signaling, resulting in short plants and normal tassel floret development in the presence of excess GA. However, D9-1 mutants are unable to block GA-induced pistil development. Gene expression in developing tassels of D8-Mpl and D9-1 mutants and their wild-type siblings was determined upon excess GA(3) and mock treatments. Using GA-sensitive transcripts as reporters of GA signaling, we identified a weak loss of repression under mock conditions in both mutants, with the effect in D9-1 being greater. D9-1 was also less able to repress GA signaling in the presence of excess GA(3) . We treated a diverse set of maize inbred lines with excess GA(3) and measured the phenotypic consequences on multiple aspects of development (e.g., height and pistil persistence in tassel florets). Genotype affected all GA-regulated phenotypes but there was no correlation between any of the GA-affected phenotypes, indicating that the complexity of the relationship between GA and development extends beyond the two-gene epistasis previously demonstrated for GA and brassinosteroid biosynthetic mutants.
PMID: 36050832
Plant J , IF:6.417 , 2022 Oct , V112 (2) : P476-492 doi: 10.1111/tpj.15960
Bioenergy sorghum stem growth regulation: intercalary meristem localization, development, and gene regulatory network analysis.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77843-2128, USA.; ABQMR, Inc., 2301 Yale Blvd. SE, Suite C2, Albuquerque, New Mexico, 87106, USA.; Department of Plant Biology, University of Illinois, Champaign-Urbana, Illinois, 61801, USA.
Bioenergy sorghum is a highly productive drought tolerant C(4) grass that accumulates 80% of its harvestable biomass in approximately 4 m length stems. Stem internode growth is regulated by development, shading, and hormones that modulate cell proliferation in intercalary meristems (IMs). In this study, sorghum stem IMs were localized above the pulvinus at the base of elongating internodes using magnetic resonance imaging, microscopy, and transcriptome analysis. A change in cell morphology/organization occurred at the junction between the pulvinus and internode where LATERAL ORGAN BOUNDARIES (SbLOB), a boundary layer gene, was expressed. Inactivation of an AGCVIII kinase in DDYM (dw2) resulted in decreased SbLOB expression, disrupted IM localization, and reduced internode cell proliferation. Transcriptome analysis identified approximately 1000 genes involved in cell proliferation, hormone signaling, and other functions selectively upregulated in the IM compared with a non-meristematic stem tissue. This cohort of genes is expressed in apical dome stem tissues before localization of the IM at the base of elongating internodes. Gene regulatory network analysis identified connections between genes involved in hormone signaling and cell proliferation. The results indicate that gibberellic acid induces accumulation of growth regulatory factors (GRFs) known to interact with ANGUSTIFOLIA (SbAN3), a master regulator of cell proliferation. GRF:AN3 was predicted to induce SbARF3/ETT expression and regulate SbAN3 expression in an auxin-dependent manner. GRFs and ARFs regulate genes involved in cytokinin and brassinosteroid signaling and cell proliferation. The results provide a molecular framework for understanding how hormone signaling regulates the expression of genes involved in cell proliferation in the stem IM.
PMID: 36038985
Ecotoxicol Environ Saf , IF:6.291 , 2022 Nov , V248 : P114298 doi: 10.1016/j.ecoenv.2022.114298
Exogenous 24-epibrassinolide boosts plant growth under alkaline stress from physiological and transcriptomic perspectives: The case of broomcorn millet (Panicum miliaceum L.).
College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: maqian1994@nwafu.edu.cn.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: weg2990762254@163.com.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: 2018050099@nwafu.edu.cn.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: yuanyuhao@nwsuaf.edu.cn.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: xzlfengyu@nwafu.edu.cn.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: ljjzl2014@163.com.; Shaanxi Provincial Research Academy of Environmental Sciences, Xi'an 710000, Shaanxi, PR China. Electronic address: zhaolin_1204@163.com.; College of Agronomy, State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A & F University, Yangling 712100, Shaanxi, PR China. Electronic address: fengbaili@nwafu.edu.cn.
Land alkalization is an abiotic stress that affects global sustainable agricultural development and the balance of natural ecosystems. In this study, two broomcorn millet cultivars, T289 (alkaline-tolerant) and S223 (alkaline-sensitive), were selected to investigate the response of broomcorn millet to alkaline stress and the role of brassinolide (BR) in alkaline tolerance. Phenotypes, physiologies, and transcriptomes of T289 and S223 plants under only alkaline stress (AS) and alkaline stress with BR (AB) were compared. The results showed that alkaline stress inhibited growth, promoted the accumulation of soluble sugars and malondialdehyde, enhanced electrolyte leakage, and destroyed the integrity of broomcorn millet stomata. In contrast, BR lessened the negative effects of alkaline stress on plants. Transcriptome sequencing analysis showed that relative to control groups (CK, nutrient solution), in AS groups, 21,113 and 12,151 differentially expressed genes (DEGs) were identified in S223 and T289, respectively. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed various terms and pathways related to metabolism. Compared to S223, alkaline stress strongly activated the brassinosteroid biosynthesis pathway in T289. Conversely, ARF, TF, and TCH4, associated with cell growth and elongation, were inhibited by alkaline stress in S223. Moreover, alkaline stress induced the activation of the mitogen-activated protein kinase (MAPK) pathway, the abscisic acid signaling pathway that initiates stomatal closure, as well as the starch and sucrose metabolism. The EG and BGL genes, which are associated with cellulose degradation, were notably activated. BR enhanced alkaline tolerance, thereby alleviating the transcriptional responses of the two cultivars. Cultivar T289 is better in alkalized regions. Taken together, these results reveal how broomcorn millet responds to alkaline stress and BR mitigates alkaline stress, thus promoting agriculture in alkalized regions.
PMID: 36403299
Front Plant Sci , IF:5.753 , 2022 , V13 : P1061196 doi: 10.3389/fpls.2022.1061196
Genome-wide association study reveals a GLYCOGEN SYNTHASE KINASE 3 gene regulating plant height in Brassica napus.
Key Laboratory of Biology and Genetic Improvement of Oil Crops, The Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, Hubei, China.; Biosystematics Group, Wageningen University and Research, Wageningen, Netherlands.; Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), School of Forestry, Hainan University, Haikou, China.; Guizhou Rapeseed Institute, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou, China.
Rapeseed (Brassica napus) is an allotetraploid crop that is the main source of edible oils and feed proteins in the world. The ideal plant architecture breeding is a major objective of rapeseed breeding and determining the appropriate plant height is a key element of the ideal plant architecture. Therefore, this study aims to improve the understanding of the genetic controls underlying plant height. The plant heights of 230 rapeseed accessions collected worldwide were investigated in field experiments over two consecutive years in Wuhan, China. Whole-genome resequencing of these accessions yielded a total of 1,707,194 informative single nucleotide polymorphisms (SNPs) that were used for genome-wide association analysis (GWAS). GWAS and haplotype analysis showed that BnaA01g09530D, which encodes BRASSINOSTEROID-INSENSITIVE 2 and belongs to the GLYCOGEN SYNTHASE KINASE 3 (GSK3) family, was significantly associated with plant height in B. napus. Moreover, a total of 31 BnGSK3s with complete domains were identified from B. napus genome and clustered into four groups according to phylogenetic analysis, gene structure, and motif distribution. The expression patterns showed that BnGSK3s exhibited significant differences in 13 developmental tissues in B. napus, suggesting that BnGSK3s may be involved in tissue-specific development. Sixteen BnGSK3 genes were highly expressed the in shoot apical meristem, which may be related to plant height or architecture development. These results are important for providing new haplotypes of plant height in B. napus and for extending valuable genetic information for rapeseed genetic improvement of plant architecture.
PMID: 36407634
Front Plant Sci , IF:5.753 , 2022 , V13 : P1022961 doi: 10.3389/fpls.2022.1022961
Transcriptome and metabolome analyses of Shatian pomelo (Citrus grandis var. Shatinyu Hort) leaves provide insights into the overexpression of the gibberellin-induced gene CcGASA4.
Life Science and Technology School, Lingnan Normal University, Zhanjiang, China.; Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, China.; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA), Guangzhou, China.; Key Laboratory of Tropical and Subtropical of Fruit Tree Research, Science and Technology Department of Guangdong Province, Guangzhou, China.
The gibberellic acid (GA)-stimulated Arabidopsis (GASA) gene family is highly specific to plants and plays crucial roles in plant growth and development. CcGASA4 is a member of the GASA gene family in citrus plants; however, the current understanding of its function in citrus is limited. We used CcGASA4-overexpression transgenic citrus (OEGA) and control (CON) plants to study the role of CcGASA4 in Shatian pomelo. The RNA sequencing (RNA-seq) analysis showed that 3,522 genes, including 1,578 upregulated and 1,944 downregulated genes, were significantly differentially expressed in the CON versus OEGA groups. The Gene Ontology enrichment analysis showed that 178 of the differentially-expressed genes (DEGs) were associated with flowers. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the DEGs were enriched in 134 pathways, including "plant-pathogen interaction", "MAPK signaling pathway-plant", "phenylpropane biosynthesis", "plant hormone signal transduction", "phenylalanine, tyrosine and tryptophan biosynthesis", and "flavonoid and flavonol biosynthesis". The most significantly-enriched pathway was "plant-pathogen interaction", in which 203 DEGs were enriched (126 DEGs were upregulated and 78 were downregulated). The metabolome analysis showed that 644 metabolites were detected in the OEGA and CON samples, including 294 differentially-accumulated metabolites (DAMs; 83 upregulated versus 211 downregulated in OEGA compared to CON). The metabolic pathway analysis showed that these DAMs were mainly involved in the metabolic pathways of secondary metabolites, such as phenylpropanoids, phenylalanine, flavone, and flavonol biosynthesis. Thirteen flavonoids and isoflavones were identified as DAMs in OEGA and CON. We also discovered 25 OEGA-specific accumulated metabolites and found 10 that were associated with disease resistance. CcGASA4 may therefore play a functional role in activating the expression of MAPK signaling transduction pathway and disease resistance genes, inhibiting the expression of auxin- and ethylene-related genes, and activating or inhibiting the expression of brassinosteroid biosynthesis- and abscisic acid-related genes. CcGASA4 may also play a role in regulating the composition and abundance of flavonoids, isoflavones, amino acids, purines, and phenolic compounds. This study provides new insights into the molecular mechanisms of action of CcGASA4 in citrus plants.
PMID: 36407630
Front Plant Sci , IF:5.753 , 2022 , V13 : P965069 doi: 10.3389/fpls.2022.965069
A novel small open reading frame gene, IbEGF, enhances drought tolerance in transgenic sweet potato.
Key Laboratory of Sweetpotato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/ Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing, China.
Small open reading frames (sORFs) can encode functional polypeptides or act as cis-translational regulators in stress responses in eukaryotes. Their number and potential importance have only recently become clear in plants. In this study, we identified a novel sORF gene in sweet potato, IbEGF, which encoded the 83-amino acid polypeptide containing an EGF_CA domain. The expression of IbEGF was induced by PEG6000, H(2)O(2), abscisic acid (ABA), methyl-jasmonate (MeJA) and brassinosteroid (BR). The IbEGF protein was localized to the nucleus and cell membrane. Under drought stress, overexpression of IbEGF enhanced drought tolerance, promoted the accumulation of ABA, MeJA, BR and proline and upregulated the genes encoding superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in transgenic sweet potato. The IbEGF protein was found to interact with IbCOP9-5alpha, a regulator in the phytohormone signalling pathways. These results suggest that IbEGF interacting with IbCOP9-5alpha enhances drought tolerance by regulating phytohormone signalling pathways, increasing proline accumulation and further activating reactive oxygen species (ROS) scavenging system in transgenic sweet potato.
PMID: 36388596
Front Plant Sci , IF:5.753 , 2022 , V13 : P961680 doi: 10.3389/fpls.2022.961680
Brassinosteroids induced drought resistance of contrasting drought-responsive genotypes of maize at physiological and transcriptomic levels.
Gansu Provincial Key Lab of Arid Land Crop Science, College of Agronomy, Lanzhou, China.; College of Agronomy, Hunan Agricultural University, Changsha, China.; Crop Breeding Department, Jilin Changfa Modern Agricultural Science and Technology Group, co., Ltd., Changchun, China.; College of Plant Protection, Gansu Agricultural University, Lanzhou, China.; Department of Environmental Sciences, Kohsar University, Murree, Pakistan.; Institute of Botany, University of the Punjab, Lahore, Pakistan.; Department of Botany, Division of Science and Technology, University of Education, Lahore, Pakistan.
The present study investigated the brassinosteroid-induced drought resistance of contrasting drought-responsive maize genotypes at physiological and transcriptomic levels. The brassinosteroid (BR) contents along with different morphology characteristics, viz., plant height (PH), shoot dry weight (SDW), root dry weight (RDW), number of leaves (NL), the specific mass of the fourth leaf, and antioxidant activities, were investigated in two maize lines that differed in their degree of drought tolerance. In response to either control, drought, or brassinosteroid treatments, the KEGG enrichment analysis showed that plant hormonal signal transduction and starch and sucrose metabolism were augmented in both lines. In contrast, the phenylpropanoid biosynthesis was augmented in lines H21L0R1 and 478. Our results demonstrate drought-responsive molecular mechanisms and provide valuable information regarding candidate gene resources for drought improvement in maize crop. The differences observed for BR content among the maize lines were correlated with their degree of drought tolerance, as the highly tolerant genotype showed higher BR content under drought stress.
PMID: 36388543
Front Plant Sci , IF:5.753 , 2022 , V13 : P1010470 doi: 10.3389/fpls.2022.1010470
BcGRP23: A novel gene involved in the chlorophyll metabolic pathway that is activated by BES1 in flowering Chinese cabbage.
College of Horticulture, South China Agricultural University, Guangzhou, China.; Institute of Vegetables, Shandong Academy of Agricultural Sciences, Jinan, China.
Glycine-rich proteins (GRPs) are a large family of proteins that play vital roles in cell wall remodeling, metabolism and development, and abiotic stress response. Although the functions of GRPs in cell wall remodeling have been extensively characterized, only a few studies have explored their effects on chlorophyll metabolism and hormone response. Accordingly, we aimed to determine the molecular mechanism of BcGRP23 and its role in chlorophyll metabolism and the BRI1-EMS-SUPPRESSOR 1 (BES1) signaling pathway in flowering Chinese cabbage. The expression levels of BcGRP23 in the leaves and stems gradually decreased with increasing growth and development of flowering Chinese cabbage, while BcGRP23 was barely expressed after flowering. As plant growth continued, the GUS (beta-glucuronidase) stain gradually became lighter in hypocotyls and was largely free of growth points. The petioles and stems of BcGRP23-silenced plants lost their green color, and the contents of chlorophyll a (Chl a) and Chl b were significantly reduced. Further research revealed that the expression levels of chlorophyll degradation-related genes were significantly increased in silenced plants compared with the control; however, the opposite was noted for the BcGRP23-overexpressing lines. The BcGRP23 promoter sequence contains numerous hormone-responsive elements. In fact, the expression of BcGRP23 was upregulated in flowering Chinese cabbage following treatment with the hormones indole-3-acetic acid (IAA), gibberellin (GA), 6-benzylaminopurine (6-BA), methyl jasmonate (MeJA), and brassinosteroid (BR). Treatment with BR led to the most significant upregulation. BES1, in response to BRs, directly activated the BcGRP23 promoter. Overall, BcGRP23 regulated the expression of chlorophyll degradation-related genes, thereby affecting the chlorophyll content. Furthermore, the expression of BcGRP23 was significantly regulated by exogenous BR application and was directly activated by BES1. These findings preliminarily suggest the molecular mechanism and regulatory pathway of BcGRP23 in the growth and development of flowering Chinese cabbage plants and their response to environmental stress.
PMID: 36352860
Front Plant Sci , IF:5.753 , 2022 , V13 : P1012741 doi: 10.3389/fpls.2022.1012741
Molecular and physiologic mechanisms of advanced ripening by trunk girdling at early veraison of 'Summer Black' grape.
College of Life Science, Leshan Normal University, Leshan, China.; Institution of Biodiversity Conservation and Utilization in Mount Emei, Leshan Normal University, Leshan, China.; Justices, Equity, Diversity, and Inclusion Department, California Association of Resource Conservation Districts, Folsom, CA, United States.; Academy of Mount Emei, Leshan Normal University, Leshan, China.; Research Institution of Industrial Crop, Leshan Academy of Agricultural Sciences, Leshan, China.
Although the effects of girdling on grape berry development have been widely studied, the underlying mechanisms are poorly understood, especially at the molecular level. This study investigated the effect of trunk girdling on grape (Vitis L.) berry maturation. Girdling was performed on 5-year-old 'Summer Black' grapevines at early veraison, and transcriptional and physiologic analyses were performed. Trunk girdling promoted sugar accumulation and color development in berries and accelerated berry ripening by 25 days. Genes related to sucrose cleavage and polysaccharide degradation were upregulated at the transcriptional level, which was associated with increased monosaccharide accumulation and berry softening. Anthocyanin biosynthesis and accumulation were also enhanced by trunk girdling through the upregulation of anthocyanin biosynthesis genes including phenylalanine ammonia-lyase and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT). The increased expression of two VvUFGT genes was accompanied by the upregulation of VvMYBA2 under girdling. The upregulation of genes involved in ethylene biosynthesis and hormone (abscisic acid and brassinosteroid) responses and downregulation of genes involved in indoleacetic acid biosynthesis and response may have also promoted berry ripening in the girdling group. A total of 120 differentially expressed transcription factor genes from 29 gene families including MYB, ERF, and MYB-related were identified in the girdling group, which may participate in the regulation of berry development and ripening. These results provide molecular-level insight into the positive effects of trunk girdling on berry development in grapes.
PMID: 36330263
Front Plant Sci , IF:5.753 , 2022 , V13 : P995815 doi: 10.3389/fpls.2022.995815
Morphological characterization and transcriptome analysis of leaf angle mutant bhlh112 in maize [Zea mays L.].
College of Agronomy, Gansu Agricultural University, Lanzhou, China.; Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, China.; Gansu Key Laboratory of Crop Improvement & Germplasm Enhancement, Gansu Agricultural University, Lanzhou, China.
Leaf angle is an important agronomic trait in maize [Zea mays L.]. The compact plant phenotype, with a smaller leaf angle, is suited for high-density planting and thus for increasing crop yields. Here, we studied the ethyl methane sulfonate (EMS)-induced mutant bhlh112. Leaf angle and plant height were significantly decreased in bhlh112 compared to the wild-type plants. After treatment of seedlings with exogenous IAA and ABA respectively, under the optimal concentration of exogenous hormones, the variation of leaf angle of the mutant was more obvious than that of the wild-type, which indicated that the mutant was more sensitive to exogenous hormones. Transcriptome analysis showed that the ZmbHLH112 gene was related to the biosynthesis of auxin and brassinosteroids, and involved in the activation of genes related to the auxin and brassinosteroid signal pathways as well as cell elongation. Among the GO enrichment terms, we found many differentially expressed genes (DEGs) enriched in the cell membrane and ribosomal biosynthesis, hormone biosynthesis and signaling pathways, and flavonoid biosynthesis, which could influence cell growth and the level of endogenous hormones affecting leaf angle. Therefore, ZmbHLH112 might regulate leaf angle development through the auxin signaling and the brassinosteroid biosynthesis pathways. 12 genes related to the development of leaf were screened by WGCNA; In GO enrichment and KEGG pathways, the genes were mainly enriched in rRNA binding, ribosome biogenesis, Structural constituent of ribosome; Arabidopsis ribosome RNA methyltransferase CMAL is involved in plant development, likely by modulating auxin derived signaling pathways; The free 60s ribosomes and polysomes in the functional defective mutant rice minute-like1 (rml1) were significantly reduced, resulting in plant phenotypic diminution, narrow leaves, and growth retardation; Hence, ribosomal subunits may play an important role in leaf development. These results provide a foundation for further elucidation of the molecular mechanism of the regulation of leaf angle in maize.
PMID: 36275532
Front Plant Sci , IF:5.753 , 2022 , V13 : P979033 doi: 10.3389/fpls.2022.979033
OsARF4 regulates leaf inclination via auxin and brassinosteroid pathways in rice.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.; Hainan Yazhou Bay Seed Laboratory, Sanya, China.; Key Laboratory of Herbage and Endemic Crop Biology of Ministry of Education, Inner Mongolia Key Laboratory of Herbage and Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot, China.
Leaf inclination is a vital agronomic trait and is important for plant architecture that affects photosynthetic efficiency and grain yield. To understand the molecular mechanisms underlying regulation of leaf inclination, we constructed an auxin response factor (arf) rice mutant-osarf4-showing increased leaf inclination using CRISPR/Cas9 gene editing technology. OsARF4 encodes a nuclear protein that is expressed in the lamina joint (LJ) at different developmental stages in rice. Histological analysis indicated that an increase in cell differentiation on the adaxial side resulted in increased leaf inclination in the osarf4 mutants; however, OsARF4-overexpressing lines showed a decrease in leaf inclination, resulting in erect leaves. Additionally, a decrease in the content and distribution of indole-3-acetic acid (IAA) in osarf4 mutant led to a greater leaf inclination, whereas the OsARF4-overexpressing lines showed the opposite phenotype with increased IAA content. RNA-sequencing analysis revealed that the expression of genes related to brassinosteroid (BR) biosynthesis and response was different in the mutants and overexpressing lines, suggesting that OsARF4 participates in the BR signaling pathway. Moreover, BR sensitivity assay revealed that OsARF4-overexpressing lines were more sensitive to exogenous BR treatment than the mutants. In conclusion, OsARF4, a transcription factor in auxin signaling, participates in leaf inclination regulation and links auxin and BR signaling pathways. Our results provide a novel insight into l leaf inclination regulation, and have significant implications for improving rice architecture and grain yield.
PMID: 36247537
Front Microbiol , IF:5.64 , 2022 , V13 : P996054 doi: 10.3389/fmicb.2022.996054
A novel PGPF Penicillium olsonii isolated from the rhizosphere of Aeluropus littoralis promotes plant growth, enhances salt stress tolerance, and reduces chemical fertilizers inputs in hydroponic system.
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.; Department of Plant Production, College of Food and Agricultural Science, King Saud University, Riyadh, Saudi Arabia.; Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Sciences of Sfax, University of Sfax, Sfax, Tunisia.; Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia.
The hydroponic farming significantly enhances the yield and enables multiple cropping per year. These advantages can be improved by using plant growth-promoting fungi (PGPF) either under normal or stress conditions. In this study, the fungal strain (A3) isolated from the rhizosphere of the halophyte plant Aeluropus littoralis was identified as Penicillium olsonii based on sequence homology of its ITS region. The A3 fungus was shown to be halotolerant (up to 1 M NaCl) and its optimal growth was at 27 degrees C, but inhibited at 40 degrees C. In liquid culture medium, the A3 produced indole acetic acid (IAA) especially in the presence of L-tryptophan. Tobacco plants grown under hydroponic farming system were used to evaluate the promoting activity of the direct effect of A3 mycelium (DE) and the indirect effect (IDE) of its cell-free culture filtrate (A3CFF). The results showed that for the two conditions (DE or IDE) the tobacco seedlings exhibited significant increase in their height, leaf area, dry weight, and total chlorophyll content. Interestingly, the A3CFF (added to the MS liquid medium or to nutrient solution (NS), prepared from commercial fertilizers) induced significantly the growth parameters, the proline concentration, the catalase (CAT) and the superoxide dismutase (SOD) activities of tobacco plants. The A3CFF maintained its activity even after extended storage at 4 degrees C for 1 year. Since the A3 is a halotolerant fungus, we tested its ability to alleviate salt stress effects. Indeed, when added at 1:50 dilution factor to NS in the presence of 250 mM NaCl, the A3CFF enhanced the plant salt tolerance by increasing the levels of total chlorophyll, proline, CAT, and SOD activities. In addition, the treated plants accumulated less Na(+) in their roots but more K(+) in their leaves. The A3CFF was also found to induce the expression of five salt stress related genes (NtSOS1, NtNHX1, NtHKT1, NtSOD, and NtCAT1). Finally, we proved that the A3CFF can reduce by half the chemical fertilizers inputs. Indeed, the tobacco plants grown in a hydroponic system using 0.5xNS supplemented with A3CFF (1:50) exhibited significantly higher growth than those grown in 0.5xNS or 1xNS. In an attempt to explain this mechanism, the expression profile of some growth related genes (nitrogen metabolism (NR1, NRT1), auxin (TRYP1, YUCCA6-like), and brassinosteroid (DET2, DWF4) biosynthesis) was performed. The results showed that all these genes were up-regulated following plant treatment with A3CFF. In summary the results revealed that the halotolerant fungus P. olsonii can stimulates tobacco plant growth, enhances its salt tolerance, and reduces by half the required chemical fertilizer inputs in a hydroponic farming system.
PMID: 36386667
Plant Cell Physiol , IF:4.927 , 2022 Oct 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, Pohang, 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, Vietnam.; Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, 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 crosstalk 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 crosstalk among multiple phytohormones to determine the yield traits.
PMID: 36255097
Plant Sci , IF:4.729 , 2022 Dec , V325 : P111482 doi: 10.1016/j.plantsci.2022.111482
OsCPD1 and OsCPD2 are functional brassinosteroid biosynthesis genes in rice.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: hdzhan@njau.edu.cn.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; College of Life Science, Nanjing Agricultural University, Nanjing 210095, China.
CONSTITUTIVE PHOTOMORPHOGENIC DWARF (CPD), member of the CYP90A family of cytochrome P450 (CYP450) monooxygenase, is an essential component of brassinosteroids (BRs) biosynthesis pathway. Compared with a single CPD/CYP90A1 in Arabidopsis thaliana, two highly homologous CPD genes, OsCPD1/CYP90A3 and OsCPD2/CYP90A4, are present in rice genome. There is still no genetic evidence so far about the requirement of OsCPD1 and OsCPD2 in rice BR biosynthesis. In this study, we reported the functional characterization of OsCPD genes using CRISPR/Cas9 gene editing technology. The overall growth and development of oscpd1 and oscpd2 single knock-out mutants was indistinguishable from the wild-type, whereas, the oscpd1 oscpd2 double mutant displayed multiple and obvious BR-related defects. Cytological analyses further indicated the defective cell elongation in oscpd1 oscpd2 double mutant. The oscpd double mutants had a lower endogenous BR level and could be restored by the application of the brassinolide (BL). Moreover, overexpression of OsCPD1 and OsCPD2 led to a typical BR enhanced phenotype, with enlarged leaf angle and increased grain size. Taken together, our results provide direct genetic evidence that OsCPD1 and OsCPD2 play essential and redundant roles in maintenance of plant architecture by modulating BR biosynthesis in rice.
PMID: 36191635
Plant Physiol Biochem , IF:4.27 , 2022 Dec , V193 : P78-89 doi: 10.1016/j.plaphy.2022.10.029
Transcriptome analysis reveals genes potentially related to maize resistance to Rhizoctonia solani.
State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai an, 271018, China.; State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai an, 271018, China. Electronic address: nli@sdau.edu.cn.
Banded leaf and sheath blight (BLSB) is a devasting disease caused by the necrotrophic fungus Rhizoctonia solani that affects maize (Zea mays L.) fields worldwide, especially in China and Southeast Asia. Understanding how maize plants respond to R. solani infection is a key step towards controlling the spread of this fungal pathogen. In this study, we determined the transcriptome of maize plants infected by a low-virulence strain (LVS) and a high-virulence strain (HVS) of R. solani for 3 and 5 days by transcriptome deep-sequencing (RNA-seq). We identified 3,015 (for LVS infection) and 1,628 (for HVS infection) differentially expressed genes (DEGs). We confirmed the expression profiles of 10 randomly selected DEGs by quantitative reverse transcription PCR. We also performed a Gene Ontology (GO) enrichment analysis to establish which biological processes are associated with these DEGs, which revealed the enrichment of defense-related GO terms in LVS- and HVS-regulated genes. We selected 388 DEGs upregulated upon fungal infection as possible candidate genes. Among them, the overexpression of ZmNAC41 (encoding NAC transcription factor 41) or ZmBAK1 (encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1) in rice enhanced resistance to R. solani. In addition, overexpressing ZmBAK1 in rice also increased plant height, plant weight, thousand-grain weight, and grain length. The identification of 388 potential key maize genes related to resistance to R. solani provides significant insights into improving BLSB resistance.
PMID: 36343463
BMC Plant Biol , IF:4.215 , 2022 Nov , V22 (1) : P531 doi: 10.1186/s12870-022-03910-4
Identification of key gene networks related to the freezing resistance of apricot kernel pistils by integrating hormone phenotypes and transcriptome profiles.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.; State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. wlibing@caf.ac.cn.
BACKGROUND: Apricot kernel, a woody oil tree species, is known for the high oil content of its almond that can be used as an ideal feedstock for biodiesel production. However, apricot kernel is vulnerable to spring frost, resulting in reduced or even no yield. There are no effective countermeasures in production, and the molecular mechanisms underlying freezing resistance are not well understood. RESULTS: We used transcriptome and hormone profiles to investigate differentially responsive hormones and their associated co-expression patterns of gene networks in the pistils of two apricot kernel cultivars with different cold resistances under freezing stress. The levels of auxin (IAA and ICA), cytokinin (IP and tZ), salicylic acid (SA) and jasmonic acid (JA and ILE-JA) were regulated differently, especially IAA between two cultivars, and external application of an IAA inhibitor and SA increased the spring frost resistance of the pistils of apricot kernels. We identified one gene network containing 65 hub genes highly correlated with IAA. Among these genes, three genes in auxin signaling pathway and three genes in brassinosteroid biosynthesis were identified. Moreover, some hub genes in this network showed a strong correlation such as protein kinases (PKs)-hormone related genes (HRGs), HRGs-HRGs and PKs-Ca(2+) related genes. CONCLUSIONS: Ca(2+), brassinosteroid and some regulators (such as PKs) may be involved in an auxin-mediated freezing response of apricot kernels. These findings add to our knowledge of the freezing response of apricot kernels and may provide new ideas for frost prevention measures and high cold-resistant apricot breeding.
PMID: 36380302
Plant Mol Biol , IF:4.076 , 2022 Oct 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 , 2022 Oct , V23 (1) : P733 doi: 10.1186/s12864-022-08935-5
Full-length fruit transcriptomes of southern highbush (Vaccinium sp.) and rabbiteye (V. virgatum Ait.) blueberry.
Department of Horticulture, University of Georgia, 1111 Miller Plant Sciences Building, 120 Carlton Street, Athens, GA, 30602, USA.; Center for Applied Genetic Technologies, University of Georgia, 111 Riverbend Road, Athens, GA, 30602, USA.; Department of Horticulture, University of Georgia, 1111 Miller Plant Sciences Building, 120 Carlton Street, Athens, GA, 30602, USA. sunamb@uga.edu.
BACKGROUND: Blueberries (Vaccinium sp.) are native to North America and breeding efforts to improve blueberry fruit quality are focused on improving traits such as increased firmness, enhanced flavor and greater shelf-life. Such efforts require additional genomic resources, especially in southern highbush and rabbiteye blueberries. RESULTS: We generated the first full-length fruit transcriptome for the southern highbush and rabbiteye blueberry using the cultivars, Suziblue and Powderblue, respectively. The transcriptome was generated using the Pacific Biosciences single-molecule long-read isoform sequencing platform with cDNA pooled from seven stages during fruit development and postharvest storage. Raw reads were processed through the Isoseq pipeline and full-length transcripts were mapped to the 'Draper' genome with unmapped reads collapsed using Cogent. Finally, we identified 16,299 and 15,882 non-redundant transcripts in 'Suziblue' and 'Powderblue' respectively by combining the reads mapped to Northern Highbush blueberry 'Draper' genome and Cogent analysis. In both cultivars, > 80% of sequences were longer than 1,000 nt, with the median transcript length around 1,700 nt. Functionally annotated transcripts using Blast2GO were > 92% in both 'Suziblue' and 'Powderblue' with overall equal distribution of gene ontology (GO) terms in the two cultivars. Analyses of alternative splicing events indicated that around 40% non-redundant sequences exhibited more than one isoform. Additionally, long non-coding RNAs were predicted to represent 5.6% and 7% of the transcriptomes in 'Suziblue' and 'Powderblue', respectively. Fruit ripening is regulated by several hormone-related genes and transcription factors. Among transcripts associated with phytohormone metabolism/signaling, the highest number of transcripts were related to abscisic acid (ABA) and auxin metabolism followed by those for brassinosteroid, jasmonic acid and ethylene metabolism. Among transcription factor-associated transcripts, those belonging to ripening-related APETALA2/ethylene-responsive element-binding factor (AP2/ERF), NAC (NAM, ATAF1/2 and CUC2), leucine zipper (HB-zip), basic helix-loop-helix (bHLH), MYB (v-MYB, discovered in avian myeloblastosis virus genome) and MADS-Box gene families, were abundant. Further we measured three fruit ripening quality traits and indicators [ABA, and anthocyanin concentration, and texture] during fruit development and ripening. ABA concentration increased during the initial stages of fruit ripening and then declined at the Ripe stage, whereas anthocyanin content increased during the final stages of fruit ripening in both cultivars. Fruit firmness declined during ripening in 'Powderblue'. Genes associated with the above parameters were identified using the full-length transcriptome. Transcript abundance patterns of these genes were consistent with changes in the fruit ripening and quality-related characteristics. CONCLUSIONS: A full-length, well-annotated fruit transcriptome was generated for two blueberry species commonly cultivated in the southeastern United States. The robustness of the transcriptome was verified by the identification and expression analyses of multiple fruit ripening and quality-regulating genes. The full-length transcriptome is a valuable addition to the blueberry genomic resources and will aid in further improving the annotation. It will also provide a useful resource for the investigation of molecular aspects of ripening and postharvest processes.
PMID: 36309640
Plants (Basel) , IF:3.935 , 2022 Oct , V11 (19) doi: 10.3390/plants11192630
Three-Fluorophore FRET Enables the Analysis of Ternary Protein Association in Living Plant Cells.
Center for Plant Molecular Biology (ZMBP), University of Tubingen, 72076 Tubingen, Germany.; Institute for Physical & Theoretical Chemistry, University of Tubingen, 72076 Tubingen, Germany.; Centre for Organismal Studies (COS), University of Heidelberg, 69117 Heidelberg, Germany.
Protein-protein interaction studies provide valuable insights into cellular signaling. Brassinosteroid (BR) signaling is initiated by the hormone-binding receptor Brassinosteroid Insensitive 1 (BRI1) and its co-receptor BRI1 Associated Kinase 1 (BAK1). BRI1 and BAK1 were shown to interact independently with the Receptor-Like Protein 44 (RLP44), which is implicated in BRI1/BAK1-dependent cell wall integrity perception. To demonstrate the proposed complex formation of BRI1, BAK1 and RLP44, we established three-fluorophore intensity-based spectral Forster resonance energy transfer (FRET) and FRET-fluorescence lifetime imaging microscopy (FLIM) for living plant cells. Our evidence indicates that RLP44, BRI1 and BAK1 form a ternary complex in a distinct plasma membrane nanodomain. In contrast, although the immune receptor Flagellin Sensing 2 (FLS2) also forms a heteromer with BAK1, the FLS2/BAK1 complexes are localized to other nanodomains. In conclusion, both three-fluorophore FRET approaches provide a feasible basis for studying the in vivo interaction and sub-compartmentalization of proteins in great detail.
PMID: 36235497
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
Curr Protoc , 2022 Oct , V2 (10) : Pe562 doi: 10.1002/cpz1.562
Maize Seedling Growth and Hormone Response Assays Using the Rolled Towel Method.
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa.; Current address: Corteva Agriscience, 8325 NW 62nd Ave, Johnston, Iowa.
Root system architecture is a critical factor in maize health and stress resilience. Determining the genetic and environmental factors that shape maize root system architecture is an active research area. However, the ability to phenotype juvenile root systems is hindered by the use of field-grown and soil-based systems. An alternative to soil- and field-based growing conditions for maize seedlings is a controlled environment with a soil-free medium, which can facilitate root system phenotyping. Here, we describe how to grow maize under soil-free conditions for up to 12 days to facilitate root phenotyping. Maize seeds are sterilized and planted on specialized seed germination paper to minimize fungal contamination and ensure synchronized seedling growth, followed by imaging at the desired time point. The root images are then analyzed to quantify traits of interest, such as primary root length, lateral root density, seminal root length, and seminal root number. In addition, juvenile shoot traits can be quantified using manual annotation methods. We also outline the steps for performing rigorous hormone response assays for four classical phytohormones: auxin, brassinosteroid, cytokinin, and jasmonic acid. This protocol can be rapidly scaled up and is compatible with genetic screens and sample collection for downstream molecular analyses such as transcriptomics and proteomics. (c) 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Maize seedling rolled towel assay and phenotyping Basic Protocol 2: Maize seedling hormone response assays using the rolled towel assay.
PMID: 36194012
Plant Commun , 2022 Nov , V3 (6) : P100419 doi: 10.1016/j.xplc.2022.100419
Brassinosteroids promote thermotolerance through releasing BIN2-mediated phosphorylation and suppression of HsfA1 transcription factors in Arabidopsis.
College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China. Electronic address: xueluw@henu.edu.cn.
High temperature adversely affects plant growth and development. The steroid phytohormones brassinosteroids (BRs) are recognized to play important roles in plant heat stress responses and thermotolerance, but the underlying mechanisms remain obscure. Here, we demonstrate that the glycogen synthase kinase 3 (GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2 (BIN2), a negative component in the BR signaling pathway, interacts with the master heat-responsive transcription factors CLASS A1 HEAT SHOCK TRANSCRIPTION FACTORS (HsfA1s). Furthermore, BIN2 phosphorylates HsfA1d on T263 and S56 to suppress its nuclear localization and inhibit its DNA-binding ability, respectively. BR signaling promotes plant thermotolerance by releasing the BIN2 suppression of HsfA1d to facilitate its nuclear localization and DNA binding. Our study provides insights into the molecular mechanisms by which BRs promote plant thermotolerance by strongly regulating HsfA1d through BIN2 and suggests potential ways to improve crop yield under extreme high temperatures.
PMID: 35927943