Plant Cell , IF:11.277 , 2022 Mar doi: 10.1093/plcell/koac092
The photomorphogenic repressors BBX28 and BBX29 integrate light and brassinosteroid signaling to inhibit seedling development in Arabidopsis.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.; Institute of Plant and Food Sciences, Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China.; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing 100871, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100039, China.; State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.; School of Life Sciences, Guangzhou University, Guangzhou 510006, China.
B-box containing proteins (BBXs) integrate light and various hormonal signals to regulate plant growth and development. Here, we demonstrate that the photomorphogenic repressors BBX28 and BBX29 positively regulate brassinosteroid (BR) signaling in Arabidopsis thaliana seedlings. Treatment with the BR brassinolide stabilized BBX28 and BBX29, which partially depended on BR INSENSITIVE1 (BRI1) and BR-INSENSITIVE2 (BIN2). bbx28 bbx29 seedlings exhibited larger cotyledon aperture than the wild type when treated with brassinazole in the dark, which partially suppressed the closed cotyledons of brassinazole resistant 1-1D (bzr1-1D). Consistently, overexpressing BBX28 and BBX29 partially rescued the short hypocotyls of bri1-5 and bin2-1 in both the dark and light, while the loss-of-function of BBX28 and BBX29 partially suppressed the long hypocotyls of bzr1-1D in the light. BBX28 and BBX29 physically interacted with BR-ENHANCED EXPRESSION1 (BEE1), BEE2, and BEE3 and enhanced their binding to and activation of their target genes. Moreover, BBX28 and BBX29 as well as BEE1, BEE2, and BEE3 increased BZR1 accumulation to promote the BR signaling pathway. Therefore, both BBX28 and BBX29 interact with BEE1, BEE2, and BEE3 to orchestrate light and BR signaling by facilitating the transcriptional activity of BEE target genes. Our study provides insights into the pivotal roles of BBX28 and BBX29 as signal integrators in ensuring normal seedling development.
PMID: 35294019
Plant Cell , IF:11.277 , 2022 Apr , V34 (5) : P1768-1783 doi: 10.1093/plcell/koac027
BRASSINOSTEROID-SIGNALING KINASE1 modulates MAP KINASE15 phosphorylation to confer powdery mildew resistance in Arabidopsis.
State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Fujian Provincial Key Laboratory of Crop Breeding by Design, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Perception of pathogen-associated molecular patterns (PAMPs) by plant cell surface-localized pattern-recognition receptors (PRRs) triggers the first line of plant innate immunity. In Arabidopsis thaliana, the receptor-like cytoplasmic kinase BRASSINOSTEROID-SIGNALING KINASE1 (BSK1) physically associates with PRR FLAGELLIN SENSING2 and plays an important role in defense against multiple pathogens. However, how BSK1 transduces signals to activate downstream immune responses remains elusive. Previously, through whole-genome phosphorylation analysis using mass spectrometry, we showed that phosphorylation of the mitogen-activated protein kinase (MAPK) MPK15 was affected in the bsk1 mutant compared with the wild-type plants. Here, we demonstrated that MPK15 is important for powdery mildew fungal resistance. PAMPs and fungal pathogens significantly induced the phosphorylation of MPK15 Ser-511, a key phosphorylation site critical for the functions of MPK15 in powdery mildew resistance. BSK1 physically associates with MPK15 and is required for basal and pathogen-induced MPK15 Ser-511 phosphorylation, which contributes to BSK1-mediated fungal resistance. Taken together, our data identified MPK15 as a player in plant defense against powdery mildew fungi and showed that BSK1 promotes fungal resistance in part by enhancing MPK15 Ser-511 phosphorylation. These results uncovered a mechanism of BSK1-mediated disease resistance and provided new insight into the role of MAPK phosphorylation in plant immunity.
PMID: 35099562
Plant Cell , IF:11.277 , 2022 Mar , V34 (3) : P1038-1053 doi: 10.1093/plcell/koab307
TOR promotes guard cell starch degradation by regulating the activity of beta-AMYLASE1 in Arabidopsis.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.; Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250014, China.; Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB Center for Plant Systems Biology, Ghent, Belgium.
Starch is the main energy storage carbohydrate in plants and serves as an essential carbon storage molecule for plant metabolism and growth under changing environmental conditions. The TARGET of RAPAMYCIN (TOR) kinase is an evolutionarily conserved master regulator that integrates energy, nutrient, hormone, and stress signaling to regulate growth in all eukaryotes. Here, we demonstrate that TOR promotes guard cell starch degradation and induces stomatal opening in Arabidopsis thaliana. Starvation caused by plants growing under short photoperiod or low light photon irradiance, as well as inactivation of TOR, impaired guard cell starch degradation and stomatal opening. Sugar and TOR induce the accumulation of beta-AMYLASE1 (BAM1), which is responsible for starch degradation in guard cells. The plant steroid hormone brassinosteroid and transcription factor BRASSINAZOLE-RESISTANT1 play crucial roles in sugar-promoted expression of BAM1. Furthermore, sugar supply induced BAM1 accumulation, but TOR inactivation led to BAM1 degradation, and the effects of TOR inactivation on BAM1 degradation were abolished by the inhibition of autophagy and proteasome pathways or by phospho-mimicking mutation of BAM1 at serine-31. Such regulation of BAM1 activity by sugar-TOR signaling allows carbon availability to regulate guard cell starch metabolism and stomatal movement, ensuring optimal photosynthesis efficiency of plants.
PMID: 34919720
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Mar , V119 (11) : Pe2118220119 doi: 10.1073/pnas.2118220119
Proteome-wide cellular thermal shift assay reveals unexpected cross-talk between brassinosteroid and auxin signaling.
Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Pelago Bioscience AB, 171 48 Solna, Sweden.; Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.; Department of Biomolecular Medicine, Ghent University, 9052 Ghent, Belgium.; Center for Medical Biotechnology, VIB, 9052 Ghent, Belgium.; VIB Proteomics Core, 9052 Ghent, Belgium.
SignificanceChemical genetics, which investigates biological processes using small molecules, is gaining interest in plant research. However, a major challenge is to uncover the mode of action of the small molecules. Here, we applied the cellular thermal shift assay coupled with mass spectrometry (CETSA MS) to intact Arabidopsis cells and showed that bikinin, the plant-specific glycogen synthase kinase 3 (GSK3) inhibitor, changed the thermal stability of some of its direct targets and putative GSK3-interacting proteins. In combination with phosphoproteomics, we also revealed that GSK3s phosphorylated the auxin carrier PIN-FORMED1 and regulated its polarity that is required for the vascular patterning in the leaf.
PMID: 35254915
Curr Biol , IF:10.834 , 2022 Mar , V32 (5) : P1102-1114.e5 doi: 10.1016/j.cub.2022.01.022
Brassinosteroid signaling regulates female germline specification 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.; 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.; 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; 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.; Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany.; 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; 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. Electronic address: yuanqin@fafu.edu.cn.
Unlike in humans and animals, plant germlines are specified de novo from somatic cells in the reproductive organs of the flower. In most flowering plant ovules, the female germline starts with the differentiation of one megaspore mother cell (MMC), which initiates a developmental program distinct from adjoining cells. Phytohormones act as a key player in physiological processes during plant development, in particular by providing positional information that supports localized differentiation events. However, little is known about the role of phytohormones for female germline initiation and establishment. Using Arabidopsis as a flowering plant model, we show that brassinosteroid (BR) biosynthesis and signaling components are accumulated in sporophytic cells of ovule primordia but not in the megaspore mother cell representing the precursor of the female germline. We further demonstrate that BR signaling restricts multiple sub-epidermal cells in the distal nucellus region of ovule primordia from acquiring MMC-like cell identity by transiently activating the WRKY23 transcription factor, expressed exclusively in L2 layer cells adjacent to the MMC. This activation is regulated through the BRI1 receptor and directly by the BZR1 transcriptional repressor family. Mutations in BR biosynthesis or signaling components and ectopic activation of BR signaling in MMCs induce multiple MMC-like cells. In summary, our findings elucidate a gene regulatory network that shows how the hormone BR generated in sporophytic ovule primordia cells restricts the origin of the female germline to a single cell.
PMID: 35108524
EMBO Rep , IF:8.807 , 2022 Apr , V23 (4) : Pe53354 doi: 10.15252/embr.202153354
Deubiquitinating enzymes UBP12 and UBP13 stabilize the brassinosteroid receptor BRI1.
Graduate School of Life Science, Hokkaido University, Sapporo, Japan.; Faculty of Science, Hokkaido University, Sapporo, Japan.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; Center for Plant Systems Biology, VIB, Ghent, Belgium.; Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, USA.; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, USA.
Protein ubiquitination is a dynamic and reversible post-translational modification that controls diverse cellular processes in eukaryotes. Ubiquitin-dependent internalization, recycling, and degradation are important mechanisms that regulate the activity and the abundance of plasma membrane (PM)-localized proteins. In plants, although several ubiquitin ligases are implicated in these processes, no deubiquitinating enzymes (DUBs), have been identified that directly remove ubiquitin from membrane proteins and limit their vacuolar degradation. Here, we discover two DUB proteins, UBP12 and UBP13, that directly target the PM-localized brassinosteroid (BR) receptor BR INSENSITIVE1 (BRI1) in Arabidopsis. BRI1 protein abundance is decreased in the ubp12i/ubp13 double mutant that displayed severe growth defects and reduced sensitivity to BRs. UBP13 directly interacts with and effectively removes K63-linked polyubiquitin chains from BRI1, thereby negatively modulating its vacuolar targeting and degradation. Our study reveals that UBP12 and UBP13 play crucial roles in governing BRI1 abundance and BR signaling activity to regulate plant growth.
PMID: 35166439
Plant Physiol , IF:8.34 , 2022 Apr doi: 10.1093/plphys/kiac185
Transcription factor OsNAC016: a convergent point of brassinosteroid and abscisic acid signaling in rice.
International Genome Center, Jiangsu University, Zhenjiang 212013, China.
PMID: 35460247
Plant Physiol , IF:8.34 , 2022 Apr doi: 10.1093/plphys/kiac157
The interplay of auxin and brassinosteroid signaling tunes root growth under low and different nitrogen forms.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India, 110067.
The coordinated signaling activity of auxin and brassinosteroids (BRs) is critical for optimal plant growth and development. Nutrient-derived signals regulate root growth by modulating the levels and spatial distribution of growth hormones to optimize nutrient uptake and assimilation. However, the effect of the interaction of these two hormones and their signaling on root plasticity during low and differential availability of nitrogen (N) forms (NH4+/NO3-) remains elusive. We demonstrate that root elongation under low nitrogen (LN) is an outcome of the interdependent activity of auxin and BR signaling pathways in Arabidopsis (Arabidopsis thaliana). LN promotes root elongation by increasing BR-induced auxin transport activity in the roots. Increased nuclear auxin signaling and its transport efficiency have a distinct impact on root elongation under LN conditions. High auxin levels reversibly inhibit BR signaling via BRI1 KINASE INHIBITOR1 (BKI1). Using the tissue-specific approach, we show that BR signaling from root vasculature (stele) tissues is sufficient to promote cell elongation and, hence, root growth under LN condition. Further, we show that N form-defined root growth attenuation or enhancement depends on the fine balance of BR and auxin signaling activity. NH4+ as a sole N source represses BR signaling and response, which in turn inhibits auxin response and transport, whereas NO3- promotes root elongation in a BR signaling-dependent manner. In this study, we demonstrate the interplay of auxin and BR-derived signals, which are critical for root growth in a heterogeneous N environment and appear essential for root N foraging response and adaptation.
PMID: 35377445
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac146
OsNAC016 regulates plant architecture and drought tolerance by interacting with the kinases GSK2 and SAPK8.
Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044, China.
Ideal plant architecture and drought tolerance are important determinants of yield potential in rice (Oryza sativa). Here, we found that OsNAC016, a rice stress-responsive NAC transcription factor, functions as a regulator in the crosslink between BR-mediated plant architecture and ABA-regulated drought responses. The loss-of-function mutant osnac016 exhibited erect leaves and shortened internodes, but OsNAC016-overexpressing plants had opposite phenotypes. Further investigation revealed that OsNAC016 regulated the expression of the brassinosteroid biosynthesis gene D2 by binding to its promoter. Moreover, OsNAC016 interacted with and was phosphorylated by GSK3/SHAGGY-LIKE KINASE2 (GSK2), a negative regulator in the BR pathway. Meanwhile, the mutant osnac016 had improved drought stress tolerance, supported by a decreased water loss rate and enhanced stomatal closure in response to exogenous ABA, but OsNAC016-overexpressing plants showed attenuated drought tolerance and reduced ABA sensitivity. Further, OSMOTIC STRESS/ABA-ACTIVATED PROTEIN KINASE8 (SAPK8) phosphorylated OsNAC016 and reduced its stability. The ubiquitin/26S proteasome system is an important degradation pathway of OsNAC016 via the interaction with PLANT U-BOX PROTEIN43 (OsPUB43) that mediates the ubiquitination of OsNAC016. Notably, RNA-sequencing analysis revealed global roles of OsNAC016 in promoting BR-mediated gene expression and repressing ABA-dependent drought-responsive gene expression, which was confirmed by ChIP-qPCR analysis. Our findings establish that OsNAC016 is positively involved in BR-regulated rice architecture, negatively modulates ABA-mediated drought tolerance, and is regulated by GSK2, SAPK8, and OsPUB43 through post-translational modification. Our data provide insights into how plants balance growth and survival by coordinately regulating the growth-promoting signaling pathway and response under abiotic stresses.
PMID: 35333328
Plant Physiol , IF:8.34 , 2022 Mar doi: 10.1093/plphys/kiac134
Sphingolipids with 2-hydroxy fatty acids aid in plasma membrane nanodomain organization and oxidative burst.
Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakuraku, Saitama 338-8570, Japan.; College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
Plant sphingolipids mostly possess 2-hydroxy fatty acids, the synthesis of which is catalyzed by fatty acid 2-hydroxylases (FAHs). In Arabidopsis (Arabidopsis thaliana), two FAHs (FAH1 and FAH2) have been identified. However, the functions of FAHs and sphingolipids with 2-hydroxy fatty acids (2-hydroxy sphingolipids) are still unknown because of the lack of Arabidopsis lines with the complete deletion of FAH1. In this study, we generated a FAH1 mutant (fah1c) using CRISPR/Cas9-based genome editing. Sphingolipid analysis of fah1c, fah2, and fah1cfah2 mutants revealed that FAH1 hydroxylates very-long-chain fatty acids (VLCFAs), whereas the substrates of FAH2 are VLCFAs and palmitic acid. However, 2-hydroxy sphingolipids are not completely lost in the fah1cfah2 double mutant, suggesting the existence of other enzymes catalyzing the hydroxylation of sphingolipid fatty acids. Plasma membrane (PM) analysis and molecular dynamics simulations revealed that hydroxyl groups of sphingolipid acyl chains play a crucial role in the organization of nanodomains, which are nanoscale liquid-ordered domains mainly formed by sphingolipids and sterols in the PM, through hydrogen bonds. In the PM of the fah1cfah2 mutant, the expression levels of 26.7% of the proteins, including defense-related proteins such as the pattern recognition receptors (PRRs) brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1) and chitin elicitor receptor kinase 1 (CERK1), NADPH oxidase respiratory burst oxidase homolog D (RBOHD), and heterotrimeric G proteins, were lower than that in the wild type. In addition, reactive oxygen species (ROS) burst was suppressed in the fah1cfah2 mutant after treatment with the pathogen-associated molecular patterns flg22 and chitin. These results indicated that 2-hydroxy sphingolipids are necessary for the organization of PM nanodomains and ROS burst through RBOHD and PRRs during pattern-triggered immunity.
PMID: 35312013
Plant Physiol , IF:8.34 , 2022 Mar , V188 (4) : P2012-2025 doi: 10.1093/plphys/kiac008
Brassinosteroid-regulated bHLH transcription factor CESTA induces the gibberellin 2-oxidase GA2ox7.
Biotechnology of Horticultural Crops, TUM School of Life Sciences, Technical University of Munich, Freising, Germany.; Sainsbury Laboratory, Cambridge University, Cambridge, UK.; Institute of Plant Biology, Technical University of Braunschweig, Braunschweig, Germany.
Brassinosteroids (BRs) are plant steroids that have growth-promoting capacities, which are partly enabled by an ability to induce biosynthesis of gibberellins (GAs), a second class of plant hormones. In addition, BRs can also activate GA catabolism; here we show that in Arabidopsis (Arabidopsis thaliana) the basic helix-loop-helix transcription factor CESTA (CES) and its homologues BRASSINOSTEROID-ENHANCED EXPRESSION (BEE) 1 and 3 contribute to this activity. CES and the BEEs are BR-regulated at the transcriptional and posttranslational level and participate in different physiological processes, including vegetative and reproduction development, shade avoidance, and cold stress responses. We show that CES/BEEs can induce the expression of the class III GA 2-oxidase GA2ox7 and that this activity is increased by BRs. In BR signaling - and CES/BEE-deficient mutants, GA2ox7 expression decreased, yielding reduced levels of GA110, a product of GA2ox7 activity. In plants that over-express CES, GA2ox7 expression is hyper-responsive to BR, GA110 levels are elevated and amounts of bioactive GA are reduced. We provide evidence that CES directly binds to the GA2ox7 promoter and is activated by BRs, but can also act by BR-independent means. Based on these results, we propose a model for CES activity in GA catabolism where CES can be recruited for GA2ox7 induction not only by BR, but also by other factors.
PMID: 35148416
J Integr Plant Biol , IF:7.061 , 2022 Mar doi: 10.1111/jipb.13257
BAK1 plays contrasting roles in regulating abscisic acid-induced stomatal closure and abscisic acid-inhibited primary root growth in Arabidopsis.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; College of Life Sciences, Qingdao University, Qingdao, 266071, China.; Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng, 475001, China.; Institute of Life Science and Green Development, School of Life Sciences, Hebei University, Baoding, 071002, China.
The mechanisms that balance plant growth and stress responses are poorly understood, but they appear to involve abscisic acid (ABA) signaling mediated by protein kinases. Here, to explore these mechanisms, we examined the responses of Arabidopsis thaliana protein kinase mutants to ABA treatment. We found that mutants of BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) were hypersensitive to the effects of ABA on both seed germination and primary root growth. The kinase OPEN STOMATA 1 (OST1) was more highly activated by ABA in bak1 mutant than the wild type. BAK1 was not activated by ABA treatment in the dominant negative mutant abi1-1 or the pyr1 pyl4 pyl5 pyl8 quadruple mutant, but it was more highly activated by this treatment in the abi1-2 abi2-2 hab1-1 loss-of-function triple mutant than the wild type. BAK1 phosphorylates OST1 T146 and inhibits its activity. Genetic analyses suggested that BAK1 acts at or upstream of core components in the ABA signaling pathway, including PYLs, PP2Cs, and SnRK2s, during seed germination and primary root growth. Although the upstream brassinosteroid (BR) signaling components BAK1 and BR INSENSITIVE 1 (BRI1) positively regulate ABA-induced stomatal closure, mutations affecting downstream components of BR signaling, including BRASSINOSTEROID-SIGNALING KINASEs (BSKs) and BRASSINOSTEROID-INSENSITIVE 2 (BIN2), did not affect ABA-mediated stomatal movement. Thus, our study uncovered an important role of BAK1 in negatively regulating ABA signaling during seed germination and primary root growth, but positively modulating ABA-induced stomatal closure, thus optimizing the plant growth under drought stress. This article is protected by copyright. All rights reserved.
PMID: 35352463
J Integr Plant Biol , IF:7.061 , 2022 Apr , V64 (4) : P836-842 doi: 10.1111/jipb.13241
Sphingolipid synthesis inhibitor fumonisin B1 causes verticillium wilt in cotton.
Key Laboratory of Biotechnology and Crop Quality Improvement of the Ministry of Agriculture, Biotechnology Research Center, Southwest University, Chongqing, 400716, China.
Verticillium wilt caused by Verticillium dahliae is a major disease of cotton. Acidic protein-lipopolysaccharide complexes are thought to be the toxins responsible for its symptoms. Here, we determined that the sphingolipid biosynthesis inhibitor fumonisin B1 (FB1) acts as a toxin and phenocopies the symptoms induced by V. dahliae. Knocking out genes required for FB1 biosynthesis reduced V. dahliae pathogenicity. Moreover, we showed that overexpression of a FB1 and V. dahliae both downregulated gene, GhIQD10, enhanced verticillium wilt resistance by promoting the expression of brassinosteroid and anti-pathogen genes. Our results provide a new strategy for preventing verticillium wilt in cotton.
PMID: 35238484
J Exp Bot , IF:6.992 , 2022 Apr , V73 (7) : P2125-2141 doi: 10.1093/jxb/erab530
Fungal oxysterol-binding protein-related proteins promote pathogen virulence and activate plant immunity.
Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.; State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China.
Oxysterol-binding protein-related proteins (ORPs) are a conserved class of lipid transfer proteins that are closely involved in multiple cellular processes in eukaryotes, but their roles in plant-pathogen interactions are mostly unknown. We show that transient expression of ORPs of Magnaporthe oryzae (MoORPs) in Nicotiana benthamina plants triggered oxidative bursts and cell death; treatment of tobacco Bright Yellow-2 suspension cells with recombinant MoORPs elicited the production of reactive oxygen species. Despite ORPs being normally described as intracellular proteins, we detected MoORPs in fungal culture filtrates and intercellular fluids from barley plants infected with the fungus. More importantly, infiltration of Arabidopsis plants with recombinant Arabidopsis or fungal ORPs activated oxidative bursts, callose deposition, and PR1 gene expression, and enhanced plant disease resistance, implying that ORPs may function as endogenous and exogenous danger signals triggering plant innate immunity. Extracellular application of fungal ORPs exerted an opposite impact on salicylic acid and jasmonic acid/ethylene signaling pathways. Brassinosteroid Insensitive 1-associated Kinase 1 was dispensable for the ORP-activated defense. Besides, simultaneous knockout of MoORP1 and MoORP3 abolished fungal colony radial growth and conidiation, whereas double knockout of MoORP1 and MoORP2 compromised fungal virulence on barley and rice plants. These observations collectively highlight the multifaceted role of MoORPs in the modulation of plant innate immunity and promotion of fungal development and virulence in M. oryzae.
PMID: 34864987
J Exp Bot , IF:6.992 , 2022 Mar , V73 (5) : P1415-1428 doi: 10.1093/jxb/erab475
Inhibition of 4-HYDROXYPHENYLPYRUVATE DIOXYGENASE expression by brassinosteroid reduces carotenoid accumulation in Arabidopsis.
Department of Life Science, Hanyang University, Seoul, 04763South Korea.; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.; Department of Life Science, Chung-Ang University, Seoul, 06974South Korea.; Research Institute for Natural Sciences, Hanyang University, Seoul 04763, South Korea.; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, South Korea.
Unlike the indispensable function of the steroid hormone brassinosteroid (BR) in regulating plant growth and development, the metabolism of secondary metabolites regulated by BR is not well known. Here we show that BR reduces carotenoid accumulation in Arabidopsis seedlings. BR-deficient or BR-insensitive mutants accumulated higher content of carotenoids than wild-type plants, whereas BR treatment reduced carotenoid content. We demonstrated that BR transcriptionally suppresses 4-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) expression involved in carotenogenesis via plastoquinone production. We found that the expression of HPPD displays an oscillation pattern that is expressed more strongly in dark than in light conditions. Moreover, BR appeared to inhibit HPPD expression more strongly in darkness than in light, leading to suppression of a diurnal oscillation of HPPD expression. BR-responsive transcription factor BRASSINAZOLE RESISTANT 1 (BZR1) directly bound to the promoter of HPPD, and HPPD suppression by BR was increased in the bzr1-1D gain-of-function mutation. Interestingly, dark-induced HPPD expression did not cause carotenoid accumulation, due to down-regulation of other carotenoid biosynthetic genes in the dark. Our results suggest that BR regulates different physiological responses in dark and light through inhibition of HPPD expression.
PMID: 34718527
Plant J , IF:6.417 , 2022 Mar doi: 10.1111/tpj.15727
OsSLA1 functions in leaf angle regulation by enhancing the interaction between OsBRI1 and OsBAK1 in rice.
Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China.
Leaf angle is an important trait in plants. Here, we demonstrate that the leucine-rich repeat receptor-like kinase OsSLA1 plays an important role in leaf angle regulation in rice (Oryza sativa). OsSLA1 mutant plants exhibited a small leaf angle phenotype due to changes of adaxial cells in the lamina joint. GUS staining revealed that OsSLA1 was highly expressed in adaxial cells of the lamina joint. The OsSLA1 mutant plants were insensitive to exogenous epibrassinolide (eBL) and showed upregulated expression of DWARF and CPD, but downregulated expression of BU1, BUL1, and ILI1, indicating that brassinosteroid (BR) signal transduction was blocked. Fluorescence microscopy showed that OsSLA1 was localized to the plasma membrane and nearby periplasmic vesicles. Further study showed that OsSLA1 interacts with OsBRI1 and OsBAK1 via its intracellular domain and promotes the interaction between OsBRI1 and OsBAK1. In addition, phosphorylation experiments revealed that OsSLA1 does not possess kinase activity, but that it can be phosphorylated by OsBRI1 in vitro. Knockout of OsSLA1 in the context of d61 caused exacerbation of the mutant phenotype. These results demonstrate that OsSLA1 regulates leaf angle formation via positive regulation of BR signaling by enhancing the interaction of OsBRI1 with OsBAK1.
PMID: 35275421
Int J Mol Sci , IF:5.923 , 2022 Apr , V23 (8) doi: 10.3390/ijms23084223
The Combination of Conventional QTL Analysis, Bulked-Segregant Analysis, and RNA-Sequencing Provide New Genetic Insights into Maize Mesocotyl Elongation under Multiple Deep-Seeding Environments.
State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China.
Mesocotyl length (MES) is an important trait that affects the emergence of maize seedlings after deep-seeding and is closely associated with abiotic stress. The elucidation of constitutive-QTLs (cQTLs) and candidate genes for MES and tightly molecular markers are thus of great importance in marker-assisted selection (MAS) breeding. Therefore, the objective of this study was to perform detailed genetic analysis of maize MES across 346 F2:3 families, 30/30 extreme bulks of an F2 population, and two parents by conventional QTL analysis, bulked-segregation analysis (BSA), and RNA-sequencing when maize was sown at the depths of 3, 15, and 20 cm, respectively. QTL analysis identified four major QTLs in Bin 1.09, Bin 3.04, Bin 4.06-4.07, and Bin 6.01 under two or more environments, which explained 2.89-13.97% of the phenotypic variance within a single environment. BSA results revealed the presence of seven significantly linked SNP/InDel regions on chromosomes 1 and 4, and six SNP/InDel regions and the major QTL of qMES4-1 overlapped and formed a cQTL, cQMES4, within the 160.98-176.22 Mb region. In total, 18,001 differentially expressed genes (DEGs) were identified across two parents by RNA-sequencing, and 24 of these genes were conserved core DEGs. Finally, we validated 15 candidate genes in cQMES4 to involve in cell wall structure, lignin biosyntheis, phytohormones (auxin, abscisic acid, brassinosteroid) signal transduction, circadian clock, and plant organ formation and development. Our findings provide a basis for MAS breeding and enhance our understanding of the deep-seeding tolerance of maize.
PMID: 35457037
PLoS Genet , IF:5.917 , 2022 Mar , V18 (3) : Pe1010077 doi: 10.1371/journal.pgen.1010077
PIN3 positively regulates the late initiation of ovule primordia in Arabidopsis thaliana.
School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, China.; Zhiyuan College, Shanghai Jiao Tong University, Shanghai, China.; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
Ovule initiation determines the maximum ovule number and has great impact on seed number and yield. However, the regulation of ovule initiation remains largely elusive. We previously reported that most of the ovule primordia initiate asynchronously at floral stage 9 and PINFORMED1 (PIN1) polarization and auxin distribution contributed to this process. Here, we further demonstrate that a small amount of ovule primordia initiate at floral stage 10 when the existing ovules initiated at floral stage 9 start to differentiate. Genetic analysis revealed that the absence of PIN3 function leads to the reduction in pistil size and the lack of late-initiated ovules, suggesting PIN3 promotes the late ovule initiation process and pistil growth. Physiological analysis illustrated that, unlike picloram, exogenous application of NAA can't restore these defective phenotypes, implying that PIN3-mediated polar auxin transport is required for the late ovule initiation and pistil length. qRT-PCR results indicated that the expression of SEEDSTICK (STK) is up-regulated under auxin analogues treatment while is down-regulated in pin3 mutants. Meanwhile, overexpressing STK rescues pin3 phenotypes, suggesting STK participates in PIN3-mediated late ovule initiation possibly by promoting pistil growth. Furthermore, brassinosteroid influences the late ovule initiation through positively regulating PIN3 expression. Collectively, this study demonstrates that PIN3 promotes the late ovule initiation and contributes to the extra ovule number. Our results give important clues for increasing seed number and yield of cruciferous and leguminous crops.
PMID: 35245283
Front Plant Sci , IF:5.753 , 2022 , V13 : P873993 doi: 10.3389/fpls.2022.873993
OsDDM1b Controls Grain Size by Influencing Cell Cycling and Regulating Homeostasis and Signaling of Brassinosteroid in Rice.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China.; College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China.; College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, China.; Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.; Biotechnology Research Institute, Fujian Provincial Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, China.; Center for Crop Biotechnology, College of Agriculture, Anhui Science and Technology University, Fengyang, China.
Snf2 family proteins are the crucial subunits of chromatin-remodeling complexes (CRCs), which contributes to the biological processes of transcription, replication, and DNA repair using ATP as energy. Some CRC subunits have been confirmed to be the critical regulators in various aspects of plant growth and development and in epigenetic mechanisms such as histone modification, DNA methylation, and histone variants. However, the functions of Snf2 family genes in rice were poorly investigated. In this study, the relative expression profile of 40 members of Snf2 family in rice was studied at certain developmental stages of seed. Our results revealed that OsCHR741/OsDDM1b (Decrease in DNA methylation 1) was accumulated highly in the early developmental stage of seeds. We further analyzed the OsDDM1b T-DNA insertion loss-of-function of mutant, which exhibited dwarfism, smaller organ size, and shorter and wider grain size than the wild type (Hwayoung, HY), yet no difference in 1,000-grain weight. Consistent with the grain size, the outer parenchyma cell layers of lemma in osddm1b developed more cells with decreased size. OsDDM1b encoded a nucleus, membrane-localized protein and was distributed predominately in young spikelets and seeds, asserting its role in grain size. Meanwhile, the osddm1b was less sensitive to brassinosteroids (BRs) while the endogenous BR levels increased. We detected changes in the expression levels of the BR signaling pathway and feedback-inhibited genes with and without exogenous BR application, and the alterations of expression were also observed in grain size-related genes in the osddm1b. Altogether, our results suggest that OsDDM1b plays a crucial role in grain size via influencing cell proliferation and regulating BR signaling and homeostasis.
PMID: 35463416
Front Plant Sci , IF:5.753 , 2022 , V13 : P865019 doi: 10.3389/fpls.2022.865019
Phytochromes A and B Mediate Light Stabilization of BIN2 to Regulate Brassinosteroid Signaling and Photomorphogenesis in Arabidopsis.
Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China.; School of Life Sciences, Fudan University, Shanghai, China.
Phytochromes A and B (phyA and phyB) are the far-red and red lights photoreceptors mediating many light responses in Arabidopsis thaliana. Brassinosteroid (BR) is a pivotal phytohormone regulating a variety of plant developmental processes including photomorphogenesis. It is known that phyB interacts with BES1 to inhibit its DNA-binding activity and repress BR signaling. Here, we show that far-red and red lights modulate BR signaling through phyA and phyB regulation of the stability of BIN2, a glycogen synthase kinase 3 (GSK3)-like kinase that phosphorylates BES1/BZR1 to inhibit BR signaling. The BIN2 gain-of-function mutant bin2-1 displays an enhanced photomorphogenic phenotype in both far-red and red lights. phyA-enhanced accumulation of BIN2 promotes the phosphorylation of BES1 in far-red light. BIN2 acts genetically downstream from PHYA to regulate photomorphogenesis under far-red light. Both phyA and phyB interact directly with BIN2, which may promote the interaction of BIN2 with BES1 and induce the phosphorylation of BES1. Our results suggest that far-red and red lights inhibit BR signaling through phyA and phyB stabilization of BIN2 and promotion of BES1 phosphorylation, which defines a new layer of the regulatory mechanism that allows plants to coordinate light and BR signaling pathways to optimize photomorphogenesis.
PMID: 35432407
Front Plant Sci , IF:5.753 , 2022 , V13 : P865302 doi: 10.3389/fpls.2022.865302
Regulation of Phytohormones on the Growth and Development of Plant Root Hair.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.; College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
The tubular-shaped unicellular extensions of plant epidermal cells known as root hairs are important components of plant roots and play crucial roles in absorbing nutrients and water and in responding to stress. The growth and development of root hair include, mainly, fate determination of root hair cells, root hair initiation, and root hair elongation. Phytohormones play important regulatory roles as signal molecules in the growth and development of root hair. In this review, we describe the regulatory roles of auxin, ethylene (ETH), jasmonate (JA), abscisic acid (ABA), gibberellin (GA), strigolactone (SL), cytokinin (CK), and brassinosteroid (BR) in the growth and development of plant root hairs. Auxin, ETH, and CK play positive regulation while BR plays negative regulation in the fate determination of root hair cells; Auxin, ETH, JA, CK, and ABA play positive regulation while BR plays negative regulation in the root hair initiation; Auxin, ETH, CK, and JA play positive regulation while BR, GA, and ABA play negative regulation in the root hair elongation. Phytohormones regulate root hair growth and development mainly by regulating transcription of root hair associated genes, including WEREWOLF (WER), GLABRA2 (GL2), CAPRICE (CPC), and HAIR DEFECTIVE 6 (RHD6). Auxin and ETH play vital roles in this regulation, with JA, ABA, SL, and BR interacting with auxin and ETH to regulate further the growth and development of root hairs.
PMID: 35401627
Front Plant Sci , IF:5.753 , 2022 , V13 : P865542 doi: 10.3389/fpls.2022.865542
Phytohormonal Regulation Through Protein S-Nitrosylation Under Stress.
Laboratory of Plant Molecular Pathology and Functional Genomics, Department of Plant Biosciences, School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea.; Laboratory of Cell Biology, Department of Entomology, Abdul Wali Khan University, Mardan, Pakistan.; Department of Horticultural Sciences, Kyungpook National University, Daegu, South Korea.
The liaison between Nitric oxide (NO) and phytohormones regulates a myriad of physiological processes at the cellular level. The interaction between NO and phytohormones is mainly influenced by NO-mediated post-translational modifications (PTMs) under basal as well as induced conditions. Protein S-nitrosylation is the most prominent and widely studied PTM among others. It is the selective but reversible redox-based covalent addition of a NO moiety to the sulfhydryl group of cysteine (Cys) molecule(s) on a target protein to form S-nitrosothiols. This process may involve either direct S-nitrosylation or indirect S-nitrosylation followed by transfer of NO group from one thiol to another (transnitrosylation). During S-nitrosylation, NO can directly target Cys residue (s) of key genes involved in hormone signaling thereby regulating their function. The phytohormones regulated by NO in this manner includes abscisic acid, auxin, gibberellic acid, cytokinin, ethylene, salicylic acid, jasmonic acid, brassinosteroid, and strigolactone during various metabolic and physiological conditions and environmental stress responses. S-nitrosylation of key proteins involved in the phytohormonal network occurs during their synthesis, degradation, or signaling roles depending upon the response required to maintain cellular homeostasis. This review presents the interaction between NO and phytohormones and the role of the canonical NO-mediated post-translational modification particularly, S-nitrosylation of key proteins involved in the phytohormonal networks under biotic and abiotic stresses.
PMID: 35401598
Front Plant Sci , IF:5.753 , 2022 , V13 : P814015 doi: 10.3389/fpls.2022.814015
Identification of Key Gene Networks and Deciphering Transcriptional Regulators Associated With Peanut Embryo Abortion Mediated by Calcium Deficiency.
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Institute of Oil Crops Research, Research Center for Genetics and Systems Biology of Leguminous Oil Plants, Fujian Agriculture and Forestry University, Fuzhou, China.; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.; State Agricultural Biotechnology Center, Center for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA, Australia.
Peanut embryo development is easily affected by a variety of nutrient elements in the soil, especially the calcium level. Peanut produces abortive embryos in calcium-deficient soil, but underlying mechanism remains unclear. Thus, identifying key transcriptional regulators and their associated regulatory networks promises to contribute to a better understanding of this process. In this study, cellular biology and gene expression analyses were performed to investigate peanut embryo development with the aim to discern the global architecture of gene regulatory networks underlying peanut embryo abortion under calcium deficiency conditions. The endomembrane systems tended to disintegrate, impairing cell growth and starch, protein and lipid body accumulation, resulting in aborted seeds. RNA-seq analysis showed that the gene expression profile in peanut embryos was significantly changed under calcium deficiency. Further analysis indicated that multiple signal pathways were involved in the peanut embryo abortion. Differential expressed genes (DEGs) related to cytoplasmic free Ca(2+) were significantly altered. DEGs in plant hormone signaling pathways tended to be associated with increased IAA and ethylene but with decreased ABA, gibberellin, cytokinin, and brassinosteroid levels. Certain vital genes, including apoptosis-inducing factor, WRKYs and ethylene-responsive transcription factors, were up-regulated, while key regulators of embryo development, such as TCP4, WRI1, FUS3, ABI3, and GLK1 were down-regulated. Weighted gene co-expression network analysis (WGCNA) identified 16 significant modules associated with the plant hormone signaling, MAPK signaling, ubiquitin mediated proteolysis, reserve substance biosynthesis and metabolism pathways to decipher regulatory network. The most significant module was darkolivegreen2 and FUS3 (AH06G23930) had the highest connectivity among this module. Importantly, key transcription factors involved in embryogenesis or ovule development including TCP4, GLK1, ABI3, bHLH115, MYC2, etc., were also present in this module and down regulated under calcium deficiency. This study presents the first global view of the gene regulatory network involved in peanut embryo abortion under calcium deficiency conditions and lays foundation for improving peanut tolerances to calcium deficiency by a targeted manipulation of molecular breeding.
PMID: 35386666
Theor Appl Genet , IF:5.699 , 2022 Mar doi: 10.1007/s00122-022-04067-2
The kinesin-13 protein BR HYPERSENSITIVE 1 is a negative brassinosteroid signaling component regulating rice growth and development.
College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China.; Rice Research Institute, Shenyang Agricultural University, Shenyang, 110866, China.; State Key Laboratory for Rice Biology, China National Rice Research Institute, Hangzhou, 310006, China.; Plant Phenomics Research Center, Nanjing Agricultural University, Nanjing, 210095, China.; College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China. ycyu@hznu.edu.cn.; College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China. lmwu2006@aliyun.com.; Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou, 310036, China. lmwu2006@aliyun.com.
Phytohormones performed critical roles in regulating plant architecture and thus determine grain yield in rice. However, the roles of brassinosteroids (BRs) compared to other phytohormones in shaping rice architecture are less studied. In this study, we report that BR hypersensitive1 (BHS1) plays a negative role in BR signaling and regulate rice architecture. BHS1 encodes the kinesin-13a protein and regulates grain length. We found that bhs1 was hypersensitive to BR, while BHS1-overexpression was less sensitive to BR compare to WT. BHS1 was down-regulated at RNA and protein level upon exogenous BR treatment, and proteasome inhibitor MG132 delayed the BHS1 degradation, indicating that both the transcriptional and posttranscriptional regulation machineries are involved in BHS1-mediated regulation of plant growth and development. Furthermore, we found that the BR-induced degradation of BHS1 was attenuated in Osbri1 and Osbak1 mutants, but not in Osbzr1 and Oslic mutants. Together, these results suggest that BHS1 is a novel component which is involved in negative regulation of the BR signaling downstream player of BRI1.
PMID: 35258682
J Agric Food Chem , IF:5.279 , 2022 Apr , V70 (14) : P4303-4315 doi: 10.1021/acs.jafc.2c00541
Novel Dioxolane Ring Compounds for the Management of Phytopathogen Diseases as Ergosterol Biosynthesis Inhibitors: Synthesis, Biological Activities, and Molecular Docking.
College of Life Science, Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou 313000, Zhejiang, China.; College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.; Natural Products Utilization Research Unit, USDA ARS, University, Mississippi 38677, United States.; College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, Zhejiang, China.; National Center for Natural Product Research, School of Pharmacy, University of Mississippi, P.O. Box 1848, University, Mississippi 38677, United States.
Thirty novel dioxolane ring compounds were designed and synthesized. Their chemical structures were confirmed by (1)H NMR, HRMS, and single crystal X-ray diffraction analysis. Bioassays indicated that these dioxolane ring derivatives exhibited excellent fungicidal activity against Rhizoctonia solani, Pyricularia oryae, Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium oxysporum, Physalospora piricola, Cercospora arachidicola and herbicidal activity against lettuce (Lactuca sativa), bentgrass (Agrostis stolonifera), and duckweed (Lemna pausicostata). Among these compounds, 1-((2-(4-chlorophenyl)-5-methyl-1,3-dioxan-2-yl)methyl)-1H-1,2,4-triazole (D17), 1-(((4R)-2-(4-chlorophenyl)-4-methyl-1,3-dioxolan-2-yl)methyl)-1H-1,2,4-triazole (D20), 1-((5-methyl-2-(4-(trifluoromethyl)phenyl)-1,3-dioxan-2-yl)methyl)-1H-1,2,4-triaz ole (D22), and 1-((2-(4-fluorophenyl)-1,3-dioxolan-2-yl)methyl)-1H-1,2,4-triazole (D26) had broad spectrum fungicidal and herbicidal activity. The IC50 values against duckweed were 20.5 +/- 9.0, 14.2 +/- 6.7, 24.0 +/- 11.0, 8.7 +/- 3.5, and 8.0 +/- 3.1 muM for D17, D20, D22, and D26 and the positive control difenoconazole, respectively. The EC50 values were 7.31 +/- 0.67, 9.74 +/- 0.83, 17.32 +/- 1.23, 11.96 +/- 0.98, and 8.93 +/- 0.91 mg/L for D17, D20, D22, and D26 and the positive control difenoconazole against the plant pathogen R. solani, respectively. Germination experiments with Arabidopsis seeds indicated that the target of these dioxolane ring compounds in plants is brassinosteroid biosynthesis. Molecular simulation docking results of compound D26 and difenoconazole with fungal CYP51 P450 confirmed that they both inhibit this enzyme involved in ergosterol biosynthesis. The structure-activity relationships (SAR) are discussed by substituent effect, molecular docking, and density functional theory analysis, which provided useful information for designing more active compounds.
PMID: 35357135
Ann Bot , IF:4.357 , 2022 Mar , V129 (4) : P403-413 doi: 10.1093/aob/mcab152
MYB42 inhibits hypocotyl cell elongation by coordinating brassinosteroid homeostasis and signalling in Arabidopsis thaliana.
College of Resources and Environment, Qingdao Agricultural University, Qingdao, China.; Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.; State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou, China.; College of Agronomy, Qingdao Agricultural University, Qingdao, China.
BACKGROUND AND AIMS: The precise control of brassinosteroid (BR) homeostasis and signalling is a prerequisite for hypocotyl cell elongation in plants. Arabidopsis MYB42 and its paralogue MYB85 were previously identified to be positive regulators of secondary cell wall formation during mature stages. Here, we aim to reveal the role of MYB42 and MYB85 in hypocotyl elongation during the seedling stage and clarify how MYB42 coordinates BR homeostasis and signalling to regulate this process. METHODS: Histochemical analysis of proMYB42-GUS transgenic plants was used for determination of the MYB42 expression pattern. The MYB42, 85 overexpression, double mutant and some crossing lines were generated for phenotypic observation and transcriptome analysis. Transcription activation assays, quantitative PCR (qPCR), chromatin immunoprecipitation (ChIP)-qPCR and electrophoretic mobility shift assays (EMSAs) were conducted to determine the relationship of MYB42 and BRASSINAZOLE-RESISTANT 1 (BZR1), a master switch activating BR signalling. KEY RESULTS: MYB42 and MYB85 redundantly and negatively regulate hypocotyl cell elongation. They function in hypocotyl elongation by mediating BR signalling. MYB42 transcription was suppressed by BR treatment or in bzr1-1D (a gain-of-function mutant of BZR1), and mutation of both MYB42 and MYB85 enhanced the dwarf phenotype of the BR receptor mutant bri1-5. BZR1 directly repressed MYB42 expression in response to BR. Consistently, hypocotyl length of bzr1-1D was increased by simultaneous mutation of MYB42 and MYB85, but was reduced by overexpression of MYB42. Expression of a number of BR-regulated BZR1 (non-)targets associated with hypocotyl elongation was suppressed by MYB42, 85. Furthermore, MYB42 enlarged its action in BR signalling through feedback repression of BR accumulation and activation of DOGT1/UGT73C5, a BR-inactivating enzyme. CONCLUSIONS: MYB42 inhibits hypocotyl elongation by coordinating BR homeostasis and signalling during primary growth. The present study shows an MYB42, 85-mediated multilevel system that contributes to fine regulation of BR-induced hypocotyl elongation.
PMID: 34922335
Foods , IF:4.35 , 2022 Mar , V11 (7) doi: 10.3390/foods11070906
Brassinosteroid Accelerates Wound Healing of Potato Tubers by Activation of Reactive Oxygen Metabolism and Phenylpropanoid Metabolism.
College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China.; Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Rishon LeZion 7505101, Israel.
Wound healing could effectively reduce the decay rate of potato tubers after harvest, but it took a long time to form typical and complete healing structures. Brassinosteroid (BR), as a sterol hormone, is important for enhancing plant resistance to abiotic and biotic stresses. However, it has not been reported that if BR affects wound healing of potato tubers. In the present study, we observed that BR played a positive role in the accumulation of lignin and suberin polyphenolic (SPP) at the wounds, and effectively reduced the weight loss and disease index of potato tubers (cv. Atlantic) during healing. At the end of healing, the weight loss and disease index of BR group was 30.8% and 23.1% lower than the control, respectively. Furthermore, BR activated the expression of StPAL, St4CL, StCAD genes and related enzyme activities in phenylpropanoid metabolism, and promoted the synthesis of lignin precursors and phenolic acids at the wound site, mainly by inducing the synthesis of caffeic acid, sinapic acid and cinnamyl alcohol. Meanwhile, the expression of StNOX was induced and the production of O(2-) and H2O2 was promoted, which mediated oxidative crosslinking of above phenolic acids and lignin precursors to form SPP and lignin. In addition, the expression level of StPOD was partially increased. In contrast, the inhibitor brassinazole inhibited phenylpropanoid metabolism and reactive oxygen metabolism, and demonstrated the function of BR hormone in healing in reverse. Taken together, the activation of reactive oxygen metabolism and phenylpropanoid metabolism by BR could accelerate the wound healing of potato tubers.
PMID: 35406993
Tree Physiol , IF:4.196 , 2022 Mar , V42 (3) : P570-584 doi: 10.1093/treephys/tpab129
Cellular and molecular characterizations of the irregular internode division zone formation of a slow-growing bamboo variant.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road Nanjing, Jiangsu 210037, China.; Boyce Thompson Institute, Cornell University, 533 Tower Road, Ithaca, NY 14853, USA.; College of Agriculture and Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.; Division of Genetics, ICAR-Indian Agricultural Research Institute, Sahyadri Ave New Delhi, 110012, India.; Jiangxi Provincial Key Laboratory for Bamboo Germplasm Resources and Utilization, Jiangxi Agriculture University, College of Forestry, 1101 Zhimin Road, Nanchang, Jiangxi 330045, China.; Changzhou Agricultural Technology Extension Center, 289-1 Changjiang Middle Road, Changzhou, Jiangsu 213000, China.
The key molecular mechanisms underlying the sectionalized growth within bamboo or other grass internodes remain largely unknown. Here, we genetically and morphologically compared the culm and rhizome internode division zones (DZs) of a slow-growing bamboo variant (sgv) having dwarf internodes, with those of the corresponding wild type (WT). Histological analysis discovers that the sgv has an irregular internode DZ. However, the shoot apical meristems in height, width, outside shape, cell number and cell width of the sgv and the WT were all similar. The DZ irregularities first appeared post apical meristem development, in 1-mm sgv rhizome internodes. Thus, the sgv is a DZ irregularity bamboo variant, which has been first reported in bamboo according to our investigation. Transcriptome sequencing analysis finds that a number of cell wall biogenesis and cell division-related genes are dramatically downregulated in the sgv DZ. Interestingly, both transcriptomic and brassinosteroid (BR) contents detection, as well as quantitative real-time PCR analyses show that these irregularities have resulted from the BR signaling pathway defects. Brassinosteroid defect might also cause the erect leaves and branches as well as the irregular epidermis of the sgv. These results suggest that BR signaling pathway plays critical roles in bamboo internode DZ and leaf development from a mutant perspective and also explain the upstream mechanisms causing the dwarf internode of the sgv bamboo.
PMID: 34633049
FEBS Lett , IF:4.124 , 2022 Apr doi: 10.1002/1873-3468.14355
Interactions between autophagy and phytohormone signaling pathways in plants.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA.
Autophagy is a conserved recycling process with important functions in plant growth, development, and stress responses. Phytohormones also play key roles in the regulation of some of the same processes. Increasing evidence indicates that a close relationship exists between autophagy and phytohormone signaling pathways, and the mechanisms of interaction between these pathways have begun to be revealed. Here, we review recent advances in our understanding of how autophagy regulates hormone signaling and, conversely, how hormones regulate the activity of autophagy, both in plant growth and development and in environmental stress responses. We highlight in particular recent mechanistic insights into the coordination between autophagy and signaling events controlled by the stress hormone abscisic acid and by the growth hormones brassinosteroid and cytokinin and briefly discuss potential connections between autophagy and other phytohormones.
PMID: 35460261
Planta , IF:4.116 , 2022 Apr , V255 (6) : P111 doi: 10.1007/s00425-022-03886-3
An ortholog of the MADS-box gene SEPALLATA3 regulates stamen development in the woody plant Jatropha curcas.
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. chenms@xtbg.org.cn.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. chenms@xtbg.org.cn.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. zfxu@gxu.edu.cn.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning, 530004, Guangxi, China. zfxu@gxu.edu.cn.
MAIN CONCLUSION: Overexpression of JcSEP3 causes defective stamen development in Jatropha curcas, in which brassinosteroid and gibberellin signaling pathways may be involved. SEPALLATAs (SEPs), the class E genes of the ABCE model, are required for floral organ determination. In this study, we investigated the role of the JcSEP3 gene in floral organ development in the woody plant Jatropha curcas. Transgenic Jatropha plants overexpressing JcSEP3 displayed abnormal phenotypes such as deficient anthers and pollen, as well as free stamen filaments, whereas JcSEP3-RNA interference (RNAi) transgenic plants had no obvious phenotypic changes, suggesting that JcSEP3 is redundant with other JcSEP genes in Jatropha. Moreover, we compared the transcriptomes of wild-type plants, JcSEP3-overexpressing, and JcSEP3-RNAi transgenic plants. In the JcSEP3-overexpressing transgenic plants, we discovered 25 upregulated genes involved in anther and pollen development, as well as 12 induced genes in brassinosteroid (BR) and gibberellin (GA) signaling pathways. These results suggest that JcSEP3 directly or indirectly regulates stamen development, concomitant with the regulation of BR and GA signaling pathways. Our findings help to understand the roles of SEP genes in stamen development in perennial woody plants.
PMID: 35478059
Planta , IF:4.116 , 2022 Mar , V255 (4) : P92 doi: 10.1007/s00425-022-03871-w
Functions of OsWRKY24, OsWRKY70 and OsWRKY53 in regulating grain size in rice.
Northeast Institute of Geography and Agroecology, Key Laboratory of Soybean Molecular Design Breeding, Chinese Academy of Sciences, Harbin, 150081, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Northeast Institute of Geography and Agroecology, Key Laboratory of Soybean Molecular Design Breeding, Chinese Academy of Sciences, Harbin, 150081, China. buqingyun@iga.ac.cn.; Northeast Institute of Geography and Agroecology, Key Laboratory of Soybean Molecular Design Breeding, Chinese Academy of Sciences, Harbin, 150081, China. tianxiaojie@iga.ac.cn.
MAIN CONCLUSION: OsWRKY24 functions redundantly with OsWRKY53, while OsWRKY70 functions differently from OsWRKY53 in regulating grain size. Grain size is a key agronomic trait that affects grain yield and quality in rice (Oryza sativa L.). The transcription factor OsWRKY53 positively regulates grain size through brassinosteroid (BR) signaling and Mitogen-Activated Protein Kinase (MAPK) cascades. However, whether the OsWRKY53 homologs OsWRKY24 and OsWRKY70 also contribute to grain size which remains unknown. Here, we report that grain size in OsWRKY24 overexpression lines and oswrky24 mutants is similar to that of the wild type. However, the oswrky24 oswrky53 double mutant produced smaller grains than the oswrky53 single mutant, indicating functional redundancy between OsWRKY24 and OsWRKY53. In addition, OsWRKY70 overexpression lines displayed an enlarged leaf angle, reduced plant height, longer grains, and higher BR sensitivity, phenotypes similar to those of OsWRKY53 overexpression lines. Importantly, a systematic characterization of seed length in the oswrky70 single, the oswrky53 oswrky70 double and the oswrky24 oswrky53 oswrky70 triple mutant indicated that loss of OsWRKY70 also leads to increased seed length, suggesting that OsWRKY70 might play a role distinct from that of OsWRKY53 in regulating grain size. Taken together, these findings suggest that OsWRKY24 and OsWRKY70 regulate rice grain size redundantly and independently from OsWRKY53.
PMID: 35322309
Plant Mol Biol , IF:4.076 , 2022 Mar doi: 10.1007/s11103-022-01258-9
TOPLESS in the regulation of plant immunity.
415, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.; 415, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India. ashis_nandi@mail.jnu.ac.in.
KEY MESSAGE: This review presents the multiple ways how topless and topless-related proteins regulate defense activation in plants and help in optimizing the defense-growth tradeoff. Eukaryotic gene expression is tightly regulated at various levels by hormones, transcription regulators, post-translational modifications, and transcriptional coregulators. TOPLESS (TPL)/TOPLESS-related (TPR) corepressors regulate gene expression by interacting with other transcription factors. TPRs regulate auxin, gibberellins, jasmonic acid, strigolactone, and brassinosteroid signaling in plants. In general, except for GA, TPLs suppress these signaling pathways to prevent unwanted activation of hormone signaling. The association of TPL/TPRs in these hormonal signaling reflects a wide role of this class of corepressors in plants' normal and stress physiology. The involvement of TPL in immune responses was first demonstrated a decade ago as a repressor of DND1 and DND2 that are negative regulators of plant immune response. Over the last decade, several research groups have established a larger role of TPL/TPRs in plant immunity during both pattern- and effector-triggered immunity. Very recent research unraveled the significant involvement of TPRs in balancing the growth and defense trade-off. TPRs, along with proteasomal degradation complex, miRNA, and phasiRNA, suppress the activation of autoimmunity in plants under normal conditions and promote defense under pathogen attack.
PMID: 35347548
Gene , IF:3.688 , 2022 Apr , V818 : P146214 doi: 10.1016/j.gene.2022.146214
Whole genome re-sequencing and transcriptome reveal an alteration in hormone signal transduction in a more-branching mutant of apple.
Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: ghj042@163.com.; College of Horticulture, Hebei Agricultural University, Baoding, Hebei 071001, China. Electronic address: liguofang@hebau.edu.cn.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: qdsnky@163.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: 774572825@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: huangyuehy@126.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: 1196328026@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: zhangruifen316@qq.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: songerg9@126.com.; Academy of Agricultural Sciences of Qingdao, Qingdao, Shandong 266100, China. Electronic address: guanglisha@126.com.
Branch number is an important trait in grafted apple breeding and cultivation. To provide new information on molecular mechanisms of apple branching, whole reduced-representation genomes and transcriptome of a wild-type (WT) apple (Malus spectabilis) and its more-branching (MB) mutant at the branching stage were examined in this study. Comparison of WT and MB genomes against the Malus domestica reference genome identified 14,908,939 single nucleotide polymorphisms (SNPs) and 173,315 insertions and deletions (InDels) in WT and 1,483,221 SNPs and 1,725,977 InDels in MB. Analysis of the genetic variation between MB and WT revealed 1,048,575 SNPs and 37,327 InDels. Among them, 24,303 SNPs and 891 InDels mapped to coding regions of 5,072 and 596 genes, respectively. GO and KEGG functional annotation of 3,846 and 944 genes, respectively, identified 32 variant genes related to plant hormone signal transduction that were involved in auxin, cytokinin, gibberellin, abscisic acid, ethylene, and brassinosteroid pathways. The transcriptome pathways of plant hormone signal transduction and zeatin biosynthesis were also significantly enriched during MB branching. Furthermore, transcriptome data suggested the regulatory roles of auxin signaling, increase of cytokinin and genes of cytokinin synthesis and signaling, and the suppressed abscisic acid signaling. Our findings suggest that branching development in apple is regulated by plant hormone signal transduction.
PMID: 35066064
J Genet Genomics , 2022 Mar doi: 10.1016/j.jgg.2022.02.026
OsASHL1 and OsASHL2, two members of the COMPASS-like complex, control floral transition and plant development in rice.
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, Heilongjiang 150081, China; University of Chinese Academy of Sciences, Beijing 100049, China.; Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, Heilongjiang 150081, China.; College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.; College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.; Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, Heilongjiang 150081, China. Electronic address: fangjun@iga.ac.cn.
COMPASS or COMPASS-like is a highly conserved polyprotein complex in eukaryotes that is often involved in methylation of histone H3 lysine 4 (H3K4). However, the biological function of this complex in rice (Oryza sativa) is unclear. Here, we report the identification of two members of the rice COMPASS-like complex, OsASHL1 and OsASHL2, and the characterization of their functions in growth and development. The osashl1 osashl2 double mutant shows a dwarf and late-flowering phenotype. Lower expression of Ehd1, OsVIL4, and OsMADS51 in the osashl1 osashl2 double mutant background accompanies a delayed vegetative growth phase and photoperiod-sensitive phase compared to that in wild type. Notably, there is less H3K4 mono-, di- and trimethylation genome-wide in the double mutant, in particular less H3K4 trimethylation at OsVIL4. Consistent with this result, knockout of OsVIL4 gives rise to a late-flowering phenotype similar to that of the osashl1 osashl2 double mutant, suggesting that OsVIL4 is a target of the COMPASS-like complex. In addition, the expression of key genes in brassinosteroid and gibberellic acid metabolism is altered in the osashl1 osashl2 double mutant, suggesting that the COMPASS-like complex regulates plant growth and development by modulating the levels of these two phytohormones. In summary, we demonstrate that OsASHL1 and OsASHL2 are important for floral transition and plant development.
PMID: 35306222