Nat Commun , IF:14.919 , 2024 Sep , V15 (1) : P7891 doi: 10.1038/s41467-024-52204-w
A secreted fungal laccase targets the receptor kinase OsSRF3 to inhibit OsBAK1-OsSRF3-mediated immunity in rice.
Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China.; State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.; Wuhan Institute of Landscape Architecture, Wuhan, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China. luzheng@mail.hzau.edu.cn.; Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China. cxy084@ahau.edu.cn.
The identification effector targets and characterization of their functions are crucial for understanding pathogen infection mechanisms and components of plant immunity. Here, we identify the effector UgsL, a ustilaginoidin synthetase with a key role in regulating virulence of the rice false smut fungus Ustilaginoidea virens. Heterologous expression of UgsL in rice (Oryza sativa) enhances plant susceptibility to multiple pathogens, and host-induced gene silencing of UgsL enhances plant resistance to U. virens, indicating that UgsL inhibits rice immunity. UgsL interacts with STRUBBELIG RECEPTOR KINASE 3 (OsSRF3). Genome editing and overexpression of OsSRF3 demonstrate that OsSRF3 plays a pivotal role in the resistance of rice to multiple pathogens. Remarkably, overexpressing OsSRF3 enhances resistance without adversely affecting plant growth or yield. We show that BRASSINOSTEROID RECEPTOR-ASSOCIATED KINASE 1 (OsBAK1) interacts with and phosphorylates OsSRF3 to activate pathogen-triggered immunity, inducing the mitogen-activated protein kinase cascade, a reactive oxygen species burst, callose deposition, and expression of defense-related genes. UgsL interferes with the phosphorylation of OsSRF3 by OsBAK1. Furthermore, UgsL mediates OsSRF3 degradation by facilitating its association with the ubiquitin-26S proteasome. Our results reveal that OsSRF3 positively regulates immunity in rice and that UgsL mediates its degradation, thereby inhibiting the activation of OsBAK1-OsSRF3-mediated immune pathways.
PMID: 39256395
Sci Adv , IF:14.136 , 2024 Sep , V10 (39) : Peadq3352 doi: 10.1126/sciadv.adq3352
The brassinosteroid receptor gene BRI1 safeguards cell-autonomous brassinosteroid signaling across tissues.
Department of Plant Molecular Biology, University of Lausanne, Lausanne, Switzerland.; Department of Biology, Duke University, Durham, NC, USA.; Howard Hughes Medical Institute, Duke University, Durham, NC, USA.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, Ghent, Belgium.
Brassinosteroid signaling is essential for plant growth as exemplified by the dwarf phenotype of loss-of-function mutants in BRASSINOSTEROID INSENSITIVE 1 (BRI1), a ubiquitously expressed Arabidopsis brassinosteroid receptor gene. Complementation of brassinosteroid-blind receptor mutants by BRI1 expression with various tissue-specific promoters implied that local brassinosteroid signaling may instruct growth non-cell autonomously. Here, we performed such rescues with a panel of receptor variants and promoters, in combination with tissue-specific transgene knockouts. Our experiments demonstrate that brassinosteroid receptor expression in several tissues is necessary but not sufficient for rescue. Moreover, complementation with tissue-specific promoters requires the genuine BRI1 gene body sequence, which confers ubiquitous expression of trace receptor amounts that are sufficient to promote brassinosteroid-dependent root growth. Our data, therefore, argue for a largely cell-autonomous action of brassinosteroid receptors.
PMID: 39321293
Plant Cell , IF:11.277 , 2024 Sep doi: 10.1093/plcell/koae251
The rice R2R3 MYB transcription factor FOUR LIPS connects brassinosteroid signaling to lignin deposition and leaf angle.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; China National Botanical Garden, Beijing 10093, China.
Leaf angle is an important agronomic trait for crop architecture and yield. In rice (Oryza sativa), the lamina joint is a unique structure connecting the leaf blade and sheath that determines leaf angle. Brassinosteroid (BR) signaling involving GLYCOGEN SYNTHASE KINASE-3 (GSK3)/SHAGGY-like kinases and BRASSINAZOLE-RESISTANT1 (BZR1) has a central role in regulating leaf angle in rice. In this study, we identified the atypical R2R3-MYB transcription factor FOUR LIPS (OsFLP), the rice homolog of Arabidopsis (Arabidopsis thaliana) AtFLP, as a participant in BR-regulated leaf angle formation. The spatiotemporal specificity of OsFLP expression in the lamina joint was closely associated with lignin deposition in vascular bundles and sclerenchyma cells. OsFLP mutation caused loose plant architecture with droopy flag leaves and hypersensitivity to BRs. OsBZR1 directly targeted OsFLP, and OsFLP transduced BR signals to lignin deposition in the lamina joint. Moreover, OsFLP promoted the transcription of the phenylalanine ammonia-lyase family genes OsPAL4 and OsPAL6. Intriguingly, OsFLP feedback regulated OsGSK1 transcription and OsBZR1 phosphorylation status. In addition, an Ala-to-Thr substitution within the OsFLP R3 helix-turn-helix domain, an equivalent mutation to that in Osflp-1, affected the DNA-binding ability and transcriptional activity of OsFLP. Our results reveal that OsFLP functions with OsGSK1 and OsBZR1 in BR signaling to maintain optimal leaf angle by modulating the lignin deposition in mechanical tissues of the lamina joint.
PMID: 39259275
Plant Cell , IF:11.277 , 2024 Sep , V36 (9) : P3498-3520 doi: 10.1093/plcell/koae163
The brassinosteroid receptor StBRI1 promotes tuber development by enhancing plasma membrane H+-ATPase activity in potato.
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China.; Department of Science and Technology of Shaanxi Province, Hybrid Rapeseed Research Center of Shaanxi Province, Yangling 712100, Shaanxi, China.; Shaanxi Engineering Research Center for Vegetables, Northwest A&F University, Yangling 712100, Shaanxi, China.
The brassinosteroid (BR) receptor BRASSINOSTEROID-INSENSITIVE 1 (BRI1) plays a critical role in plant growth and development. Although much is known about how BR signaling regulates growth and development in many crop species, the role of StBRI1 in regulating potato (Solanum tuberosum) tuber development is not well understood. To address this question, a series of comprehensive genetic and biochemical methods were applied in this investigation. It was determined that StBRI1 and Solanum tuberosum PLASMA MEMBRANE (PM) PROTON ATPASE2 (PHA2), a PM-localized proton ATPase, play important roles in potato tuber development. The individual overexpression of StBRI1 and PHA2 led to a 22% and 25% increase in tuber yield per plant, respectively. Consistent with the genetic evidence, in vivo interaction analysis using double transgenic lines and PM H+-ATPase activity assays indicated that StBRI1 interacts with the C-terminus of PHA2, which restrains the intramolecular interaction of the PHA2 C-terminus with the PHA2 central loop to attenuate autoinhibition of PM H+-ATPase activity, resulting in increased PHA2 activity. Furthermore, the extent of PM H+-ATPase autoinhibition involving phosphorylation-dependent mechanisms corresponds to phosphorylation of the penultimate Thr residue (Thr-951) in PHA2. These results suggest that StBRI1 phosphorylates PHA2 and enhances its activity, which subsequently promotes tuber development. Altogether, our results uncover a BR-StBRI1-PHA2 module that regulates tuber development and suggest a prospective strategy for improving tuberous crop growth and increasing yield via the cell surface-based BR signaling pathway.
PMID: 38819320
Proc Natl Acad Sci U S A , IF:11.205 , 2024 Sep , V121 (36) : Pe2403040121 doi: 10.1073/pnas.2403040121
SlCPK27 cross-links SlHY5 and SlPIF4 in brassinosteroid-dependent photo- and thermo-morphogenesis in tomato.
Department of Horticulture, Zhejiang University, Hangzhou 310058, China.; Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China.; Key Laboratory of Horticultural Plant Growth and Development, Agricultural and Rural Ministry of China, Zhejiang University, Hangzhou 310058, China.; School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston B15 2TT, United Kingdom.
ELONGATED HYPOCOTOYL5 (HY5) and PHYTOCHROME INTERACTING FACTORs (PIFs) are two types of important light-related regulators of plant growth, however, their interplay remains elusive. Here, we report that the activated tomato (Solanum lycopersicum) HY5 (SlHY5) triggers the transcription of a Calcium-dependent Protein Kinase SlCPK27. SlCPK27 interacts with and phosphorylates SlPIF4 at Ser-252 and Ser-308 phosphosites to promote its degradation. SlPIF4 promotes hypocotyl elongation mainly by activating the transcription of SlDWF, a key gene in brassinosteroid (BR) biosynthesis. Such a SlHY5-SlCPK27-SlPIF4-BR cascade not only plays a crucial role in photomorphogenesis but also regulates thermomorphogenesis. Our results uncover a previously unidentified mechanism that integrates Ca(2+) signaling with the light signaling pathways to regulate plant growth by modulating BR biosynthesis in response to changes in ambient light and temperature.
PMID: 39190354
Plant Biotechnol J , IF:9.803 , 2024 Sep doi: 10.1111/pbi.14461
Untargeted mutagenesis of brassinosteroid receptor SbBRI1 confers drought tolerance by altering phenylpropanoid metabolism in Sorghum bicolor.
Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona, Spain.; Institute for Integrative Systems Biology (I2SysBio), Universitat de Valencia-CSIC, Paterna, Valencia, Spain.; Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.; Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria.; Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.
Drought is a critical issue in modern agriculture; therefore, there is a need to create crops with drought resilience. The complexity of plant responses to abiotic stresses, particularly in the field of brassinosteroid (BR) signalling, has been the subject of extensive research. In this study, we unveil compelling insights indicating that the BRASSINOSTEROID-INSENSITIVE 1 (BRI1) receptor in Arabidopsis and Sorghum plays a critical role as a negative regulator of drought responses. Introducing untargeted mutation in the sorghum BRI1 receptor (SbBRI1) effectively enhances the plant's ability to withstand osmotic and drought stress. Through DNA Affinity Purification sequencing (DAP-seq), we show that the sorghum BRI1-EMS-SUPPRESSOR 1 (SbBES1) transcription factor, a downstream player of the BR signalling, binds to a conserved G-box binding motif, and it is responsible for regulating BR homeostasis, as its Arabidopsis ortholog AtBES1. We further characterized the drought tolerance of sorghum bri1 mutants and decipher SbBES1-mediated regulation of phenylpropanoid pathway. Our findings suggest that SbBRI1 signalling serves a dual purpose: under normal conditions, it regulates lignin biosynthesis by SbBES1, but during drought conditions, BES1 becomes less active, allowing the activation of the flavonoid pathway. This adaptive shift improves the photosynthetic rate and photoprotection, reinforcing crop adaptation to drought.
PMID: 39325724
Plant Physiol , IF:8.34 , 2024 Sep doi: 10.1093/plphys/kiae489
Phosphorylation of the transcription factor SlBIML1 by SlBIN2 kinases delays flowering in tomato.
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China.; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200000, China.; Hybrid Rapeseed Research Center of Shaanxi Province, Yangling 712100, Shaanxi, China.; Shaanxi Engineering Research Center for Vegetables, Northwest A&F University, Yangling 712100, Shaanxi, China.
Brassinosteroids (BRs) are well known for their important role in the regulation of plant growth and development. Plants with deficiency in BR signaling show delayed plant development and exhibit late flowering phenotypes. However, the precise mechanisms involved in this process require investigation. In this study, we cloned homologs of BRASSINOSTEROID INSENSITIVE 2 (SlBIN2), the GSK3-like protein kinase in tomato (Solanum lycopersicum). We characterized growth-related processes and phenotypic changes in the transgenic lines and found that SlBIN2s transgenic lines have delayed development and slow growing phenotypes. SlBIN2s work redundantly to negatively regulate BR signaling in tomato. Furthermore, the transcription factor SlBIN2.1-INTERACTING MYB-LIKE 1 (SlBIML1) was identified as a downstream substrate of SlBIN2s that SlBIN2s interact with and phosphorylate to synergistically regulate tomato developmental processes. Specifically, SlBIN2s modulated protein stability of SlBIML1 by phosphorylating multiple amino acid residues, including the sites Thr266 and Thr280. This study reveals a branch of the BR signaling pathway that regulates the vegetative growth phase and delays floral transition in tomato without the feedback affecting BR signaling. This information enriches our understanding of the downstream transduction pathway of BR signaling and provides potential targets for adjusting tomato flowering time.
PMID: 39288195
Plant Physiol , IF:8.34 , 2024 Sep doi: 10.1093/plphys/kiae486
A DUF21 domain-containing protein regulates plant dwarfing in watermelon.
College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China.; Guangdong Key Laboratory for New Technology Research of Vegetables, Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510640, China.; College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China.
Dwarf or semi-dwarf plant structures are well-suited for intensive farming, maximizing yield, and minimizing labor costs. Watermelon (Citrullus lanatus) is classified as an annual vine plant with elongated internodes, yet the mechanism governing watermelon dwarfing remains unclear. In this study, a compact watermelon mutant dwarf, induced by the insertion of T-DNA, was discovered. Through re-sequencing, a gene named domain of unknown function 21 (ClDUF21), located downstream of the T-DNA insertion site, was identified as the candidate gene for the dwarf mutant, and its functionality was subsequently confirmed. Watermelon mutants generated through CRISPR/Cas9-mediated knockout of ClDUF21 revealed that homozygous mutants displayed a pronounced dwarfing phenotype, and protein-protein interaction analysis confirmed the direct interaction between ClDUF21 and ClDWF1. Subsequently, we employed CRISPR/Cas9 technology to precisely modify the homologous gene CsDUF21 in cucumber (Cucumis sativus) and performed protein interaction validation between CsDUF21 and CsDWF1, thereby demonstrating that the CsDUF21 gene also exhibits analogous functionality in plant dwarfing. These findings demonstrate that ClDUF21 governs plant dwarfism by modulating the brassinosteroid synthesis pathway via ClDWF1.
PMID: 39268875
Plant Physiol , IF:8.34 , 2024 Sep doi: 10.1093/plphys/kiae465
YELLOW, SERRATED LEAF is essential for cotyledon vein patterning in Arabidopsis.
State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Venation develops complex patterns within the leaves of angiosperms, and the mechanism of leaf vein patterning remains poorly understood. Here, we report a spontaneous mutant that exhibits yellow serrated leaves and defective cotyledon vein patterning. We mapped and cloned the relevant gene YELLOW, SERRATED LEAF (YSL), a previously unreported gene in plants. YSL interacts with VH1-interacting kinase (VIK), a protein that functions in cotyledon venation development. VIK is a vascular-specific adaptor protein kinase that interacts with another vascular developmental protein, VASCULAR HIGHWAY1 (VH1)/BRASSINOSTEROID INSENSITIVE 1-LIKE 2 (BRL2), which is a receptor-like kinase of the BRASSINOSTEROID INSENSITIVE 1 (BRI1) family. Mutation of YSL affects the auxin response and the expression of auxin-related genes in Arabidopsis (Arabidopsis thaliana). Our results reveal that YSL affects cotyledon vein patterning by interacting with VIK in Arabidopsis.
PMID: 39226151
Plant Physiol , IF:8.34 , 2024 Sep , V196 (1) : P579-591 doi: 10.1093/plphys/kiae286
Effector Cs02526 from Ciboria shiraiana induces cell death and modulates plant immunity.
State Key Laboratory of Resource Insects, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, China.; Resource Institute for Chinese & Ethnic Materia Medica, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.; Chinese Academy of Tropical Agricultural Sciences, Institute of Environment and Plant Protection, Haikou 570100, China.
Sclerotinia disease is one of the most devastating fungal diseases worldwide, as it reduces the yields of many economically important crops. Pathogen-secreted effectors play crucial roles in infection processes. However, key effectors of Ciboria shiraiana, the pathogen primarily responsible for sclerotinia disease in mulberry (Morus spp.), remain poorly understood. In this study, we identified and functionally characterized the effector Cs02526 in C. shiraiana and found that Cs02526 could induce cell death in a variety of plants. Moreover, Cs02526-induced cell death was mediated by the central immune regulator brassinosteroid insensitive 1-associated receptor kinase 1, dependent on a 67-amino acid fragment. Notably, Cs02526 homologs were widely distributed in hemibiotrophic and necrotrophic phytopathogenic fungi, but the homologs failed to induce cell death in plants. Pretreatment of plants with recombinant Cs02526 protein enhanced resistance against both C. shiraiana and Sclerotinia sclerotiorum. Furthermore, the pathogenicity of C. shiraiana was diminished upon spraying plants with synthetic dsRNA-Cs02526. In conclusion, our findings highlight the cell death-inducing effector Cs02526 as a potential target for future biological control strategies against plant diseases.
PMID: 38753366
Sci Total Environ , IF:7.963 , 2024 Sep , V954 : P176369 doi: 10.1016/j.scitotenv.2024.176369
Synergistic interaction between brassinosteroid and jasmonate pathways in rice response to cadmium toxicity.
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; College of Bee Science and Biomedicine, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; Key Laboratory of Biological Breeding for Fujian and Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China. Electronic address: lulong_fafu@163.com.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fujian Province, Fuzhou 350002, PR China.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; Key Laboratory of Biological Breeding for Fujian and Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China. Electronic address: yyuansong@fafu.edu.cn.; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; Key Laboratory of Biological Breeding for Fujian and Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China. Electronic address: rszeng@fafu.edu.cn.
Brassinosteroids (BRs) and jasmonic acid (JA) are known to be involved in regulating plant responses to cadmium (Cd) stress. However, their specific roles and interaction in this process remain unclear. In this study, we discovered that exogenous BR alleviated Cd-mediated growth inhibition of rice seedlings. Enhanced Cd tolerance was also observed in m107, a BR-overproduction mutant. Phenotypic analysis of genetic materials involved in BR signaling confirmed the positive role of BR in regulating rice response to Cd toxicity. OsDLT, a key component in the BR signaling pathway, was found to be crucial for BR-mediated Cd tolerance. Further analysis demonstrated that activation of the BR pathway reduced the accumulation of Cd and reactive oxygen species (ROS) by modulating the expression of genes associated with Cd transport and ROS scavenging. Interestingly, transcriptome analysis indicated that the JA pathway was enriched in OsDLT-regulated differently expressed genes (DEGs). Gene expression and hormone assays showed that BR promoted the expression of JA pathway genes and JA levels in plants. Moreover, BR-induced tolerance was compromised in the JA signaling-deficient mutant osmyc2, suggesting that BR-mediated Cd resistance depends on the activation of the JA signaling pathway. Overall, our study revealed the synergistic interaction between BR and JA pathways in rice response to Cd stress, providing insights into the complex hormonal interplay in plant tolerance to heavy metals.
PMID: 39299342
J Exp Bot , IF:6.992 , 2024 Sep , V75 (18) : P5557-5567 doi: 10.1093/jxb/erae307
New insights into plasmodesmata: complex 'protoplasmic connecting threads'.
Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA.
Intercellular communication in plants, as in other multicellular organisms, allows cells in tissues to coordinate their responses for development and in response to environmental stimuli. Much of this communication is facilitated by plasmodesmata (PD), consisting of membranes and cytoplasm, that connect adjacent cells to each other. PD have long been viewed as passive conduits for the movement of a variety of metabolites and molecular cargoes, but this perception has been changing over the last two decades or so. Research from the last few years has revealed the importance of PD as signaling hubs and as crucial players in hormone signaling. The adoption of advanced biochemical approaches, molecular tools, and high-resolution imaging modalities has led to several recent breakthroughs in our understanding of the roles of PD, revealing the structural and regulatory complexity of these 'protoplasmic connecting threads'. We highlight several of these findings that we think well illustrate the current understanding of PD as functioning at the nexus of plant physiology, development, and acclimation to the environment.
PMID: 39001658
Int J Biol Macromol , IF:6.953 , 2024 Oct , V278 (Pt 3) : P134918 doi: 10.1016/j.ijbiomac.2024.134918
Alternaria solani core effector Aex59 is a new member of the Alt a 1 protein family and is recognized as a PAMP.
Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.; Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China; Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, Anhui 230036, China.; Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China; Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, Anhui 230036, China. Electronic address: zliu@ahau.edu.cn.
Early blight caused by Alternaria solani is a destructive disease in potato production. Here, through systematically screening of an effector protein pool consisting of 115 small cysteine-containing candidate Aex (Alternariaextracellular proteins) in A. solani, we identified a core effector protein named Aex59, a pathogen-associated molecular pattern (PAMP) molecule. Aex59 is uniquely present in the Ascomycota of fungi and can activate defense responses in multiple plants. Targeted gene disruption showed that Aex59 is a virulence factor and participates in spore development. Perception of Aex59 in Nicotiana benthamiana does not depend on the receptor-like kinases Brassinosteroid-associated kinase1 (BAK1) and Suppressor of BIR1-1 (SOBIR1), which are required for multiple pattern recognition receptors (PRR) pathways. Sequence analysis revealed that Aex59 is a new member of the Alt a 1 protein family and is a potential molecular marker capable of aiding in the classification of the fungi Alternaria spp.
PMID: 39179073
Plant J , IF:6.417 , 2024 Oct , V120 (1) : P45-59 doi: 10.1111/tpj.16968
BRASSINOSTEROID-SIGNALING KINASE 1 modulates OPEN STOMATA 1 phosphorylation and contributes to stomatal closure and plant immunity.
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.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.; College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Stomatal movement plays a critical role in plant immunity by limiting the entry of pathogens. OPEN STOMATA 1 (OST1) is a key component that mediates stomatal closure in plants, however, how OST1 functions in response to pathogens is not well understood. RECEPTOR-LIKE KINASE 902 (RLK902) phosphorylates BRASSINOSTEROID-SIGNALING KINASE 1 (BSK1) and positively modulates plant resistance. In this study, by a genome-wide phosphorylation analysis, we found that the phosphorylation of BSK1 and OST1 was missing in the rlk902 mutant compared with the wild-type plants, indicating a potential connection between the RLK902-BSK1 module and OST1-mediated stomatal closure. We showed that RLK902 and BSK1 contribute to stomatal immunity, as the stomatal closure induced by the bacterial pathogen Pto DC3000 was impaired in rlk902 and bsk1-1 mutants. Stomatal immunity mediated by RLK902 was dependent on BSK1 phosphorylation at Ser230, a key phosphorylation site for BSK1 functions. Several phosphorylation sites of OST1 were important for RLK902- and BSK1-mediated stomatal immunity. Interestingly, the phosphorylation of Ser171 and Ser175 in OST1 contributed to the stomatal immunity mediated by RLK902 but not by BSK1, while phosphorylation of OST1 at Ser29 and Thr176 residues was critical for BSK1-mediated stomatal immunity. Taken together, these results indicate that RLK902 and BSK1 contribute to disease resistance via OST1-mediated stomatal closure. This work revealed a new function of BSK1 in activating stomatal immunity, and the role of RLK902-BSK1 and OST1 module in regulating pathogen-induced stomatal movement.
PMID: 39126292
Int J Mol Sci , IF:5.923 , 2024 Sep , V25 (17) doi: 10.3390/ijms25179562
Characterization of the Bax Inhibitor-1 Family in Cauliflower and Functional Analysis of BobBIL4.
College of Life Science, Sichuan Agricultural University, No. 46, Xinkang Road, Ya'an 625014, China.; State Key Laboratory of Vegetable Biobreeding, National Engineering Research Center for Vegetables, Beijing Key Laboratory of Vegetable Germplasms Improvement, Key Laboratory of Biology and Genetics Improvement of Horticultural Crops (North China), Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
The Bax inhibitor-1 (BI-1) gene family, which is important for plant growth, development, and stress tolerance, remains largely unexplored in cauliflower. In this study, we identified and characterized cauliflower BI-1 family genes. Based on aligned homologous sequences and collinearity with Arabidopsis genes, we identified nine cauliflower BI-1 genes, which encode proteins that varied in length, molecular weight, isoelectric point, and predicted subcellular localization, including the Golgi apparatus, plasma membrane, and various compartments within the chloroplast. Phylogenetic analyses detected evolutionary conservation and divergence among these genes. Ten structural motifs were identified, with Motif 5 found to be crucial for inhibiting apoptosis. According to the cis-regulatory elements in their promoters, these genes likely influence hormone signaling and stress responses. Expression profiles among tissues highlighted the functional diversity of these genes, with particularly high expression levels observed in the silique and root. Focusing on BobBIL4, we investigated its role in brassinosteroid (BR)-mediated root development and salt stress tolerance. BobBIL4 expression levels increased in response to BR and salt treatments. The functional characterization of this gene in Arabidopsis revealed that it enhances root growth and salinity tolerance. These findings provide insights into BI-1 gene functions in cauliflower while also highlighting the potential utility of BobBIL4 for improving crop stress resistance.
PMID: 39273509
J Agric Food Chem , IF:5.279 , 2024 Sep , V72 (37) : P20646-20657 doi: 10.1021/acs.jafc.4c06316
Brassinosteroids Confer Resistance to Isoproturon through OsBZR4-Mediated Degradation Genes in Rice (Oryza sativa L.).
Research Institute of Plant Protection, Guangdong Academy of Agricultural Sciences & Key Laboratory of Green Prevention and Control of Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs & Key Laboratory of High Technology for Plant Protection of Guangdong Province, Guangzhou 510640, China.; Institute of Agricultural Facilities and Equipment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Plants have complex detoxification and metabolic systems that enable them to deal with environmental pollutants. We report accumulation of the pesticide isoproturon (IPU) in a BR signaling pathway for mutant bzr4-3/5 rice to be significantly higher than in wild-type (WT) rice controls and for exogenous 24-epibrassinolide to reverse toxic symptoms in WT rice but not in mutants. A genome-wide RNA sequencing study of WT/bzr4 rice is performed to identify transcriptomic changes and metabolic mechanisms under IPU exposure. Three differentially expressed genes in yeast cells increase the degradation rate of IPU in a growth medium by factors of 1.61, 1.51, and 1.29 after 72 h. Using UPLC/Q-TOF-MS/MS, five phase I metabolites and five phase II conjugates are characterized in rice grains, with concentrations generally decreasing in bzr4 rice grains. OsBZR4, a regulator of IPU degradation in rice, may eliminate IPU from edible parts of food crops by regulating downstream metabolic genes.
PMID: 39231315
J Agric Food Chem , IF:5.279 , 2024 Sep , V72 (36) : P19629-19643 doi: 10.1021/acs.jafc.4c04248
BLA1 Affects Leaf Angles by Altering Brassinosteroid Biosynthesis in Rice (Oryza sativa L.).
College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China.; School of Life Sciences, Central South University, Changsha 410083, Hunan, China.; State Key Laboratory for Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, China.
Brassinosteroids (BRs) are crucial plant hormones influencing diverse developmental processes in rice. While several enzymes in BR biosynthesis have been identified, their regulatory mechanisms remain largely unknown. This study highlights a novel regulatory pathway wherein the CHD3 chromatin remodeler, BLA1, epigenetically modulates the expression of key BR biosynthesis genes, BRD1 and D2. Phenotypic analysis of bla1 mutants revealed significant alterations, such as increased leaf angles and longer mesocotyls, which were alleviated by BR synthesis inhibitors. Moreover, the bla1 mutants showed elevated BR levels that correlated with the significant upregulation of the expression levels of BRD1 and D2, particularly at the lamina joint sites. Mechanistically, the yeast one-hybrid and chromatin immunoprecipitation assays revealed specific binding of BLA1 to the promoter regions of BRD1 and D2, accompanied by a marked enrichment of the transcriptionally active histone modification, H3K4me3, on these loci in the bla1 mutant. Functional assessments of the brd1 and d2 mutants confirmed their reduced sensitivity to BR, further underscoring their critical regulatory roles in BR-mediated developmental processes. Our findings uncovered an epigenetic mechanism that governs BR biosynthesis and orchestrates the expression of BRD1 and D2 to modulate BR levels and influence rice growth and development.
PMID: 39207175
Plant Mol Biol , IF:4.076 , 2024 Sep , V114 (5) : P104 doi: 10.1007/s11103-024-01494-1
The underlying molecular mechanisms of hormonal regulation of fruit color in fruit-bearing plants.
College of Forestry, Hebei Agricultural University, Baoding, 071001, Hebei, China. noorpk_1990@yahoo.com.; Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071001, Hebei, China. noorpk_1990@yahoo.com.; College of Horticulture, Hebei Agricultural University, Baoding, 071001, Hebei, China. noorpk_1990@yahoo.com.; Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071001, Hebei, China.; College of Horticulture, Hebei Agricultural University, Baoding, 071001, Hebei, China.; College of Forestry, Hebei Agricultural University, Baoding, 071001, Hebei, China. yangms100@126.com.; Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071001, Hebei, China. lmj1234567@aliyun.com.; College of Horticulture, Hebei Agricultural University, Baoding, 071001, Hebei, China. lmj1234567@aliyun.com.
Fruit color is a key feature of fruit quality, primarily influenced by anthocyanin or carotenoid accumulation or chlorophyll degradation. Adapting the pigment content is crucial to improve the fruit's nutritional and commercial value. Genetic factors along with other environmental components (i.e., light, temperature, nutrition, etc.) regulate fruit coloration. The fruit coloration process is influenced by plant hormones, which also play a vital role in various physiological and biochemical metabolic processes. Additionally, phytohormones play a role in the regulation of a highly conserved transcription factor complex, called MBW (MYB-bHLH-WD40). The MBW complex, which consists of myeloblastosis (MYB), basic helix-loop-helix (bHLH), and WD40 repeat (WDR) proteins, coordinates the expression of downstream structural genes associated with anthocyanin formation. In fruit production, the application of plant hormones may be important for promoting coloration. However, concerns such as improper concentration or application time must be addressed. This article explores the molecular processes underlying pigment formation and how they are influenced by various plant hormones. The ABA, jasmonate, and brassinosteroid increase anthocyanin and carotenoid formation, but ethylene, auxin, cytokinin, and gibberellin have positive as well as negative effects on anthocyanin formation. This article establishes the necessary groundwork for future studies into the molecular mechanisms of plant hormones regulating fruit color, ultimately aiding in their effective and scientific application towards fruit coloration.
PMID: 39316226
Biochem Biophys Res Commun , IF:3.575 , 2024 Sep , V723 : P150222 doi: 10.1016/j.bbrc.2024.150222
Brassinosteroid-signaling kinase ZmBSK7 enhances salt stress tolerance in maize.
College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.; College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing, 210095, China. Electronic address: ayzhang@njau.edu.cn.
Salinity has become a crucial environmental factor that restricts plant growth, development, and productivity. Nevertheless, the mechanisms by which plants react to salt stress remain inadequately comprehended. In this study, we identified maize brassinosteroid-signaling kinase gene ZmBSK7 which is homologous to AtBSK1. Our results showed that ZmBSK7 is induced by salt stress and ZmBSK7 localizes in the plasma membrane. ZmBSK7 overexpression increases salt tolerance, while its knockdown decreases salt tolerance in maize. ZmBSK7 reduces the malondialdehyde (MDA) content and the percentage of electrolyte leakage, and also elevates the activities of antioxidant enzymes. Furthermore, ZmBSK7 promotes K(+) content accumulation and reduces Na(+)/K(+) ratio. Further found that ZmBSK7 physically interacts with K(+) efflux antiporter 2 (ZmKEA2) in vivo and in vitro. Salt stress also increased the expression of ZmKEA2. Thus, ZmBSK7 improves salt tolerance in maize by affecting ZmKEA2 expression to promote K(+) content accumulation and reduce Na(+)/K(+) ratio. This study enhances the comprehension of BSK proteins and establishes a theoretical foundation for investigating salt stress tolerance in plants.
PMID: 38850813
J Plant Physiol , IF:3.549 , 2024 Nov , V302 : P154318 doi: 10.1016/j.jplph.2024.154318
NHX5/NHX6/SPY22 complex regulates BRI1 and brassinosteroid signaling in Arabidopsis.
Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China; College of Life Science and Technology, Tarim University, Alar, 843300, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China. Electronic address: qiuqsh@lzu.edu.cn.
NHX5 and NHX6, Arabidopsis endosomal antiporters, play a vital role in facilitating ion and pH homeostasis in endosomal compartments. Studies have found that NHX5 and NHX6 are essential for protein trafficking, auxin homeostasis, and plant growth and development. Here, we report the role of NHX5 and NHX6 in brassinosteroid (BR) signaling. We found that hypocotyl growth was enhanced in nhx5 nhx6 under epibrassinolide (eBR) treatment. nhx5 nhx6 bri1 was insensitive to eBR treatment, indicating that NHX5 and NHX6 are downstream of the BRI1 receptor in BR signaling. Moreover, confocal observation with both hypocotyls and root tips showed that BRI1-YFP localization in the plasma membrane (PM) was reduced in nhx5 nhx6. Interestingly, brefeldin A (BFA) treatment showed that formation of the BFA bodies containing BRI1 and their disassembling were disrupted in nhx5 nhx6. Further genetic analysis showed that NHX5/NHX6 and SYP22 may act coordinately in BR signaling. NHX5 and NHX6 may regulate SYP22 function by modulating cellular K(+) and pH homeostasis. Importantly, NHX5 and NHX6 colocalize and interact with SYP22, but do not interact with BRI1. In summary, our findings indicate that NHX5/NHX6/SYP22 complex is essential for the regulation of BRI1 recycling and PM localization. The H(+)-leak facilitated by NHX5 and NHX6 offers a means of controlling BR signaling in plants.
PMID: 39059150
J Plant Physiol , IF:3.549 , 2024 Oct , V301 : P154304 doi: 10.1016/j.jplph.2024.154304
Modulation of plant polyamine and ethylene biosynthesis; and brassinosteroid signaling during Bacillus endophyticus J13-mediated salinity tolerance in Arabidopsis thaliana.
Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, India.; Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, India. Electronic address: sridev.mohapatra@hyderabad.bits-pilani.ac.in.
Salinity stress adversely impacts plant growth and development. Plant growth-promoting rhizobacteria (PGPR) are known to confer salinity stress tolerance in plants through several mechanisms. Here, we report the role of an abiotic stress-tolerant PGPR strain, Bacillus endophyticus J13, in promoting salinity stress tolerance in Arabidopsis thaliana, by elucidating its impact on physiological responses, polyamine (PA) and ethylene biosynthesis, and brassinosteroid signaling. Physiological analysis revealed that J13 can significantly improve the overall plant growth under salt stress by increasing the biomass, relative water content, and chlorophyll content, decreasing membrane damage and lipid peroxidation, and modulating proline homeostasis in plants. Evaluation of shoot polyamine levels upon J13 inoculation revealed an overall decrease in the levels of the three major PAs, putrescine (Put), spermidine (Spd), and spermine (Spm), under non-stressed conditions. Salt stress significantly increased the levels of Put and Spm, while decreasing the Spd levels in the plants. J13 inoculation under salt-stressed conditions, significantly decreased the Put levels, bringing them closer to those of the untreated control plants, whereas Spd and Spm levels did not change relative to the non-inoculated salt-stressed plants. The modulation of PA levels was accompanied by changes in the expressions of key PA biosynthetic genes under all treatments. Among the ethylene biosynthetic genes that we studied, ACS1 was induced by J13 inoculation under salt stress. J13 inoculation under salt stress resulted in the modulation of the expressions of BR-signaling genes, upregulating the expressions of the positive regulators of BR-signaling (BZR1 and BES2) and downregulating that of the negative regulator (BIN2). Our results provide a new avenue for J13-mediated salt stress amelioration in Arabidopsis, via tight control of polyamine and ethylene biosynthesis and enhanced brassinosteroid signaling.
PMID: 38991234
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2404807 doi: 10.1080/15592324.2024.2404807
Crosstalk among plant hormone regulates the root development.
Ministry of Education Key Laboratory of Molecular and Cellular Biology; Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation; Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China.; College of Life Sciences, Hengshui University, Hengshui, China.
The plant root absorbs water and nutrients, anchors the plant in the soil, and promotes plant development. Root is developed from root apical meristem (RAM), which is formed during embryo stage and is maintained by dividing stem cells. Plant hormones have a predominant role in RAM maintenance. This review evaluates the functional crosstalk among three major hormones (auxin, cytokinin, and brassinolide) in RAM development in Arabidopsis, integrating a variety of experimental data into a regulatory network and revealing multiple layers of complexity in the crosstalk among these three hormones. We also discuss possible directions for future research on the roles of hormones in regulating RAM development and maintenance.
PMID: 39279500
Plant Commun , 2024 Sep , V5 (9) : P100982 doi: 10.1016/j.xplc.2024.100982
Brassinosteroid biosynthesis and signaling: Conserved and diversified functions of core genes across multiple plant species.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA; Interdepartmental Genetics and Genomics Graduate Program, Iowa State University, Ames, IA 50011, USA.; Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA; Interdepartmental Genetics and Genomics Graduate Program, Iowa State University, Ames, IA 50011, USA. Electronic address: vollbrec@iastate.edu.; USDA-ARS, Plant Genetics Research Unit, Columbia, MO 65201, USA. Electronic address: norman.best@usda.gov.
Brassinosteroids (BRs) are important regulators that control myriad aspects of plant growth and development, including biotic and abiotic stress responses, such that modulating BR homeostasis and signaling presents abundant opportunities for plant breeding and crop improvement. Enzymes and other proteins involved in the biosynthesis and signaling of BRs are well understood from molecular genetics and phenotypic analysis in Arabidopsis thaliana; however, knowledge of the molecular functions of these genes in other plant species, especially cereal crop plants, is minimal. In this manuscript, we comprehensively review functional studies of BR genes in Arabidopsis, maize, rice, Setaria, Brachypodium, and soybean to identify conserved and diversified functions across plant species and to highlight cases for which additional research is in order. We performed phylogenetic analysis of gene families involved in the biosynthesis and signaling of BRs and re-analyzed publicly available transcriptomic data. Gene trees coupled with expression data provide a valuable guide to supplement future research on BRs in these important crop species, enabling researchers to identify gene-editing targets for BR-related functional studies.
PMID: 38816993