Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-5...Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.展开更多
Chitin elicitor receptor kinase 1(OsCERK1)from Oryza sativa plays a central role in coordinating symbiotic and immune responses by recognizing fungal chitin fragments of different lengths.Although the extracellular do...Chitin elicitor receptor kinase 1(OsCERK1)from Oryza sativa plays a central role in coordinating symbiotic and immune responses by recognizing fungal chitin fragments of different lengths.Although the extracellular domain of OsCERK1 has been well characterized with respect to chitin recognition,the structural basis underlying intracellular activation and downstream signal transduction remains poorly understood.In this study,we determined nine crystal structures of truncated OsCERK1 cytoplasmic kinase domains in either phosphorylated or dephosphorylated states,resolved in the absence of nucleotide or in complex with ADP,ATP,or the ATP analog AMP-PNP.Structural analyses reveal that OsCERK1 consistently adopts an intermediate kinase conformation characterized by anαC helix-out and DFG-in configuration,regardless of phosphorylation status or nucleotide binding.Functional assays further demonstrate that both the symbiotic receptor OsMYR1 and the receptor-like cytoplasmic kinase OsRLCK185 act as substrates that allosterically enhance OsCERK1 activity,with OsMYR1 exerting a stronger activation effect.This enhancement correlates with substrate-binding affinity,whereas phosphorylation does not uniformly increase substrate association.Notably,intermolecular autophosphorylation of OsCERK1 markedly elevates its catalytic activity.In addition,T479,T484,and Y492 within the activation segment are identified as critical residues required for OsCERK1 catalytic activity and substrate phosphorylation.Collectively,these findings support a dual regulatory model in which autophosphorylation enhances catalytic capacity,while substrate binding promotes allosteric activation.This study provides structural insight into OsCERK1 activation and establishes a mechanistic framework for receptor-like kinase-mediated signaling in plant immunity and symbiosis.展开更多
基金financially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFD0100903-9 and 2016YFD0100101-14)the Natural Science Foundation of Shandong Province (Grant No. ZR2014CQ007)the Rice Industry Technology Program of Shandong Province, China (Grant No. SDAIT-17-03)
文摘Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.
基金supported by grants from the National Natural Science Foundation of China(32160064)the Guangxi Bagui Youth Talent Training Program(to Z.M.)+2 种基金the Guangxi Natural Science Foundation(2024GXNSFGA010003)the State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources(sklcusa-a02)the Innovation Project of Guangxi Graduate Education(YCBZ2024012).
文摘Chitin elicitor receptor kinase 1(OsCERK1)from Oryza sativa plays a central role in coordinating symbiotic and immune responses by recognizing fungal chitin fragments of different lengths.Although the extracellular domain of OsCERK1 has been well characterized with respect to chitin recognition,the structural basis underlying intracellular activation and downstream signal transduction remains poorly understood.In this study,we determined nine crystal structures of truncated OsCERK1 cytoplasmic kinase domains in either phosphorylated or dephosphorylated states,resolved in the absence of nucleotide or in complex with ADP,ATP,or the ATP analog AMP-PNP.Structural analyses reveal that OsCERK1 consistently adopts an intermediate kinase conformation characterized by anαC helix-out and DFG-in configuration,regardless of phosphorylation status or nucleotide binding.Functional assays further demonstrate that both the symbiotic receptor OsMYR1 and the receptor-like cytoplasmic kinase OsRLCK185 act as substrates that allosterically enhance OsCERK1 activity,with OsMYR1 exerting a stronger activation effect.This enhancement correlates with substrate-binding affinity,whereas phosphorylation does not uniformly increase substrate association.Notably,intermolecular autophosphorylation of OsCERK1 markedly elevates its catalytic activity.In addition,T479,T484,and Y492 within the activation segment are identified as critical residues required for OsCERK1 catalytic activity and substrate phosphorylation.Collectively,these findings support a dual regulatory model in which autophosphorylation enhances catalytic capacity,while substrate binding promotes allosteric activation.This study provides structural insight into OsCERK1 activation and establishes a mechanistic framework for receptor-like kinase-mediated signaling in plant immunity and symbiosis.
