棉花凝集素受体激酶类基因 GhLRK1 介导抗黄萎病的分子机制

Verticillium wilt is the most destructive fungal disease in cotton production. Excavating and revealing the mechanism of disease resistance genes has become a popular research field in research for cotton resistance to Verticillium wilt. Previous study indicated that the family of lectin receptor-like kinases genes mediates disease resistance by recognizing pathogen effector. However, the function of these genes in cotton resistance to Verticillium wilt is still unknown. In this project, a lectin receptor kinase gene GhLRK1 involved in the resistance to Verticillium wilt disease was identified by position of the resistance locus, analysis of resistance locus and overexpression of candidate gene, etc. The characterization of GhLRK1 for resistance to Verticillium wilt will be demonstrated by subcellular localization, gene expression and polymorphism analysis. The binding function to RGD containing effector of GhLRK1 will be validated by interaction with IPI-O gene and resistance identification of transgenic Arabidopsis to Phytophthora. The interaction effector of GhLRK1 will be identified by prediction of Verticillium dahliae RGD containing effectors and validation of candidate effector. The defense reaction to Verticillium wilt mediated by GhLRK1 will be revealed by cell wall-plasma membrane adhesion observation and immune response detection. The results will expand our knowledge in signal recognition and revealing disease resistance mechanism involved in cotton resistance mediated by GhLRK1, and will provide theoretical foundations for genetic engineer modification of cotton resistance to Verticillium wilt.

黄萎病是我国棉花生产上最具毁灭性的真菌病害，挖掘抗病基因、解析抗病机理现已成为棉花抗黄萎病研究的热点课题。研究表明，凝集素受体激酶（LecRK）基因可通过识别病原菌效应因子介导抗病性，但参与棉花抗黄萎病的LecRK基因报道较少。本项目前期通过抗性位点定位、位点解析和候选基因过表达等得到具有抗黄萎病功能的LecRK类靶标基因GhLRK1。在此基础上，通过亚细胞定位、表达模式和多态性分析，研究基因抗黄萎病特性；通过与RGD效应因子IPI-O互作验证和介导拟南芥疫霉抗性鉴定，明确基因与RGD效应因子结合功能；通过大丽轮枝菌RGD效应因子预测和候选效应因子筛选，鉴定基因大丽轮枝菌中互作效应因子；通过细胞壁与质膜粘连观察和免疫反应检测，探索基因介导的抗黄萎病防御机制。上述研究将初步解析GhLRK1基因介导的抗病信号识别和抗病机理，为棉花抗黄萎病基因工程改良提供理论依据。

黄萎病是我国棉花生产上最具毁灭性的真菌病害，挖掘抗病基因、解析抗病机理现已成为棉花抗黄萎病研究的热点课题。本项目前期通过抗性位点定位、位点解析和候选基因过表达等得到具有抗黄萎病功能的凝集素受体激酶类（Lectin receptor-like kinases, LecRK）靶标基因GhLRK1。在此基础上，通过亚细胞定位、表达模式和多态性分析，研究GhLRK1基因抗黄萎病特性；通过与RGD效应因子IPI-O互作验证和介导疫霉抗性鉴定，明确GhLRK1基因与RGD效应因子结合功能；通过大丽轮枝菌RGD效应因子预测和候选效应因子筛选，鉴定GhLRK1基因在大丽轮枝菌中的互作效应因子；通过细胞壁与质膜（Cell wall-plasma membrane, CW-PM）粘连观察和免疫反应检测，探索GhLRK1基因介导的抗黄萎病防御机制。结果表明，GhLRK1可以通过凝集素结构域中ASYY基序结合大丽轮枝菌效应因子VdCE1中RGD基序，从而维持寄主细胞CW-PM粘连稳定，同时GhLRK1胞内激酶结构域可以激活寄主胞内免疫反应，从而阻止大丽轮枝菌侵染，介导棉花黄萎病抗性。本研究初步解析了GhLRK1基因介导的抗病机理，将为棉花抗黄萎病基因工程改良提供理论依据，为其他LecRK类抗病基因挖掘和功能解析提供借鉴。