小麦抗条锈菌基因Yr10的抗病机制研究

Growing resistant cultivars is the most fundamental and effective method of disease control. Rapid virulence variation of pathogen results in “resistance loss” of wheat cultivars, which severely impacts the security of wheat production and foods. It is urgent to reveal the mechanism of resistance against stripe rust for wheat resistance reasonable utilization and disease control. We isolated the first seedling or all stage resistance R gene against stripe rust from wheat (Triticum aestivum L.) using a map-based cloning approach was identified as Yr10 and pseudogene 4E. Thus, in this project, we plan to further study the resistance to wheat stripe rust mediated by Yr10 gene, analyze the reason of 4E inability to encode mRNA, identify the up and down interacted target genes, elucidate the resistant signal pathway by Yr10 wheat near-isogenic line(NIL) via screening the yeast two-hybrid library, transient expression, gene silencing, RNAi, Pull-Down, bimolecular fluorescence complementation, immuno-colloidal gold technology and so on. Our results will reveal the resistant mechanism mediated by Yr10, which will offer further possibilities for stripe rust resistance using biotechnological approaches of modification the targets and lay the theoretical foundation for developing new strategies to control disease persistently.

利用抗病品种是防治病害最根本有效的措施。然而，条锈菌致病性变异频繁，导致大部分小麦生产品种“丧失”抗锈性，对小麦生产和粮食安全构成了极大威胁。因而，加强小麦抗锈机制研究，寻求防治病害新策略，对持续控制条锈病意义重大。因此，本项目拟在前期通过图位克隆获得的小麦全生育期抗条锈菌基因Yr10及其假基因4E的基础上，通过酵母双杂、瞬时表达、基因沉默、RNAi、Pull-down、双分子荧光互补、免疫胶体金等技术方法，借助Yr10抗病基因近等基因系材料，揭示Yr10假基因4E抗性丧失原因，鉴定Yr10上下游互作靶标，分析靶标功能，明确其抗病反应信号通路，深入揭示Yr10基因在小麦抗条锈病中的作用机理，为通过修饰和改造抗病通路中的功能蛋白创制新型抗病材料，进而为培育持久高效的小麦抗病品种提供理论基础和技术支撑。

利用抗病品种是防治病害最根本有效的措施。然而，条锈菌致病性变异频繁，导致大部分小麦生产品种“丧失”抗锈性，对小麦生产和粮食安全构成了极大威胁。因而，加强小麦抗锈机制研究，寻求防治病害新策略，对持续控制条锈病意义重大。前期通过图位克隆获得的小麦全生育期抗条锈菌基因Yr10属于coiled-coil（CC）NLRs家族。借助Yr10抗病基因近等基因系材料，通过细胞组织学观察和统计明确了在小麦和条锈菌互作体系中的抗病反应和条锈菌侵染的规律；通过染色体步移法克隆和烟草瞬时表达验证了Yr10启动子的活性；通过酵母双杂库筛选到Yr10的下游互作靶标TaNF-YC，并通过Pull-down、BiFC和Co-IP进行了验证，其功能是通过与Yr10的互作，进而引发活性氧的升高，从而参与了Yr10防御病原菌引起的HR反应过程；对Yr10功能结构域进行分析，发现全长和CC结构域表达的蛋白在细胞质中定位能够引起细胞坏死。同时，抗病相关基因TaRar1参与了对条锈菌的防御反应，其机制是通过调节SA的水平进而引起活性氧和HR反应而产生抗性。这些研究为深入揭示Yr10基因在小麦抗条锈病中的作用机理，为通过修饰和改造抗病通路中的功能蛋白创制新型抗病材料，进而为培育持久高效的小麦抗病品种提供理论基础和技术支撑。