小麦抗条锈基因Yr10的抗病通路研究

Resistance Pathway of Wheat Stripe Rust Resistance Gene Yr10

小麦抗条锈病基因Yr10作为全生育期抗性基因,对国内大部分的条锈菌生理小种表现抗性,为探究Yr10介导的抗病通路,以小麦AvocetS(AvS)和其近等基因系AvS Yr10 NIL(AvS+Yr10)为材料,接种条锈菌CYR31后分别构成亲和与非亲和体系,通过分析含有抗病基因Yr10非亲和体系中的信号分子变化,比较非亲和与亲和体系中抗病过程相关基因的表达差异和功能,进而解析Yr10的抗病通路。结果表明,在含有抗病基因Yr10的非亲和体系中,RAR1、HSP90和SGT1可能参与抗病基因(R)激活下游的抗病通路。R基因的激活引发活性氧在接菌后早期迅速积累,同时内源SA水平在接菌后出现高峰,随后寄主细胞迸发活性氧,并引起下游病程相关基因PR1表达显著上调,促进植物细胞的坏死,表现为过敏性坏死反应(HR)。总体来说,Yr10的抗病通路为通过R基因的激活后引发SA信号分子,进而影响活性氧的积累,最终诱导下游PR基因的表达和HR反应的发生。

Yr10 confers resistance to stripe rust starting at seedling stage,which is also called all-stage resistance,performing resistance to the most popular stripe rust.To explore the resistance pathway mediated by Yr10,a wheat cultivar AvocetS(AvS)and its near-isogenic line AvS Yr10 NIL(AvS+Yr10)were individually inoculated with CYR31 to serve as the compatible and incompatible interaction system.The resistance mechanism mediated by Yr10 was analyzed by comparing the difference in the expression of signal molecules in the incompatible interaction and related genes expression between the incompatible and the compatible interactions.In the incompatible interaction,RAR1,SGT1 and HSP90 may participate to regulate and active the downstream signaling pathways mediated by R gene.The activation of R gene triggers the rapid accumulation of reactive oxygen species(ROS)at early stage after inoculation,and the endogenous SA level peaks appeared at early stage after inoculation.Then the host cells burst out ROS after inoculation,and the downstream disease-related gene PR1 were significantly up-regulated.Meanwhile,it caused a rapid cell death,manifested as hypersensitive response(HR).Overall,after the activation of R gene,the accumulation of ROS through SA signaling molecules in the Yr10 resistance pathway ultimately led to the expression of downstream PR gene and HR.