小麦条锈菌细胞质效应子Hasp8抑制植物基础免疫  

Cytoplasmic effector Hasp8 of Puccinia striiformis f.sp.tritici inhibits plant immunity

作　　者：赵聪聪 盛丽梅 许强 汤春蕾[1] 康振生[1] 王晓杰[1] ZHAO Congcong;SHENG Limei;XU Qiang;TANG Chunlei;KANG Zhensheng;WANG XiaoJie(State Key Laboratory of Crop Stress Biology for Arid Areas,College of Plant Protection,Northwest A&F University,Yangling 712100,Shaanxi Province,China)

机构地区：[1]西北农林科技大学植物保护学院,旱区作物逆境生物学国家重点实验室,陕西杨凌712100

出　　处：《植物保护学报》2020年第3期537-545,共9页Journal of Plant Protection

基　　金：国家重点研发计划(2018YFD0200403);国家现代农业(小麦)产业技术体系(CARS-3);陕西省科技创新团队(2018TD-004)。

摘　　要：为明确小麦条锈菌Puccinia striiformis f. sp. tritici效应子Hasp8的功能,以小麦条锈菌CYR31侵染水源11小麦叶片的cDNA为模板,通过PCR技术扩增获得Hasp8基因的完整编码区序列,采用qRTPCR技术测定Hasp8基因的表达情况,利用农杆菌介导马铃薯X病毒(potato virus X,PVX)瞬时表达体系在烟草上验证Hasp8基因是否能够抑制由Bax蛋白诱导的细胞坏死,将Hasp8基因构建到pCAMBIA1302载体用于在烟草上瞬时表达Hasp8进行亚细胞定位以明确该效应蛋白的作用空间;并将Hasp8基因构建到p EDV6载体上用于荧光假单胞菌Pseudomonas fluorescens介导的瞬时表达系统以明确该效应蛋白是否能够抑制病原相关分子模式引发的免疫反应和效应蛋白诱导的免疫反应。结果表明,Hasp8基因编码117个氨基酸,N端含22 aa的信号肽;qRT-PCR结果显示,Hasp8基因在小麦条锈菌CYR31侵染小麦水源11的早期上调表达。烟草瞬时表达Hasp8基因能够抑制由Bax诱导的细胞坏死;烟草上亚细胞定位发现效应子Hasp8定位于细胞质和细胞核;荧光假单胞菌介导的抑制植物免疫试验结果显示效应子Hasp8能够抑制由荧光假单胞菌诱导的胼胝质积累,并且抑制由小麦条锈菌无毒性生理小种CYR23引起的过敏性坏死和活性氧积累,促进病菌的侵染,菌丝面积和菌丝长度增加。To clarify the function of cytoplasmic effector Hasp8, a secreted protein of Puccinia striiformis f. sp. tritici, the CDS of Hasp8 was obtained from the cDNA of wheat leaves infected by Pu. striiformis f. sp. tritici CYR31 using PCR. The Hasp 8 gene expression in wheat Suwon 11 infected with race CYR31 was analyzed by qRT-PCR. Whether Hasp8 could inhibit BAX-induced cell death was verified in Nicotiana benthamiana via PVX mediated by Agrobacterium tumefaciens. Hasp8 was constructed into p Cambia1302 to examine its sub-localization in N. benthamiana. To clarify whether Hasp8 could inhibit PAMPs triggered immunity and effectors triggered immunity, Hasp8 was constructed into pEDV6 plasmid for Pseudomonas fluorescence-mediated transient expression in wheat. The sequence analysis revealed that Hasp8 encoded 117 amino acids with a 22 aa signal peptide at the N-terminal. qRTPCR analysis showed that Hasp8 was up-regulated in wheat Suwon 11 infected with race CYR31. Overexpressing Hasp8 could inhibit BAX-induced cell death via A. tumefaciens-mediated transient expression system. The result of sub-localization showed that Hasp8 accumulated in N. benthamiana. The suppression of plant PTI and ETI demonstrated that Hasp8 inhibited the accumulation of callose triggered by Ps. fluorescens in wheat via the type Ⅲ secretion system, and reduced the necrotic area and the reactive oxygen area caused by Pu. striiformis f. sp. tritici avirulent race CYR23, resulting in increasing hyphal area and hyphal length.

关 键 词：小麦条锈菌 效应子 植物病原相关分子模式引发的免疫反应 效应子诱导的免疫反应 

分 类 号：S435.121.42[农业科学—农业昆虫与害虫防治]