番茄斑萎病毒属病毒是寄主范围广、发生严重且较难控制的一类植物负义链RNA病毒，每年在全球农业经济作物上造成极为严重的损失。Sw-5b是番茄上对番茄斑萎病毒属病毒具广谱抗性的一个植物免疫受体蛋白，它含有典型的CC-NB-LRR结构并进化出了一个额外的N端结构域(NTD)，但是Sw-5b如何识别番茄斑萎病毒并发挥广谱抗性的调控分子机制目前仍不清楚。项目组前期研究初步表明Sw-5b与番茄斑萎病毒移动蛋白NSm存在多层识别与互作调控机制，本项目拟进一步深入阐述Sw-5b的NB-LRR、CC和额外的N端NTD结构域与NSm的识别与互作调控机制，并在此基础上解析Sw-5b的广谱抗性分子机制。研究结果有望阐明Sw-5b如何识别番茄斑萎病毒的侵染并揭示其广谱抗性机制，同时可揭示病毒与茄科作物免疫共进化中的新的识别与互作机制，为利用该类茄科免疫受体蛋白有效防控相关病毒病害提供重要的基础理论知识。

Tospovirus belongs to a class of plant negative strand RNA viruses which have broad host range, cause severe disease and are difficult to control. Tospoviruses caused serious damage in agricultural important crops worldwide each year. Sw-5b in tomato is a plant immune receptor protein which confers broad-spectrum resistance to tospoviruses. Sw-5b is a typical CC-NB-LRR protein but it evolutes an additional N-terminal domain (NTD). How Sw-5b recognizes the invasion of tospovirus and why Sw-5b confers broad-spectrum resistance against tospoviruses remains unclear. Our preliminary studies of Sw-5b showed that Sw-5b has multilayered regulatory mechanism of autoinhibition and activation in the presence of tospovirus movement protein NSm, a viral elicitor. In this proposal, we aims to further elaborate how Sw-5b NB-LRR, CC and additional N-terminal domain (NTD) recognizes and interacts with the viral elicitor NSm, and to disclose how this multilayered interactions between Sw-5b and NSm lead to broad-spectrum resistance of Sw-5b against different tospoviruses. The implementation of this project is expected to understand how Sw-5b recognizes the infection of tospovirus and to reveal the molecular mechanism of Sw-5b broad-spectrum resistance. Meanwhile, it may acquire novel mechanism for the recognition and interaction between the tospoviruses and tomato immune receptor during their co-evolution. This project can gain important knowledge which could be appiled to utilize this class of Solanaceae immune receptor protein with broad-spectrum resistance to effectively control the viral diseases or other pathogens caused diseases.