水稻的产量及品质长期经受着病原微生物的威胁，而通过利用植物自身抗病基因（R基因）培育抗性品种是最为经济有效的应对措施。水稻中迄今已鉴定到多个抗病基因并成功应用于抗病育种，但由于R基因抗病性丧失现象的广泛存在，使得对水稻R基因介导的抗病分子机制的深入研究变的更为重要。在前期工作中，我们克隆到一个新的CC-NB-LRR类抗病基因Nls1，该基因的功能获得型突变通过自主激活下游不依赖于SA和NPR1的未知抗病信号途径，从而引起一系列的抗病表型。为了进一步明确这一未知的R基因介导的抗病信号途径，通过开展nls1-1D回复突变体的筛选， 我们鉴定到son1回复突变体。本项目拟在上述基础上，利用图位克隆技术鉴定Nls1介导的抗病信号途径的关键组分Son1，并阐明该基因可能的作用模式，该基因与其他信号分子在调控水稻抗病性中的相互作用，以及探索该基因对水稻生产上使用较频繁的其他R基因潜在的调控功能。

Both yield and quality of rice are constantly affected by several major diseases. The use of resistance cultivars is economical and the best approach for disease management. So far, many resistance genes have been identified and used in rice breeding programs. However, due to rapid changes in pathogen populations, resistance conferred by R genes may not be long lasting. Thus, understanding the molecular mechanisms underlying R gene-mediated defense responses is of utmost important. Previously, we have cloned a new CC-NB-LRR-type R gene, Nls1, in rice. Our results suggested that gain-of-function mutations in Nls1 cause auto-activation of defense responses through activating of both SA and NPR1-independent defense signaling pathways .To further analyze these unknown signal transduction pathways downstream of Nls1, a suppressor of nls1-1D, son1, was isolated. In this project, we are going to identify Son1 using map-based cloning. And then, the molecular mechanisms by which Son1 affects Nls1-mediated defense responses,the interactions between SON1 and other identified defense-related factors, the potential role of Son1 in other R genes-mediated defense responses, will be analyzed.