水稻转录因子ZFP3对稻瘟病害的分子调控

Rice blast, caused by Magnaporthe oryzae (M. oryzae), is one of the devastating diseases of rice, the main staple food worldwide. Developing rice with genetic resistance against pathogens is the effective way to protect rice from damage caused by this severe disease. Up to now, most studies focused on exploring and studying resistant genes. Less study on disease-related genes that are essential for pathogenesis of M. oryzae was reported. By using microarray strategy, we performed analysis on transcriptomic differences between susceptible and resistant rice varieties post infection with M. oryzae and identified a transcription factor gene ZFP3, of which the transcription expression was up-regulated specifically in the susceptible rice. By using RNA interference (RNAi) silencing approach, we found that rice plants silenced for ZFP3 exhibit enhanced disease resistance to M. oryzae. These results suggest that ZFP3 is a critical gene that is required for pathogenesis of M. oryzae. In this study, we will determine whether plants silenced for ZFP3 possess broad-spectrum resistance to diverse isolates of M. oryzae. We will then identify ZFP3-interacting proteins (ZFP3IPs) using GST Pull-down and yeast two-hybrid strategies, respectively, and elucidate the function of some important ZFP3IPs. Furthermore, we will screen the transcriptional factor ZFP3-targeting promoters using Chromosome Immune Precipitation (ChIP) method and identify the genes whose expressions are regulated by ZFP3. Finally, we will construct the molecular network of ZFP3 in rice and reveal its mechanism in regulation of pathogenesis of M. oryzae. Our study will provide basic knowledge in understanding rice disease molecularly and likely produce a novel approach for breeding rice with enhanced resistance to blast.

稻瘟病严重危害水稻的产量和品质。提高水稻稻瘟病抗性是确保粮食安全的重要保障。目前抗病性研究主要集中于水稻稻瘟病抗性基因的发掘和功能研究，而水稻中益于稻瘟病菌侵害的感病基因的报道较少。利用基因芯片对接稻瘟病菌后的抗病和感病水稻的转录组进行比较分析，我们发现转录因子基因ZFP3特异性地在水稻感病过程中受稻瘟病菌诱导上调表达。通过RNA干扰，我们发现ZFP3抑制表达后明显提高了水稻的抗病性，表明该基因是稻瘟病菌侵害水稻的必需基因。本研究拟通过病理学方法检测ZFP3是否能够广泛的影响水稻对稻瘟病的抗性；通过GST Pull-down技术筛选获得ZFP3的互作蛋白并进行验证，解析关键互作蛋白对ZFP3的功能的调节作用；利用染色体免疫沉淀（ChIP）技术筛选获得ZFP3调控的下游靶基因并进行验证；进一步构建ZFP3调控稻瘟病害的分子调控网络，揭示其分子调控机制。为稻瘟病抗病理论研究和应用提供指导。

稻瘟病是水稻重大病害之一，严重危害水稻的产量和品质。水稻的稻瘟病抗性研究一直是植物保护研究领域中的热点和难点。本项目以受稻瘟病菌诱导表达的ZFP3为研究对象，通过研究RNA干涉和过量表达该基因对稻瘟病的响应，发现ZFP3负调控稻瘟病的抗性，且不具有小种特异性；同时，利用GST Pull-down试验筛选ZFP3的互作蛋白，并通过酵母双杂交验证了ZPF3IP2和ZPF3IP3能够与ZFP3直接互作。此外，利用ChIP实验筛选了ZFP3的候选靶基因，并通过酵母单杂试验验证了ZFP3能够结合ZTG1的启动子。解析的ZFP3调控稻瘟病抗性的分子机制为稻瘟病抗病理论研究提供了重要的理论基础。