整合寄主因子（IHF）对水稻基腐病细菌致病性调控机理研究

玉米狄克氏菌（Dickeya zeae，简称D. zeae）是世界上重要病原细菌，侵染水稻、玉米、马铃薯和香蕉等10多种寄主植物。由该菌引起的水稻基腐病是水稻上重要病害之一，在东南亚一些国家和我国15个省市先后报道发生，严重时造成水稻绝产，目前对该病原细菌的致病性及其调控机理了解较少。申请人前期研究首次发现，整合寄主因子（ integration host factor，IHF）是水稻基腐病菌的全局性调控因子，包括IhfA和IhfB两个亚基，在致病性调控中都起重要作用，但其调控机理尚不清楚。本项目拟通过构建突变体，致病表型测定、链特异性转录本测序分析、蛋白表达纯化、DNA-蛋白质互作等研究方法和技术，分析IHF所调控的下游致病基因，明确IHF结合的DNA特征及其调控分子机理。项目的完成对于深入了解D.zeae致病性调控的分子机制，寻找新的药物靶标和病害防控策略，具有理论和实际意义。

Dickeya zeae（D. zeae) is an important pathogenic bacteria in the world, which can infect 10 kinds of host plants，such as rice, maize, potato and banana.Rice bacterial foot rot caused by D. zeae is one of the most important diseases on rice. It occurred seriously in some countries in Southeast Asia and 15 provinces in China. Little is known for the virulence and its regulation mechanism in D. zeae. Our previous research had found that the integration host factor (IHF) is a global regulator of D. zeae. IHF has two subunits IhfA and IhfB, which have played an important role in the virulence regulation. However the regulation mechanism is still not clear.This project intends to construct mutants as well as the investigation for pathogenic phenotype determination, strand-specific transcripts sequencing, expression and purification of proteins and DNA-protein interaction so as to determine the downstream genes regulated by IHF. In addition, we will make clear the DNA features of specific IHF binding and its regulation mechanism.The completion of our project will provide scientific values for understanding of molecular mechanism of virulence regulation in D. zeae, as wel as looking for the target of drugs and the disease control.