水稻基腐细菌ExpS感受蛋白中Hamp结构域的敲除及功能分析

Knock-Out and Functional Analysis of Hamp Domain of ExpS in Dickeya zeae

双组分调控系统是细菌中普遍存在和非常保守的一种重要调节机制,研究水稻基腐细菌Dickeya zeae中双组分信号转导系统及其对致病性的调控具有重要的意义.本文通过同源重组、标记置换等分子遗传操作方法,成功敲除了水稻基腐病细菌双组分系统感受蛋白ExpS中的Hamp功能域,获得了Hamp功能片段缺失突变株及互补体.致病性及毒素产生能力测定试验结果表明,Hamp在ExpS/ExpA双组分系统的信号转导途径中起重要作用,调控水稻基腐菌毒素的产生并影响水稻的致病性及烟草的HR反应.

Two-component signal transduction systems（TCS） is a kind of important regulation mechanism and very conservative in many bacteria.It has great significance for the study of virulence regulation about TCS in Dickeya zeae,the pathogen of bacterial foot rot disease in rice.In this study,mutant of Hamp domain（ΔHamp） from sensor ExpS and its complementary strain were successfully acquired by the way of homologous recombination and marking replacement（gene knock-out）.Further investigations of Hamp mutant showed the virulence decreation on rice,reduced HR on tobacco and lower production of toxin.The results indicated that Hamp in ExpS might play an important role in signal transduction between the two-component system ExpS/ExpA and it was required for the virulence regulation in Dickeya zeae.