水稻白叶枯病菌hrcU基因缺失突变体构建及功能研究  

Site-Directed Mutagenesis and Functional Analysis of hrcU Gene from Rice Pathogen Xanthomonas oryzae pv. oryzae

作　　者：刘希玲[1] 邹华松[2] 邹丽芳[2] 陈功友[1,2] 

机构地区：[1]南京农业大学植物保护学院/农业部病虫监测与治理重点开放实验室,江苏南京210095 [2]上海交通大学农业与生物学院,上海200240

出　　处：《中国水稻科学》2010年第4期348-352,共5页Chinese Journal of Rice Science

基　　金：国家973计划资助项目(2006CB101902);国家自然科学基金资助项目(30710103902;30671354);公益性行业(农业)科研专项经费资助项目(NYHYZX07-056)

摘　　要：通过基因敲除方式,构建了水稻白叶枯病菌hrcU基因的缺失突变体。突变体丧失了在水稻上的致病性和在非寄主植物上的过敏反应。携带hrcU基因的黏粒完全互补了hrcU突变菌株的表型,互补菌在水稻组织中的生长能力也与野生型菌株相当。免疫杂交结果显示,hrcU基因突变后,水稻白叶枯病菌的Harpin蛋白Hpa1不能从细胞内分泌到胞外。这些结果表明,水稻白叶枯病菌hrcU基因的主要功能是形成Ⅲ型分泌系统,将效应分子分泌到病原细菌胞外,从而决定了在非寄主上的过敏反应和在水稻上的致病性。The hrp gene cluster is composed of 27 members in rice pathogen Xanthomonas oryzae pv.oryzae（Xoo）.To analyze the function of hrcU gene,the hrcU gene was knocked out by allelic exchange.The resulting hrcU mutant lost the pathogenicity in rice and the ability to trigger hypersensitive response in nonhost plant tobacco.The sole hrcU gene fully restored the phenotypic alterations in pathogenicity in rice,hypersensitive response in tobacco,and bacterial growth in rice.Western blot displayed that the typeⅢ secretion system was destroyed in hrcU mutant in which the T3S effectors Hpa1 could not be secreted into extracellular.This indicates that the hrcU gene of Xoo was essential for type Ⅲ secretion system to deliver effectors into plants.

关 键 词：水稻白叶枯病菌 定点突变 致病性 过敏反应 Ⅲ型分泌系统 

分 类 号：S435.111.4[农业科学—农业昆虫与害虫防治]