水稻白叶枯病菌tatB基因的克隆及功能分析  

Cloning and functional characterization of tatB gene from Xanthomonas oryzae pv. oryzae

作　　者：沈晴[1] 张雁冰[1] 陈磊[2] 钱国良[1] 范加勤[1] 胡白石[1] 刘凤权[1] 

机构地区：[1]南京农业大学植物保护学院/农作物生物灾害综合治理教育部重点实验室,江苏南京210095 [2]上海市农业技术推广服务中心,上海201103

出　　处：《南京农业大学学报》2012年第3期57-63,共7页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(31071657;31171810;30971894);国家公益性行业(农业)科研专项(201003021;3-23)

摘　　要：根据水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae,Xoo)PXO99的tatB基因序列设计引物,采用PCR方法从PXO99中克隆了tatB基因,命名为tatBXoo。通过同源重组的方法,构建了tatBXoo的插入突变株TBM,在含有X-gluc的抗性平板上筛选,并经Southern blot杂交验证确认。表型测定结果表明:与野生型相比,tatB突变株在水稻(寄主)上的致病性减弱,但在烟草(非寄主)上仍具有引起过敏反应的能力;tatB突变导致Xoo致病相关的重要表型如胞外多糖减少,游动性及趋化性减弱。但是,tatB突变不影响Xoo在基本培养基(MMX)中正常生长、胞外纤维素酶产生和生物膜形成。A tatB homologue,designated as tatBXoo,was cloned from the genomic DNA of Xanthomonas oryzae pv.oryzae（Xoo）strain PXO99 by PCR amplification.A tatBXoo disruption mutant was successfully generated by a single cross-over event,selected by resistance on NA medium with X-gluc,and confirmed by Southern blot analysis.Phenotypic tests showed that the tatB mutant exhibited a significant reduction of virulence on host rice,but had the wild-type ability in triggering hypersensitive response in non-host tobacco.Meanwhile,the mutation of tatB impaired Xoo′s three virulence-associated functions,including extracellular polysaccharide（EPS）production,cell motility and chemotaxis.However,the disruption of tatB did not impair Xoo′s growth ability in MMX medium,production of extracellular cellulase and biofilm formation.

关 键 词：水稻白叶枯病菌 tatB基因 致病性 胞外多糖 

分 类 号：Q754[生物学—分子生物学] S435.111.47[农业科学—农业昆虫与害虫防治]