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.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
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)
关键词
水稻白叶枯病菌
tatB基因
致病性
胞外多糖
Xanthomonas oryzae pv.oryzae(Xoo) tatB gene pathogenicity extracellular polysaccharide(EPS)