水稻白叶枯病菌鞭毛基体基因fliExoo缺失突变分析  

Deletion analysis of fliExoo,the gene encoding a flagellar base body protein in Xanthomonas oryzae pv.oryzae

作　　者：傅本重[1] 吴茂森[1] 陈华民[1] 何晨阳[1] 

机构地区：[1]中国农业科学院植物保护研究所,植物病虫害生物学国家重点实验室,北京100193

出　　处：《植物病理学报》2010年第1期33-39,共7页Acta Phytopathologica Sinica

基　　金：中央财政国家重点实验室自主研究课题专项(SKL2007SR06)

摘　　要：为了阐明水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae,简称Xoo)鞭毛基体组分蛋白基因fliExoo的生物学功能,本研究用GmR抗性基因标记交换法成功构建了基因缺失突变体△fliExoo。与野生型菌株PXO99A相比,△fliExoo鞭毛缺失,菌体易沉降,在0.3%半固体培养基上运动能力明显降低;尽管生长速率和胞外纤维素酶活性无明显变化,但胞外多糖产生和生物膜形成能力明显下降;对水稻品种日本晴的致病性和对非寄主烟草的致敏性反应明显减弱。基因互补可以使上述突变表型恢复。因此,鞭毛基因fliExoo突变不仅影响了细菌鞭毛依赖的运动性,而且对病原菌毒性相关的表型也产生了影响。To elucidate the function of fliExoo gene encoding a putative flagellar base body protein in Xanthomonas oryzae pv. oryzae （Xoo）, the gene deletion mutant △fliExoo was generated by the Gm^R marker exchange from the wild-type strain PXO99^A. Non-flagellum, cell precipitation in the culture and significantly attenuated motility on 0.3% semi-solid medium were observed in △fliExoo compared to those of PXO99^A. While there were no apparent alterations in bacterial growth and activity of cellulase in vitro, significant decreases in extracellular polysaccharide （EPS） production and biofilm formation were found in △fliExoo. The pathogenicity on rice （Oryza sativa L cv. Nipponbare） and induction of hypersensitive response （HR） on tobacco （Nicotiana tabacum L.） were attenuated in △fliExoo. △fliExoo-C, the complementation strain restored the phenotypes of the mutant △fliExoo partially or completely. As a result, the fliExoo mutation not only influenced on flagellar motility,but also virulence-related phenotypes in Xoo.

关 键 词：水稻白叶枯病菌 fliExoo 缺失突变 运动性 毒性 

分 类 号：S432[农业科学—植物病理学]