水稻白叶枯病菌Ⅲ型效应物基因hpaF与毒力相关  

Type Ⅲ secretion effector gene hpaF is required for full virulence of Xanthomonas oryzae pv. oryzae

作　　者：刘国芳[1] 蒋蓉[2] 苏辉昭[2] 牛祥娜 玉延华[2] 姜伟[2] 何勇强[2] 

机构地区：[1]广西大学农学院,广西南宁530004 [2]广西大学生命科学与技术学院,广西南宁530004

出　　处：《华南农业大学学报》2015年第5期67-74,共8页Journal of South China Agricultural University

基　　金：973计划项目(2011CB100701);公益性行业(农业)科研专项(201303015)

摘　　要：【目的】稻黄单胞杆菌水稻致病变种Xanthomonas oryzae pv.oryzae(Xoo)PXO99A菌株中PXO_03420基因被注释为编码具有多个LRR的Ⅲ型效应物基因hpaF,本研究旨在明确hpaF基因的功能,为完善XooⅢ型效应物的研究提供一定的理论基础.【方法】通过同源双交换构建hpaF基因的缺失突变体,并通过表型分析、致病性试验和遗传互补对该基因的功能进行研究.【结果和结论】本研究发现,hpaF基因突变后对水稻日本晴品种的致病力降低了51.81%,减弱了细菌在非寄主植物蓖麻上的过敏反应.而带有hpaF全基因片段的pLAFR3能够恢复hpaF突变体的致病表型,结果表明hpaF基因与水稻白叶枯病菌的致病性相关.【Objective】Xanthomonas oryzae pv. oryzae( Xoo) is the causal agent of rice bacterial leaf blight disease. The type III secretion system( T3SS) and type III secretion effectors( T3SEs) play important roles in the pathogenesis of this phytopathogen. The gene PXO_03420 of Philippines strain Xoo PXO99 Ais annotated as hpa F gene,which was predicted to encode T3 SE gene with leucine-rich repeat domains. The purpose of the study is to identify the function of gene PXO_03420( hpa F),which can provide theoretical supports for the study of type III secretion effectors of Xoo.【Method】The hpa F gene deletion mutant was constructed by homologous double exchange mutational method. The mutant was subjected to phenotypic analysis,virulence assays and genetic complementation experiments. 【Result and conclusion】It was found that the virulence of hpa F gene mutant on rice,Oryza sativa L. japonica cv.Nipponbare,was reduced by 51. 81% compared with the wild type strain,and the hypersensitive response( HR) induction of the mutant on the leaves of non-host castor oil plant,Ricinus communis,was significantly weakened. The intact coding region of hpa F carried by p LAFR3 could partly complement the virulence of mutant to the level of wild type strain. This study demonstrates that hpa F gene is required for full virulence of Xoo.

关 键 词：水稻白叶枯病菌 Ⅲ型效应物 hpaF基因 毒力 过敏反应 

分 类 号：S435[农业科学—农业昆虫与害虫防治]