摘要
阐述青枯雷尔氏菌致病基因以及它们之间的相互调节。由于青枯雷尔氏菌的复杂性,进而发展了许多青枯雷尔氏菌分子鉴定技术,并且对青枯雷尔氏菌的鉴定逐渐走向快速、便捷和灵敏高的趋势。青枯雷尔氏菌基因组约5.8Mb,具有高(G+C)含量和约5 120个可能的编码基因;它是由3.7Mb的染色体和2.1Mb的大质粒所组成,主要的致病因子有Ⅲ型hrp分泌系统产物、胞外多糖、细胞壁降解酶(包括果胶质酶以及纤维素酶等),其涉及的基因主要包括hrp基因簇、avr基因、毒性基因;青枯雷尔氏菌通过Ⅲ型分泌系统(T3SS)、II型分泌系统(T2SS)等分泌系统将多种毒性因子输送到胞外使寄主植物致病。同时,T3SS和T2SS之间也是相互影响的。上述致病因子的协调作用是由一个复杂的网络调节系统控制的,并以PhcA调节基因的启动和转录为核心,自动而精密地调节有关致病基因的表达及关闭,从而控制细菌的生长状态。
This review was focused on the virulent and avirulent genes and the regulation of Ralstonia solanacearum pathogenicity.Ralstonia solanacearum had been described as a species-complex bacterium,therefore,many technology were applied to identify this bacterium.Meanwhile,the identification of R.solanacearum became more and more quick,convenient and sensitive.The genome of R.solanacearum strain had a size of 5.8 Mb with a high（G＋C） content and a coding potential for approximately 5 120 proteins.It was organized in two replicons,a 3.7 Mb chromosome and a 2.1 Mb megaplasmid.The products of type III hrp section system,extrapolysaccharide,cell wall degrading enzymes such as pectinolytic and cellalolytic enzymes constituted were the major factors for the pathogenicity.All of these were mainly related to the hrp gene cluster,avr gene and virulence genes.The Type III secretion system（T3SS） and Type II secretion system（T2SS） that directly translocated effector proteins into the host cells were essential for the development of disease.Moreover,T2SS functionally interacts with T3SS.The virulence and pathogenicity genes of R.solanacearum were controlled by an elaborate sensory network.The system used PhcA concentration as a core to regulate the expression of pathogenic factors,and thus the growth status of bacteria.
出处
《福建农业学报》
CAS
2011年第5期899-906,共8页
Fujian Journal of Agricultural Sciences
基金
国家自然科学基金项目(30871667)
福建省自然科学基金项目(2008J0054
2009J01087)
福建省财政专项--福建省农业科学院科技创新团队建设基金(STIF-Y03)
关键词
青枯雷尔氏菌
菌株鉴定
致病因子
致病基因
致病机制
Ralstonia solanacearum
strains identification
virulence factors
pathogenicity genes
pathogenicity mechanism
