青枯雷尔氏菌致病机制及其相关基因的研究进展.doc

11青枯雷尔氏菌致病机制及其相关基因的研究进展摘要：青枯雷尔氏菌是广泛存在的重要植物病原菌，对许多重要的经济作物和观赏性植物可造成严重的危害。本文主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5120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，其涉及到的基因主要包括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。而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。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AdvancesinpathogenicitymechanismandrelatedgenesofRalstoniasolanacearumAbstract:Ralstoniasolanacearumwasarelevantandwidespreadphytopathogenicbacteriumthatcausedabacterialwiltdiseasewithdeadlyeffectsonmanyeconomicallyimportantcropsandornamentals.ThisreviewwasfocusedonthevirulentandavirulentgenesandtheregulationofR.solanacearumpathogenicity.R.solanacearumhadbeendescribedasaspecies-complexbacterium,therefore,manytechnologywereappliedtoidentifythisbacterium.Meanwhile,theidentificationofR.solanacearumbecamemoreandmorequick,convenientandsensitive.ThegenomeofR.solanacearumstrainhadasizeof5.8Mbwithahigh(G+C)contentandacodingpotentialforapproximately5120proteins.Itwasorganizedintworeplicons,a3.7Mbchromosomeanda2.1Mbmegaplasmid.TheproductsoftypeIIIhrpsectionsystem,extrapolysaccharide,cellwalldegradingenzymessuchaspectinolyticandcellalolyticenzymesconstitutedwerethemajorfactorsforthepathogenicity.Alloftheseweremainlyrelatedtothehrpgenecluster,avrgeneandvirulencegenes.TheTypeIIIsecretionsystem(T3SS)andTypeIIsecretionsystem(T2SS)thatdirectlytranslocatedeffectorproteinsintothehostcellswereessentialforthedevelopmentofdisease.Moreover,T2SSfunctionallyinteractswithT3SS.ThevirulenceandpathogenicitygenesofR.solanacearumwerecontrolledbyanelaboratesensorynetwork.ThesystemusedPhcAconcentrationasacoretoregulatetheexpressionofpathogenicfactors,andthusthegrowthstatusofbacteria.Keywords:Ralstoniasolanacearum;strainsidentification;virulencefactors;pathogenicitygenes;pathogenicitymechanism引言青枯雷尔氏菌（Ralstonia