7种检疫性植物病原黄单胞菌Ⅲ型分泌系统和效应蛋白编码基因的差异性分析  

Comparative analysis of type-Ⅲ secretion system and T3SS-secreted effectors among seven quarantine Xanthomonas pathovars

作　　者：刘良[1] 马文秀[1] 邹丽芳[1] 陈晓斌[1] 陈功友[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《植物病理学报》2016年第1期37-46,共10页Acta Phytopathologica Sinica

基　　金：国家自然科学基金资助项目(31471742;31470235)

摘　　要：γ-变形菌纲（γ-Proteobactefia）的黄单胞菌属（Xanthomonas）的大多数种类可引起植物病害，多数是我国检疫对象。与其他革兰氏阴性植物病原细菌一样，植物病原黄单胞菌可通过高度保守的Ⅲ型分泌系统（type-Ⅲsecretionsystem，T3SS）分泌效应蛋白（T3SS-secreted effectors，T3SEs）进入植物细胞，在非寄主植物和抗病寄主植物上产生过敏反应（hypersensi-tive response，HR）以及在感病寄主植物上具有致病性。尚不清楚哪些种类的黄单胞菌具有T3SS和缺少哪些T3SE是否可作为检疫的依据。搜集7种检疫性植物病原黄单胞菌，通过PCR和Southern杂交试验结果发现：香蕉细菌性青枯病菌（X．campestrispv．musacearum）的ICMP287和ATCC49084菌株、甘蔗流胶病菌（X．axonopodispv．vasculorum）ATCCl3901菌株、洋葱细菌性叶枯病菌（X．axonopodispv．allii）的LMG576和LMG578菌株中不含有tale基因，并且ATCCl3901菌株既不含有T3SS基因也不含有hpal和xopQ基因；菜豆细菌性疫病菌（X．campestrispv．phaseoli）ATCC49119菌株不含有hpal基因。相应地，推测含有2～12个tale基因的黄单胞菌有：大豆斑疹病菌（X．axonopodispv．glycines）ICMP5732和ATCC43911菌株、豌豆细菌性疫病菌（x．axonopodispv．vignicola）ATCCll648菌株、棉花细菌性角斑病菌（X．campestrispv．malvacearum）ATCCl2131和（X．campestrispv．phaseoli）ATCC49119菌株。大豆细菌性斑疹病菌ATCC43911菌株尽管含有hpal、xopQ和hrcC基因，但在非寄主烟草上不能激发HR反应；而甘蔗流胶病菌ATCCl3901菌株不含有助al、xopQ和hrcC基因，却激发烟草产生HR反应。这些结果对于分析比较不同植物病原黄单胞菌的致病性因子和设计特定的植物检疫靶点提供了科学线索．Most species of Xanthomonas genus in γ-Proteobacteria are plant pathogenic bacteria, causing hyper- sensitive response （HR） on non-host plants and resistant host plants and pathogenicity on susceptible host plants via highly conserved type-Ⅲ secretion system （T3SS） through which T3SS effectors （T3SEs） are injected into plant cells. However, it remains unclear which Xanthomonas species lacking of T3SS and T3SEs that can be the targets to understand pathogenicity factors and to design specific probes for quarantine detection. Here, seven Xanthomonas species were collected and detected. PCR and Southern blot results showed that X. campestris pv. musacearum ICMP287 and ATCC49084 strains （the causal agents of banana bacterial wilt）, X. axonopodis pv. vasculorum ATCC13901 strain （gumming in sugarcane）, and X.axonopodis pv. allii LMG576 and LMG578 strains （bacterial blight of onion） lacked the tale genes which encode transcriptional activator-like effectors, of these three species X. axonopodis pv. vasculorum ATCC13901 possesses neither hpal nor xopQ and hrcC genes for the T3SS; and X. campestris pv. phaseoli ATCC49119 strain （common bacterial blight in phaseolus beans） possesses xopQ and hrcC genes but hpal. In contrast, 2 to 12 putative tale genes were detected in the other strains including X. axonopodis pv. glycines ICMP5732 and ATCC43911 （bacterial pustule of soybean）, X. axo- nopodis pv. vignicola ATCCl16443 （Cowpea Bacterial Blight and Pustule）, X. campestris pv. malvacearum ATCC12131 （cotton bacterial blight）, and X. c. pv. phaseoli ATCC49119. HR assays on tobacco demonstrated that only X. axonopodis pv. glycines ATCC48911 strain did not trigger HR, despite that hpal, xopQ, hrcC and tale genes were detected in this strain. These results provided fundamental basis for further understanding the differences of pathogenic determinants and designing specific quarantine probes among them.

关 键 词：黄单胞菌 Ⅲ型分泌系统 效应蛋白 过敏反应 

分 类 号：S432.42[农业科学—植物病理学]