青枯菌hrp基因的研究进展

Progress in hrp Gene of Ralstonia solanacearum

青枯菌的hrp基因可诱发植物的超敏反应。对其基因组全序列测定表明:hrp基因簇位于基因组的大质粒上,共有20多个基因组成。从青枯菌中分离得到的可直接诱发植物超敏反应的效应蛋白主要为pop基因编码,它由hrp基因编码的类型III蛋白分泌通道释放。目前的研究表明:(1)在hrp基因簇中,hrpY、hrpX及hrpV与分泌通道的一种纤毛的组装有关;(2)hrpB是整个类型III蛋白分泌通道基因的转录激活子并作用于基因组中的其它效应基因;(3)hrpG是植物信号对hrp基因的表达进行级联调控的组分之一。

The hrp gene of Ralstonia solanacearum can induce hypersemitivity reaction （HR）in plant. The analysis of its complete genome sequence indicated that the hrp cluster is located in megaplasmid and is composed by over 20 genes. The effector which was isolated from bacteria to elicit the HR of plant is coded by pop gene and was released through hrp 111 secretion system. Recent studies of the hrp gene cluster revealed that：（1）hrpY,hrpV and hrpX genes are required for Hrp pilus assembly, （2）Activation of the type Ⅲ secretion system and effector genes in Ralstonia solanacearum is mediated by hrpB gene,（3）hrpG is one of components of the plant signal-dependent regulatory cascade to control hrp expression in Ralstonia solanacearum.