青枯劳尔氏菌多基因家族III型效应蛋白在植物病害发展及防御系统中的作用

Functions of type III effectors from multigenic family of Ralstonia solanacearum in plant disease development and immunity defense system

摘要:

青枯劳尔氏菌是导致多种重要经济作物毁灭性枯萎（bacterial wilt）的一种土传病害，严重危害热带和亚热带地区食品安全。该细菌通过III型分泌系统（T3SS）向寄主细胞注射大量效应蛋白（T3Es）。效应蛋白是把双刃剑，既可诱导植物感病，又能激活植物防御系统。具有特殊重复结构的效应蛋白被归类成多基因家族，各家族成员协同致病，但其分子机制尚不清楚。本文围绕近年来有关多基因家族效应蛋白结构、功能和致病性等方面最新进展进行综述，为青枯菌致病机理和病害防治提供新思路。

Abstract:

Ralstonia solanacearum causes lethal wilting disease in many economic plants, threatening food security in tropical and subtropical agriculture. It injects type III effectors (T3Es) into the host cells via the type III secretion system. T3Es act as molecular double agents that are involved in either pathogenicity in the susceptible host plants or induction of hypersensitive response in the resistant host plants. A notable feature in this T3E repertoire is the existence of several multigenic families and their various internal repeats. T3Es from multigenic family of R. solanacearum contribute differently to pathogenicity towards the host plants and localize on the plant cell plasma membrane or nucleus. Previous researches demonstrate that the multigenic effectors jointly contribute to the plant disease development but are barely activated individually. However, the pathogenicity mechanism on the most multigenic effectors remains unclear. This review summarizes the recent achievements on elucidating the function of T3Es from multigenic family (GALA, HLK, SKWP, AWR and PopP) in R. solanacearum.