丁香假单胞菌中的III型分泌系统及其调控机制研究进展

丁香假单胞菌(Pseudomonas syringae)是引起许多作物病害的一种革兰氏阴性病原细菌。该细菌入侵寄主植物细胞主要通过其III型分泌系统(type III secretion system，T3SS)将效应蛋白转入到寄主真核细胞内，抑制寄主免疫功能，以达到成功侵染和定殖的目的。III型分泌系统的主调控因子RhpR/S通过感受环境信号的变化直接调控hrpR/S及其他毒力相关通路。同时III型分泌系统基因的表达也受到其他调控因子的影响，包括σ因子HrpL、双组分系统GacA/S、Lon蛋白酶、第二信使分子和环境信号等。本文在简要介绍丁香假单胞菌III型分泌系统组成和功能的基础上，综述丁香假单胞菌III型分泌系统调控机制的最新研究进展，以期为深入探究病原菌的致病机制提供参考和思路。

T3SS in Pseudomonas syringae and the regulatory mechanism:a review

The Gram-negative Pseudomonas syringae causes diverse plant diseases. It injects effector proteins into host cells via type III secretion system (T3SS), thereby suppressing the immune system of the host and colonizing the host. RhpR/S, the main regulator of T3SS, directly regulates hrpR/S and other virulence-related pathways in response to changes in environmental signals. The expression of the T3SS genes is also affected by other regulatory factors, including sigma factor HrpL, two-component system GacA/S, Lon protease, second messenger molecules, and environmental signals. This paper aims to brief the composition and functions of T3SS in P. syringae and review the regulatory mechanism of T3SS in the bacterial species, which is expected to serve as a reference for in-depth research on the pathogenic mechanisms of P. syringae.