Pseudomonas type III effector AvrPtoB induces plant disease susceptibility by inhibition of host programmed cell death
Pseudomonas type III effector AvrPtoB induces plant disease susceptibility by inhibition of host programmed cell death
复制标题
DOI：
10.1093/emboj/cdg006
复制
发表时间：
2003-01-02
期刊：
影响因子：
11.4
通讯作者：
Martin, GB
中科院分区：
文献类型：
--
作者：
Abramovitch, RB;Kim, YJ;Martin, GB
AvrPtoB III型效应蛋白在植物病原体的不同属中是保守的，表明其在致病机理中起重要作用。在这里，我们报告说，假单胞菌AvrPtoB的植物细胞内的行为，以抑制程序性细胞死亡（PCD）启动的Pto和Cf 9抗病蛋白，显着的，促凋亡的小鼠蛋白Bax。AvrPtoB还抑制了酵母中的PCD，表明AvrPtoB作为跨界的细胞死亡抑制剂发挥作用。使用截短的AvrPtoB蛋白，我们确定了不同的N-和C-末端结构域的AvrPtoB是足够的主机识别和PCD抑制，分别。我们还鉴定了一种新的抗性表型Rsb，其由在抗PCD结构域中破坏的AvrPtoB截短触发。一株假单胞菌Pv.番茄DC 3000株染色体突变的AvrPtoB C-末端引起RSB介导的免疫力在以前敏感的番茄植物和疾病恢复时，全长AvrPtoB的反式表达。因此，我们的研究结果表明，III型效应可以诱导植物对细菌感染的易感性，通过抑制宿主PCD。
The AvrPtoB type III effector protein is conserved among diverse genera of plant pathogens suggesting it plays an important role in pathogenesis. Here we report that Pseudomonas AvrPtoB acts inside the plant cell to inhibit programmed cell death (PCD) initiated by the Pto and Cf9 disease resistance proteins and, remarkably, the pro-apoptotic mouse protein Bax. AvrPtoB also suppressed PCD in yeast, demonstrating that AvrPtoB functions as a cell death inhibitor across kingdoms. Using truncated AvrPtoB proteins, we identified distinct N- and C-terminal domains of AvrPtoB that are sufficient for host recognition and PCD inhibition, respectively. We also identified a novel resistance phenotype, Rsb, that is triggered by an AvrPtoB truncation disrupted in the anti-PCD domain. A Pseudomonas syringae pv. tomato DC3000 strain with a chromosomal mutation in the AvrPtoB C-terminus elicited Rsb-mediated immunity in previously susceptible tomato plants and disease was restored when full-length AvrPtoB was expressed in trans. Thus, our results indicate that a type III effector can induce plant susceptibility to bacterial infection by inhibiting host PCD.