Chp8, a diguanylate cyclase from Pseudomonas syringae pv. Tomato DC3000, suppresses the pathogen-associated molecular pattern flagellin, increases extracellular polysaccharides, and promotes plant immune evasion.
Chp8, a diguanylate cyclase from Pseudomonas syringae pv. Tomato DC3000, suppresses the pathogen-associated molecular pattern flagellin, increases extracellular polysaccharides, and promotes plant immune evasion.
复制标题
DOI：
10.1128/mbio.01168-14
复制
发表时间：
2014-05-20
期刊：
影响因子：
6.4
通讯作者：
Buck M
中科院分区：
文献类型：
--
作者：
Engl C;Waite CJ;McKenna JF;Bennett MH;Hamann T;Buck M
植物病原菌丁香假单胞菌在多种植物中引起疾病。随之而来的作物产量下降造成经济损失，并威胁到全球粮食安全。植物免疫系统与病原体之间存在竞争，其基本原理可应用于动物感染途径。丁香假单胞菌使用III型分泌系统（T3SS）将毒力因子输送到植物中，促进细菌的存活。P. syringae T3SS是由过敏症反应和致病性（hrp）和过敏症反应和保守性（hrc）基因簇结合而成的产物，受到相互依赖的增强子结合蛋白HrpR和HrpS的严格控制。通过结合细菌基因调控和表型研究、植物感染试验和植物激素定量，我们现在报道，Chp8 (i)嵌入Hrp调控并响应植物信号和hrpr表达，（ii）是一种功能性二鸟苷酸环化酶，（iii）降低主要病原体相关分子模式（PAMP）鞭毛蛋白的表达并增加细胞外多糖（EPS）。（iv）影响水杨酸/茉莉酸激素免疫反应和疾病进展。我们认为Chp8的表达抑制了植物感染早期pamp触发的免疫。预计到2030年，全球粮食需求将增长50%，因此，这是21世纪的主要挑战之一，需要改进作物管理。由植物病原体引起的疾病降低作物产量，造成重大经济损失，并威胁到全球粮食安全。获得植物-病原体界面事件的机制洞察并利用这些知识使作物更具抗病性是改善作物管理的一个重要策略。植物与病原体相互作用的特点是在病原体识别后引起的植物免疫和病原体的免疫逃避之间发生复杂的相互作用。在这里，我们确定了Chp8是植物病原体丁香假单胞菌pv的主要贡献者。番茄DC3000以逃避植物的免疫反应。
The bacterial plant pathogen Pseudomonas syringae causes disease in a wide range of plants. The associated decrease in crop yields results in economic losses and threatens global food security. Competition exists between the plant immune system and the pathogen, the basic principles of which can be applied to animal infection pathways. P. syringae uses a type III secretion system (T3SS) to deliver virulence factors into the plant that promote survival of the bacterium. The P. syringae T3SS is a product of the hypersensitive response and pathogenicity (hrp) and hypersensitive response and conserved (hrc) gene cluster, which is strictly controlled by the codependent enhancer-binding proteins HrpR and HrpS. Through a combination of bacterial gene regulation and phenotypic studies, plant infection assays, and plant hormone quantifications, we now report that Chp8 (i) is embedded in the Hrp regulon and expressed in response to plant signals and HrpRS, (ii) is a functional diguanylate cyclase, (iii) decreases the expression of the major pathogen-associated molecular pattern (PAMP) flagellin and increases extracellular polysaccharides (EPS), and (iv) impacts the salicylic acid/jasmonic acid hormonal immune response and disease progression. We propose that Chp8 expression dampens PAMP-triggered immunity during early plant infection. The global demand for food is projected to rise by 50% by 2030 and, as such, represents one of the major challenges of the 21st century, requiring improved crop management. Diseases caused by plant pathogens decrease crop yields, result in significant economic losses, and threaten global food security. Gaining mechanistic insights into the events at the plant-pathogen interface and employing this knowledge to make crops more resilient is one important strategy for improving crop management. Plant-pathogen interactions are characterized by the sophisticated interplay between plant immunity elicited upon pathogen recognition and immune evasion by the pathogen. Here, we identify Chp8 as a contributor to the major effort of the plant pathogen Pseudomonas syringae pv. tomato DC3000 to evade immune responses of the plant.