西瓜噬酸菌趋化性及鞭毛素基因ΔcheAΔfliC双突变体构建及功能

发布时间：2018-03-02 00:18

本文关键词： 西瓜噬酸菌鞭毛素趋化性致病力　出处：《农业生物技术学报》2017年11期 　论文类型：期刊论文

【摘要】：鞭毛是细菌的主要运动器官,也是一种重要的致病因子。趋化性是有运动能力的细菌趋向有益刺激,逃避有害刺激的反应。前期研究表明,缺乏趋化性核心基因che A的西瓜噬酸菌(Acidovorax citrulli)致病力下降;为明确鞭毛素基因和趋化性核心基因同时缺失对西瓜噬酸菌的影响以及趋化性与鞭毛基因间的关系,本研究构建了西瓜噬酸菌双缺失突变菌株ΔcheAΔfliC及其互补菌株ΔcheAΔfliC::che A::fliC、突变菌株ΔfliC及互补菌株ΔfliC::fliC,并对致病力与生物学特性进行测定。结果显示,双缺失突变菌株ΔcheAΔfliC致病力、运动能力、生长能力、种子粘附能力均显著降低,生物膜形成能力显著增强;与ΔfliC和ΔcheA单缺失突变株相比,双缺失突变菌株ΔcheAΔfliC致病力显著下降,生物膜形成能力显著提升,说明fliC和che A同时缺失对西瓜噬酸菌致病力和生物膜形成能力影响更为显著;三者运动能力基本保持一致,说明fliC缺失与che A缺失同样影响西瓜噬酸菌的运动能力,进一步说明了西瓜噬酸菌趋化性核心基因che A通过调控鞭毛的运动从而影响西瓜噬酸菌的运动能力。ΔfliC、ΔcheAΔfliC突变株种子上粘附能力显著下降,且均低于ΔcheA,说明鞭毛素基因fliC对西瓜噬酸菌粘附能力起着重要作用,这将对瓜类细菌性果斑病的防控和有效防治药剂的研制提供了基础。
[Abstract]:Flagella is the main movement organ of bacteria and an important pathogenic factor. Chemotaxis is the tendency of bacteria with the ability to move towards beneficial stimulation and escape from harmful stimuli. The pathogenicity of Acidovorax citrullii, which lacks che A, was decreased, and the relationship between chemotaxis and flagellin gene and flagellin gene in watermelon phagocytic bacteria was studied in order to clarify the effect of both flagellin gene and chemoattractant core gene deletion on watermelon phagocytic bacteria, and the relationship between chemotaxis and flagellin gene. In this study, the double deletion mutant 螖 cheA 螖 fliC and its complementary strain 螖 cheA 螖 fliC::che A: 1: fliC, the mutant 螖 fliC and the complementary strain 螖 fliCw: fliCwere constructed. The pathogenicity and biological characteristics of the double deletion mutant 螖 cheA 螖 fliC were determined. The results showed that the mutant 螖 cheA 螖 fliC was virulent and athletic. Compared with 螖 fliC and 螖 cheA single deletion mutants, the virulence of double deletion mutant 螖 cheA 螖 fliC was significantly decreased, and the biofilm formation ability was significantly increased. The results showed that the effects of fliC and che A deficiency on pathogenicity and biofilm formation ability of watermelon were more significant, and the motor ability of the three was basically the same, which indicated that fliC deficiency and che A deficiency also affected the ability of watermelon phagocytomytic bacteria. The results further indicated that the chemoattractant core gene cheA of watermelon phagocytic bacteria affected the motility of watermelon phagocytic bacteria by regulating the movement of flagella. The adhesion ability of 螖 fliC, 螖 cheA 螖 fliC mutants decreased significantly. All of them were lower than 螖 cheA, indicating that flagellin gene fliC played an important role in the adhesion of watermelon phagocytic bacteria, which would provide a basis for the prevention and control of melon bacterial fruit spot disease and the development of effective control agent.
【作者单位】：中国农业科学院植物保护研究所/植物病虫害生物学国家重点实验室;吉林农业大学农学院;
【基金】：国家西甜瓜产业技术体系(No.CARS-26) 北京市自然科学基金(No.6162023) 中国农业科学院科技创新工程项目公益性行业(农业)科研专项(No.201003066)
【分类号】：S432.4

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