欧美杨细菌性溃疡病菌双组分信号转导系统LqHK1基因的功能

发布时间：2019-03-31 12:40

【摘要】：【目的】明确欧美杨细菌性溃疡病病原菌中双组分信号转导系统LqHK1基因的生物学功能,以阐明该病原菌的致病机制。【方法】采用生物信息学方法鉴定双组分系统LqHK1,利用同源重组方法获得该基因缺失突变体菌株△LqHK1,分析突变体及其互补菌株的生长速率、游动性、生物膜形成、致病性等生物学特性。同时,采用qRT-PCR检测与病原菌游动性相关的基因flgB、flgC、flgE的表达水平,并定量分析接种病原菌后在接种点部位杨树组织内病原菌的DNA含量。【结果】鉴定出病原细菌的双组分系统基因LqHK1,通过同源重组获得缺失突变体△LqHK1。表型分析显示:△LqHK1在1年生107杨茎干上的致病力显著下降;突变体在寄主体内定殖的菌量明显少于野生型菌株;突变体菌株的游动能力比野生型显著降低,游动性相关基因flgB、flgC、flgE在突变体中的表达量显著下降;LqHK1突变体生物膜的形成能力显著降低,生长速率与野生型无显著差异。【结论】LqHK1基因缺失突变体在107杨上的致病能力显著下降,欧美杨细菌性溃疡病病原菌双组分信号转导系统LqHK1基因与病原菌的致病性密切相关。
[Abstract]:[objective] to clarify the biological function of the bicomponent signal transduction system LqHK1 gene in the pathogen of bacterial canker of Poplar. [methods] to identify the bicomponent system LqHK1, by bioinformatics method. The growth rate, mobility, biofilm formation and pathogenicity of the mutant and its complementary strain were analyzed by homologous recombination method (LqHK1,). At the same time, qRT-PCR was used to detect the expression level of gene flgB,flgC,flgE related to pathogen mobility. The content of DNA in poplar tissue after inoculation was quantitatively analyzed. [results] the two-component system gene LqHK1, of pathogenic bacteria was identified by homologous recombination to obtain the deletion mutant LqHK1.. Phenotypic analysis showed that the pathogenicity of LqHK1 on the stem of 1-year-old poplar decreased significantly, and the number of mutant colonized in host body was significantly less than that of wild-type strain. The swimming ability of the mutant strain was significantly lower than that of the wild type, and the expression level of flgB,flgC,flgE gene was significantly lower than that of the wild type strain. The ability of biofilm formation of LqHK1 mutant was significantly decreased, and there was no significant difference between the growth rate and the wild type. [conclusion] the pathogenicity of LqHK1 gene deletion mutant on Populus poplar was significantly lower than that of wild type. The two-component signal transduction system LqHK1 gene is closely related to the pathogenicity of bacterial canker of Poplar.
【作者单位】：北京林业大学林学院;
【基金】：国家自然科学基金项目(31400545) 中央高校基本科研业务费专项资金(BLX2013015)
【分类号】：S763.7

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