磷酸甘油转移酶基因在水稻白叶枯病菌致病力中的作用研究  

Study on the role of glycerophosphotransferase gene in the pathogenicity of Xanthomonas oryzae pv.oryzae

作　　者：任沛东 叶文新 刘倩倩[2] 卢卓健 朱桂宁[1] 贤小勇[1] 李瑞芳[1,3] REN Peidong;YE Wenxin;LIU Qianqian;LU Zhuojian;ZHU Guining;XIAN Xiaoyong;LI Ruifang(Plant Protection Research Institute,Guangxi Academy of Agricultural Sciences,Nanning 530017,China;College of Life Science and Technology,Guangxi University,Nanning530005,China;Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests,Nanning 530017,China)

机构地区：[1]广西农业科学院植物保护研究所,南宁530017 [2]广西大学生命科学与技术学院,南宁530005 [3]广西作物病虫害生物学重点实验室,南宁530017

出　　处：《植物病理学报》2022年第6期940-949,共10页Acta Phytopathologica Sinica

基　　金：国家自然科学基金(32160617);广西作物病虫害生物学重点实验室系统课题(2019-ST-07);广西农业科学院科技发展基金(桂农科2021JM13、桂农科2021ZX23)。

摘　　要：稻黄单胞菌稻致病变种(Xanthomonas oryzae pv.oryzae,Xoo)引起的水稻白叶枯病,是水稻上的重要致灾病害之一。前期基因组学分析发现,Xoo菌株PXO99^(A)的PXO_04062基因可能编码一个磷酸甘油转移酶,推测与病原菌的致病力有关。本研究采用自杀质粒pK18mobsacB介导的方法,构建了该基因的缺失突变体,并对突变体进行了反式互补。水稻上致病性测定发现,与野生型菌株相比,PXO_04062基因的缺失突变体DM04062在寄主水稻日本晴上的致病力显著下降,并且其胞外多糖产量、运动性、生物膜形成等均明显降低。进一步采用RNA-seq方法比较突变体转录组的变化,发现突变体中的差异表达基因共有533个,其中包括多个致病相关基因,如胞外多糖合成和细胞运动性等相关基因。与野生型相比,这些基因在突变体中的表达均显著下调。这些结果说明,白叶枯病菌的磷酸甘油转移酶基因是通过影响多种致病力相关因子的合成,来影响病菌在水稻上的致病力。The prokaryotic Gram-negative bacterium Xanthomonas oryzae pv.oryzae(Xoo)is the causal agent of bacterial blight disease of rice.A scanning of the genome sequence of the Xoo wild-type strain PXO99^(A)revealed that the PXO_04062 gene,which predicted to encode a CDP-glycerol glycerophosphotransferase,might contribute to the bacterial virulence.To investigate the role of PXO_04062 in the virulence in Xoo,a deletion mutant was constructed by using the suicide vector pK18 mobsacB in the wild-type strain PXO99^(A).Phenotypic analysis revealed that the virulence of the PXO_04062 deletion mutant DM04062 in the host plant Japonica cultivar Nipponbare was significantly reduced compared to the wild-type.Moreover,the native PXO_04062 gene can restore the virulence of DM04062 to the wild type level.Additionally,the DM04062 mutant displayed an obvious reduction in EPS production,cell motility and cell aggregate.Transcriptional profiling using RNA-sequencing revealed that 533 genes were differentially expressed in the DM04062 mutant compared to the wild-type.Among these differentially expressed genes,a number of genes were attributed to the production of several virulence factors such as extracellular polysaccharide and cell motility.These virulence-related genes were down-regulated in the DM04062 mutant.These combined data indicated that the PXO_04062 gene plays roles in a series of cell processes including virulence in Xoo and also has impact on the expression of series of virulence-related genes.

关 键 词：水稻白叶枯病菌 磷酸甘油转移酶 致病力 致病相关基因 转录组 

分 类 号：S435.111.47[农业科学—农业昆虫与害虫防治]