十字花科黑腐病菌中一个与趋化性相关基因的突变分析  

Mutation Analysis of a Gene Involved in Chemotaxis in Xanthomonas campestris pv. Campestris

作　　者：丘献娟 吴柳[1] 陈正培 陆光涛[1,2] 

机构地区：[1]广西大学生命科学与技术学院,南宁530005 [2]广西大学亚热带农业生物资源保护利用国家重点实验室,南宁530005

出　　处：《基因组学与应用生物学》2015年第6期1225-1231,共7页Genomics and Applied Biology

基　　金：国家自然科学基金项目(31160453)资助

摘　　要：十字花科作物黑腐病,又称为野油菜黄单胞菌野油菜变种(Xanthomonas campestris pv.campestris,简称Xcc),该细菌是引起十字花科作物等植物发生黑腐病的病原菌,同时该细菌也是人们研究寄主与病原微生物相互作用的具体分子机理的模式菌之一。在Xcc 8004菌株基因组中,XC_2304编码的产物为一个趋化性蛋白。由于细菌的趋化性在病原学方面的意义是非常重要的,为评估XC_2304的功能,本研究利用p K18mob Sac B对XC_2304进行缺失突变,获得缺失突变体DM2304。植株试验发现,突变体DM2304对寄主植物的致病力下降约30%,其互补菌株CDM2304的致病力基本恢复至野生型水平,这表明XC_2304与Xcc致病力有关。利用毛细管法检测DM2304对18种物质的趋化性,结果表明突变体对木糖、苯丙氨酸、精氨酸、蔗糖以及核糖的趋化性比野生型弱。运动性分析发现,DM2304在含有0.3%、0.6%琼脂的NYGA板的游动性稍微降低,表明XC_2304与游动性有关。而DM2304的胞外纤维素酶、胞外蛋白酶、胞外淀粉酶、EPS产量、HR与野生型菌株相比均没有明显差异。本研究为十字花科黑腐病菌中其它与趋化性相关基因提供实验思路,对病原菌如何趋利避害的机制的研究具有一定的意义。Xanthomonas campestris pv. campestris(Xcc) is the causal agent of the black rot disease of cruciferous crops, and Xcc is a model strain for studying the molecular mechanisms of plant-microbe interactions. According to the annotation of Xcc 8004 genome, XC_2304 was predicted to encode chemotaxis protein. As the significant of bacterial chemotaxis in ecology and etiology have been approved, to assess the function of XC_2304 in this work,XC_2304 was deleted by p K18 mob Sac B, and the deletion mutant was named as DM2304. Plant test found that the pathogenicity virulence of DM2304 to the host plants reduce about 30%, and the Complementary strain can restore its virulence to the wild type level, this result demonstrated that that XC_2304 is related to pathogenicity virulence of Xcc 8004. The capillary tube method was applied on the chemotaxis analysis, we found that XC_2304 is involved in the chemotaxis of xylose, phenylalanine, arginine, sucrose and ribose. Motility analysis found that the mutations of DM2304 results in reducing motility in 0.3% and 0.6% agarose swimming medium, it was showed that XC_2304is involved in motility. When the mutation of DM2304 compared with the wild-type strain, the extracellular protease,extracellular cellulase, extracellular amylase, EPS production, HR, biofilm formation and heavy metal resistance,have no significant difference. This work provide ideas for the study of other genes related with chemotaxis in Xcc and the mechanism of how pathogens avoid disadvantages.

关 键 词：十字花科黑腐病菌 趋化性 致病性 XC2304 

分 类 号：S432.4[农业科学—植物病理学]