十字花科黑腐病菌的XC1193基因与致病相关  

Gene XC1193 of Xanthomonas campestris pv. campestris Contributes to Pathogenicity

作　　者：王凛[1,2] 阳丽艳 杨丽超[1] 甘永亮 姜伯乐[1,3] Wang Lin 1,2 ,Yang Liyan 1 ,Yang Lichao 1, Gan Yongliang 1 ,Jiang Bole 1,3(1 College of Life Sciences, Guangxi University, Nanning, 530004; 2 College of Biotechnology, Guilin Medical University, Guilin, 541004; 3 State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Nanning, 53000)

机构地区：[1]广西大学生命科学与技术学院,南宁530004 [2]桂林医学院生物技术学院,桂林541004 [3]亚热带农业生物资源保护与利用国家重点实验室,南宁530004

出　　处：《基因组学与应用生物学》2018年第2期789-795,共7页Genomics and Applied Biology

基　　金：广西自然科学基金项目（2014GXNSFFA118005;2013GXNSFBA019088）; 国家自然科学基金项目（31260443;31460025）共同资助

摘　　要：十字花科黑腐病菌（Xanthomonas campestris pv.campestris,Xcc）是一种重要植物病原细菌,在全球范围内侵染十字花科植物引起黑腐病,其σ因子在基因表达中起到重要调节作用。XC1193基因在Xcc 8004菌株编码一个σ-70因子,为进一步研究该σ因子在Xcc中的调控作用,利用自杀质粒p K18mobsac B构建了XC1193基因的缺失突变体DM1193。与野生型菌株的比较发现,XC1193基因突变不影响菌体在丰富培养基和基本培养基上的生长;突变体的胞外蛋白酶、纤维素酶、淀粉酶等生化表型也与野生型一致;植株实验表明XC1193突变不影响过敏反应。采用剪叶接种法进行致病性检测,突变体致病力与野生型一致。而采用喷雾接种法,突变体致病力显著降低,互补菌株致病力恢复至野生型水平。结果表明,该σ因子在十字花科黑腐病菌致病过程中发挥作用,并与Xcc侵染寄主的早期事件有关。Xanthomonas campestris pv. campestris（Xcc） is the main pathogenic agent of black rot disease of cruciferous plants in worldwide, the σ factor has a critical role in regulating the gene expression of Xcc. XC1193 gene encodes a putative σ-70 factor in Xcc 8004. For further research on this σ factor function, the XC1193 is deleted by using a suicide plasmid p K18 mobsac B to generate the mutant DM1193. Compared with the wild type strain, there is no difference in growth rates both in rich and minimal medium, and in the extracellular protease, amylase, and cellulose activities. The deletion of XC1193 didn＇t affect hypersensitive reaction（HR）. The pathogenicity test on the host plant showed that the lesion length on the leaf caused by the mutant DM1193 was nearly closed to the wild type strain when inoculated by leaf cutting, but the virulence of DM1193 is significantly decreased when infected by spray inoculation. The altered decreased virulence of the mutant could be restored by the intact XC1193 gene carried in p LAFRJ. These results indicated that XC1193 plays an important role in the pathogenicity of Xcc, and it is associated with early events when Xcc infects the host.

关 键 词：十字花科黑腐病菌 Σ因子 致病性 

分 类 号：S432.4[农业科学—植物病理学]