野油菜黄单胞菌XC1892基因与致病力关系的分析

野油菜黄单胞菌野油菜变种(简称Xcc)是十字花科作物黑腐病的病原菌。在前期工作中,从Xcc8004菌株获得1株编号为XC1892的基因的转座子Tn5gusA5突变体,其致病力降低。根据基因组注释,XC1892编码1个DsbE蛋白,参与细胞色素的合成。为评估XC1892的功能,采用自杀质粒pK18mob对XC1892进行诱变,获得非极性突变体1892nk。对突变体的表型分析发现,其致病力及胞外多糖产量分别是野生型的59%和55%。用一段包含XC1892基因的DNA片段对突变体1982nk进行功能互补,其致病力和胞外多糖产量基本得到恢复。这表明XC1892基因与Xcc的致病力和胞外多糖合成产量有关。

Analysis for XC1892 gene of Xanthomonas campestris in pathogenesis

Xanthomonas campestris pv.campestris(Xcc) is the causal agency of the black rot disease of cruciferous plants.In preliminary work,a transposon Tn5gusA5 insertional mutant of Xcc strain 8004,which with defects in pathogenicity,is identified to be the disruption of the gene XC1892.In the genome annotation,XC1892 is assigned to encode the protein DsbE,which involved in the c-type cytochrome biogenesis.Here XC1892 was mutated using the suicide plasmid pK18mob,and resulting nopolar integrated mutant named 1892nk.The XC1892 mutant revealed about 59% of the wild-type level of virulence on the host plant Chinese radish(Raphanus sativus),and 55% of the wild-type of extracellular polysaccharide(EPS) production.The virulence and EPS production of the XC1892 mutant 1892nk could be restored by intact XC1892 genes when provided in trans.These data confirmed that the XC1892 gene is required for full virulence and EPS production in Xcc.