金属离子对十字花科黑腐病菌不同致病系统表达的影响

The Impact of Metal Ions on Expression of Different Virulence System in Xanthomonas campestris pv. campestris

十字花科黑腐病菌(Xanthomonas campestris pv.campestris,Xcc)是引起十字花科植物黑腐病的病原细菌,其通过不同的分泌系统将效应物蛋白或细胞毒素转运进真核宿主细胞产生病害,对农业生产造成巨大的经济损失。本研究利用GUS融合报告系统,考察了常见的几种不同金属离子(Zn2+,Mn2+,Ca2+,Fe2+)对Xcc 8004不同致病系统装置基因表达的影响。结果表明,在1滋mol/L^1 mmol/L浓度区间,Zn2+和Mn2+同时对Xcc域型分泌系统(T2SS)和芋型分泌系统(T3SS)有抑制作用;在大于0.01 mmol/L浓度时,Ca2+特异性抑制T3SS;Fe2+同时抑制T2SS、T3SS和郁型分泌系统(T4SS)装置基因的表达。金属离子Zn2+、Mn2+、Ca2+和Fe2+在不同浓度下对Xcc的致病系统均有抑制作用。本研究为分析病原细菌不同分泌系统响应金属离子的模式奠定了基础。

Xanthomonas campestris pv. campestris（Xcc） is the pathogen of black rot in cruciferous plants. Xcc delivered diverse effector proteins or cell toxins into the eukaryotic host cells to result in disease via different virulence system, causing huge economic loss in agricultural production. We examined the influence of different metal ions（Zn^2＋, Mn^2＋, Ca^2＋and Fe^2＋） on the gene expression of diverse virulence system in Xcc 8004. Results indicated that the metal ions of Zn^2＋and Mn^2＋at the concentration range of 1 μmol/L-1 mmol/L should repress expression of the apparatus genes of type II secretion system（T2SS） and type III secretion system（T3SS）, Ca^2＋can specifically inhibit T3SS when the concentration is greater than 0.01 mmol/L, and Fe2＋suppressed T2SS, T3 SS and type IV secretion system（T4SS） simultaneously. The metal ions of Zn^2＋, Mn^2＋, Ca^2＋and Fe2＋inhibited the virulence system of Xcc under certain concentration. This study laid a solid foundation for analyzing the pattern that different secretion system of pathogenic bacteria response to metal ions.