rpoN1, but not rpoN2, is required for twitching motility, natural competence, growth on nitrate, and virulence of Ralstonia solanacearum.
rpoN1, but not rpoN2, is required for twitching motility, natural competence, growth on nitrate, and virulence of Ralstonia solanacearum.
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DOI：
10.3389/fmicb.2015.00229
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发表时间：
2015
影响因子：
5.2
通讯作者：
Genin S
中科院分区：
文献类型：
--
作者：
Ray SK;Kumar R;Peeters N;Boucher C;Genin S
植物病原体青枯雷尔氏菌（Ralstonia solanacearum）具有编码σ因子σ54的两个基因：位于染色体中的rpoNl和位于不同的“大质粒”复制子中的rpoN2。在本研究中，在R.青枯菌菌株GMI1000中的一个基因，以确定这两个基因之间的功能重叠程度。通过毒力测定，我们观察到rpoN1是毒力所必需的，而rpoN2不是。此外，与rpoN2不同，rpoN1控制其他重要功能，如抽搐运动，自然转化和硝酸盐生长。rpoN1和rpoN2基因具有不同的表达模式，rpoN1的表达是组成型的，而rpoN2的表达是在基本培养基中和植物细胞存在下诱导的。此外，rpoN2的表达依赖于rpoN1。因此，我们的工作揭示了两个rpoN基因在R.青枯菌属在R中确定了潜在的σ54靶标列表。青枯菌基因组，并表明多个性状的控制下，这些监管机构。基于这些发现，我们提供了一个模型，描述了RpoN1和PehR致病性调节因子之间的功能联系，以及它们在控制几种R.青枯菌毒力决定因子
The plant pathogen Ralstonia solanacearum has two genes encoding for the sigma factor σ54: rpoN1, located in the chromosome and rpoN2, located in a distinct “megaplasmid” replicon. In this study, individual mutants as well as a double mutant of rpoN were created in R. solanacearum strain GMI1000 in order to determine the extent of functional overlap between these two genes. By virulence assay we observed that rpoN1 is required for virulence whereas rpoN2 is not. In addition rpoN1 controls other important functions such twitching motility, natural transformation and growth on nitrate, unlike rpoN2. The rpoN1 and rpoN2 genes have different expression pattern, the expression of rpoN1 being constitutive whereas rpoN2 expression is induced in minimal medium and in the presence of plant cells. Moreover, the expression of rpoN2 is dependent upon rpoN1. Our work therefore reveals that the two rpoN genes are not functionally redundant in R. solanacearum. A list of potential σ54 targets was identified in the R. solanacearum genome and suggests that multiple traits are under the control of these regulators. Based on these findings, we provide a model describing the functional connection between RpoN1 and the PehR pathogenicity regulator and their dual role in the control of several R. solanacearum virulence determinants.