Flp, a Fis-like protein, contributes to the regulation of type III secretion and virulence processes in the phytopathogen Xanthomonas campestris pv. campestris
Flp, a Fis-like protein, contributes to the regulation of type III secretion and virulence processes in the phytopathogen Xanthomonas campestris pv. campestris
复制标题
Flp 是一种 Fis 样蛋白，有助于调节植物病原体黄单胞菌 pv 的 III 型分泌和毒力过程。
DOI：
10.1111/mpp.12818
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发表时间：
2019-08-01
影响因子：
4.9
通讯作者：
Tang, Ji-Liang
中科院分区：
文献类型：
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作者：
Leng, Ming;Lu, Zhuo-Jian;Tang, Ji-Liang
油菜黄单胞菌致病变种（Xanthomonascampestrispv.）白菜型油菜（Xcc）的致病性依赖于其在感染过程中对宿主环境的快速适应能力。像大多数细菌病原体一样，Xcc已经进化出复杂的调控网络，以确保其毒力基因的表达和调控。在这里，我们描述了一个Fis-like蛋白（命名为Flp）的鉴定和表征，它在Xcc的毒力和III型分泌系统（T3 SS）基因表达中起着重要作用。flp基因的缺失降低了Xcc的毒力和过敏反应（HR）诱导，并改变了胁迫耐受性。全局转录组分析显示Flp具有广泛的调节作用，并且大多数T3 SS HR和致病性（hrp）基因在flp突变体中下调。β-葡萄糖醛酸酶活性测定表明Flp通过调控hrpX的表达来调控hrp基因的表达。更多的实验证实Flp与hrpX的启动子结合并直接影响hrpX的转录。有趣的是，在flp突变体中hrpX的组成型表达恢复了HR表型，但没有完全毒力。两者合计，研究结果描述了未被认识到的Flp蛋白的调节作用，控制HRP基因的表达和发病机制在XCC。
The ability of the plant pathogen Xanthomonas campestris pv. campestris (Xcc) to cause disease is dependent on its ability to adapt quickly to the host environment during infection. Like most bacterial pathogens, Xcc has evolved complex regulatory networks that ensure expression and regulation of their virulence genes. Here, we describe the identification and characterization of a Fis-like protein (named Flp), which plays an important role in virulence and type III secretion system (T3SS) gene expression in Xcc. Deletion of flp caused reduced virulence and hypersensitive response (HR) induction of Xcc and alterations in stress tolerance. Global transcriptome analyses revealed the Flp had a broad regulatory role and that most T3SS HR and pathogenicity (hrp) genes were down-regulated in the flp mutant. beta-glucuronidase activity assays implied that Flp regulates the expression of hrp genes via controlling the expression of hrpX. More assays confirmed that Flp binds to the promoter of hrpX and affected the transcription of hrpX directly. Interestingly, the constitutive expression of hrpX in the flp mutant restored the HR phenotype but not full virulence. Taken together, the findings describe the unrecognized regulatory role of Flp protein that controls hrp gene expression and pathogenesis in Xcc.