The Thm1 Zn(II)2Cys6 transcription factor contributes to heat, membrane integrity and virulence in the insect pathogenic fungus Beauveria bassiana
The Thm1 Zn(II)2Cys6 transcription factor contributes to heat, membrane integrity and virulence in the insect pathogenic fungus Beauveria bassiana
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Thm1 Zn(II)2Cys6 转录因子有助于昆虫病原真菌白僵菌的热、膜完整性和毒力
DOI：
10.1111/1462-2920.14718
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发表时间：
2019-08-01
影响因子：
5.1
通讯作者：
Zhang, Yongjun
中科院分区：
文献类型：
--
作者：
Huang, Shuaishuai;Keyhani, Nemat O.;Zhang, Yongjun
耐高温和细胞壁应力的能力是许多致病真菌成功感染目标宿主的关键。我们报道了BbThm1（热和膜完整性转录因子）的特性，这是一个Zn(II)(2)Cys(6) （gal4样）家族成员，在昆虫病原真菌白僵菌（Beauveria bassiana）中调节耐热（32℃）和特定洗涤剂的抗性。BbThm1基因敲除突变体在32℃和SDS下表现出严重的生长/抗性受损，但对其他胁迫（包括氧化、渗透和细胞壁靶向化合物）或各种杀菌剂表现出轻度至中度的表型反应。Delta BbThm1突变体的细胞壁特性、粘附性和活力下降发生了变化。外源麦角甾醇能恢复对SDS的敏感性，但不能恢复对热的敏感性。昆虫生物测定结果表明，Delta BbThm1突变体对mellonella Galleria的局部和血内注射毒力下降，这与昆虫菌丝体形成受损和宿主免疫异丙酚氧化酶（PO）激活改变有关。野生型和Delta BbThm1突变体的转录组学分析显示，水解酶上调，但下调了广泛的基本代谢过程。这些数据揭示了调控特定应激反应的转录因子网络的微调方面，从而促进了整个致病过程。
The ability to withstand heat and cell wall stress is critical for successful infection of target hosts by many pathogenic fungi. We report on the characterization of BbThm1 (transcription factor for heat and membrane integrity), a Zn(II)(2)Cys(6) (Gal4-like) family member, which regulates resistance to heat (32 degrees C) and specific detergents in the insect pathogenic fungus, Beauveria bassiana. BbThm1 gene knock-out mutants showed severely impaired growth/resistance at 32 degrees C and to SDS, but mild to moderate phenotypic responses to other stresses including oxidative, osmotic and cell-wall targeting compounds, or to various fungicides. Shifts in cell wall properties, adhesion and decreased viability were noted for the Delta BbThm1 mutant. Susceptibility to SDS but not heat could be rescued by exogenous ergosterol. Insect bioassays revealed decreased virulence of the Delta BbThm1 mutant against Galleria mellonella both topically and via intrahemocoel injection assays that correlated with impaired in insecta hyphal body formation and altered host immune prophenol oxidase (PO) activation. Transcriptomic analyses of the wild-type and Delta BbThm1 mutants revealed up-regulation of hydrolases but down-regulation of a wide range of basic metabolic processes. These data reveal fine tune aspects of the transcription factor network that regulates specific stress responses to contribute to the overall pathogenic process.