The Photoreceptor Components FaWC1 and FaWC2 of Fusarium asiaticum Cooperatively Regulate Light Responses but Play Independent Roles in Virulence Expression
The Photoreceptor Components FaWC1 and FaWC2 of Fusarium asiaticum Cooperatively Regulate Light Responses but Play Independent Roles in Virulence Expression
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DOI：
10.3390/microorganisms8030365
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发表时间：
2020-03-01
期刊：
影响因子：
4.5
通讯作者：
Xu, Ling
中科院分区：
文献类型：
--
作者：
Tang, Ying;Zhu, Pinkuan;Xu, Ling
亚洲镰刀菌（Fusarium asiaticum）属于镰刀菌（F.禾谷镰刀菌属（graminearum）植物种类复杂，在东亚地区居优势。研究了F. asiaticum受光的调节作用显著。本研究对真菌蓝光受体白色领复合物（WCC）FaWC 1和FaWC 2进行了研究。亚洲人。敲除突变体Delta Fawc 1和Delta Fawc 2是通过同源重组事件替换靶基因而产生的。这两个突变体在光诱导类胡萝卜素生物合成、UV-C抗性、有性子实体发育和光响应标记基因表达等方面表现出相似的缺陷，而野生型及其互补菌株的光响应特征均与此相反，表明FaWC 1和FaWC 2参与了F.亚洲人。然而，出乎意料的是，Fawc 1和Fawc 2在调节毒力方面的功能有所不同，因为Delta Fawc 1对所测试的宿主植物材料是无毒的，而Delta Fawc 2在毒力方面与WT相当。此外，通过部分破坏的FaWC 1的功能分析显示，其光氧电压（LOV）结构域是光传感所需的，但毒性是必需的，其锌指结构域是毒力表达所需的，但不是光信号转导。这些结果表明，保守的真菌蓝光受体WCC不仅赋予F。Asiaticum具有光敏感能力以实现对环境的适应，但它也以光非依赖的方式调节单个组分FaWC 1的毒力表达，后者的功能为研究这一重要作物病原体的致病机制开辟了道路。
Fusarium asiaticum belongs to one of the phylogenetical subgroups of the F. graminearum species complex and is epidemically predominant in the East Asia area. The life cycle of F. asiaticum is significantly regulated by light. In this study, the fungal blue light receptor white collar complex (WCC), including FaWC1 and FaWC2, were characterized in F. asiaticum. The knockout mutants Delta Fawc1 and Delta Fawc2 were generated by replacing the target genes via homologous recombination events. The two mutants showed similar defects in light-induced carotenoid biosynthesis, UV-C resistance, sexual fruiting body development, and the expression of the light-responsive marker genes, while in contrast, all these light responses were characteristics in wild-type (WT) and their complementation strains, indicating that FaWC1 and FaWC2 are involved in the light sensing of F. asiaticum. Unexpectedly, however, the functions of Fawc1 and Fawc2 diverged in regulating virulence, as the Delta Fawc1 was avirulent to the tested host plant materials, but Delta Fawc2 was equivalent to WT in virulence. Moreover, functional analysis of FaWC1 by partial disruption revealed that its light-oxygen-voltage (LOV) domain was required for light sensing but dispensable for virulence, and its Zinc-finger domain was required for virulence expression but not for light signal transduction. Collectively, these results suggest that the conserved fungal blue light receptor WCC not only endows F. asiaticum with light-sensing ability to achieve adaptation to environment, but it also regulates virulence expression by the individual component FaWC1 in a light-independent manner, and the latter function opens a way for investigating the pathogenicity mechanisms of this important crop disease agent.