State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Microbiol. 2021 Apr;23(4):1991-2003. doi: 10.1111/1462-2920.15319. Epub 2020 Nov 21.
The soil-borne ascomycete Verticillium dahliae causes wilt disease in more than two hundred dicotyledonous plants including the economically important crop cotton, and results in a severe reduction in cotton fiber yield and quality. During infection, V. dahliae secretes numerous secondary metabolites, which act as toxic factors to promote the infection process. However, the mechanism underlying how V. dahliae secondary metabolites regulate cotton infection remains largely unexplored. In this study, we report that VdBre1, an ubiquitin ligase (E3) enzyme to modify H2B, regulates radial growth and conidia production of V. dahliae. The VdBre1 deletion strains show nonpathogenic symptoms on cotton, and microscopic inspection and penetration assay indicated that penetration ability of the ∆VdBre1 strain was dramatically reduced. RNA-seq revealed that a total of 1643 differentially expressed genes between the ∆VdBre1 strain and the wild type strain V592, among which genes related to lipid metabolism were significantly overrepresented. Remarkably, the volume of lipid droplets in the ∆VdBre1 conidia was shown to be smaller than that of wild-type strains. Further metabolomics analysis revealed that the pathways of lipid metabolism and secondary metabolites, such as steroid biosynthesis and metabolism of terpenoids and polyketides, have dramatically changed in the ∆VdBre1 metabolome. Taken together, these results indicate that VdBre1 plays crucial roles in cotton infection and pathogenecity, by globally regulating lipid metabolism and secondary metabolism of V. dahliae.
土壤真菌尖孢镰刀菌可引起 200 多种双子叶植物萎蔫病，包括经济上重要的棉花作物，导致棉花纤维产量和质量严重下降。在感染过程中，尖孢镰刀菌会分泌许多次生代谢物，这些代谢物作为毒性因子促进感染过程。然而，尖孢镰刀菌次生代谢物如何调节棉花感染的机制在很大程度上仍未得到探索。在这项研究中，我们报告称，泛素连接酶（E3）酶 VdBre1 修饰 H2B，调节尖孢镰刀菌的径向生长和分生孢子产生。VdBre1 缺失菌株在棉花上表现出非致病性症状，显微镜检查和穿透试验表明，ΔVdBre1 菌株的穿透能力显著降低。RNA-seq 显示，ΔVdBre1 菌株和野生型菌株 V592 之间总共存在 1643 个差异表达基因，其中与脂质代谢相关的基因显著富集。值得注意的是，ΔVdBre1 分生孢子中的脂滴体积明显小于野生型菌株。进一步的代谢组学分析表明，ΔVdBre1 代谢组中的脂质代谢和次生代谢物途径（如类固醇生物合成和萜类和聚酮类代谢）发生了显著变化。综上所述，这些结果表明，VdBre1 通过全局调节尖孢镰刀菌的脂质代谢和次生代谢物，在棉花感染和致病性中发挥着至关重要的作用。
