College of Plant Health and Medicine, The Key Lab of Integrated Crop Pests Management of Shandong Province, Qingdao Agricultural University, No. 700 Changcheng Road, Chengyang, Qingdao, 266109, Shandong, China.
State Key Laboratory of Crop Stress Biology for Arid Aeras, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Curr Genet. 2020 Jun;66(3):517-529. doi: 10.1007/s00294-019-01043-0. Epub 2019 Nov 14.
Fusarium graminearum is a destructive fungal pathogen and a major cause of Fusarium head blight (FHB) which results in severe grain yield losses and quality reduction. Additionally, the pathogen produces mycotoxins during plant infection, which are harmful to the health of humans and livestock. As it is well known that lysine acetyltransferase complexes play important roles in pathogenesis, the roles of the Eaf6 homolog-containing complex have not been reported in fungal pathogen. In this study, a Eaf6 homolog FgEaf6 was identified in F. graminearum. To investigate the functions of FgEaf6, the gene was deleted using the split-marker method. ΔFgEaf6 mutant exhibited manifold defects in hyphal growth, conidial septation, asexual and sexual reproduction. Moreover, the virulence of the ΔFgEaf6 mutant was drastically reduced in both wheat heads and wheat coleoptiles. However, the FgEaf6 gene deletion did not impact DON production. An FgEaf6-gfp fusion localized to the nucleus and a conserved coiled-coil (C-C) domain was predicted in the sequence. Mutants with deletions in the C-C domain displayed similar defects during development and virulence as observed in the ΔFgEaf6 mutant. Moreover, the truncated gene was cytoplasm localized. In conclusion, the FgEaf6 encodes a nuclear protein, which plays key regulatory roles in hyphal growth, conidial septation, asexual/sexual reproduction, and the virulence of F. graminearum. The C-C is an indispensable domain in the gene. This is the first report on Eaf6 homolog functioning in virulence of fungal pathogen.
镰刀菌禾谷孢是一种具有破坏性的真菌病原体，也是禾谷镰刀菌穗腐病（FHB）的主要病因，可导致严重的谷物产量损失和质量下降。此外，该病原体在感染植物时会产生霉菌毒素，对人类和牲畜的健康有害。众所周知，赖氨酸乙酰转移酶复合物在发病机制中起着重要作用，而 Eaf6 同源物包含的复合物在真菌病原体中的作用尚未被报道。在本研究中，在禾谷镰刀菌中鉴定出一个 Eaf6 同源物 FgEaf6。为了研究 FgEaf6 的功能，使用分割标记法删除了该基因。ΔFgEaf6 突变体在菌丝生长、分生孢子分隔、无性和有性生殖方面表现出多种缺陷。此外，ΔFgEaf6 突变体在小麦穗和小麦胚芽中的毒力大大降低。然而，FgEaf6 基因缺失并不影响 DON 的产生。FgEaf6-gfp 融合蛋白定位于细胞核，序列中预测存在保守的卷曲螺旋（C-C）结构域。在发育和毒力方面，C-C 结构域缺失的突变体表现出与ΔFgEaf6 突变体相似的缺陷。此外，截短的基因定位于细胞质。总之，FgEaf6 编码一种核蛋白，在菌丝生长、分生孢子分隔、无性/有性繁殖以及禾谷镰刀菌的毒力中起关键调节作用。C-C 是该基因中不可或缺的结构域。这是第一个关于 Eaf6 同源物在真菌病原体毒力中的作用的报告。
