State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, 350002, Fuzhou, China.
Key Laboratory of Biopesticides and Chemical Biology of Education Ministry, Fujian Agriculture and Forestry University, 350002, Fuzhou, China.
Curr Genet. 2020 Apr;66(2):421-435. doi: 10.1007/s00294-019-01037-y. Epub 2019 Oct 30.
SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) facilitate intracellular vesicle trafficking and membrane fusion in eukaryotic cells, and play a vital role in growth, development and pathogenicity of phytopathogens. Fusarium head blight (FHB) caused by F. graminearum is one of the most devastating diseases of wheat and barley worldwide. Sec22 is a member of the SNARE family of proteins and its homologues have been shown to have diverse biological roles in different organisms. However, the functions of this protein in the development and pathogenesis of F. graminearum are currently unknown. In this study, we employed integrated biochemical, microbiological and molecular genetic approaches to investigate the roles of FgSec22 in F. graminearum. Our data reveal that this SNARE protein is localized to endoplasmic reticulum (ER) and is indispensable for normal conidiation, conidial morphology and pathogenesis of this phytopathogenic fungus. Our biochemical assay of deoxynivalenol (DON) reveals the active involvement of this protein in the production of this mycotoxin in F. graminearum. This has further been confirmed by qRT-PCR analyses of trichothecene (TRI) genes' expression where the ΔFgsec22 deletion mutant demonstrated a significant down-regulation of these genes in comparison to the wild-type PH-1. Unlike the wild-type and the complemented strain, the mutant strain presents a remarkable defect in colony formation which reflects the critical role it plays in vegetative growth. Collectively, our data support that the SNARE protein FgSec22 is required for vegetative growth, pathogenesis and DON biosynthesis in F. graminearum.
SNAREs（可溶性 N-乙基马来酰亚胺敏感因子附着蛋白受体）促进真核细胞内囊泡运输和膜融合，在植物病原体的生长、发育和致病性中起着至关重要的作用。由禾谷镰刀菌引起的赤霉病是小麦和大麦在世界范围内遭受的最具破坏性的疾病之一。Sec22 是 SNARE 家族蛋白的成员，其同源物在不同的生物体中具有多种生物学功能。然而，该蛋白在禾谷镰刀菌发育和致病性中的功能目前尚不清楚。在本研究中，我们采用综合的生化、微生物学和分子遗传学方法来研究 FgSec22 在禾谷镰刀菌中的作用。我们的数据表明，这种 SNARE 蛋白定位于内质网（ER），对于该植物病原体真菌的正常分生孢子形成、分生孢子形态和致病性是必不可少的。我们对脱氧雪腐镰刀菌烯醇（DON）的生化分析表明，该蛋白积极参与禾谷镰刀菌中这种真菌毒素的产生。这进一步通过 qRT-PCR 分析三萜烯（TRI）基因的表达得到了证实，与野生型 PH-1 相比，ΔFgsec22 缺失突变体中这些基因的表达显著下调。与野生型和互补菌株不同，突变菌株在菌落形成方面表现出显著缺陷，这反映了它在营养生长中起着关键作用。总之，我们的数据支持 SNARE 蛋白 FgSec22 是禾谷镰刀菌营养生长、致病性和 DON 生物合成所必需的。
