Department of Plant Pathology and Microbiology, the Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Nat Commun. 2019 Jun 28;10(1):2886. doi: 10.1038/s41467-019-10860-3.
Glucosinolates accumulate mainly in cruciferous plants and their hydrolysis-derived products play important roles in plant resistance against pathogens. The pathogen Botrytis cinerea has variable sensitivity to glucosinolates, but the mechanisms by which it responds to them are mostly unknown. Exposure of B. cinerea to glucosinolate-breakdown products induces expression of the Major Facilitator Superfamily transporter, mfsG, which functions in fungitoxic compound efflux. Inoculation of B. cinerea on wild-type Arabidopsis thaliana plants induces mfsG expression to higher levels than on glucosinolate-deficient A. thaliana mutants. A B. cinerea strain lacking functional mfsG transporter is deficient in efflux ability. It accumulates more isothiocyanates (ITCs) and is therefore more sensitive to this compound in vitro; it is also less virulent to glucosinolates-containing plants. Moreover, mfsG mediates ITC efflux in Saccharomyces cerevisiae cells, thereby conferring tolerance to ITCs in the yeast. These findings suggest that mfsG transporter is a virulence factor that increases tolerance to glucosinolates.
硫代葡萄糖苷主要积累在十字花科植物中，其水解产物在植物抵抗病原体方面发挥着重要作用。病原菌 Botrytis cinerea 对硫代葡萄糖苷的敏感性不同，但它对硫代葡萄糖苷的反应机制大多未知。B. cinerea 暴露于硫代葡萄糖苷分解产物会诱导 Major Facilitator Superfamily 转运蛋白 mfsG 的表达，该蛋白在真菌毒性化合物外排中起作用。与硫代葡萄糖苷缺乏型拟南芥突变体相比，B. cinerea 接种在野生型拟南芥植物上会诱导 mfsG 表达更高水平。缺乏功能 mfsG 转运蛋白的 B. cinerea 菌株在流出能力上存在缺陷。它积累了更多的异硫氰酸酯 (ITC)，因此在体外对这种化合物更敏感；它对含硫代葡萄糖苷的植物的毒性也较低。此外，mfsG 在酿酒酵母细胞中介导 ITC 外排，从而使酵母对 ITC 具有耐受性。这些发现表明 mfsG 转运蛋白是一种毒力因子，可增加对硫代葡萄糖苷的耐受性。
