A novel Botrytis cinerea MFS transporter provides tolerance towards glucosinolate breakdown products and act as virulence factor

Glucosinolates are secondary metabolites that accumulate mainly in cruciferous plants. Glucosinolates hydrolytic products have antifungal properties and play a role in plants` resistance against pathogens. Botrytis cinerea, a necrotrophic pathogen, has variable sensitivity to glucosinolates. Here we studied the mechanisms of tolerance to glucosinolates in the fungus B. cinerea. Exposure of B. cinerea to glucosinolate breakdown products induced expression of Botrytis cinerea major facilitator superfamily transporter that involved in Isothiocyanates detoxification (BcmfsI). B. cinerea inoculated on wild-type Arabidopsis thaliana or on plants transgenic for high glucosinolate level activated BcmfsI expression to higher levels than B. cinerea on glucosinolate-deficient A. thaliana mutants. B. cinerea strains lacking functional MFSI (ΔBcmfsI) were more sensitive to glucosinolate breakdown products in vitro and in planta. ΔBcmfsI strains were less virulent on wild-type Arabidopsis plants, but not on glucosinolate-deficient mutants. We demonstrate here that the MFSI transporter is a virulence factor that increases tolerance of the pathogen to glucosinolates. We also demonstrate that BcmfsI can confer tolerance to hydrolytic products of glucosinolate in the yeast Saccharomyces cerevisiae.