Glucosinolates, the main secondary metabolites accumulated in cruciferous flora, have a major impact on fortifying plant immunity against diverse pathogens. Although Botrytis cinerea exhibits varying sensitivity to these compounds, current research has yet to fully understand the intricate mechanisms governing its response to glucosinolates. Different species of the genus Botrytis were exposed to glucosinolate-breakdown products revealing that B. fabae, B. deweyae and B. convoluta, species lacking the mfsG transporter gene (Bcin06g00026), were more sensitive to glucosin-olate-breakdown products than Botrytis species containing that gene such as B. cinerea, B. pseudo-cinerea and B. byssoidea. This finding was further corroborated by the inability of species lacking the mfsG gene to infect plants with a high concentration of glucosinolate breakdown products. These results challenge established correlations, revealing varying aggressiveness on different plant substrates. Expression analysis highlighted the gene's induction in the presence of isothiocyanate, and bioinformatic investigation identified homologous genes in other Botrytis species. Our study underscored the importance of advanced biotechnology to help understand these proteins and thus offer innovative solutions for agriculture