MgMfs1, a major facilitator superfamily transporter from the fungal wheat pathogen Mycosphaerella graminicola, is a strong protectant against natural toxic compounds and fungicides

MgMfs1, a major facilitator superfamily (MFS)gene from the wheat pathogenic fungus Mycosphaerella graminicola, was identiWed in expressed sequence tag (EST)libraries. The encoded protein has high homology to members of the drug:H+ antiporter eZux family of MFS transporters with 14 predicted transmembrane spanners (DHA14), implicated in mycotoxin secretion and multidrug resistance. Heterologous expression of MgMfs1 in a hypersensitive Saccharomyces cerevisiae strain resulted in a strong decrease in sensitivity of this organism to a broad range of unrelated synthetic and natural toxic compounds. The sensitivity of MgMfs1 disruption mutants of M. graminicola to most of these compounds was similar when compared to the wild-type but the sensitivity to strobilurin fungicides and the mycotoxin cercosporin was increased. Virulence of the disruption mutants on wheat seedlings was not aVected. The results indicate that MgMfs1 is a true multidrug transporter that can function as a determinant of pathogen sensitivity and resistance to fungal toxins and fungicides.