An ABC transporter gene from Fusarium verticillioides, FvABC1, may confer tolerance to corn antimicrobial compounds

An ABC transporter gene, FvABC1, was cloned and sequenced from the corn pathogen Fusarium verticillioides in order to study non-degradative tolerance to corn antimicrobial compounds. The predicted protein encoded by FvABC1 showed the typical topology of ABC transporters from the pleiotropic drug resistance (PDR) family: two nucleotide-binding domains (NBDs) and two transmembrane domains (TMDs) in the [NBD-TMD]2 orientation. FvABC1p showed the same topology as the ABC transporter from Magnaporthe grisea (ABC1) and Gibberella pulicaris (Gpabc1). Both ABC1 and Gpabc1 transporters were classified as pathogenicity factors and were needed for colonization of host tissues. A southern blot analysis showed that several Fusarium species from the Gibberella fujikuroi species complex possessed an FvABC1 homolog. Other species outside the complex but associated with corn also possessed the homolog. An analysis of F. verticillioides genomic data identified thirteen additional ABC transporters and all of them belonged to the PDR family.