Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2007
Publication Date: March 20, 2007
Citation: Proctor, R., Busman, M., Plattner, R.D. 2007. Characterization of a fumonisin biosynthetic gene cluster in fusarium oxysporum strain O-1890 [abstract]. Fungal Genetics Conference. p. 105. Technical Abstract: Fumonisins are carcinogenic mycotoxins produced by some Fusarium species. Most species, including F. verticillioides, produce predominantly B fumonisins (FBs), but the F. oxysporum strain O-1890 produces predominantly C fumonisins (FCs). FBs have an alanine-derived, methyl function that is absent in FCs. In this study, we determined the nucleotide sequence of the fumonisin biosynthetic gene (FUM) cluster in strain O-1890. Genes in the cluster were present in the same order and orientations as in the previously described F. verticillioides cluster. The FUM gene coding and intergenic regions were 89-92% and 40-77% identical, respectively, in F. oxysporum and F. verticillioides. In contrast, the sequences flanking the cluster were completely different in the two species. As previously reported, the F. verticillioides FUM cluster gene FUM8 encodes an oxoamine synthase and fum8 mutants cannot produce fumonisins. In the current study, transformation of a fum8 mutant with a wild-type F. verticillioides FUM8 restored FB production while transformation with a F. oxysporum O-1890 FUM8 resulted in FC production. These data indicate that the ability to produce FBs versus FCs is determined by different FUM8 homologues.