Submitted to: Mycological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2004
Publication Date: 7/20/2004
Citation: Proctor, R., Plattner, R.D., Brown, D.W., Seo, J.-A., Lee, Y.-W. 2004. Discontinuous distribution of fumonisin biosynthetic genes in the Gibberella fujikuroi species complex. Mycological Research. 108:815-822. Interpretive Summary: Fumonisins are toxic substances produced by the corn ear rot fungus Fusarium verticillioides and some related species of fungi. Fumonisins can cause several fatal diseases in animals including cancer in laboratory rodents. Our goal is to eliminate or reduce fumonisins in U.S. corn. In an effort to accomplish this goal, we surveyed twenty-seven species of Fusarium for their ability to produce fumonisins and for the presence of four genes, known as FUM genes, required for production of fumonisins. The genes were found in only seven species, F. anthophilum, F. fujikuroi, F. globosum, F. nygamai, F. oxysporum, F. proliferatum, and F. verticillioides. Fumonisin production was also detected in these same species except for F. anthophilum. The presence of the FUM genes in only seven of the 27 species analyzed indicates that the potential to produce fumonisins is relatively limited in the genus Fusarium.
Technical Abstract: Production of the carcinogenic mycotoxins fumonisins has been reported in several Fusarium species, most of which are members of the of the Gibberella fujikuroi (Gf) complex. In this study, we examined 15 Fusarium species in the Gf complex and 12 species outside the complex for fumonisin biosynthetic genes (FUM) and fumonisin production. Among species within the Gf complex, FUM genes were detected only in F. anthophilum, F. fujikuroi, F. globosum, F. proliferatum, F. nygamai, and F. verticillioides. These six species include at least one member of each of the three major clades delineated in the Gf complex. Fumonisin production was also detected in these same six species except for F. anthophilum. Among the species outside the Gf complex, FUM genes and fumonisin production were detected only in F. oxysporum. Phylogenetic analyses of nucleotide sequences from two FUM gene fragments inferred relationships similar to those inferred from previous analyses of other genes. The results indicate the FUM genes are discontinuously distributed in the Gf complex and that this distribution gives rise to the differential ability of closely related species to produce fumonisins.