Submitted to: Aflatoxin Workshop
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2002
Publication Date: October 25, 2002
Citation: Butchko, R.A., Plattner, R.D., Desjardins, A.E., Proctor, R. 2002. Characterizing fumonisin biosynthesis through analysis of fum gene deletion mutants. Aflatoxin Workshop. Technical Abstract: Fumonisins are produced by Gibberella moniliformis, a causal agent of maize ear and stalk rot, and pose a health risk to humans and livestock alike. Recently, a fumonisin biosynthetic gene cluster was described in G. moniliformis. The cluster consists of 15 co-regulated genes (FUM1 and FUM6 through FUM19) with patterns of expression that are correlated with fumonisin production. In an effort to determine the functions of FUM genes and to more fully characterize the biochemical pathway leading to the formation of fumonisins, we used targeted gene disruption to generate individual deletion mutants for FUM7, FUM9, FUM10, FUM11, FUM12, FUM13, FUM14 and FUM16. LC-MS analysis of deletion mutant culture filtrates and extracts revealed that all but the FUM16 deletion mutants accumulated one or more putative fumonisin pathway intermediates, including some metabolites that have not been previously described. NMR analysis confirmed the novel structure of some of the compounds. The accumulation of these metabolites suggested functions for the enzymes encoded by the FUM genes. These functions were consistent with the functions predicted by BLAST analysis of the genes. From the results reported here and those previously reported for FUM1, FUM6 and FUM8, a biochemical pathway leading to the formation of fumonisins is emerging.