ARS | Publication request: CHARACTERIZATION OF POLYKETIDE SYNTHASE GENES FROM FUSARIUM VERTICILLIOIDES

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 22, 2006
Publication Date: October 26, 2006
Citation: Proctor, R., Butchko, R.A., Brown, D.W., Busman, M., Plattner, R.D. 2006. Characterization of polyketide synthase genes from fusarium verticillioides [abstract]. American Phytopathological Society Annual Meeting. 96:S95.

Technical Abstract: The fungus Fusarium verticillioides can cause ear and stalk rot of maize and can produce the carcinogenic mycotoxins fumonisins in infected ears. A previous genomic sequence analysis has identified 15 polyketides synthase (PKS) genes in F. verticillioides. We are characterizing these genes to determine: (1) the polyketide metabolites synthesized by the PKSs; (2) whether production of the polyketide metabolites contributes to pathogenesis on maize; and (3) whether the PKS genes are located within gene clusters. Disruption analysis of eight of the PKS genes indicated that PKS3 is required for production of the dark pigment in perithecial walls, that PKS4 is required for production of the pigment bikaverin, and that PKS10 is required for production of the fusarin mycotoxins, as previously reported in other Fusarium species. Microarray analysis indicated that PKS10 and eight contiguous genes on one side of it are co-expressed whereas genes on the other side of PKS10 are not. Sequence comparisons indicate that six of the co-expressed genes encode enzymes (e.g. oxidoreductases and a carboxymethly transferase) expected to be required for fusarin biosynthesis. PKS4 and 7 contiguous genes adjacent to it are also co-expressed. These results indicate that PKS4 and PKS10 are members of polyketide biosynthetic gene clusters.