ARS | Publication request: Isolation and Sequence Analysis of Polyketide Synthase Genes from Three Fusaria Commonly Found in Corn

Submitted to: Fungal Genetics Conference/Asilomar
Publication Type: Abstract
Publication Acceptance Date: March 20, 2005
Publication Date: N/A

Technical Abstract: Mycotoxins are fungal secondary metabolites that often contaminate grains following plant infestation. Synthesis of many mycotoxins (e.g. fumonisins and fusarins produced by Fusarium verticillioides is initiated by a member of a family of enzymes called polyketide synthases (PKSs). Degenerate primers were developed that target a highly conserved portion of genomic sequence that encodes the PKS ketosynthase (KS) domain. The first objective of the research was to isolate KS gene fragments from F. verticillioides, F. proliferatum, and F. subglutinans genomic DNA. Based on the genomic sequence of F. verticillioides and F. graminearum, between 10 and 20 PKS genes are expected per genome. To date five novel KS fragments from both F. proliferatum and F. subglutinans have been isolated. We conducted a phylogenetic analysis of the new KS sequences and KS sequences from fungal PKSs with known as well as unknown function. We identified a number of species specific PKS genes as well as PKS genes that appear to be shared by multiple Fusarium sps. In addition, the unique sequence data has provided us tools to help identify species in mixed cultures.