|Gaffoor, Shidad - MSU, EAST LANSING, MI|
|Qi, Weihong - MSU, EAST LANSING, MI|
|Trail, Frances - MSU, EAST LANSING, MI|
Submitted to: Great Lakes Regional American Chemical Society Symposium
Publication Type: Abstract Only
Publication Acceptance Date: October 20, 2004
Publication Date: N/A
Technical Abstract: Type I polyketide synthases (PKS) are multidomain enzymes responsible for synthesizing a diverse array of compounds having varied functions. Some of these polyketide metabolites act as mycotoxins; others are pigments and antimicrobials. From the genomic sequence of the filamentous fungus Gibberella zeae (anamorph Fusarium graminearum) we have identified 16 putative PKS genes. We have disrupted each of these and analyzed the mutated strains for traits such as vegetative growth characteristics, mycotoxin and pigment production, perithecium development and function, and pathogenicity on wheat. Among the functions we have assigned are zearalenone biosynthesis, and biosynthesis of the carmine and black perithecial pigments. Expression analysis of these genes under varied culture conditions and developmental stages shows that they are differentially expressed. While one PKS gene appears to be expressed under most of the conditions tested, 3 others are not expressed under any of these conditions. Further analysis of the mutant strains and identification of the unknown polyketide compounds will enable us to assign functions to the remaining PKS and elucidate the role they play in the life cycle of the fungus.