Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 2007
Publication Date: October 31, 2007
Citation: Desjardins, A.E. 2007. Mycotoxin chemistry meets genomics: When is a genotype a chemotype? [abstract]. American Chemical Society National Meeting. Available: http://www.acs.org. Paper #AGFD #87. Technical Abstract: The chemotype of a microbial or plant species has traditionally been defined as its profile of secondary metabolites, while the genotype is its DNA sequence. For the fungus Fusarium, DNA sequence analysis has associated diversity of trichothecene biosynthetic (TRI) genes with diversity of trichothecene chemotypes. PCR amplification of TRI genes is being developed as a substitute for chemical analysis in the detection of trichothecene chemotypes. For TRI13, gene nonfunctionalization by insertions and deletions is the direct cause of the change from a nivalenol chemotype to a deoxynivalenol chemotype. For other TRI genes, however, sequence polymorphisms have not yet been shown to be causative, and have only been associated with chemotypes. Thus, the predictive value of DNA sequence polymorphisms of different TRI genes and for different fungal groups will have to be validated by chemical analysis. Development and validation of PCR-based technology for predicting trichothecene chemotypes will require collaboration between molecular biologists and chemists and clear standards for data interpretation and usage. To avoid confusion and over-statement, I propose that the terminology “genotype” or “molecular chemotype” be used to refer to TRI genotypes and the terminology “chemotype” be reserved for its original meaning of an actual trichothecene chemical phenotype.