Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/13/2014
Publication Date: 8/13/2014
Citation: Proctor, R., Lee, T., Amatulli, M.T., McCormick, S.P., Brown, D.W., Busman, M., Maragos, C.M., Ward, T.J. 2014. Insights into the evolution of mycotoxin biosynthesis in the fungus Fusarium [abstract]. American Phytopathological Society. Interpretive Summary:
Technical Abstract: Collectively species of Fusarium are pathogens of almost all economically important plants and produce over 50 structurally distinct families of secondary metabolites (SMs), including some of the mycotoxins (e.g. fumonisins and trichothecenes) of greatest concern to food and feed safety. In fungi, genes directly responsible for biosynthesis of an SM family are usually located next to one another in a gene cluster. A typical biosynthetic gene cluster encodes enzymes that catalyze SM synthesis, a transport protein for SM secretion, and a regulatory protein that controls transcription of cluster genes. Comparative analyses of such clusters have provided insight into evolutionary processes responsible for distribution of and qualitative variation in mycotoxin production in Fusarium. Presence and absence of a given cluster is the primary contributor to inter-species differences in ability versus inability to produce the corresponding mycotoxin. In some cases, this variation in ability has resulted from relatively recent horizontal transfer or loss of the cluster. In addition, intra- and inter-species differences in production of different analogues in the same mycotoxin family can result from the presence or absence of a single biosynthetic gene or from differences in function of homologs of the same gene. In contrast, some clusters exhibit considerable variation in DNA sequences or gene organization without discernable effects on mycotoxin production. Thus, SM biosynthetic gene clusters can be dynamic genetic elements, and this dynamism is largely responsible for qualitative differences in mycotoxin production that exist within and among species of Fusarium.