|LEE, THERESA - National Academy Of Agricultural Science|
|VILLANI, ALESSANDRA - National Research Council - Italy|
|SUSCA, ANTONIA - National Research Council - Italy|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/14/2015
Publication Date: 5/14/2015
Citation: Proctor, R., Lee, T., Villani, A., Susca, A., McCormick, S.P., Ward, T.J., Brown, D.W. 2015. Comparative genomics reveals multiple causes of variation in mycotoxin production among Fusarium [abstract].
Technical Abstract: Collectively, species of Fusarium produce a structurally diverse array of mycotoxins and other secondary metabolites (SMs), but individual species contribute to only a fraction of this diversity. To elucidate causes of variation in SM production among species, we are examining the distribution and evolution of SM biosynthetic gene clusters in Fusarium. These analyses indicate marked variability in distribution of SM clusters among species. For example, the fusarubin cluster is widely and uniformly distributed among fusaria that have been examined; the fusarin cluster is widely but not uniformly distributed; the trichothecene and fusaric acid clusters are narrowly distributed, and their presence is nearly uniform within the multispecies lineages in which they occur; and the fumonisin and zearalenone clusters are narrowly and discontinuously distributed. In most species, the presence of an SM gene cluster is likely the result of vertical inheritance, but in some species, the presence of certain clusters is likely the result of recent horizontal transfers between fusaria. Gene loss appears to be a major contributor to the discontinuous distribution of clusters. The fumonisin cluster is exemplary of this; we have evidence for at least 20 independent events leading to complete or partial loss of the cluster. Our results also suggest that some clusters were present in Fusarium prior to its divergence into existing lineages, whereas other clusters were likely introduced into certain lineages relatively recently. Together, these finding indicate that variation in production of mycotoxins and other SMs among fusaria has resulted from multiple evolutionary processes.