|LARABA, IMANE - Orise Fellow|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/17/2020
Publication Date: 2/20/2020
Citation: Proctor, R., Kim, H.-K., Laraba, I., Hao, G., Vaughan, M.M., Naumann, T.A., Brown, D.W., Ward, T.J., O'Donnell, K., Busman, M., McCormick, S.P. 2020. Evolution of secondary metabolite diversity in fungi [abstract].
Technical Abstract: Fungi produce thousands of secondary metabolites (SMs) that are diverse in chemical structure and biological activity. SMs produced by plant pathogenic species of Fusarium include pigments, plant hormones, and some of the mycotoxins of greatest concern to agricultural production and food safety. Chemical and genetic analyses over the last four decades have provided tremendous insights into biosynthesis of Fusarium SMs, which has contributed to understanding of fungal secondary metabolism in general, particularly with respect to genetic and evolutionary bases for variation in SM production. Such variation includes: 1) production versus nonproduction of SM families; and 2) production of different structural analogs of the same SM family. The former can result from the presence versus absence of the corresponding SM biosynthetic loci, whereas the latter typically results from sequence differences within homologous biosynthetic loci. Gene loss and horizontal gene transfer (HGT) appear to be major contributors to differences in presence and absence of SM clusters. The presence of closely related homologous biosynthetic loci in one species appears to result from HGT more often than it does from recent duplication of the loci. Sequence differences within homologous loci that affect SM structural variation can result from loss, acquisition and changes in function of individual biosynthetic genes. The evolutionary drivers of SM structural diversity likely depend on the ecological advantage(s) provided by a particular SM. Because of their role in plant pathogenesis, we propose that resistance of plants to trichothecenes can drive structural diversity of this important family of mycotoxin