Genomics and evolution of secondary metabolism in Fusarium

Authors: Proctor, Robert; Kim, Hye-Seon; Brown, Daren

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Fusarium is a species-rich genus that causes disease on virtually all plant crops and produces diverse secondary metabolites (SMs), including pigments, plant hormones, and some of the mycotoxins of greatest concern to food and feed safety. To better understand the potential SM diversity in Fusarium as well as the distribution and evolution of SM biosynthetic genes, we have assessed the presence and absence of known and novel SM biosynthetic genes and gene clusters in genome sequences of >200 isolates representative of 24 lineages (species complexes) of Fusarium. AntiSMASH analysis indicates that 1.1 – 6.4% of the genes in Fusarium genomes are involved in secondary metabolism, and that collectively Fusarium species have the genetic potential to produce hundreds of structurally distinct families of SMs, including analogs of multiple SMs described in other fungi. Fusarium SM clusters exhibit marked variation in distribution within and among species complexes: some are present in almost all members of all species complexes; others exhibit largely continuous distributions within one or several complexes; and others exhibit discontinuous distributions within one or more complexes. Phylogenetic analyses indicate that vertical inheritance, horizontal transfer, and gene loss have been major contributors to the current distribution of SM clusters among Fusaria, but that recent duplication events have contributed little to the current distribution of clusters. Further, if the ancestral Fusarium had a similar number (26 – 68) of SM gene clusters as extant species, hundreds of horizontal transfer and loss events would be necessary to account for the current diversity and distribution of SM gene clusters in Fusarium.