Home • Fusarium camptoceras NRRL 13381 v1.0
F. camptoceras
Left – tree showing phylogenetic relationships of 23 Fusarium species complexes and placement of F. camptoceras within the F. incarnatum-equiseti species complex. In the tree, species complex names are abbreviated using specific epithets of the species after which the complexes are named (e.g., the F. incarnatum-equiseti species complex is abbreviated as incarnatum-equiseti). Center right – comparison of the trichothecene biosynthetic gene cluster in a typical member of the F. incarnatum-equiseti species complex and in F. camptoceras. Bottom center – culture of F. camptoceras strain NRRL 13381 growing on potato dextrose agar medium. Bottom right – chemical structure of deoxynivalenol, the trichothecene analog predicted to be produced by F. camptoceras based on genes present in its trichothecene biosynthetic gene cluster.
Image Credit: Robert Proctor, Amy McGovern and Crystal Probyn.

Fusarium (family Nectriaceae) is a species-rich fungal genus that poses a dual threat to agriculture because many species cause destructive crop diseases and/or contaminate infected crops with toxic secondary metabolites (mycotoxins) that are health hazards to humans and other animals. Plant hosts of some Fusarium species include important bioenergy crops such as maize, soybean and sugar cane. Some species can also occur as saprotrophs in soil and plant debris and/or as endophytes in plants, including bioenergy crops. When grain is contaminated with Fusarium mycotoxins, the toxins can become concentrated in dried distillers’ grains, a coproduct of grain-based ethanol production that is used as livestock feed.

DNA-based phylogenetic analyses have resolved Fusarium into 23 multispecies lineages, or species complexes (Geiser et al., 2021). Fusarium camptoceras is a member of the Fusarium incarnatum-equiseti species complex (FIESC), which is comprised of at least 36 phylogenetically distinct species that further resolve into two distinct clades, the Incarnatum clade and Equiseti clade (Xia et al., 2019). Recent analyses indicate that Fusarium camptoceras is the basal-most known lineage of the Equiseti clade. Collectively, members of FIESC are geographically wide-spread and occur in soil and/or on diverse crops. However, they are not typically associated with severe crop disease epidemics. Fusarium camptoceras strain NRRL 13381 was isolated from a cocoa tree (Theobroma cacao) growing in Costa Rica.

Members of FIESC are not associated with severe mycotoxin contamination of crops, but all members that have been examined have the trichothecene mycotoxin biosynthetic gene cluster. Comparison of members of FIESC and the F. sambucinum species complex (FSAMSC) revealed how the trichothecene biosynthetic gene cluster has grown by translocation of genes into it from other loci (Proctor et al., 2009). The absence of two key genes in the F. camptoceras trichothecene cluster indicates that the cluster likely confers production of trichothecene analog deoxynivalenol (vomitoxin) or an analog with a deoxynivalenol-like structure, which is unique among FIESC members that have been analyzed (Villani et al., 2019). This finding also suggests that deoxynivalenol biosynthesis has arisen twice, once in F. camptoceras and once within FSAMSC.

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