Submitted to: Current Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/23/2003
Publication Date: 11/18/2003
Citation: Alexander, N.J., Mc Cormick, S.P., Larson, T.M., Jurgenson, J.E. 2004. Expression of Tri15 in Fusarium sporotrichioides. Current Genetics. 45:157-162. Interpretive Summary: The mold Fusarium is a common contaminant of grain and other livestock feeds. Several species of Fusarium produce trichothecene toxins such as T-2 toxin and vomitoxin that cause adverse effects on human and animal health. These toxins are also important factors in determining the severity of the plant disease called wheat head scab. In the search for the unknown genes in the biosynthetic pathway of toxin production, we have studied Tri16. This gene is a regulatory gene but does not appear to control toxin production. This research has identified a gene which may serve as a potential target to control Fusarium and will be of great interest to the food and feed industry.
Technical Abstract: In the fungus Fusarium sporotrichioides, biosynthesis of trichothecene mycotoxins requires at least three genetic loci: a core 12-gene cluster, a smaller two-gene cluster, and a single-gene locus. Here we describe the Tri15 gene, which represents a fourth locus involved in trichothecene biosynthesis. Tri15 is predicted to encode a Cys2-His2 zinc finger protein and is expressed in a manner similar to genes in the core trichothecene gene cluster. However, disruption of F. sporotrichioides Tri15 did not affect production of T-2 toxin, the major trichothecene produced by this fungus. This result suggests that Tri15 is not necessary for the production of toxin. Cultures with exogenously added T-2 toxin have high levels of Tri15 expression and no detectable expression of the trichothecene biosynthetic genes Tri5 and Tri6. The expression analysis is consistent with Tri15 being a negative regulator of at least some of the trichothecene biosynthetic genes. In F. graminearum, Tri15 has been mapped to Linkage Group 2 and is therefore unlinked to the main trichothecene biosynthetic gene cluster.