|Jurgenson, James - U OF N IA/CEDAR FALLS, IA|
Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2003
Publication Date: N/A
Technical Abstract: Many of the genes involved in the trichothecene biosynthetic pathway in Fusarium have now been identified within a 29 kb section of DNA. Within this cluster are 3 genes encoding P450 oxygenases, a gene encoding sesquiterpene cyclase, a gene encoding an esterase, two acetyltransferase genes, a transport pump gene, and two regulatory genes. One gene encoding an acetyltransferase is not located within the cluster. In the search for the remaining trichothecene genes, the use of an EST library from a toxin over-producing strain carrying an altered Tri10 has identified Tri16, a gene believed to be involved with trichothecene biosynthesis. We isolated and cloned this gene from F. sporotrichioides and F. graminearum, then formed disruption vectors through insertional disruption and truncated disruption. Insertional disruption vectors produced only single cross-over events when the vector was transformed into the host protoplasts thus producing a transformant with both a disrupted as well as an intact copy of the gene. Transformants carrying the truncated disruption vector were also tested by PCR and Southern hybridization for disruption events and analyzed for toxin production. Northern analyses suggest that Tri16 is regulated like a secondary metabolite as it is turned on in later cultures like several of the other toxin biosynthetic genes. Tri16 is physically located on linkage group 2 whereas the main trichothecene cluster is on linkage group 1.