Expression of Tri15 in Fusarium sporotrichioides.
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 Cys(2)-His(2 )zinc finger protein and is expressed in a manner similar to genes in the core trichothecene gene cluster. However, disruption of F. sporotrichioides Tri15 does 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.
Alexander
Nancy J
NJ
Mycotoxin Research Unit, USDA/ARS, National Center for Agricultural Utilization Research, 1815 N. University St., Peoria, IL 61604, USA. alexannj@ncaur.usda.gov
McCormick
Susan P
SP
Larson
Troy M
TM
Jurgenson
James E
JE
D000595:Amino Acid Sequence; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins; D020224:Expressed Sequence Tags; D025461:Feedback, Physiological / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D005670:Fusarium / Q000235:genetics*; D015870:Gene Expression; D005800:Genes, Fungal / Q000502:physiology*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013605:T-2 Toxin / Q000096:biosynthesis; D014157:Transcription Factors / Q000235:genetics*; D014170:Transformation, Genetic / Q000235:genetics; D014255:Trichothecenes / Q000494:pharmacology
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D014157:Transcription Factors; D014255:Trichothecenes; D013605:T-2 Toxin; C007262:deoxynivalenol