Tri1 in Fusarium graminearum Encodes a P450 Oxygenase

ABSTRACT Gibberella zeae (asexual state Fusarium graminearum) is a major causal agent of wheat head blight and maize ear rot in North America and is responsible for contamination of grain with deoxynivalenol and related trichothecene mycotoxins. To identify additional trichothecene biosynthetic genes, cDNA libraries were prepared from fungal cultures under trichothecene-inducing conditions in culture and in planta. A gene designated LH1 that was highly expressed under these conditions exhibited only moderate (59%) similarity to known trichothecene biosynthetic cytochrome P450s. To determine the function of LH1, gene disruptants were produced and assessed for trichothecene production. Gene disruptants no longer produced 15-acetyldeoxynivalenol, which is oxygenated at carbon 7 (C-7) and C-8, but rather accumulated calonectrin and 3-deacetylcalonectrin, which are not oxygenated at either C-7 or C-8. These results indicate that gene LH1 encodes a cytochrome P450 responsible for oxygenation at one or both of these positions. Despite the relatively low level of DNA and amino acid sequence similarity between the two genes, LH1 from G. zeae is the probable homologue of Tri1, which encodes a cytochrome P450 required for C-8 oxygenation in F. sporotrichioides.

[1]  T. Phillips,et al.  Tri16 Is Required for Esterification of Position C-8 during Trichothecene Mycotoxin Production by Fusarium sporotrichioides , 2003, Applied and Environmental Microbiology.

[2]  M. Kimura,et al.  The trichothecene biosynthesis gene cluster of Fusarium graminearum F15 contains a limited number of essential pathway genes and expressed non‐essential genes , 2003, FEBS letters.

[3]  T. Phillips,et al.  Tri1 Encodes the Cytochrome P450 Monooxygenase for C-8 Hydroxylation during Trichothecene Biosynthesis in Fusarium sporotrichioides and Resides Upstream of Another New Tri Gene , 2003, Applied and Environmental Microbiology.

[4]  H. Kistler,et al.  Analysis of expressed sequence tags from Gibberella zeae (anamorph Fusarium graminearum). , 2003, Fungal genetics and biology : FG & B.

[5]  R. Proctor,et al.  Inactivation of a cytochrome P-450 is a determinant of trichothecene diversity in Fusarium species. , 2002, Fungal genetics and biology : FG & B.

[6]  P. Hedden,et al.  The Gibberellin 20-Oxidase of Gibberella fujikuroi Is a Multifunctional Monooxygenase* , 2002, The Journal of Biological Chemistry.

[7]  S. McCormick,et al.  Fusarium Tri8 Encodes a Trichothecene C-3 Esterase , 2002, Applied and Environmental Microbiology.

[8]  Y. Han,et al.  Tri13 and Tri7 Determine Deoxynivalenol- and Nivalenol-Producing Chemotypes of Gibberella zeae , 2002, Applied and Environmental Microbiology.

[9]  J. Leslie,et al.  A genetic map of Gibberella zeae (Fusarium graminearum). , 2002, Genetics.

[10]  Yin-Won Lee,et al.  Identification of Deoxynivalenol- and Nivalenol-Producing Chemotypes of Gibberella zeae by Using PCR , 2001, Applied and Environmental Microbiology.

[11]  P. Hedden,et al.  The P450–1 gene of Gibberella fujikuroi encodes a multifunctional enzyme in gibberellin biosynthesis , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[12]  R. Proctor,et al.  A genetic and biochemical approach to study trichothecene diversity in Fusarium sporotrichioides and Fusarium graminearum. , 2001, Fungal genetics and biology : FG & B.

[13]  C. Helliwell,et al.  The CYP88A cytochrome P450, ent-kaurenoic acid oxidase, catalyzes three steps of the gibberellin biosynthesis pathway. , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[14]  S. McCormick,et al.  Disruption of TRI101, the Gene Encoding Trichothecene 3-O-Acetyltransferase, fromFusarium sporotrichioides , 1999, Applied and Environmental Microbiology.

[15]  R. Proctor,et al.  Characterization of a transcriptional activator controlling trichothecene toxin biosynthesis. , 1999, Fungal genetics and biology : FG & B.

[16]  K. O’Donnell,et al.  New Fusarium species and combinations within the Gibberella fujikuroi species complex , 1998 .

[17]  M. Kimura,et al.  Trichothecene 3-O-Acetyltransferase Protects Both the Producing Organism and Transformed Yeast from Related Mycotoxins , 1998, The Journal of Biological Chemistry.

[18]  S. McCormick,et al.  Accumulation of Trichothecenes in Liquid Cultures of a Fusarium sporotrichioides Mutant Lacking a Functional Trichothecene C-15 Hydroxylase , 1997, Applied and environmental microbiology.

[19]  M. Savard,et al.  Comparison of immunoassay and gas chromatography methods for the detection of the mycotoxin deoxynivalenol in grain samples , 1996 .

[20]  Aaron P. Campbell,et al.  Suppression subtractive hybridization: a method for generating differentially regulated or tissue-specific cDNA probes and libraries. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[21]  A. E. Desjardins,et al.  Isolation and characterization of Tri3, a gene encoding 15-O-acetyltransferase from Fusarium sporotrichioides , 1996, Applied and environmental microbiology.

[22]  G. Bai,et al.  Reduced virulence of trichothecene-nonproducing mutants of Gibberella zeae in wheat field tests , 1996 .

[23]  R. Proctor,et al.  Reduced virulence of Gibberella zeae caused by disruption of a trichothecene toxin biosynthetic gene. , 1995, Molecular plant-microbe interactions : MPMI.

[24]  E. Espeso,et al.  The Aspergillus PacC zinc finger transcription factor mediates regulation of both acid‐ and alkaline‐expressed genes by ambient pH. , 1995, The EMBO journal.

[25]  P. Dewick,et al.  Potential inhibitors of trichothecene biosynthesis in Fusarium culmorum: Epoxidation of a trichodiene derivative , 1992 .

[26]  J. Leslie,et al.  Nitrate-nonutilizing mutants ofGibberella zeae (Fusarium graminearum) and their use in determining vegetative compatibility , 1992 .

[27]  B. Turgeon,et al.  Development of a fungal transformation system based on selection of sequences with promoter activity , 1987, Molecular and cellular biology.

[28]  J. Miller,et al.  Biosynthesis of 3-acetyldeoxynivalenol and other metabolites by Fusarium culmorum HLX 1503 in a stirred jar fermentor , 1986 .

[29]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .