Fumonisin production in the maize pathogen Fusarium verticillioides: genetic basis of naturally occurring chemical variation.
Fumonisins are polyketide-derived mycotoxins produced by the maize pathogen Fusarium verticillioides. Previous analyses identified naturally occurring variants of the fungus that are deficient in fumonisin C-10 hydroxylation or that do not produce any fumonisins. In the current study, gene deletion and genetic complementation analyses localized the C-10 hydroxylation deficiency to a cytochrome P450 monooxygenase gene in the fumonisin biosynthetic gene (FUM) cluster. Sequence analysis indicated that the hydroxylation deficiency resulted from a single nucleotide insertion that caused a frame shift in the coding region of the gene. Genetic complementation localized the fumonisin-nonproduction phenotype to the polyketide synthase gene in the FUM cluster, and sequence analysis indicated that the nonproduction phenotype resulted from a nucleotide substitution, which introduced a premature stop codon in the coding region. These results provide the first direct evidence that altered fumonisin production phenotypes of naturally occurring F. verticillioides variants can result from single point mutations in the FUM cluster.
National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, Illinois 61604, USA. proctorh@ncaur.usda.gov
Robert H
RH
Proctor
Ronald D
RD
Plattner
Anne E
AE
Desjardins
Mark
M
Busman
Robert A E
RA
Butchko
D037341:Fumonisins / Q000737:chemistry* / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation; D006899:Mixed Function Oxygenases / Q000235:genetics; D010641:Phenotype; D017354:Point Mutation; D003313:Zea mays / Q000382:microbiology*
D037341:Fumonisins; D006899:Mixed Function Oxygenases