Low pH regulates the production of deoxynivalenol by Fusarium graminearum.
Fusarium graminearum, which causes the globally important head blight disease of wheat, is responsible for the production of the harmful mycotoxin deoxynivalenol (DON) in infected grain. The production of DON by F. graminearum occurs at much higher levels during infection than during axenic growth, and it is therefore important to understand how DON production is regulated in the fungus. Recently, we have identified amines as potent inducers of in vitro DON production in F. graminearum. Although amines strongly induced expression of the key DON biosynthesis gene TRI5 and DON production to levels equivalent to those observed during infection, the timing of this induction suggested that other factors are also likely to be important for the regulation of DON biosynthesis. Here we demonstrate that low extracellular pH both promotes and is required for DON production in F. graminearum. A combination of low pH and amines results in significantly enhanced expression of the TRI5 gene and increased DON production during axenic growth. A better understanding of DON production in F. graminearum would have implications in developing future toxin management strategies.
Gardiner
Donald M
DM
CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, Brisbane, Queensland 4067, Australia.
Osborne
Sheree
S
CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, Brisbane, Queensland 4067, Australia.
Kazan
Kemal
K
CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, Brisbane, Queensland 4067, Australia.
Manners
John M
JM
CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, Brisbane, Queensland 4067, Australia.
D000588:Amines / Q000378:metabolism; D005670:Fusarium / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006863:Hydrogen-Ion Concentration; D010935:Plant Diseases / Q000382:microbiology*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015533:Transcriptional Activation; D014255:Trichothecenes / Q000096:biosynthesis*; D014908:Triticum / Q000382:microbiology*
D000588:Amines; D014255:Trichothecenes; D049452:Green Fluorescent Proteins; C007262:deoxynivalenol