Novel FHB control strategy using the volatile trichodiene to reduce mycotoxins

Authors: Vaughan, Martha; GUTIERREZ, SANTIAGO - University Of Leon; Proctor, Robert; Bakker, Matthew; McCormick, Susan

Submitted to: National Fusarium Head Blight Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/5/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Fusarium graminearum (Fg), the primary fungal pathogen responsible for Fusarium head blight (FHB), reduces crop yield and contaminates grain with trichothecene mycotoxins that are deleterious to plant, human and animal health. The first committed step in trichothecene biosynthesis is the formation of trichodiene (TD), which readily escapes into the atmosphere. The volatile nature of TD suggests that it may be a useful signal for coordinating the production of trichothecenes. However, little is known about the potential of TD to regulate genes related to trichothecene biosynthesis. Fumigation of Fg cultures and Fg-infected wheat heads with TD reduced trichothecene production, downregulated expression of trichothecene biosynthetic genes (TRI genes), and upregulated host plant defense genes. To further investigate whether this phenomenon has potential application in FHB control, the trichodiene synthase gene, TRI5, was transformed into the previously characterized biocontrol fungus Trichoderma harzianum (Th) to generate strain Th+TRI5 as a delivery system for TD, but with the potential added benefit that Th itself could provide some control. Wheat plants pre-treated with Th+TRI5 developed significantly less disease and accumulated less trichothecenes than Th-treated or untreated plants. These results indicate that Th+TRI5 would be an effective management strategy for FHB and trichothecene contamination in wheat.