Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat

Authors: TAYLOR, LAURIE - University Of Poitiers; GUTIERREZ, SANTIAGO - University Of Leon; McCormick, Susan; BAKKER, MATTHEW - Former ARS Employee; Proctor, Robert; Teresi, Jennifer; KURTZMAN, BEN - Former ARS Employee; Hao, Guixia; Vaughan, Martha

Submitted to: Microbial Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2020
Publication Date: 2/2/2021
Citation: Taylor, L., Gutierrez, S., McCormick, S.P., Bakker, M.G., Proctor, R.H., Teresi, J., Kurtzman, B., Hao, G., Vaughan, M.M. 2021. Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat. Microbial Biotechnology. https://doi.org/10.1111/1751-7915.13742.
DOI: https://doi.org/10.1111/1751-7915.13742

Interpretive Summary: Fusarium head blight (FHB) is a devastating disease of wheat and other small cereal crops worldwide. The disease is caused by a fungal pathogen that produces harmful toxic compounds that contaminate grain making it unsafe for consumption. Herein we discovered that an intermediate gaseous chemical involved in the production of the toxin also functions as a regulatory signal. Furthermore, we show that beneficial fungi modified to produce this signal have enhanced antagonistic activity and can be used as a new method to control FHB and mycotoxin contamination thereby enhancing food safety.

Technical Abstract: Fusarium graminearum, the primary fungal pathogen responsible for Fusarium head blight (FHB), reduces crop yield and contaminates grain with trichothecene mycotoxins, including deoxynivalenol (DON), that are deleterious to plant, human and animal health. The first committed step in trichothecene biosynthesis is the formation of trichodiene (TD). The volatile nature of TD suggests that it may be a useful intra- or inter- species signaling molecule, but little is known about the potential signaling role of TD during the F. graminearum-wheat interactions. Previous work using a transgenic Trichoderma harzianum strain engineered to emit TD (Th+TRI5) found that TD can function as a signal that can modulate pathogen virulence and host plant resistance. Herein we demonstrate that Th+TRI5 has enhanced biocontrol activity against F. graminearum and reduced DON contamination by 66% and 70% in a moderately resistant and a susceptible cultivar, respectively. While Th+TRI5 volatiles significantly influenced the expression of the pathogenesis-related 1 (PR1) gene, the effect was dependent on the cultivar. Th+TRI5 volatiles strongly reduced DON production in F. graminearum plate cultures and downregulated the expression of TRI genes. Finally, we confirm that TD fumigation reduced DON accumulation in a detached wheat head assay.