Elevated CO2 can worsen Fusarium Head Blight disease severity in wheat, but the Fhb1 QTL provides reliable disease resistance

Authors: Hay, William; ANDERSON, JAMES - University Of Minnesota; GARVIN, DAVID - University Of Minnesota; McCormick, Susan; Busman, Mark; Vaughan, Martha

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/7/2023
Publication Date: 10/11/2023
Citation: Hay, W.T., Anderson, J.A., Garvin, D.F., McCormick, S.P., Busman, M., Vaughan, M.M. 2023. Elevated CO2 can worsen Fusarium Head Blight disease severity in wheat, but the Fhb1 QTL provides reliable disease resistance. Plants. 12(20). https://doi.org/10.3390/plants12203527.
DOI: https://doi.org/10.3390/plants12203527

Interpretive Summary: Fusarium head blight is a destructive disease of wheat and other cereal crops and can cause significant yield losses and contaminate food with mycotoxins. Head blight has been predicted to worsen with rising atmospheric CO2. Only a handful of plant traits provide some resistance to the disease, and it was not known if these traits would still provide resistance at higher CO2. ARS scientists in Peoria, Illinois, evaluated the climate resilience of wheat with or without Fhb1, the most widely used disease resistance trait in wheat breeding programs. Although elevated CO2 worsened Fusarium head blight damage and mycotoxin contamination, Fhb1 provided reliable disease resistance even at elevated CO2. This study identified Fhb1 as a climate resilient trait suitable for future wheat breeding efforts.

Technical Abstract: Fusarium head blight (FHB) is a destructive fungal disease of wheat which causes significant economic loss due to lower yields and the contamination of grain with fungal toxins (mycotoxins), particularly deoxynivalenol (DON). FHB disease spread and mycotoxin contamination has been shown to worsen at elevated CO2, therefore it is important to identify climate resilient disease resistance. This work evaluates whether wheat with the Fhb1 quantitative trait locus (QTL), the most widely deployed FHB resistance locus in wheat breeding programs, provides reliable disease resistance at elevated CO2. Near-isogenic wheat lines (NILs) derived from either a highly FHB susceptible or a more FHB resistant genetic background, with or without the Fhb1 QTL, were grown in growth chambers at ambient (400 ppm) and elevated (1000 ppm) CO2 conditions. Wheat was inoculated with Fusarium graminearum and evaluated for FHB severity. At elevated CO2, the NILs derived from more FHB resistant wheat had increased disease spread, greater pathogen biomass and mycotoxin contamination, and lower rates of DON detoxification – this was not observed in wheat from a FHB susceptible genetic background. The Fhb1 QTL was not associated with increased disease severity in wheat grown at elevated CO2 and provided reliable disease resistance.