Fusarium head blight resistance exacerbates nutritional loss of wheat grain at elevated CO2

Authors: Hay, William; ANDERSON, JAMES - University Of Minnesota; McCormick, Susan; Hojilla-Evangelista, Milagros - Mila; Selling, Gordon; Utt, Kelly; Bowman, Michael; Doll, Kenneth - Ken; Ascherl, Kim; Berhow, Mark; Vaughan, Martha

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2021
Publication Date: 1/7/2022
Citation: Hay, W.T., Anderson, J.A., McCormick, S.P., Hojilla-Evangelista, M.P., Selling, G.W., Utt, K.D., Bowman, M.J., Doll, K.M., Ascherl, K.L., Berhow, M.A., Vaughan, M.M. 2022. Fusarium head blight resistance exacerbates nutritional loss of wheat grain at elevated CO2. Scientific Reports. 12. Article 15. https://doi.org/10.1038/s41598-021-03890-9.
DOI: https://doi.org/10.1038/s41598-021-03890-9

Interpretive Summary: Higher concentrations of carbon dioxide in the atmosphere can cause some cereal crops to grow larger and produce more starch. This increase in starch can decrease the amount of protein and minerals in the grain, making it less nutritious. In addition, these crops may become more susceptible to disease. Fusarium head blight is a fungal disease of wheat, barley, and other cereal crops that has caused billions of dollars in annual yield losses and contamination with mycotoxins which makes the grain unsafe to eat. Breeding programs have produced wheat varieties that are moderately resistant to the disease. ARS researchers at Peoria, Illinois, in collaboration with wheat breeders from the University of Minnesota, compared wheat varieties that were susceptible or moderately resistant to the disease and measured the nutritional quality of the grain from plants grown with current or elevated concentrations of carbon dioxide. They discovered that some wheat varieties that were moderately resistant to Fusarium head blight produced grain with less nutritional quality when they were grown at elevated carbon dioxide. In the future, farmers may abandon disease resistant varieties for more nutritious susceptible cultivars, significantly increasing the risk of disease outbreaks. This study demonstrated the importance of identifying wheat cultivars that maintain nutritional quality and disease resistance with rising atmospheric carbon dioxide.

Technical Abstract: The nutritional integrity of wheat is jeopardized by rapidly rising atmospheric carbon dioxide (CO2) and the associated emergence and enhanced virulence of plant pathogens. To evaluate how disease resistance traits may impact wheat climate resilience, 15 wheat cultivars with varying levels of resistance to Fusarium Head Blight (FHB) were grown at ambient and elevated CO2. Although all wheat cultivars had increased yield when grown at elevated CO2, the nutritional contents of FHB moderately resistant (MR) cultivars were impacted more than susceptible cultivars. At elevated CO2, the MR cultivars had more significant differences in plant growth, grain protein, starch, fructan, and macro and micro-nutrient content compared with susceptible wheat. Furthermore, changes in protein, starch, phosphorus, and magnesium content were correlated with the cultivar FHB resistance rating, with more FHB resistant cultivars having greater changes in nutrient content. This is the first report of a correlation between the degree of plant pathogen resistance and grain nutritional content loss in response to elevated CO2. Our results demonstrate the importance of identifying wheat cultivars that can maintain nutritional integrity and FHB resistance in future atmospheric CO2 conditions.