Elevated CO₂ induces cultivar-dependent changes in wheat proteins linked to wheat-related disorders and baking quality

Rising atmospheric CO₂ concentrations may alter the protein composition of wheat and thereby affect grain quality. Ten wheat cultivars were treated with elevated CO 2 concentration (eCO 2 , 546 ppm) and compared to ambient CO 2 concentration (aCO 2 , 450 ppm) in the field to assess changes in amylase/trypsin-inhibitors (ATI), puroindolins (PIN), and gluten proteins using targeted LC-MS/MS and stable isotope dilution analysis. ATI content was higher under eCO 2 than under aCO 2 , whereas PIN, gluten proteins, and selected celiac disease-active peptides were lower. The response to eCO 2 was strongly genotype-dependant. The lower gluten protein content under eCO 2 was associated with reduced baking quality. While the observed changes in ATI and selected celiac disease-active peptides may be relevant for wheat-related disorders, their biological and immunological significance remains to be established. The findings highlight the importance of identifying cultivars with low levels of ATI and celiac disease-active peptides while maintaining good baking quality under rising CO 2 .