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 CO₂ concentration (eCO₂, 546 ppm) and compared to
ambient CO₂ concentration (aCO₂, 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 eCO₂ than under aCO₂, whereas PIN, gluten proteins, and selected celiac disease-active
peptides were lower. The response to eCO₂ was strongly genotype-dependant. The lower gluten protein content
under eCO₂ 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 signif-
icance 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$_2$.