Elevated Atmospheric $CO_2$ Concentrations on the Nutrient Density and Gluten Protein Fractionation of Spring Wheat

Abstract

Rising atmospheric carbon dioxide (CO₂) concentrations are expected to influence crop productivity and grain quality, with important implications for food and nutritional security. This study investigates the effect of elevated CO₂ levels on nutrient density and gluten protein fractionation in spring wheat under controlled growth conditions. Wheat plants were grown under ambient and elevated CO₂ environments to evaluate changes in grain composition, including protein content, mineral nutrients, and gluten fractions such as gliadins and glutenins. Key parameters assessed included grain yield, nitrogen accumulation, micronutrient concentrations, and dough quality-related protein characteristics. Results indicated that elevated CO₂ enhanced biomass production and grain yield; however, it led to a dilution effect on nutrient density, particularly reducing grain protein and essential micronutrients such as iron and zinc. Changes in gluten protein composition were also observed, with alterations in the ratio of gliadin to glutenin fractions, potentially affecting dough strength and baking quality. Despite increased carbohydrate accumulation, the decline in protein quality and mineral concentration raises concerns regarding the nutritional value of wheat under future climate scenarios. The study highlights the need to integrate agronomic and breeding strategies to mitigate the negative effects of elevated CO₂ on grain quality. While analytical methods were used to assess compositional changes, the primary focus remains on crop quality and agricultural sustainability. These findings provide practical insights for farmers, breeders, and policymakers to develop adaptive strategies that ensure both productivity and nutritional quality of wheat in the context of climate change.