Joint ozone pollution and climate warming reduce yield but enhance grain protein content in a resistant wheat variety

Ozone (O3) pollution and climate warming jointly threaten crop productivity and undermine global food security. However, their combined effects on wheat under real-world conditions are not well understood, limiting the potential for adaptation. Here, we investigated yield and grain protein of a main wheat variety under joint elevated O3 and warming manipulations in three years (2021-2023), using a real-world simulation with a free-air controlled enrichment (FACE) facility. We found that O3 pollution reduced grain yield mainly by limiting the carbon source by accelerating flag leaf senescence and declining leaf area index. Warming enhanced nitrogen uptake before heading, which mitigates leaf senescence and increases grain protein content. This main wheat variety shows less variability in responses to independently elevated O3 and warming than those varieties reported in previous literature. Cultivating this resistant wheat variety reduced yield losses by only 6% under O3 pollution and warming, while increasing grain nitrogen content by 9%. These findings demonstrate that it is critical to breed wheat varieties that optimize high yield in tandem with adaptation to air pollution and climate change.