Effect of elevated CO2 and temperature on the oxidative stress response to drought in Lolium perenne L. and Medicago sativa L.

► Elevated CO2 and warming do not affect lipid peroxidation and protein oxidation. ► Future climate increased polyphenols but did not change total antioxidant capacity. ► Elevated CO2 increased ascorbate and glutathione levels and their redox status. ► Lower H2O2 scavenging activity in future climate suggests reduced oxidative pressure. ► Elevated CO2 has a protective effect on water deficit-stress at the molecular level.