Divergent responses of ascorbate and glutathione pools in ozone-sensitive and ozone-tolerant wheat cultivars under elevated ozone and carbon dioxide interaction.

Crop plants face complex tropospheric ozone (O) stress, emphasizing the need for a food security-focused management strategy. While research extensively explores O's harmful effects, this study delves into the combined impacts of O and CO. This study investigates the contrasting responses of O-sensitive (PBW-550) and O-resistant (HUW-55) wheat cultivars, towards elevated ozone (eO) and elevated carbon dioxide (eCO), both individually and in combination. The output of the present study confirms the positive effect of eCO on wheat cultivars exposed to eO stress, with more prominent effects on O-sensitive cultivar PBW-550, as compared to the O-resistant HUW-55. The differential response of the two wheat cultivars can be attributed to the mechanistic variations in the enzyme activities of the Halliwell-Asada pathway (AsA-GSH cycle) and the ascorbate and glutathione pool. The results indicate that eCO was unable to uplift the regeneration of the glutathione pool in HUW-55, however, PBW-550 responded well, under similar eO conditions. The study's findings, highlighting mechanistic variations in antioxidants, show a more positive yield response in PBW-550 compared to HUW-55 under ECO treatment. This insight can inform agricultural strategies, emphasizing the use of O-sensitive cultivars for sustained productivity in future conditions with high O and CO concentrations.