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

Abstract

Crop plants face complex tropospheric ozone (O3) stress, emphasizing the need for a food security-focused management strategy. While research extensively explores O3's harmful effects, this study delves into the combined impacts of O3 and CO2. This study investigates the contrasting responses of O3-sensitive (PBW-550) and O3-resistant (HUW-55) wheat cultivars, towards elevated ozone (eO3) and elevated carbon dioxide (eCO2), both individually and in combination. The output of the present study confirms the positive effect of eCO2 on wheat cultivars exposed to eO3 stress, with more prominent effects on O3-sensitive cultivar PBW-550, as compared to the O3-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 eCO2 was unable to uplift the regeneration of the glutathione pool in HUW-55, however, PBW-550 responded well, under similar eO3 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 O3-sensitive cultivars for sustained productivity in future conditions with high O3 and CO2 concentrations.