Understanding the impact of elevated CO2 and O3 on growth and yield in Indian wheat cultivars: Implications for food security in a changing climate

Ashish Kumar Mishra; Gereraj Sen Gupta; Shashi Bhushan Agrawal; Supriya Tiwari

doi:10.1016/j.envpol.2024.124990

Understanding the impact of elevated CO₂ and O₃ on growth and yield in Indian wheat cultivars: Implications for food security in a changing climate

Environ Pollut. 2024 Sep 19:362:124990. doi: 10.1016/j.envpol.2024.124990. Online ahead of print.

Authors

Ashish Kumar Mishra¹, Gereraj Sen Gupta¹, Shashi Bhushan Agrawal², Supriya Tiwari³

Affiliations

¹ Laboratory of Ecotoxicology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
² Laboratory of Air Pollution and Global Climate Change, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address: sbagrawal56@gmail.com.
³ Laboratory of Ecotoxicology, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India. Electronic address: supriyabhu@gmail.com.

PMID: 39303935
DOI: 10.1016/j.envpol.2024.124990

Abstract

The pressing issue of increasing tropospheric ozone (O₃) levels necessitates the development of effective stress management strategies for plant protection. While considerable research has elucidated the adverse impacts of O₃, understanding the combined effects of O₃ and CO₂ requires further investigation. This study focuses on assessing the response of stomatal O₃ flux under various O₃ and CO₂ treatments, individually and in combination, and their repercussions on physiological, growth, and yield attributes in two Indian wheat cultivars, HUW-55 and PBW-550, which exhibit varying levels of sensitivities against elevated O₃. Results indicated significant alterations in stomatal O₃ flux in both O₃-sensitive and tolerant wheat cultivars across different treatments, influencing the overall yield outcomes. Particularly, the ECO₂+EO₃ treatment demonstrated more positive yield protection in the O₃-sensitive cultivar PBW-550, compared to HUW-55 indicating enhanced allocation of photosynthates towards reproductive development in PBW-550, compared to the tolerant cultivar HUW-55, as evidenced by higher harvest index (HI). Furthermore, the study revealed a stronger correlation between yield response and stomatal O₃ flux in PBW-550 (R² = 0.88) compared to HUW-55 (R² = 0.79), as indicated by a steeper regression slope for PBW-550. The research also confirmed the role of elevated CO₂ in reducing stomatal O_3- flux in the tested cultivars, with discernible effects on their respective yield responses. Further experimentation is necessary to confirm these results across different cultivars exhibiting varying sensitivities to O₃. These findings can potentially revolutionize agricultural productivity in regions affected by O₃ stress. The criteria for recommending cultivars for agricultural practices should not be based only on their sensitivity/tolerance to O₃. Still, they should also consider the effect of CO₂ fertilization in the growing area. This experiment offers hope to sustain global food security, as the O₃-sensitive wheat cultivar also showed promising results at elevated CO₂. In essence, this research could pave the way for more resilient agricultural systems in the era of changing climate under elevated O₃ and CO₂ conditions.

Keywords: Elevated CO(2); Elevated O(3); Stomatal O(3) flux; Stomatal conductance; Wheat; Yield.