Role of stomatal and leaf anatomical features in defining plant performance under elevated carbon dioxide and ozone, in the changing climate scenario.

This research investigates the interactive effects of elevated ozone (eO) and carbon dioxide (eCO) on stomatal morphology and leaf anatomical characteristics in two wheat cultivars with varying O sensitivities. Elevated O increased stomatal density and conductance, causing oxidative stress and cellular damage, particularly in the O-sensitive cultivar PBW-550 (PW), compared to HUW-55 (HW). Conversely, eCO reduced stomatal density and pore size, mitigating O-induced damage by limiting O influx. Ultrastructural analysis showed that eO increased plastoglobule density and damaged chloroplast structure, while eCO preserved chloroplast integrity and enhanced photosynthetic efficiency. Additionally, eCO increased leaf thickness and improved mesophyll conductance, counteracting the negative effects of O on leaf anatomy. The CO-induced modifications in stomatal and leaf anatomy significantly impacted plant physiology by altering stomatal conductance and O uptake. The protective effect of eCO was more pronounced in the O-sensitive cultivar PW than in the O-tolerant HW. These findings provide insights into the stomatal and leaf anatomical responses of plants under future climate conditions, aiding in the developing strategies to improve crop resilience and productivity under O stress.