Comparative Efficiency of Different Nanoparticles in Mitigating Copper Stress in Wheat (Triticum aestivum L.): Insights into Morpho–Physio–Biochemical Attributes

Copper (Cu) pollution in agricultural soils is considered as a serious health risk due to its accumulation in plants. Thus, there is an urgent need to optimize nutrient application for higher yield with lower Cu uptake to ensure food security. A pot experiment was conducted to examine the plant growth and biomass, photosynthetic pigments, gas exchange attributes, oxidative stress and response of antioxidant compounds (enzymatic and nonenzymatic), sugars, nutritional status of the plant and Cu accumulation from the different parts of the plants in wheat (Triticum aestivum L.) under the different As concentrations i.e., 0 (no As), 100 and 200 mg kg^{− 1} which were treated with a foliar application of IO–NPs, CeO₂–NPs and ZnO–NPs at 100 mg L⁻¹. Results from the present study showed that the increasing levels of Cu in the soil significantly (P < 0.05) decreased plant growth and biomass, photosynthetic pigments, gas exchange attributes, sugars, and nutritional contents from the roots and shoots of the plants. In contrast, increasing levels of Cu in the soil significantly (P < 0.05) increased oxidative stress indicators in term of malondialdehyde, hydrogen peroxide, and electrolyte leakage in T. aestivum. The negative impact of Cu toxicity can overcome the application of IO–NPs, CeO₂–NPs and ZnO–NPs which ultimately increased plant growth and biomass by capturing the reactive oxygen species, and decreased oxidative stress in T. aestivum by decreasing the Cu contents in the roots and shoots of the plants. Research findings, therefore, suggest that the application of IO–NPs, CeO₂–NPs and ZnO–NPs can ameliorate Cu toxicity in T. aestivum, resulting in improved plant growth and composition under As stress, as depicted by increased antioxidant defense and nutrient homeostasis. These nanoparticles represent promising tools for promoting sustainable agriculture and ensuring food security under heavy metal toxicity.