Investigation the activities of photosynthetic pigments, antioxidant enzymes and inducing genotoxicity of cucumber seedling exposed to copper oxides nanoparticles stress

The anthropogenic increment of metallic nanoparticles in the agricultural environment may contaminate vegetables through foliar uptake. This study investigates the impact of cuprous and cupric nanoparticles (100, 200 and 400 mg L-1) on the early growth stages of cucumber plants and assessed their phenotypical and physiological effect. The potential phytotoxic effect of copper oxides NPs, as air-induced stress, was studied on plant growth, photosynthetic pigments and antioxidant systems in Cucumis sativus L. in addition to assessing inducing genotoxicity. The results showed that the foliar application of both Cu2O and CuO nanoparticles causes a decrease in seedling height, root length, average leaf area and RWC. Chlorophylls contents and nitrogen percentage on cucumber leaves were reduced while chlorophyll ratio, carotene content, electrolyte leakage, Fe and Cu contents were increased in the leaves by exposing them to Copper NPs. While Cu-NPs inhibit SOD and POD activities, CAT and MDA activities are promoted by applying copper oxides. At the same time, just the maximum doses of both oxides decreased APX activity. CuO nanoparticles induce genotoxicity and negatively affect cucumber seedlings' growth and physiological processes more than Cu2O.