Effect of Copper Oxide Nanoparticles (CuO- NPs) on Lettuce Growth and Uptake by Plant in Greenhouse Condition

Increasing the production and use of nanoparticles in the environment has raised concerns about their effects on living organisms. In this study the effect of CuO- NPs on the lettuce growth and its uptake by the plant were investigated in a research greenhouse and in soil environment at Davis university of California. Treatments included control (distilled water), CuCl2 and CuO- NPs which applied 14 days after planting. During the plant growth, Plastochron Index (PI), Leaf Plastochron Index (LPI) of leaf number 4, copper (Cu) concentration in leaf number 4 by ICP-MS and Cu concentration in leaves with specific plastochron index by Laser Ablation-ICP-MS were measured. Results showed that the effect of nanoparticles on the PI of whole plant and leaf number 4 was not significant. The Cu concentration in leaf number 4 was decreased with time after application of nanoparticles treatment. Measurement of Cu concentration by LA-ICP-MS showed the insignificant difference in Cu concentration between different parts of leaf and between nanoparticles treatment with other treatment. Also, the highest concentration of Cu was observed in between veins than other parts of the leaf. It seems that CuO- NPs have not been absorbed by the plant and have little effect on plant growth. More studies with other plants are recommended.