Post-germination growth showed that CuO NPs resulted in longer roots and shoots for both species, especially in the concentrations of 25 mg/L and 50 mg/L (Figure ). Cu is an essential cofactor for many enzymes, playing crucial roles in several processes, such as photosynthesis, respiration, nucleotide metabolism, cell wall formation, reproductive development, and stress tolerance . This can explain the increased growth in shoot and root observed in seeds treated