Oxidative Stress Responses and Toxicity of Green Synthesized Silver Nanoparticles (AgNPs) on Basil (Ocimum basilicum) Seedlings

This study aimed at investigating how treatment of basil seedlings with green synthesized AgNPs affects their Ag content, oxidative damage and antioxidant enzymes activity. This research was studied as a completely randomized design in four replications. Four levels of silver nanoparticles (0, 4, 10 and 40 mg L-1) were used. After germination, the seedlings were treated for 7 days and then seedlings were harvested for analysis. Findings showed that AgNP treatment increased Ag content O2•−, H2O2, MDA, and ion leakage in basil seedlings. The use of AgNPs caused a significant increase in the activities of SOD, APX, CAT, and GR enzymes in plants. However, at high levels (40 mg L-1) of AgNPs, enzymes activity decreased significantly. These findings suggest that the application of green synthesized AgNPs to basil seedlings led to oxidative stress. Moreover, the observed changes in radical scavenging enzyme activity indicate that synthetic green nanoparticles have a harmful effect on basil seedlings. This toxicity is more pronounced at higher concentrations.