Silver Nanoparticles Reduce the Toxic Effects of Cadmium on Datura stramonium Callus Culture

Cadmium (Cd) is one the most toxic metals harmful for both animals and plants. In this study, we test whether silver nanoparticles (AgNPs) can protect plants from cadmium toxicity. AgNPs treatments (0 and 100 μg/L) were applied to Datura stramonium calli grown in different cadmium metal environments (0, 150, 300, 450, and 600 μM). Cd application led to a decrease in fresh weight (FW), dry weight (DW), relative water content (RWC), total chlorophyll content (Chl.T), tolerance index (Ti), and bioaccumulation factor (BCF). The Cd treatment increased the hydrogen peroxide (H2O2), catalase (CAT), and guaiacol peroxidase (GPX) contents and Cd accumulation (Cd con). These results show the positive role of AgNPs in protecting the callus cultures from oxidative stress. The AgNPs pretreatment improved the growth of tissue cultures compared to nontreatment, increasing FW, DW, RWC, and Chl.T; the highest CAT and GPX activities were detected in the AgNPs pretreatment condition; and AgNPs pretreatment improved Ti and BCF, despite increased Cd. Also, this treatment caused a decrease in H2O2. Based on these results, we propose AgNPs as an effective agent to reduce the toxic effects of Cd metal on D. stramonium.