A soil mediated phyto-toxicological study of iron doped zinc oxide nanoparticles (Fe@ZnO) in green peas (Pisum sativum L.)

Abstract

• This is the first study on the impacts of Fe@ZnO NPs in terrestrial plants. • At 500 mg/kg, Fe@ZnO NPs reduced chlorophyll (27%) and ROS production (∼50%) compared to control. • Fe@ZnO NPs showed less phytotoxic effects compared to bare ZnO NPs. • At all concentrations Fe@ZnO NPs decreased APOX activity (33–86%) in all tissues. • At 500 mg/kg, Fe@ZnO NPs increased catalase activity in roots (30%) and leaves (400%). Iron doping has shown to reduce toxicity of zinc oxide nanoparticles (ZnO NPs) in several organisms. To the best of authors’ knowledge, this is the first report on toxicological studies of Fe@ZnO NPs on terrestrial plants. In this study, green pea plants ( Pisum sativum L.) were grown for 25 days in soil treated with 10% Fe@ZnO NPs at 0–500 mg/kg. Effects were compared with our previous study where phytotoxicity of bare-ZnO NPs had been investigated on green pea plants grown under similar environmental conditions. Different physiological and biochemical growth parameters were measured. Results showed increased Zn bioaccumulation in roots (200%) and stems (31–48%) as the exposed NP concentration increased ( p ⩽ 0.05) but Fe absorption was not affected. At 500 mg/kg Fe@ZnO NPs treatment, chlorophyll content (27%) and H 2 O 2 production (∼50%) decreased significantly ( p ≤ 0.05) compared to control. Toxicity of doped ZnO NPs is less than that of bare ZnO NPs as per zinc uptake, chlorophyll content, and ROS (H 2 O 2 ) production are considered. Therefore, iron doping can be considered as a safer approach to reduce toxicity of ZnO NPs in terrestrial plants.