Toxicity of ZnO engineered nanoparticles and evaluation of their effect on growth, metabolism and tissue specific accumulation in Brassica juncea

Metal nanoparticles have many potential technological applications; it hassled the issue regarding unidentified consequences of their release into the environment. Present study deals with the effects of zinc oxide (ZnO) engineered nanoparticles (ENPs) on plant growth, bioaccumulation and antioxidative enzyme activity in Brassica juncea. The seed was germinated under hydroponic condition with a varying concentration of ZnO ENPs (0, 200, 500, 1000, 1500 mg/l) for 96 h. Significant decrease in plant biomass was recorded with gradual increase in proline content and lipid peroxidation upto a concentration of 1000 mg/l. Estimation of the antioxidant enzyme [catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and superoxide dismutase (SOD)] activities in different plant tissues was done. Further, bioaccumulation of ZnO ENPs was also recorded. ENPs caused a significant effect due to their accumulation along with the generation of reactive oxygen species in plant tissues, thus signifying its hazardous effect on B. juncea.