Interaction of ZnO Nanoparticle with Humic acid on Germination of Rapeseed (Brassica napus L.)

Humic acid by binding to biotoxin, can vary their toxicity and mobility at different environments. Therefore, the interaction between nanoparticles and humic acid is considered environmental point of view specially. The objective of this study was investigation of ZnO nanoparticle toxicity on rapeseed at germination growing stage, and also study of the nanoparticle toxicity reduction by humic acid in laboratory condition. The experiment was conducted with 9 concentrations of 0, 250, 500, 750, 1000, 1250, 1500, 1750, 2000 mg / L zinc oxide nanoparticle and two concentrations of 0, 100 mg / L humic acid, as factorial in a completely randomized design with three replications. The results showed that increasing the ZnO nanoparticle concentration resulted in increasing the activity of superoxide dismutase, ascorbate peroxidase, catalase and peroxidase enzymes. While the protein content showed a reduction trend and humic acid application decreased the toxicity effects of ZnO nanoparticle. Increasing the concentration of ZnO nanoparticle caused reduction in germination indices (such as final germination percentage, germination energy, germination rate and seed vigor index). However, application of humic acid resulted in improving the germination indices and antioxidants activity in the plant and reduction of toxicity by protecting the plant against the ZnO nanoparticle