Influence of nano CuO on uptake and translocation of bifenthrin in rape (Brassica napus L.)

The widely utilization of pesticides in agriculture may increase their residues in soil and vegetables. Nowadays, nanoparticles (NPs) could enter soil due to extensive usage. However, the influence of NPs on the translocation of pesticides from soil to vegetables and mechanisms involved are still uncertain. In this study, bifenthrin (200 μg/kg) and nano CuO (0, 10, 50 and 100 mg/kg) were simultaneously added into the soil to cultivate rape (Brassica napus L.) to determine the influence of nano CuO on the translocation of bifenthrin to the plant. The highest concentration of bifenthrin in rape root on day 40 reached 111.6 ng/g in treatment BF + CuO 100, which was 1.65 times of that in single bifenthrin treatment, indicating that high concentration of nano CuO (100 mg/kg) in soil promoted rape root to absorb bifenthrin. The higher accumulation of CuO in root resulted in cell membrane lipid peroxidation and increased MDA contents, and led to higher electrolytic leakage in root tissue and root damage. Therefore, extra bifenthrin may enter rape through the damaged root. Our findings highlight the need to consider plant physiology and mixture effects in studying accumulation of NPs and pesticides in plants.