2.2.2. Pesticide exposure experiments- oxidative stress in cucumber plants
Single root exposure of CLO, DFN and DFZ:Hydroponic experiment conditions and plant growth conditions were the same as the“uptake and translocation.” Given the tendency for repeated application of pesticides, a series of preliminary experiments using various concentrations of pesticides were carried to evaluated the cucumber growth parameters. When the root application of CLO at 10mg L-1, DFN at 20mg L-1 and DFZ at 10mg L-1, the fresh biomass of cucumber plants significantly decreased, respectively. We estimated that at these concentrations, the three pesticides caused significant stress responses, respectively (Fig S1 ). Therefore, we set the concentration of CLO at 10 mg L-1, DFN at 20 mg L-1 and DFZ at 10 mg L-1, and with SA supplementation at 1mg L-1, 10mg L-1 and 50mg L-1, the root, stem and leaf samples were collected after 10 days of growth, respectively. A total of 12 treatments were set in this part of experiment. The plants were grown in blank nutrient solution as a control group. After the root, stem and leaf samples were weighed, the root samples were stored at -80℃ until measured.