3.4.1 Fresh biomass and total chlorophyll content
Single root exposure of CLO (10 mg L-1), DFN (20 mg L-1) and DFZ (10 mg L-1) significantly affected the fresh biomass of plants and total chlorophyll content (Fig. 4 A and B ). Compared with the controls, for CLO, DFN and DFZ, the values of fresh biomass of plants decreased by 15.4 %, 24.5 % and 53.8% after single root exposure, respectively (Fig. 4 A ); the values of total chlorophyll content decreased by 26.2 %, 28 %, 31 %, respectively (Fig. 4 B ). As shown in Fig. 4 Aand B , among the treatments with SA supplementation, the fresh biomass of plants increased compared with the without SA treatments. With SA supplementation at 1mg L-1, the fresh biomass of plants increased by 25.5 %, 1.18 %, 66.7 % compared to the single root exposure of CLO, DFN and DFZ treatments, respectively. With SA supplementation at 10 mg L-1, the fresh biomass of plants significantly increased by 33.8 %, 18.9 %, 74.6 % compared to the single root exposure of CLO, DFN and DFZ treatments, respectively. (Fig. 4 A ). Similarly, compared with the treatments with CLO, DFN or DFZ alone, SA at 1mg L-1 and 10 mg L-1 significantly improved the total chlorophyll content, which increased by 47. 1%, 124 %, 144 % and 41.1 %, 150 %, 113 % (Fig. 4 B ).