Fig. 1.

Effects of glutathione on gas exchange attributes in broccoli plants under Pb stress. Data display means ± SE of 4 replicates. Different letters above the bars specify significant variations between the treatments at _P ≤ 0.05. C = un-contaminated control, Pb = contaminated control (300 mg/kg Pb), GSH1 = 25 μM L⁻¹ Glutathione, GSH2 = 50 μM L⁻¹ Glutathione, GSH3 = 75 μM L⁻¹ Glutathione, Pb + GSH1 = 300 mg/kg Pb + 25 μM L⁻¹ GSH, Pb + GSH2 = 300 mg/kg Pb + 50 μM L⁻¹ GSH, Pb + GSH3 = 300 mg/kg Pb + 75 μM L⁻¹ GSH