Fig. 2

Micrographs of S. babylonica roots using PI dye at longitudinal root tips exposed to different Pb concentrations (0, 1, 10, 50, or 100 μmol/L) for different treatment times (0, 3, 6, 12, and 24 h). A1–D1: Control without Pb for 3, 6, 12, and 24 h; A2–D2: 1 μmol/L Pb for 3, 6, 12, and 24 h; A3–D3: 10 μmol/L Pb for 3, 6, 12, and 24 h; A4–D4: 50 μmol/L Pb for 3, 6, 12, and 24 h; A5–D5: 100 μmol/L Pb for 3, 6, 12, and 24 h. Scale bar = 1 mm