Fig. 1. Alleviatory role of putrescine (PUT) in cadmium (Cd)-stressed rice. A and B, Root (A) and shoot (B) biomass of rice plants at different concentrations of PUT with or without 1 µmol/L Cd treatments. C, Root elongation at different concentrations of PUT with or without 1 µmol/L Cd treatments. D and E, Cd content in roots (D) and shoots (E) with or without 0.01 µmol/L PUT treatments. F, Ratio of shoot to root Cd content with or without 0.01 µmol/L PUT treatments. G, Cd content in xylem with or without 0.01 µmol/L PUT treatments. H, Rice phenotype at the seedling stage when treated with or without 1 µmol/L Cd and different concentrations of PUT. Scale bar, 5 cm. I and K, Cd content in root (I) and shoot (K) cell wall hemicellulose treated with or without 0.01 µmol/L PUT. J and L, Total sugar content in root (J) and shoot (L) hemicellulose with or without 0.01 µmol/L PUT and 1 µmol/L Cd treatments. M, Fluorescence images of nitric oxide (NO) in rice roots. Scale bars, 1 mm. N, Relative fluorescence intensity of NO when treated with or without 0.01 µmol/L PUT and 1 µmol/L Cd at the seedling stage. O and P, Cd content in roots (O) and shoots (P) treated with 10 µmol/L c-PTIO and 1 µmol/L Cd, with or without 0.01 µmol/L PUT. Data are Mean ± SD (n = 10 in A to C, and N, and 4 in D to G, I to O, and P). Different lowercase letters and asterisks above the bars indicate significant differences at P < 0.05.