Figure 4.

Effects of spermidine (Spd) on the accumulation of H₂O₂ in cucumber under salt stress. (A) H₂O₂ content in leaves. (B) H₂O₂ content in roots. (C) DCF-DA staining of H₂O₂ accumulation in stems. Bars: 300 μm. (D) Relative intensity of H₂O₂ fluorescence in (C). (E) DCF-DA staining of H₂O₂ accumulation in roots. Bars: 300 μm. (F) Relative intensity of H₂O₂ fluorescence in (E). Cucumber leaves, stems and roots were collected at 3 h, 6 h, and 12 h under 75 mM NaCl with or without 1 mM Spd treatment, and the accumulation of H₂O₂ was measured. All data are presented as the means of 3 biological replicates (± SE). Means with the same letter did not significantly differ at P < 0.05, according to Tukey’s test. Three independent experiments were performed with similar results. FW, fresh weight