Figure 7.

Antioxidant genes and corresponding enzymatic activities were modulated by melatonin-mediated NO. Three-day-old rapeseed seedlings were pretreated with 1 μM melatonin, 10 μM SNP, 200 μM PTIO, alone or their combinations for 12 h, and then transferred to 200 mM NaCl for another 12 h (A–C) or 2 days (D,E). Then, the mRNA expression of APX (A), Cu/ZnSOD (B), and MnSOD (C) in root tissues was analyzed by qPCR. The activities of ascorbate peroxidase (APX; (D)) and superoxide dismutase (SOD; (E)) were determined. The sample without chemicals was the control (Con). Values are means ± SE of three independent experiments with at least three replicates for each. Bars with different letters are significant different at p < 0.05 according to Duncan’s multiple range test.