Figure 5.

The removal of NO did not alter endogenous melatonin level, but melatonin triggered NO production. 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 2 days. Afterwards, NO ((A); determined by laser confocal scanning microscopy; (C); determined by visible spectrophotography) and melatonin contents ((D); detected by enzyme-linked immunosorbent assay) in root tissues were detected. Scale bar = 1 mm. DAF-FM DA fluorescence densities according to (A) were also given (B). 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.