Fig. 3

Effects of melatonin (5 μM) on (A) H₂O₂ content, O₂^•– content and MDA content, (B) Antioxidant enzymes (SOD, POD, CAT and APX) activities of L. bicolor seedlings subjected to 300 mM NaCl for 15 days. Values are mean ± standard deviation of five biological replicates. Bars labeled with different letters are significantly different at P < 0.05 according to Duncan’s multiple range tests. 0 mM NaCl, plants cultivated with only Hoagland nutrient solution; 0 mM NaCl + 5 μM MT, plants cultivated with Hoagland nutrient solution plus 5 μM melatonin; 300 mM NaCl, plants cultivated with Hoagland nutrient solution plus 300 mM NaCl; 300 mM NaCl + 5 μM MT, plants cultivated with Hoagland nutrient solution plus 300 mM NaCl and 5 μM melatonin