Determination of activities of antioxidant enzymes and hydrogen
peroxide concentration
Leaf samples were homogenized in a pre-chilled mortar and pestle placed
on ice with 3 mL potassium phosphate buffer . The homogenate was
centrifuged at for 20 min at and the supernatant was used to determine
enzymes activities. Superoxide dismutase activity was measured following
the method described by Giannopotitis and Ries (Giannopolitis & Ries,
1977). The activity of peroxidase (POD) were analyzed through measuring
the oxidation of guaiacol
(Raoet al ., 1996). Catalase activity was assayed using the method by
Aebi (Aebi, 1984). Hydrogen peroxide
(H2O2)
analyses were conducted as described previously (Alexieva et al .,
2001).