Content of hydrogen
peroxide was measured according to the procedure of Velikova et
al. 10
. Fresh leaf samples (0.5 g) were homogenized with 5 mL 0.1%
(w:v) trichloroacetic acid (TCA) in ice bath and the homogenate
was centrifuged at 12,000 g for 15 min. Then 0.5 mL of 10 mM
phosphate buffer and 1 mL of 1 M KI were added to 0.5 mL of the
supernatant. The absorbance of supernatant was read at 390 nm.
The content of H2
O2
was estimated using a standard curve