The CAT (EC 1.11.1.6) activity was measured according
to the method described by Aebi (1984) by measuring thedecrease in absorbance at wavelength k = 240 nm (UV–
VIS Helios Beta spectrophotometer). 2.5 g plant material
was ground on ice in a mortar and pestle with 20 cm3
0.05 M potassium phosphate buffer (pH 7.0). Samples were
then subjected to centrifugation at 3492g for 15 min at
4 C. Test tubes contained 1.8 cm3 0.05 M phosphate
buffer (pH 7.0) and 1.0 cm3 0.05 % H2O2 solution in
0.05 M potassium phosphate buffer (pH 7.0). The decrease
of absorbance was measured after adding 0.2 cm3 supernatant
every minute for 5 min. A mixture of 2.0 cm3
0.05 M potassium phosphate buffer (pH 7.0) and 1.0 cm3
0.05 % H2O2 solution in potassium phosphate buffer was
used as a blank. The specific activity was calculated and
presented as micromoles H2O2 per 1 min per 1 g FM.