The frozen newly grown leaves and p

The frozen newly grown leaves and pseudostems (0.5 g) from each treatment and replicate were homogenized separately using a pre-cooled mortar and pestle with 0.05 M sodium phosphate buffer(pH 7.8) containing 3% polyvinylpolypyrrolidone. The homogenate was then centrifuged at 10000 rpm for 15 min at 4◦C. The supernatant was used to analyze the soluble protein content, the SOD(E.C. 1.15.1.1) activity and the POD (E.C. 1.15.1.7) activity. The above steps were carried out at 4◦C.