Seedling roots (200 mg F.W.) were homogenized in 1 ml of Trismaleate buffer pH 6.5 (0.1M) containing Triton x-100 (0.1 g/l). After centrifugation at 10 000 g for 15 min, the supernatant was used for enzymatic activities determination. Peroxidase (POX) activity was assayed by measuring the oxidation of guaiacol at 470 nm. Twenty microliters of enzyme extractwas added to 2ml of reaction mixture consisting of a solution of 0.1 M Tris–maleate buffer (pH 6.5), 25 mM guaiacol and 25 mM H2O2. Polyphenoloxidase activity was determined by measuring oxidation of 0.2 M catechol at 410 nm in 0.1 M sodium phosphate buffer (pH 6). Enzymatic activities were
expressed as enzymatic unit g1FW.