FLUORESCENT LIPID-PEROXIDATION PRODUCTS AND ANTIOXIDANT ENZYMES IN TISSUE-CULTURES OF VITIS-VINIFERA L

Fluorescent lipid peroxidation products were determined in nodal and internodal stem explants from micropropagated Vitis vinifera L. cv. Sultanina. Fluorescent compounds extracted in the aqueous phase increased in both explants during micropropagation. Solvent extractable products initially decreased in internodal explants, but, later increased during micropropagation. Superoxide dismutase (EC 1.15.1.1) activity did not change significantly during micropropagation. Catalase (EC 1.11.1.6) activity was only detectable in nodal stem sections from micropropagated plants, but, was present in nodal and internodal explants undergoing callogenesis. Fluorescent product content changed considerably in both explants during early callus initiation. Superoxide dismutase activities were similar in nodes and internodes undergoing callogenesis. A reduction in explant fluorescent oxidation products during the latter stages of callus induction was concomitant with increased antioxidant activity.