TIME-COURSE OF CATALASE AND SUPEROXIDE-DISMUTASE DURING ACCLIMATIZATION AND GROWTH OF MICROPROPAGATED CALATHEA AND SPATHIPHYLLUM PLANTS

Catalase and superoxide dismutase (SOD) activities were followed in le aves during ex vitro acclimatization and growth of micropropagated Spa thiphyllum floribundum Schott 'Petite' and Calathea louisae Gagnep 'Ma ui Queen'. During acclimatization of both plants catalase activity inc reased, reaching a maximum 4 weeks after transplantation, while total superoxide dismutase activity increased with plant growth reaching a m aximum in the 24th week. Variations in the pattern of catalase and SOD isoforms were observed; a second Mn-SOD band appeared in Spathiphyllu m 12 weeks after transfer from in vitro, while in Calathea plants an a dditional Mn-SOD form was present from the second until the fourth wee k after transplantation. The observed changes reflect the plants' capa city to develop antioxidant mechanisms during acclimatization. These f indings indicate that the adaptation of micropropagated plants to ex v itro conditions is more extended in time than generally accepted.