The role of reactive oxygen species and antioxidants during precooling stages of axis cryopreservation in recalcitrant Trichilia dregeana
Cryopreservation is currently the only feasible method for long term conservation of non orthodox germplasm. Previous attempts to cryopreserve embryonic axes of Trichilia dregeana Sond. indicated that the inability to produce shoots, suggestedly associated with a wound induced burst of reactive oxygen species (ROS) accompanied by declining antioxidant potential, consistently accompanied procedures necessary for cryopreservation. This study involved the provision of cathodic protection, both in the aqueous phase (electrolysis of a solution containing dilute electrolytes) and dry state (rapid drying of axes on a grid on which a static field is generated via the cathode of a power pack) with the addition of other antioxidants, i.e. ascorbic acid and DMSO, to counteract uncontrolled ROS activity. The production of superoxide (O2 hydrogen peroxide (H2O2) and hydroxyl radical (OH in conjunction with the corresponding total aqueous antioxidant activity and viability was quantitatively assessed after ea.