ANTIOXIDANTS AND CRYOPRESERVATION, THE NEW NORMAL?
Cryopreservation protocols are established for many plant species. Cryopreservation provides a stable, long-term and low-cost backup that is safe from the diseases or environmental damage that challenge whole plant collections. However, many plants respond poorly to cryopreservation due to osmotic stress or lack of tolerance to low temperatures. Various stresses can increase reactive oxygen species (ROS) formation to toxic levels in cells and tissues. ROS include superoxide radicals, hydroxyl radicals, hydrogen peroxide and singlet oxygen. Plants have evolved natural antioxidant defense mechanisms to combat the effects of ROS that are produced during physiological stress. These ROS scavenging mechanisms include antioxidant enzymes such as superoxide dismutase, peroxidases, mono- and dehydroascorbate reductase, glutathione reductase and catalase. In addition to temperature-induced stresses, cryopreservation protocols have osmotic and chemical effects on plant cells that contribute to the vitrification process, but also increase cellular oxidation. Cryopreservation protocols that include antioxidants during the cryopreservation process resulted in reduced oxidation and increased regrowth of plant tissues. These studies suggest that adding antioxidants should become a standard part of cryopreservation protocols.
Reed, B.M. (2014). ANTIOXIDANTS AND CRYOPRESERVATION, THE NEW NORMAL?. Acta Hortic. 1039, 41-48
antioxidants, cryopreservation, enzyme action, reactive oxygen species, scavenging