Viability loss pattern under rapid dehydration of Antiaris toxicaria axes and its relation to oxidative damage.
The relation between oxidative damage and viability loss of excised embryonic axes of Antiaris toxicaria subjected to rapid drying with silica gel at 15 degrees C was studied. Changes of survival rate, accumulation of thiobarbituric acid-reactive substances (TBARs), activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and the permeability of cell membrane that was determined as relative electrolyte leakage (REL) were measured. The half-life moisture content (MC(L50)) was 0.41 g H2O/g DW (dry weight basis). During drying, the activities of SOD, CAT and APX increased until MC(L50), and declined thereafter. The generation speed of (.)O2(-), and content of H2O2 and TBARs remained steadily or even decreased at MC levels higher than MC(L50), demonstrating a low oxidative level in these axes. There was no significant correlation between viability loss and accumulation of reactive oxygen species or lipid peroxidation within the dehydration process until MC(L50). Whereas the increase in REL from the beginning of the drying process indicated that the cell membrane was damaged. In conclusion, under rapid drying with silica gel the viability loss of excised recalcitrant A. toxicaria axes seemed to be triggered by mechanical or physical damage, rather than metabolic damage.
Xin
Xia
X
Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China.
Jing
Xin-Ming
XM
Liu
Yong
Y
Song
Song-Quan
SQ
D031621:Antiaris / Q000196:embryology* / Q000201:enzymology / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003681:Dehydration; D004573:Electrolytes / Q000378:metabolism; D016166:Free Radical Scavengers / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D012639:Seeds / Q000201:enzymology / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D016019:Survival Analysis; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D014022:Tissue Survival / Q000502:physiology*; D014867:Water
D004573:Electrolytes; D016166:Free Radical Scavengers; D017392:Thiobarbituric Acid Reactive Substances; D014867:Water; D013481:Superoxides; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase