Cryopreservation affects ROS-induced oxidative stress and antioxidant response in XXXX seedlings.

@entity274 @entity2700 @entity1865 @entity958 @entity26 @entity2197 @entity1234 @entity1281 @entity2145
UNASSIGNED: Plant recovery status after cryopreservation by vitrification had a negative relationship to the oxidative stress induced by reactive @entity26 species (ROS). @entity958 seedlings germinated for 48h or 72h with different survival tolerances were examined at five steps of cryopreservation, to determine the role of ROS (O2(-), @entity274 and @entity2145 ) and antioxidant systems (SOD, POD, CAT, AsA and @entity2197 ) in cryo-injury. In addition, the effects of the steps on membrane lipid peroxidation were studied using @entity1234 ( @entity1865 ) as an indicator. The results indicated that @entity274 -induced oxidative stress at the steps of @entity2700 and rapid warming was the main cause of cryo-injury of 48-h seedlings (high survival rate) and 72-h seedlings (no survival). The @entity274 was mainly generated in cotyledons, shoot tips and roots of seedlings as indicated by Amplex Red staining. Low survival of 72-h seedlings was associated with severe membrane lipid peroxidation, which was caused by increased @entity2145 generation activity and decreased SOD activity. The antioxidant-related gene expression by qRT-PCR and physiological assays suggested that the antioxidant system of 48-h seedlings were activated by ROS, and they mounted a defense against oxidative stress. A high level of ROS led to the weakening of the antioxidant system of 72-h seedlings. Correlation analysis indicated that enhanced antioxidant enzymes activities contributed to the high survival rate of 48-h seedlings, which could reflect by cryopreservation of antioxidant mutant seedlings. This model system indicated that elevated CAT activity and @entity1281 content were determinants of cryogenic stress tolerance, whose manipulation could improve the recovery of seedlings after cryopreservation.
