ROS-INDUCED OXIDATIVE STRESS IN NOBILE-TYPE DENDROBIUM PROTOCORM-LIKE BODIES (PLBS) DURING VITRIFICATION.

BACKGROUND: Oxidative stress involved in cryopreservation protocols may be responsible for the poor survival of tissues after cryopreservation.

OBJECTIVE: In the current study, we aimed to clarify the role of oxidative stress and its relationship with survival rate during cryopreservation of PLBs from nobile-type Dendrobium.

MATERIALS AND METHODS: ROS, antioxidants and oxidative products and the survival rate in PLBs from Dendrobium Hamanal Lake Dream were determined during vitrification.

RESULTS: Relative survival of PLBs decreased significantly after preculture and rewarming (P<0.01). Generation of ·O2(-) and protein carbonyl (PCO) increased significantly after preculture. Dramatic increases in ·O2(-), H2O2 and MDA, and significant decreases in AsA content, activities of SOD and CAT were observed after rewarming.

CONCLUSION: ROS-induced oxidative stress was associated with the poor survival of PLBs following vitrification. ·O2(-) was the predominant ROS resulting in the decreased survival after preculture, while H2O2 together with ·O2(-) appear to be responsible for the survival decrease after rewarming.