SYNERGISTIC ENHANCEMENT OF THE POSTTHAW GROWTH OF CRYOPRESERVED RICE CELLS BY OXYGENATED PERFLUOROCARBON AND PLURONIC F-68

The beneficial effects were assessed of supplementing culture medium w ith oxygenated perfluorocarbon, both alone and in combination with 0.0 1 (w/v) Pluronic F-68, on the postthaw viability, following cryopreser vation, of suspension cultured cells of the Japonica rice, Oryza sativ a cv. Taipei 309. The mean viability, as assessed by triphenyl tetrazo lium chloride reduction, of cells at 4 days after thawing was increase d 20% over control by oxygenated perfluorodecalin (P < 0.05) in 100-ml glass jars and similarly by 24% (P < 0.01) when recovered on a smalle r scale in 24-well petri dishes. In a separate assessment, a 21% incre ase above control treatments (P < 0.05) in postthaw viability was also observed. with oxygenated perfluorodecalin. A similar, 36% increase ( P < 0.05) in postthaw viability occurred with cells exposed to 0.01% ( w/v) Pluronic F-68 alone. A more pronounced, synergistic increase in v iability, up to 57% over control (P < 0.05), occurred with cells recov ered in the presence of both oxygenated perfluorodecalin and 0.01% (w/ v) Pluronic F-68. No significant difference was observed between Pluro nic F-68 and oxygenated perfluorodecalin treatments. Both the perfluor odecalin and the Pluronic F-68 treatments alone and in combination als o promoted an increase in biomass, measured as fresh weight gain 30 da ys after thawing, to a maximum of 38% above control (P < 0.05). These results demonstrate the marked cytoprotectant effects of oxygenated pe rfluorodecalin and Pluronic F-68, both alone and/or in combination, fo r plant cells recovered from cryostorage. Such options offer alternati ve postthaw handling strategies to cells of those plant species which, normally, respond poorly to conventional recovery procedures. (C) 199 7 Academic Press.