PLURONIC F-68 INCREASES THE POSTTHAW GROWTH OF CRYOPRESERVED PLANT-CELLS

The beneficial effects of supplementing culture media with Pluronic F- 68 (0.01-0.2% w/v), on post thaw growth following cryopreservation of suspension-cultured cells of Oryza sativa cvs. Taipei 309 and Tarom (J aponica rices), together with Lolium multiflorum um (Italian ryegrass) , were studied. The mean absorbance, following triphenyltetrazolium ch loride (TTC) reduction, of Taipei 309 cells 4 days after thawing was i ncreased twofold over control by 0.01% (w/v) Pluronic F-68 (P < 0.01) and almost twofold by 0.1% (w/v) surfactant. A more pronounced, fourfo ld increase (P < 0.001) in post-thaw absorbance occurred with Tarom ce lls exposed to 0.1% (w/v) Pluronic F-68; cell absorbance was elevated threefold with 0.2% (w/v) Pluronic (P < 0.001) and twofold (P < 0.001) by 0.01% (w/v) surfactant. TTC reduction by Lolium cells was elevated 31% (P < 0.01) with 0.01% (w/v) surfactant. Pluronic F-68 (0.01% w/v) also promoted sustained mitotic activity since biomass, measured 30 d ays post-thawing. was increased to a maximum of 32% above control (P < 0.05), in both Taipei 309 and Lolium. There was no measurable benefic ial effect of adding Pluronic F-68 to the cryoprotectant before freezi ng. These results, which demonstrate a marked cytoprotection of Pluron ic F-68 on plant cells recovered from cryostorage, suggest that this s urfactant is a useful additive agent in post-thaw handling strategies. (C) 1996 Academic Press, Inc.