ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Protoplasts were enzymically isolated from 2-week-old non-acclimated rye (Secale cereale L. cv. Puma) seedlings. They were resuspended in isotonic sorbitol with different concentrations (0–10%) of dimethyl sulfoxide (DMSO). The survival of the protoplasts frozen in isotonic sorbitol solutions declined at temperatures below the freezing point with the LT50 being -8°C. Addition of DMSO to the osmoticum increased survival at freezing temperatures. The optimum concentration of DMSO was 4% and lowered the LT50 to -19°C. Freeze-fracture studies of the plasma membrane revealed aparticulate lipid lamellae at -4°C, but the first appearance of lateral phase separations, striations and inverted cylindrical micelles (hexagonal11-type structures) occurred at -6°C. At lower temperatures, -8 and -10°C, the occurrence of nonbilayer structures became more common. The addition of DMSO decreased the incidence of the ultrastructural changes. With 2 or 4% DMSO, non-bilayer structures were not observed at temperatures above -10°C. Instead, striations and H11-type structures were observed at - 15 and -20°C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1987.tb01982.x
