What Do We Really Know About Desiccation Tolerance Mechanisms?

摘要

Desiccation tolerance implies an organism's ability to cope with the stresses of almost complete water loss and of rehydration. In practice, the rehydrated desiccation-tolerant organism is capable of resuming normal metabolism after a previous desiccation to water contents as low as 0.05 g H_2O/g dry matter. Di- and oligosaccharides have been found to accumulate to high levels in desiccation-tolerant (anhydrobiotic) organisms. This has led to an increased interest in the possible role of these sugars. From drying experiments with model systems, it emerged that sugars are capable of preventing phase changes in membranes and conformational changes in proteins (Crowe et al., 1998). Consequently, membranes do not leak and enzyme activities are retained.