Cytoplasmic vitrification and survival of anhydrobiotic organisms

Abstract

We examine the relationship between cytoplasmic vitrification and survival of anhydrobiotic organisms under extreme desiccation conditions. The ability of anhydrobiotic organisms to survive desiccation is associated with the accumulation of carbohydrates. Spores, yeasts and microscopic animals accumulate trehalose, whereas pollen, plant seeds and resurrection plants contain sucrose and oligosaccharides such as raffinose and stachyose. During dehydration, these carbohydrates and other components help the organisms enter into the vitreous state (cytoplasmic vitrification). The immobilization by vitrification may minimize stress damages on the cellular structures and protect their biological capabilities during dehydration and rehydration; however, cytoplasmic vitrification alone is found to be insufficient for anhydrobiotic organisms to survive extreme dehydration. The survival of dry organisms in the desiccated state requires the maintenance of the vitreous state. When the vitreous state is lost, free radical oxidation, phase separation and cytoplasmic crystallization would occur and impose real threat to the survival of dry organisms.