Surviving desiccation: key factors underlying tolerance in prokaryotes and eukaryotes

Water is essential for all forms of life, and its loss triggers a series of protective responses in both prokaryotic and eukaryotic organisms. This review summarizes the fundamental mechanisms that underlie desiccation tolerance, focusing on the phenomenon of anhydrobiosis. Key strategies include osmoprotection, accumulation of compatible solutes such as trehalose and sucrose, protein anti-aggregation, and enhanced antioxidant activity. Osmoadaptation enables cells to regulate osmotic pressure and maintain membrane integrity during water loss. Intrinsically disordered proteins, particularly late embryogenesis abundant (LEA) proteins, contribute to protein stabilization by forming molecular shields under desiccation stress. Furthermore, the upregulation of antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), mitigates oxidative damage to nucleic acids and proteins. Together, these mechanisms preserve cellular integrity and functionality, facilitating recovery upon rehydration.