Mechanisms of seed desiccation tolerance and survival under dry conditions

Desiccation tolerance is a critical adaptive trait that enables seeds to survive extreme dehydration and maintain viability during prolonged storage and unfavorable environmental conditions. This ability has been fundamental to plant evolution, contributing to successful reproduction, dispersal and long-term persistence of higher plants. In orthodox seeds, desiccation tolerance is acquired during seed maturation through coordinated physiological, biochemical and molecular processes, including dormancy induction, metabolic reprogramming and the accumulation of protective compounds such as late embryogenesis abundant (LEA) proteins, small heat-shock proteins, soluble sugars and antioxidants. These protective molecules stabilize cellular structures, prevent protein denaturation and aggregation and promote the formation of a cytoplasmic glassy state that preserves macromolecular integrity during dehydration. Hormonal regulation, particularly through abscisic acid (ABA) signaling and transcription factors such as ABI3 and ABI5, plays a central role in controlling these adaptive responses. Understanding the mechanisms underlying desiccation tolerance is essential for improving seed conservation strategies, enhancing crop resilience to environmental stress and supporting long-term germplasm preservation. This review summarizes the major physiological, biochemical and molecular mechanisms involved in seed desiccation tolerance and highlights their significance in seed biology and plant survival.