Traditionally the seeds have been divided into three storage behaviour classes: recalcitrant, desiccation-sensitive (orthodox) and intermediate. Desiccation tolerance is one of fundamental properties of the orthodox seeds. Desiccation evolves a water stress that leads to many physiological, phenological and morfological changes. Several hypotheses were proposed to explain the physiological basis of desiccation tolerance, including accumulation of osmoprotectants, protein synthesis and genes with upregulated expression in response to dehydratation. Numerous studies on the seeds demonstrated their accumulation of soluble sugars during the acquisition of desiccation tolerance.