Colligative Effects of Solutions of Low-Molecular Sugars and Their Role in Plants under Hypothermia

The colligative effects of endogenous highly concentrated sugar solutions on frost-resistant plants subjected to negative temperatures are reviewed. These effects prevent cell dehydration and formation of intercellular ice; they decrease the protoplast freezing point and neutralize toxic products. Several protective activities of plant sugars occurring under hypothermia are discussed. These are structural stabilization of membranes, lipids and proteins, deactivation of reactive oxygen species, participation in signaling, and involvement in metabolism as both energy sources and precursors for synthesis of different protective compounds.