The plasma membrane is considered to be the primary site of injury when plant cells are subjected to extracellular freezing. In order for plants or plant cells to acquire freezing tolerance, it is, thus, necessary that the plasma membrane increases its cryostability during freeze-thaw excursion. During cold acclimation both under natural and artificial conditions, there are compositional, structural and functional changes occurring in the plasma membrane, many, if not all, of which ultimately contribute to increased stability of the plasma membrane under freezing conditions. In addition, changes in the cytosol or intracellular compartments also affect the cryobehaviour of the plasma membrane during freeze-induced dehydration. Although many alterations occurring during cold acclimation influence the cryobehaviour of the plasma membrane comprehensively, recent advances in functional genomics approaches provide interesting information on the function of specific proteins for plasma membrane behaviour under freezing conditions.

This paper focuses on several selected cold-responsive plasma membrane proteins and examines their functions in direct relation to cold acclimatization. The proteins include dehydrins (ERD10 and ERD14), outer membrane lipoprotein-like protein (lipocalin-like: AtLCN), and DREPP-like protein and nodulin VfNOD18-like protein; all of these five proteins are found in the solubilized fraction. The genes encoding this subset of five proteins are initially characterized and their effects on the freezing tolerance and freeze-induced lesions of Arabidopsis thaliana in planta with independent transgenic plants that constitutively express one of these genes are analysed subsequently.