EXPRESSION OF A SYNTHETIC ANTIFREEZE PROTEIN IN POTATO REDUCES ELECTROLYTE RELEASE AT FREEZING TEMPERATURES

A synthetic antifreeze protein gene was expressed in plants and reduce d electrolyte leakage from the leaves at freezing temperatures. The sy nthetic AFP was expressed as a fusion to a signal peptide, directing i t to the extracytoplasmic space where ice crystallization first occurs . The gene was introduced to Solanum tuberosum L. cv. Russet Burbank b y Agrobacterium-mediated transformation. Transformants were identified by PCR screening and expression of the introduced protein was verifie d by immunoblot. Electrolyte-release analysis of transgenic plant leav es established a correlation between the level of transgenic protein e xpression and degree of tolerance to freezing. This is the first ident ification of a phenotype associated with antifreeze protein expression in plant tissue.