This invention relates to polynucleotides isolated from forage grass tissues, specifically from Lolium perenne (perennial ryegrass) and Festuca arundinacea (tall fescue), as well as oligonucleotide probes and primers, genetic constructs comprising the polynucleotides, biological materials (including host cells and plants) incorporating the polynucleotides, polypeptides encoded by the polynucleotides, and methods for using the polynucleotides and polypeptides. More particularly, the invention relates to
antifreeze polypeptides involved in ice recrystallization pathways, and to polynucleotides encoding such polypeptides that confer freezing tolerance to plants.