title: Antifreeze proteins in overwintering plants: a tale of two activities.
abstract: Antifreeze proteins are found in a wide range of overwintering plants where they inhibit the growth and recrystallization of ice that forms in intercellular spaces. Unlike antifreeze proteins found in fish and insects, plant antifreeze proteins have multiple, hydrophilic ice-binding domains. Surprisingly, antifreeze proteins from plants are homologous to pathogenesis-related proteins and also provide protection against psychrophilic pathogens. In winter rye (Secale cereale), antifreeze proteins accumulate in response to cold, short daylength, dehydration and ethylene, but not pathogens. Transferring single genes encoding antifreeze proteins to freezing-sensitive plants lowered their freezing temperatures by approximately 1 degrees C. Genes encoding dual-function plant antifreeze proteins are excellent models for use in evolutionary studies to determine how genes acquire new expression patterns and how proteins acquire new activities.
authors.affiliation: Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo ON, Canada N2L 3G1. griffith@uwaterloo.ca
authors.forename: Marilyn
authors.initials: M
authors.lastname: Griffith
authors.forename: Mahmoud W F
authors.initials: MW
authors.lastname: Yaish
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D021301:Antifreeze Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007053:Ice / Q000032:analysis; D063245:Plant Development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D012621:Seasons
chemical_list: D021301:Antifreeze Proteins; D007053:Ice; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant