Abstract
Freezing behavior of tropical and subtropical plants was examined by means of Cryo-SEM and freeze-fracture replica electron microscopy. Saintpaulia (Saintpaulia grotei mutant) leaf cells and mungbean (Vigna radiatd) seedling cells produced intracellular freezing by inoculate freezing at -2℃, whereas orchid (Paphiopedilum insigne) leaf cells responded to freezing at -2℃ by extracellular freezing. Because chilling treatment (supercooling) at -2℃ did not cause intracellular freezing, intracellular freezing in Saintpaulia and mungbean is suggested to be due to seeding of extracellular ice thorough cells. The relationships between chilling-induced plasma membrane changes and occurrence of intracellular freezing were discussed.
