Acute morphological changes of palisade cells of Saintpaulia leaves induced by a rapid temperature drop

Early changes in fine structures of intracellular organelles of Saintpaulia leaves exhibiting chilling-induced degeneration of photosynthetic activities were investigated by electron microscopy. As early as 3 min after exposure to 10C water, thylakoid lamellae in the palisade cells showed extensive disarrangement, especially in intergrana lamellae. Simultaneously, other organelles showed drastic morphological changes, including the condensation of chromatin in the nucleus.