With a view of studying programmed cell death (PCD) in a halophytic plant at the molecular level,we report here that apoptotic-like changes are induced by NaCl stress in Thellungiella halophila.The dose of 300 mM NaCl induced some apoptotic-like features in Thellungiella halophila cells,including the retraction of the plasma membrane from the cell wall,nuclear condensation,DNA laddering and the release of cytochrome c accompanying the increase of caspase 3-like protease activity.This process resulted in ultrastructural changes of mitochondria and Golgi oodles,and the appearance of autophagic vacuoles.This suggests that T.halophila suspension cell culture is an ideal system for studying severe salt stress-induced plant PCD.The results indicate that 300 mM NaCl stress-induced programmed cell death in T.halophila cells is similar to apoptosis and mitochondria play an important role in the early stage of plant PCD.