Programmed cell death of Ulmus pumila L. seeds during aging

In this study, the characteristics of programmed cell death (PCD) of Ulmus pumila L.seeds were investigated.The seeds were treated at a high temperature of 37℃ and high humidity (100% relative humidity) for six days.DAPI staining revealed that the aging treatment induced condensation and margination of chromatin, as well as the formation of apoptotic bodies.The result of DNA electrophoresis of U.pumila seeds on an agarose gel showed a characteristic of "ladder" pattern.Levels of electrolyte leakage of seed cells showed that membranes remained integrally form during almost the entire aging time.There was an immediate increase of superoxide anion (\rmO_2^\rm\bar \cdot) production rate and hydrogen peroxide (H₂O₂) content, which stayed at μmol level.All of the above common characteristics indicate that seed aging can be classified as PCD.