论文部分内容阅读
Morphological variations of the nucleus in starchy endosperm cell were observed by theelectron-transmisson microscope during endosperm development in rice. Along with thedevelopment of the starchy endosperm, the nuclei of the cells showed chromatin condensation,the typical feature of programmed cell death (PCD). The nuclei also showed nucleusdeformation, disruption of nuclear envelope, nucleoplasm leaking into the cytoplasm andnucleus disintegration resulting in nuclear residue formation. From the nucleus deformationto the nucleus disintegration, the morphological changes of the nucleus were orderlyprogressive. This indicated that the cell death of starchy endosperm in rice wasprogrammed cell death. Evans Blue staining observation showed that the cell death wasinitially detected in the central part of starchy endosperm in rice, then expandedoutward. The activities of superoxide dismutase (SOD) and catalase (CAT) in rice starchyendosperm both descended continuously as development progressed. The analysis of DNA ofrice starchy endosperm did not show the presence of DNA laddering. The above resultsshowed that the cell death of starchy endosperm in rice was a special form of PCD.
Morphological variations of the nucleus in starchy endosperm cell were observed by the electron-transmisson microscope during endosperm development in rice. Along with the development of the starchy endosperm, the nuclei of the cells showed chromatin condensation, the typical feature of programmed cell death (PCD). The nuclei also showed nucleus deformation, disruption of nuclear envelope, nucleoplasm leaking into the cytoplasm and nucleus disintegration resulting in nuclear residue formation. From the nucleus deformation to the nucleus disintegration, the morphological changes of the nucleus were orderly progressive. This indicates that the cell death of starchy endosperm in activities of superoxide dismutase (SOD) and catalase (CAT) in rice starchyendosperm both ascended continuously as development progre ssed. The analysis of DNA ofrice starchy endosperm did not show the presence of DNA laddering. The above resultsshowed that the cell death of starchy endosperm in rice was a special form of PCD.