The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phos...The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phosphatase was localized in the slightly condensed nuclear chromatin in nucellar cells without any sign of ultrastructural degeneration. As the nucellar cells started degenerating, the enzyme activity in the cell was observed, in the order from small vacuoles to cell walls, mitochondria, plastids and endoplasmic reticulum. Enzyme activity was the highest in most components of the nucellar cells adjacent to the embryo sac where the degeneration of nucellar cells was the strongest, but it was not observed in the nuclei of the degenerated nucellar cells. The results indicated that the degeneration of nucellar cells was a progressive and orderly process and supported that the degeneration of nucellar cells was a programmed cell death.展开更多
Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, acti...Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, active ATPase was mainly distributed in an embryo sac wall, nucleus, and plasma membrane. At the early stage of development and differentiation, active ATPase was observed in the plasma membrane. At the grain filling stage, ATPase was highly active in the plasma membrane, intercellular space, and plasmodesmata in aleurone, moderately active on the plasma membrane in subaleurone. In starchy endosperm, ATPase was localized in the plasma membrane and degenerated nucleus. ATPase activity also appeared around vacuole and protein body in endosperm cell. The relationships between the ultracytochemical localization of ATPase and its function during the development of rice endosperm were discussed. Overall, ATPase was involved in the process of nutrition absorption and protein synthesis.展开更多
文摘The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phosphatase was localized in the slightly condensed nuclear chromatin in nucellar cells without any sign of ultrastructural degeneration. As the nucellar cells started degenerating, the enzyme activity in the cell was observed, in the order from small vacuoles to cell walls, mitochondria, plastids and endoplasmic reticulum. Enzyme activity was the highest in most components of the nucellar cells adjacent to the embryo sac where the degeneration of nucellar cells was the strongest, but it was not observed in the nuclei of the degenerated nucellar cells. The results indicated that the degeneration of nucellar cells was a progressive and orderly process and supported that the degeneration of nucellar cells was a programmed cell death.
基金supported by the National Natural Science Foundation of China(30070363) the Research Foundation for Doctorate in Universities of China(2000050401).
文摘Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, active ATPase was mainly distributed in an embryo sac wall, nucleus, and plasma membrane. At the early stage of development and differentiation, active ATPase was observed in the plasma membrane. At the grain filling stage, ATPase was highly active in the plasma membrane, intercellular space, and plasmodesmata in aleurone, moderately active on the plasma membrane in subaleurone. In starchy endosperm, ATPase was localized in the plasma membrane and degenerated nucleus. ATPase activity also appeared around vacuole and protein body in endosperm cell. The relationships between the ultracytochemical localization of ATPase and its function during the development of rice endosperm were discussed. Overall, ATPase was involved in the process of nutrition absorption and protein synthesis.
