Changes in ultrastructure of Golgi apparatus during the cell cycle in a synchronous culture of Catharanthus roseus.

Changes in the ultrastructure of the Golgi apparatus during the cell cycle were investigated using a highly synchronized cell division system in a Catharanthus roseus (L.) G. Don suspension culture. During the G2 phase and cytokinesis, diameters of the dictyosomes and the number of cisternae significantly increased. Electron micrographs of cells in cytokinesis suggested that dictyosomes were dividing into two. Numerous secretory vesicles were associated with the dictyosomes in cells of the second G1 phase, the time when cell wall synthesis is most active. Structural changes in the Golgi apparatus are discussed in relation to the cell cycle and changes in cell wall synthesis.