Electron-Microscopic Study of Osmium Ferricyanide Staining in Meristematic, Extending and Differentiated Mesophyll Cells of Winter Rye Seedlings

The osmium ferricyanide (OsFeCN) cytochemical technique was used in the electron microscopic study of organelles in cells of functionally different leaf zones of winter rye seedlings. In meristematic cells, the endoplasmic reticulum and nuclear envelope were the main structures reacting with OsFeCN; in cells of the extension zone and in differentiated mesophyll cells it was the peripheral reticulum and the intermembrane space of the chloroplast envelope. The change in OsFeCN staining character of organelles between the various zones of leaves is considered to be due to cell exit from the meristem. The participation of the peripheral reticulum of chloroplasts in the sequestration of Ca2+ ions is proposed.