Callose and osmiophilic material deposition into walls of developing megagametophyte in Stellaria

Abstract

Extensive rough ER cisternae are developing and disappearing during each of intermitotic periods in two and four nucleate embryo sac and synergids. The synergid cisternae are transformed into vesicles. Some long cisternae come in close contact with the embryo sac and the synergid walls. Numerous osmiophilic droplets from the cytoplasm seem to be incorporated into the walls during the period of wall-cisternae relation.