Electron microscopic immunocytochemical localization of storage proteins in Vicia faba seeds.

The main storage proteins legumin and vicilin were located by immuno-labeling with protein A-gold in formaldehyde fixed tissues of Vicia faba seeds at different developmental stages. Both proteins were found to be accumulated together in the same protein bodies. Besides these organelles only the rough endoplasmic reticulum (ER) is labeled in particular developmental stages of the cotyledons. A fraction of proteins accumulated in the vacuoles at earlier stages of development also represents storage proteins. Besides the formation of protein bodies by the ER a second route of origination from vacuoles is proposed for Vicia faba seeds at early developmental stages.