The formation of vacuoles in wheat (Triticum aestivum cv. Highbury) starchy endosperm cells was studied using electron microscopy. Some vacuoles were always present, even in the coenocytic cytoplasm. The first formed endosperm cells were highly vacuolated, but became filled with cytoplasm as they grew older. Various-sized pieces of cytoplasm were found in vacuoles of developing endosperm cells, probably as a result of autophagic sequestration. The membranes of the autographic vacuoles appeared to originate from the rough endoplasmic reticulum and from extensions of already-formed vacuoles. Autographic activity was confirmed by localizing the hydrolytic enzyme acid phosphatase within the vacuoles. The rough endoplasmic reticulum (RER) also stained positive for this enzyme.
Bechtel, D. B.; Frend, A.; Kaleikau, L. A.; Wilson, J. D.; and Shewry, P. R.
"Vacuole Formation in Wheat Starchy Endosperm,"
2, Article 3.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol8/iss2/3