Cereal Chem 63:14-18   |  VIEW ARTICLE
The Influence of Phosphorus Nutrition on the Appearance and Composition of Globoid Crystals in Wheat Aleurone Cells.

G. D. Batten and J. N. A. Lott. Copyright 1986 by the American Association of Cereal Chemists, Inc. 

Wheat plants were grown in the greenhouse with contrasting levels of phosphorus (control and low P). Ultrastructure and elemental composition of globoid crystals in aleurone cells were studied in grains at 31 days after pollination (when the low-P grains began to accumulate phytate phosphorus) and at maturity. The structure of aleurone protein bodies was altered considerably by low-P conditions. Transmission electron microscopy showed that protein bodies in aleurone cells of control grains had large, dense globoid crystals. Globoid crystals were difficult to locate in immature, low-P grains and were small and numerous in mature, low-P grains. Energy-dispersive X-ray analyses of immature and mature grains of control and low-P samples determined that the elemental composition of the globoid crystals was dominated by P, K, and Mg. A significant increase in the K:P ratio was observed in low-P grains. This, together with the small size of the globoid crystals in low-P grains, may have caused the loss of globoids when grains were fixed using traditional aqueous methods.