Cereal Chem 44:353 - 358.  |  VIEW ARTICLE
The Incorporation of Nitrogen-15 into the Constituents of the Wheat Kernel.

W. B. McConnell and A. J. Finlayson. Copyright 1967 by the American Association of Cereal Chemists, Inc. 

Ammonium chloride-15N was administered to maturing wheat plants by injection into the top intermode of the plants. Nitrogen-15 was readily incorporated into kernel components, as indicated by the observation of 4.67 atom % excess 15N in kernel nitrogen. Gluten protein contained 5.00 atom % excess 15N, whereas nitrogen of the salt-soluble kernel proteins contained 4.01 atom % excess 15N. Examination of the nitrogen- 15 distribution among eleven of the gluten amino acids showed difference in the labeling of individual amino acids. Glutamic acid (6.34 atom % excess 15N) was most highly labeled, and proline, an amino acid derived from glutamic acid, contained 5.44 atom % excess 15N. The other nine amino acids contained from 2.7 to 4.6 atom % excess 15N. The processes involved in the incorporation of the tracer and the feasibility of utilizing nitrogen-15 for further study on the formation of cereal protein is discussed.