Cereal Chem 40:487 - 492.  |  VIEW ARTICLE

Studies with Radioactive Tracers. VIII. The Incorporation of S35-Labeled Sulfate by Maturing Thatcher Wheat.

C. C. Lee and L. M. Reynolds. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

Sulfate-S35 was injected into the stems of maturing Thatcher wheat plants, and the distribution of S35 in the mature plants was examined. The kernels appeared to be the most active site of S35 assimilation, but only about one-half of the administered sulfate was utilized. Gluten was the most radioactive component of flour milled from the labeled kernels. The activity per mg. of flour or per mg. of gliadin or glutenin was greater when the tracer was present in the plant for longer periods of time. The results indicated that at any stage during the growth period studied, the gliadin fraction was increasing in specific activity about 20% faster than the glutenin fraction. It is suggested that sulfate is utilized slowly and that an excess is constantly available to the plants.