Studies on the Aleurone Layer I. Oonventional and Fluorescence Microscopy of the Cell Wall With Emphasis on Phenol-Carbohydrate Complexes in Wheat

In the ungerminated seed, the cell walls of the aleurone layer of wheat (Triticum aestivum cv. Heron) are strongly autofluorescent and are stained by aniline blue, resorcinol blue, toluidine blue, and the periodic acid-Schiff's reaction. Thin-layer chromatography of acid or alkaline extracts and microspectrofluorimetry indicate that the fluorescent component of the wall is ferulic acid. During germina-tion, the ferulic acid disappears from the aleurone cell wall in a specific pattern and its loss is accompanied by loss of stainable substance except in the innermost layer of the wall. These facts suggest that the aleurone cell wall contains a ferulic acid-carbohydrate complex which renders it relatively resistant to the action of the hydro-lases which digest the endosperm.

Properties of Gluten Fractions Prepared by Ion-Exchange Chromatography on Carboxymethyl-Cellulose

Seven fractions obtained from wheat gluten by chromatography on carboxy~ methyl-cellulose were studied by ultracentrifugation, gel electrophoresis, chemical, and N-terminal amino acid analysis. On rechromatography, five fractions eluted by sodium chloride behaved as distinct entities. illtracentrifuge experiments indicated that four of these were each undergoing rapid, reversible association. Several N-terminal amino acids were found in each of the fractions which, moreover, could be resolved by the gel technique into a number of electrophoretic bands, some bands being common to those of neighbouring fractions. Total nitrogen values showed the chromatographic samples to be essentially free from non-protein material.

The protein composition of gluten extracted from different wheats

The gluten proteins from eight commercial wheat varieties and four tetraploid Triticum species were separated by chromatograph on carboxymethyl-cellulose and by electrophoresis on polyacrylamide gels. There are obvious differences in the protein profiles of many of the commercial wheat varieties. Furthermore, the tetraploid species differ in many respects from the T. vulgare varieties. The possible relationship between baking quality and protein profile is discussed.