CHANGES IN THE AMINO ACID CONTENT OF THE FIRST THREE LEAVES OF RIDEAU WHEAT FOLLOWING VERNALIZATION

Abstract

The after effect of chilling winter wheat, Triticum aestivum (var. Rideau), after a period of imbibition, was studiedby making a periodic partial analysis of the metabolism of some nitrogen compounds in the first three emergent leaves throughout their growth period. Total protein nitrogen measurements indicated that prior chilling (vernalization) accelerated some stages of leaf development. The composition of the alcohol-soluble amino acid fraction varied with leaf ontogeny in both control and vernalized plants. The most pronounced effect of vernalization was to depress the relative content of arginine, which was one of the major constituents of the soluble amino acid fraction in leaves from untreated seed. The concentrations of other important amino acids, v-aminobutyric acid, glutamic acid, and the amine, glutamine, varied with the physiological age of the leaf, and vernalization did not alter this relationship.