Contrasts in the Nitrogenous Composition of Rapidly Growing and Non-growing Plant Tissues1

Publisher Website
Google Scholar
Abstract
Contrasts have been drawn between the nitrogenous composition of rapidly proliferating tissue and that of the resting, non-growing tissues from which it was derived. The alcohol soluble fraction and the hydrolysate of the alcohol-insoluble fraction of tissue in these contrasted states have been examined by the methods of quantitative partition chromatography. The ratio of alcohol-soluble to alcohol-insoluble nitrogen was much greater in the resting than in the proliferating tissue. These differences were due mainly to a very much lower content of amino-acids and amides in the growing tissue, especially of asparagine, glutamine, and arginine. Only γ-aminobutyric acid increased in its content in the growing potato cells. Without regard to the means adopted to induce growth the protein-nitrogen of the dividing cells was conspicuously rich in hydroxy-L-proline, an amino acid, which is conspicuous in collagen but not normally so in plant proteins. The proteins of the growing cells also tend to be rich in the basic amino-acids. It is suggested that the hydroxyproline-rich protein moiety is a characteristic feature of the proliferating cells and its possible significance is noted.