THE NITROGENOUS COMPONENTS OF THE SHOOT APEX OF ADIANTUM PEDATUM

Abstract

THE PRESENT communication is a sequel to a previous paper (Steward et al., 1954) which described an investigation, by quantitative paper chromatography, of the nitrogen compounds which, when free, comprise the soluble nitrogen fraction and, when combined, the protein nitrogen of certain shoot apices. The earlier investigation revealed general effects of two kinds. First, the angiosperm shoot apices which were investigated differed greatly from the fern apex studied with respect to the range of soluble amino-nitrogen compounds that they contained. Second, there were evident signs that differences in composition in these apices occurred pari passu with development. The data here reported extend our knowledge with respect to Adianlum pedatum. The shoot apex of Adiantum as earlier reported was somewhat remarkable in contrast to that of Lupinus in that the alcohol soluble nitrogen consisted of relatively few identifiable amino acids and amides present in quantity (aspartic, glutamic, /aminobutyric acids, valine, leucine and glutamine) and a substance, not identified, which was present in far greater quantity than any of these. The reexamination of the apex of Adiantum had the following objectives: (i) To investigate the apex at a time when it was most actively growing. (ii) To determine the composition of various regions of the apex which were sampled according to their state of maturity. (iii) To shed further light on the chemical nature of the hitherto unidentified nitrogen compound that occurs in the Adiantum apex.