Nucleotides of Sugarcane: TCA-Soluble and Protein-Bound Nucleotides of Sugarcane Meristem

Abstract

Initial studies of sugarcane nucleotides were conducted by anion-exchange and paper chromatographic techniques. Ultraviolet-absorbing materials were extracted from lyophilized meristem tissues with trichloroacetic acid and absorbed on columns of Dowex-1 formate. Nucleotides were removed in two peaks with a 2N, formic acid-sodium formate eluting system at pH 2.0. A third nucleotide peak was obtained with 6N formic acid, pH 0.6. Meristem protein was extracted with water, precipitated between 0 and 90-percent saturation by ammonium sulfate, and dialyzed against distilled water. Dialysate was concentrated by lyophilization and chromatographed on Dowex-1 formate. Again, two U.V.-absorbing peaks were gained with the pH 2.0 eluting system, and a third peak with 6N formic acid. U.V.absorbing materials were obtained with HCl (0.01 N and 1.0 N) from both TCA and protein preparations, but HCl was less satisfactory than the formate-formic acid systems. Analyses of U.V.-absorbing concentrates included reducing sugar, phosphorus, U.V.-extinction ratios, fluorescence spectra, total nucleotides, and infrared absorption. Paper chromatograms were prepared for nucleotide and sugar constituents of peak fractions. Nucleosides identified chromatographically were uridine, adenosine, and cytidine. Uracil was possibly present, while guanosine and cytosine were in doubt. Glucoseamine was apparently present in the TCA extracts. Uridine diphosphate glucose was tentatively identified in both preparations, as was ribose or a ribose derivative. No evidence for coenzymes I and II, coenzyme A, or flavin nucleotides was obtained. Significance of nucleotide research in sugarcane is briefly discussed.