Analysis of the Nucleotide Pool During Growth of Suspension Cultured Cells of Nicotiana Tabacum by High Performance Liquid Chromatography

In suspension cultured cells of Nicotiana tabacum L. cv. Wisconsin 38 the .concentration of 18 nucleotides and 3 nucleosides have been determined using a new procedure developed for the extraction, purification and HPLC separation of these compounds from plant tissue. The different nucleotide pools increase in size immediately at the onset of the batch culture and reach distinct maxima at the very beginning of the proliferative phase. The main component are the uracil nucleotides with UDP‐sugars as the predominant fraction followed by the adenine nucleotides; the energy charge is maintained at a high and constant value throughout the whole culture time. During the growth interval the increases in the nucleotide pools reveal that the cell proliferation phase is followed by an extensive phase of cell elongation. Whereas the concentration of the total nucleotides varies by a factor of about 3 along the growth curve, the ratio of uracil to adenine nucleotides is kept fairly constant indicating regulatory mechanisms for correlation of the individual nucleotide pools.