Studies on nucleic acid metabolism in suspension cultures of Cucumis melo L

Studies on nucleic acid metabolism in Cucumis melo L. suspension cultures revealed greater concentrations of total RNA, DNA and proteins at growth-promoting NAA levels. Soluble-nucleotides, supernatant-RNA, soluble protein contents and RNase activity were also higher during the initial lag period. During the phase of rapid increase in dry weight nucleic acids and proteins and RNase activity declined. At growth-inhibiting concentrations of NAA smaller amounts of nucleotides, nucleic acids and proteins were present and a reduction in the specific activity of ribonuclease was observed. Chloramphenicol readily inhibited auxin-induced growth and caused a reduction in soluble-nucleotides, soluble-protein, supernatant-RNA and RNase activity if added to the medium as late as the fifth day, the effect on the pattern of changes remained the same.