Figure 6.

Growth of suspension-cultured tomato cells in +RNA/−Pi medium and analysis of monomeric products of RNA hydrolysis during culture growth. Yeast RNA (1.6 mg mL⁻¹) was substituted for KH₂PO₄ as a source of phosphorus, and growth of +Pi (○) and +RNA/−Pi (●) cultures was monitored (inset in B). HPLC separation of ribonucleosides on dihydroxyboryl-Si 100 were performed as described in “Materials and Methods.” Shown are elution profiles of standard ribonucleosides (A) and of monomeric RNA degradation products at 0 h (B) and 3 d (C) after cell transfer to +RNA/−Pi medium. Peak identities: 1, Uridine; 2, cytidine; 3, guanosine; 4, adenosine.