Fig. 4: Accumulation and retention of the accumulated *P_i by Synechococcus.

a The total P_i accumulated in live cells (grey bars) compared with the amount of P_i in PFA-fixed cellular macromolecules (red bars) and TCA-precipitated nucleic acids (blue bars). Cells washed to remove the free P_i were re-suspended in ASW-P_i, supplemented with 100 Bq ml⁻¹ of H₃³²PO₄, incubated under standard cultivation conditions and sampled after 2 and 4 h. b Retention of the total accumulated P_i in *P_i pre-labelled cells and its internalization into macromolecules and nucleic acids. The pre-labelled cells re-suspended in ASW-P_i were incubated under standard cultivation conditions and sampled after 1 and 19 h. The plots show the results of representative experiments. Bars present mean values of technical duplicates indicated as crosses. Horizontal grey lines indicate major ticks of the Y-axis to assist comparing values. Source data are provided as a Source Data file.