Figure 3.

Time course of ³²Pi uptake with 0.1 mm KH₂PO₄ (A) and 1 mm KH₂PO₄ (B) at pH 4.3, by excised corn roots. Four-day-old seedlings were exposed for 72 h to hydroponic medium alone (control, –●–), or containing an additional 0.1 mm AlCl₃ (dotted line), 1 mm NaF (dashed line; symbols are omitted for clarity in these two curves), or a combination of both: 0.1 mm AlCl₃ plus 1 mm NaF (AlF_x, –▴–). Values represent the means ± se of four (A) or three (B) independent experiments.