Fig. 6.

Pi uptake via the direct Pi uptake pathway and the mycorrhizal pathway. (A) Root length-specific shoot Pi uptake from pot A and (C) the minimum contribution by AM fungi from pot B to shoot P of wild-type plants at three soil P additions: 0 (white bars), 20 (grey bars), and 50 (black bars) mg P kg^–1. (B) Root length-specific shoot Pi uptake from pot A in the wild type (horizontal bars) and mtpt4 mutant (diagonal bars) at P20 only. Values are mean ±standard error, n=5. Means followed by the same letter were not significantly different at the P<0.05 level (Tukey’s HSD). For (A) data were analysed in more detail at each P level by a Student’s t-test comparing the treatment pots (NM of NM,M) and the NM control (NM,NM), which revealed significantly reduced P uptake from pot A in NM,M plants grown at P0 and P20. For (C) different sets of letters (ab, xy) indicate a significant difference (at the P<0.05 level, Student’s t-test) between M,M and NM,M pots. (This figure is available in colour at JXB online.)