Figure 2.

Characterization of the quadruple and quintuple mutants. A, Pi content in leaves (gray bars) and roots (white bars) of plantlets grown in +P at 11 dpg, including a wild-type (WT) control grown in –P. sds are shown. B, Western-blot analysis of PHT1;1, PHT1;2, and PHT1;3 on root membrane protein extracts. No residual protein was detected in the mut5 line. The first lane was loaded with 10 μL of Bio-Rad Precision Plus Protein Standards (Std); the following lanes were loaded with 0.5 to 20 μg of root proteins extracted from plants grown in –P medium, as detailed in the figure. A loading control western blot, using the anti-PIP1 antibody, is shown at bottom. C, ³³P uptake capacity is strongly affected in mut4 and mut5 lines. Pi uptake capacity was calculated as nmol Pi h^–1 cm^–1 root. Pi uptake was performed with 12-dpg plantlets grown in +P (gray bars) or in –P media (white bars). Each bar corresponds to 17 to 24 individual plants. Error bars represent se. Values above each bar correspond to Pi uptake percentage compared with the wild type. Data shown are from a representative experiment; experiments were performed in triplicate. FW, Fresh weight.