Figure 3.

PI and PIP5K Polarity Indexes.

Apical/basal-to-lateral fluorescence ratio (polarity index) of PI biosensors expressed under the control of the 35S promoter and PIP5K1 proteins in root epidermis (epi) and procambial (proc) cells expressed under the control of the DNAJc17 promoter. As an apolar marker, we measured the aquaporin PLASMA MEMBRANE INTRINSIC PROTEIN2 (aqPIP2)-GFP in root epidermis cells, and we used PIN1-GFP and PIN2-GFP as polar markers in stele and epidermal root cells, respectively. The dotted line indicates a 1:1 ratio corresponding to a theoretical symmetrically localized PM protein. Root cells of seedlings 4 d after germination were quantified. Bars show means ± sd. A two-tailed Student’s t test compared data with aqPIP2-GFP values. *P < 0.05, **P < 0.005. n ˃ 20 cells corresponding to roots imaged under comparable conditions.