Figure 7.

The syp121-1 Mutation Does Not Affect K⁺ Channel Expression at the Root Epidermal Plasma Membrane.

(A) Longitudinal optical section (top three panels: bright-field, composite, YFP fluorescence) and three-dimensional transect analysis (bottom six panels) of KC1-YFP distribution in an Arabidopsis syp121-1 mutant root hair. Transects taken at positions (in μm) from the apex as indicated by the dashed lines above. Note the peripheral distribution of the fluorescence and its virtual absence from the dense cytosol and tonoplast boundary behind the tip (top, labeled schematic illustration drawn to scale for reference). Similar results were obtained in each of nine separate experiments with the syp121 mutant and in five experiments with expression in wild-type seedlings (data not shown). Bar = 5 μm.

(B) Mean fluorescence intensities ± se (arbitrary units) of root hairs expressing AKT1-GFP after correction for background of control measurements transfected with nontransformed Agrobacterium (n > 12 independent experiments in each case; means differ significantly at P < 0.05).