Figure 5.

IAA does not induce swelling of abp1-5 and Co-1 hypocotyl protoplasts. A, Model of ABP1 protein (not in scale) indicating the amino acid (aa) exchanges in abp1-5 and Co-1. Both alterations occur in the auxin-binding pocket. SP, Signal peptide. B and C, Protoplasts of abp1-5 (B) and Co-1 (C) treated with 10 µm IAA at 0 min (indicated by the arrows) did not respond with rapid swelling. C-terminal peptide at a concentration of 1 µm was applied as a control. It induced a fast swelling response in B and C. Results are means ± se of a minimum of n = 7 protoplasts from at least two independent experiments.