Figure 2. PID negatively regulates PIN1-mediated auxin efflux in planta(A) Co-transfection of N. benthamiana protoplasts with PID strongly blocks PIN1 activity (mean ± SE; n = 4). Significant differences (unpaired t-test with Welch’s correction, p < 0.05) between –PID controls are indicated by asterisks. (B) Co-transfection of N. benthamiana protoplasts with PID-GFP does not significantly alter PIN1-YFP location and expression. Arrow marks partially intracellular membrane locations of PIN1-YFP in the presence of PID-GFP.