Fig. 3.

IAMT1 restricts polar auxin transport in 3-d-old etiolated hypocotyls. (A) PAT in unstimulated etiolated hypocotyls. Seedling were treated for 6 h with NPA, followed by a 3-h incubation with [³H]-IAA. (B) Effect of 6 h of gravistimulation on PAT in etiolated hypocotyls. (C) Effect of NPA on hypocotyl curvature at 12 h after gravitropic reorientation. (D) Expression of PIN1 and PIN3 in seedlings gravistimulated for 4 h in 0.5 µM NPA or mock solution, determined by qRT-PCR. Values in A and B are the mean of three biological replicates. In C, values are the average of at least 15 seedlings. In all cases, the error bar represents SD. Asterisks indicate that the difference is statistically significant (Student’s t test, *P < 0.05; **P < 0.01; ***P < 0.001). Letters indicate significant differences between groups (P < 0.05, one-way ANOVA, Tukey’s HSD post hoc test). In D, error bars represent SD from three technical replicates. Data from a representative experiment are shown. Two other biological replicates yielded similar results.