Fig. 5: NPA impedes auxin flux rootward, shootward, and inward, whereas 1-NOA affects only shootward auxin movement.

a Cell-type-specific IAA inducible lines were grown for 4 days on MS agar before transfer to agar containing vehicle (Mock) or 25 μM NPA or 50 μM 1-NOA for 20 h. Seedlings were then mock treated or treated with 5 μM estradiol (E2) for 24 h and imaged. Representative root confocal microscope images are displayed. Propidium iodide staining is shown in red, DR5:VENUS activity in green. Scale bar = 100 μm. b Schematic representation of root geometry. The dashed color-coded boxes define regions of interest for DR5:VENUS signal quantification. The arrows represent auxin fluxes. c Fluorescence intensity quantification of DR5:VENUS roots treated as described in panel a, measured at regions of interest corresponding to colors shown in panel b. Shown are means (±SE), n = 5 plants, P value two tailed t test is indicated for each analysis. d DR5:VENUS expression (green) in cells above and below laser-assisted elimination of epidermis, 1 and 24 h after ablation. Cell walls and ablated cells are stained with propidium iodide (10 µM) shown in white. Scale bar = 15 μm. e Fluorescence intensity quantification of DR5:VENUS below and above ablations as described in panel d. n = 19–27 cells from 3 independent experiments for each category (n = 27 for 1 h, n = 25 for 12 h and n = 19 for 24 h treatments). Shown are means (±SE). Statistical significance between upper (green arrow) and lower (red arrow) cells was computed from a paired, two-tailed Wilcoxon test, considering the non-normal distribution of the data.