Fig. 1: Arabidopsis WAV3/WAHV genes act in root gravitropism and polar auxin transport in root meristems.

a Comparison of wild type (w.t.), wav triple (wtrp), eir1-4, eir1-4 wav triple, wav triple XVE»Ven:WAV3 in presence of solvent (DMSO) or 2 μM estradiol. 5 DAG seedlings grown on vertically oriented plates are on display. Arrow indicates gravity vector. Reporter signals in WAHV1::WAVH1:Ven (b), wav triple WAV3::Ven:WAV3 (c), WAHV2::WAVH2:Ven (d), eir1-4 PIN2::PIN2:VEN (e) and wav triple XVE»Ven:WAV3 in presence of 2 μM estradiol (f). Roots of 5 DAG seedlings are on display. g Orientation of root tips, expressed as degrees deviation from vertical of 5 DAG wild type (n = 46 roots/3 experiments), wav triple (n = 44 roots/3 experiments), wav triple WAV3::Ven:WAV3 (n = 52 roots/3 experiments), wav triple XVE»Ven:WAV3 seedlings grown on solvent (DMSO, ‘c.’; n = 43 roots/3 experiments) or in presence of 2 µM estradiol (‘estr.’; n = 54 roots/3 experiments). Expression of DR5rev:3XVENUS-N7 in wild type (w.t.; h) and wav triple (wtrp; i) root meristems at 5 DAG. Arrowheads indicate ectopic reporter signals. j Root shootward (basipetal) PAT measurement using ³H-IAA and as a control, ¹⁴C-benzoic acid (BA, diffusion control) performed with 5 DAG wild type and wav triple XVE»Ven:WAV3 seedlings. Radiotracers were applied to the root tip followed by their quantification 5 mm above the very root tip. Assays were conducted in presence of 2 μM 17β-estradiol (‘estradiol’) or in presence of DMSO solvent only (‘depleted’); for further details see Methods (n = 4, with 20 seedlings each). Three independent experiments were performed for (a), (b–f), and (h, i) with similar results. Circles represent data points; boxes: first and third quartiles; center line: median; ‘x’: mean value. Levene’s tests were employed to determine the equality of variances (g); One-way ANOVA with post hoc Tukey HSD was performed (j); *: p < 0.05; **: p < 0.01; ***: p < 0.001; a, b: p > 0.05. Scale bars: a = 10 mm; b–f = 50 μm; h, i = 25 μm. Source data are provided as Source Data file.