The ctl1 mutant shows altered auxin distribution pattern.
(A–H) DR5::GUS expression pattern in 7-day-old wild type (DR5::GUS/WT) (A–D) and ctl1 mutant (DR5::GUS/ctl1) (E–H). The red arrows point to the areas where signals are different between DR5::GUS/WT and DR5::GUS/ctl1. Scale bars in panel A and panel E are 1 mm, and those in panels B–D and F–H are 100 μm. (I) Expression pattern of DR5::GFP in the wild type (DR5::GFP/WT) (upper panel) and the ctl1 mutant (DR5::GFP/ctl1) (lower panel) treated with 0, 0.1, 0.3, 0.5, or 1 μM 1-naphthylacetic acid (NAA). Scale bars are 50 μm. (J) DR5::GFP signals in the concave side of the apical hook of the wild type (WT) and the ctl1 mutant at 1 and 3 days after germination. The red arrows show the sites where green fluorescent protein (GFP) signals were accumulated in the WT but not in the mutant. Scale bars are 20 μm. DR5, DIRECT REPEAT5; GUS, β-glucuronidase.