Altered auxin accumulation and transport in gain- and loss-of-function <i>idd</i> mutants.

<p>(A) Auxin accumulation assayed with the <i>DR5∶GUS</i> reporter in WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant leaves. The leaves at 3, 5, and 15 days after initiation (from top to bottom panels) were subjected to GUS staining. The scale bars represent 50 µm in the top and middle panels and 5 mm in the bottom panel. (B) Expression of the <i>DR5∶GUS</i> reporter in inflorescence stems of WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant plants. The scale bars represent 2 mm in the top panel and 100 µm in the bottom panel. (C) GFP fluorescence signals in the primary roots of WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant carrying a <i>DR5∶GFP</i> reporter. The scale bar represents 50 µm. (D) Quantification of the GUS activity in the organs of the WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant carrying a <i>DR5∶GUS</i> reporter. Data are from three biological replicates and shown as mean values ± one SD (Student's <i>t</i>-test, *P<0.05 and **P<0.01). (E) Endogenous free IAA levels in WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant plants. Aerial organs of 15-day-old plants were used for measurement of free IAA levels. Data are from four biological replicates and are shown as mean values ± one SD (Student's <i>t</i>-test, *P<0.05 and **P<0.01). (F) Polar auxin transport capability of WT, <i>idd14-1D</i>, and <i>idd</i> triple mutant stems. The inflorescence stem segments of 5-week-old plants were used to determine the basipetal IAA transport efficiency and the background acropetal movement. Data are from four biological replicates and shown as mean values ± one SD (Student's <i>t</i>-test, *P<0.05 and **P<0.01).