Hydrotropism: Root Bending Does Not Require Auxin Redistribution Doron Shkolnik, Gat Krieger, Roye Nuriel, Hillel Fromm  Molecular Plant  Volume 9, Issue 5, Pages 757-759 (May 2016) DOI: 10.1016/j.molp.2016.02.001 Copyright © 2016 The Author Terms and Conditions

Figure 1 Auxin Redistribution and TIR-Dependent Auxin Signaling Are Not Required for Hydrotropism. (A) DII-VENUS fluorescence was visualized by confocal microscopy in root tips of hydrostimulated seedlings, for the indicated times, in the presence or absence of 1 μM NPA. Camera photographs of hydrostimulated roots are presented in Supplemental Figure 1B. Arrowheads indicate a fluorescent signal in columella cells. Scale bar, 20 μm. (B) Schematic presentation of root bending in the presence or absence of NPA upon hydrostimulation as visualized in (A). Curvature represents the mean of 10 measurements per time point as in (C). Green arrows depict auxin flow. Dashed lines stand for diminished auxin flow in the presence of NPA. The definition of concave/convex side in this figure is relevant for hydrotropic bending but not for subsequent gravitropic bending that was observed after 10 h of hydrostimulation. (C) Curvature of hydrostimulated roots in the presence of the indicated chemicals was measured at 20-min intervals over 6 h. Error bars represent mean ± SE (three biological independent experiments, 10 seedlings each). In (A) and (B), arrows represent the direction of the gravity vector (g) relative to the average root tip curvature angle, and triangles depict the moisture gradient (ѱ), at each time point (the base of the triangle designates the side with higher water potential). Molecular Plant 2016 9, 757-759DOI: (10.1016/j.molp.2016.02.001) Copyright © 2016 The Author Terms and Conditions