Fig. 3.

Several chemicals inhibit gravitropism in a tissue-specific manner. Dose-response experiments were done in the presence of 5403629 (A), the control auxin 2,4-D (B), 5271050 (C), 585247 (D), and 6220480 (E) at the concentrations indicated. Four-day-old seedlings grown in the presence of compounds were gravistimulated for 24 h, and the angle of curvature from a vertical position was measured. Solid lines indicate hypocotyl angles; dashed lines indicate root angles. All points are the mean ± standard error of at least duplicate experiments (n = 21-78 measurements per point). The hypocotyl and root-tip angles, respectively, of control seedlings without chemicals were: 68.0 ± 3.1, 88.3 ± 2.5 (A); 67.8 ± 3.1, 88.6 ± 2.0 (B); 68.8 ± 2.6, 79.7 ± 1.9 (C); 63.8 ± 2.3, 74.9 ± 2.9 (D); and 70.7 ± 3.6, 91.0 ± 3.9 (E). Chemical structures are shown in Table 1.