Fig. 2

ASP decreased root growth in A. thaliana. a: Dose-response curve for wild type (Col-0) seedlings on ASP. Seedlings were treated for six days with different concentrations of ASP from 0 to 30 μM as indicated on X axis. b: Dose-response curve for Col-0 seedlings on 2,4-D. The concentrations of 2,4-D were from 10 nM to 10 μM as indicated on X axis. c: The cumulative rate of primary root length measured at 24-h interval. Seedlings were treated with 5 μM ASP and 30 nM 2,4-D respectively. DMSO was used as control. Each point represented the mean of at least 20 measurements. Error bars indicated the standard deviation. d: Effect of ASP and 2,4-D on lateral root density of WT seedlings. Seedlings were grown on 1/2 MS medium supplemented with 10 nM 2,4-D, 30 nM 2,4-D, 2 μM ASP and 5 μM ASP for nine days. DMSO was used as control (number of samples N = 10, P < 0.05). e: ASP reduced the gravitropic response. 2 μM ASP was used for gravitropism test. Col-0 seedlings grown on agar medium were rotated 90° at time 0. The angle of curvature from the horizontal was measured at the times indicated. Each point represents the mean of 24 measurements. Error bars indicate the standard deviation. f and g: Root hair of Col-0 seedlings response to ASP and 2,4-D. Seedlings vertically grown on the medium supplemented with 0–5 μM ASP and 30 nM 2,4-D for six days. Root hair upward root tips 5 mm was selected to measure and count (number of samples N = 50, P < 0.05). f: Statistics of root hair number. g: Measurements of root hair length