Figure 4.

Time course of free IAA concentration and distribution in maize stem pulvini during gravistimulation. Maize plants were gravistimulated for the time indicated, and upper and lower halves were harvested. Free IAA concentration was measured by GC-MS-selected ion monitoring (SIM). Mean values from two independent experiments (±se) are shown. The upper one-half sample at 12 h after onset has no error bar as we were only able to include one data point for this sample. Ratio of free IAA levels in the lower compared with the upper halves was calculated from the mean values (inset).