Reversal of NPA-induced lateral root inhibition by localized IAA application
| Agar4-a | Lateral Root No. | Lateral Root Density | |
|---|---|---|---|
| Upper | Lower | ||
| Control | Control | 6.7 ± 0.85 | 0.19 ± 0.02 |
| IAA | Control | 10.0 ± 0.56 | 0.43 ± 0.03 |
| Control | NPA | 0.33 ± 0.14 | 0.02 ± 0.01 |
| NPA | IAA | 4.25 ± 0.73 | 0.24 ± 0.04 |
| IAA | NPA | 1.72 ± 0.46 | 0.08 ± 0.02 |
After the indicated treatments, lateral root number and root length were determined after 4 d of additional growth in the light. The reported values are averages ± se of 10 plants.
↵F4-a Two, thin (1-mm), parallel lines of agar either with or without 10 μm IAA and 100 μm NPA were applied to the root-shoot junction of seedlings that were 4 d old. This technique allowed for the simultaneous application of two compounds to seedlings. Although both lines were over the root-shoot junction of the seedlings, one line was closer to the plant shoot (the Upper line) and the other was closer to the root (the Lower line).