Table II.
Effects of localized NPA application at the root-shoot junction on free IAA concentration
| Treatment | Free IAA Concentrationa | Lateral Root No.b |
|---|---|---|
| ng/g fresh wt | ||
| Control agar | 25.8 ± 4.7 | 15.5 ± 0.8 |
| NPA agar | 17.6 ± 2.2 | 5.9 ± 0.5 |
Seven- or 8-d-old seedlings were treated by application of agar with or without NPA to the root-shoot junction. After 3 additional d of growth, roots were harvested and the free IAA concentration was determined by GC-SIM-MS or the number of lateral roots was determined.
a
The reduction in free IAA concentration was statistically significant using a Mann-Whitney U test (P = 0.04).
b
The reduction in lateral root number was statistically significant using Student's t test (P ≤ 0.001).