Table 2.
Effect of treatments with phytohormones on EHS induction.
(A) P. ramosa germinated seeds were treated with an array of phytohormones at concentrations ranging from 10–4 M to 10−10 M. (B) Inhibiting activities were determined using a co-treatment with either c/tZ at optimum concentration (10–7 M) and NAA or ABA at concentrations ranging from 10–4 M to 10−10 M, or root exudates (Ex) and NAA or ABA at concentrations ranging from 10–4 M to 10−10 M. Results for treatments with c/tZ or exudates alone are displayed in (A). Exudates were half-diluted in buffer solution (0.5 mM HEPES, 0.05% PPM).
| Compound | EHS induction (%) | |||||||
|---|---|---|---|---|---|---|---|---|
| 10–4M | 10–5M | 10–6M | 10–7M | 10–8M | 10–9M | / | ||
| A | GR24 | NI | NI | NI | NI | NI | NI | |
| Cstosterone | NI | NI | NI | NI | NI | NI | ||
| GA3 | NI | NI | NI | NI | NI | NI | ||
| ABA | NI | NI | NI | NI | NI | NI | ||
| NAA | NI | NI | NI | NI | NI | NI | ||
| ACC | NI | NI | NI | NI | NI | NI | ||
| JA | NI | NI | NI | NI | NI | NI | ||
| c/tZ | NI | NI | NI | 82 ± 4 | 81 ± 1 | NI | ||
| Exudates | – | – | – | / | / | / | 88 ± 2 | |
| B | c/tZ (10–7 M)+NAA | NI | NI | 2 ± 2*** | 87 ± 2 | 86 ± 2 | 87 ± 3 | |
| c/tZ (10–7 M)+ABA | NI | 19 ± 3*** | 40 ± 2*** | 85 ± 1 | 86 ± 1 | 85 ± 2 | ||
| Ex+NAA | NI | NI | 87 ± 2 | 84 ± 4 | 88 ± 2 | 86 ± 3 | ||
| Ex+ BA | 36 ± 8*** | 50 ± 6*** | 92 ± 2 | 89 ± 1 | 95 ± 3 | 91 ± 2 | ||
NI, non-induced.
Means are values ±SE (n=6 wells).
Means annotated with asterisks are significantly different from the highest induction value (t-test, ***P<0.001).