Table 1.
Membrane potential (Em, mV) in parenchymal coleoptile cells. Data (mean ± s.e.) are means of at least seven independent experiments
| Treatment | A | B | C | D | E | F | Em at depolarization | F–A |
|---|---|---|---|---|---|---|---|---|
| 0 min | 3 min | 6 min | 10 min | 20 min | 30 min | |||
| 1 mm KCla | –120·1 ± 4·3 | –119·8 ± 3·9 | –119·2 ± 4·6 | –120·5 ± 5·8 | –121·0 ± 5·4 | –122·4 ± 6·1 | – | –2·3ns |
| 1 mm KCl + IAAb | –120·6 ± 7·4 | –121·0 ± 6·6 | –116·6 ± 4·9 | –117·3 ± 5·2 | –126·1 ± 6·7 | –131·3 ± 7·5 | –115·5 ± 5·9 | –10·7* |
| 1 mm KCl + A-9-Cc + IAAb | –108·4 ± 4·7 | –107·9 ± 5·4 | –105·4 ± 6·2 | –108·1 ± 5·2 | –115·8 ± 6·1 | –118·5 ± 6·8 | –105·3 ± 5·8 | –10·1* |
| 10 mm KCl | –70·6 ± 4·1 | –68·8 ± 3·9 | –67·9 ± 4·3 | –68·2 ± 4·5 | –68·4 ± 3·8 | –67·9 ± 4·2 | – | 2·7ns |
| 10 mm KCl + IAAb | –68·7 ± 4·5 | –69·2 ± 4·7 | –67·8 ± 3·8 | –70·0 ± 3·4 | –72·8 ± 4·1 | –74·1 ± 4·3 | –64·7 ± 4·2 | –5·4* |
| 10 mm KCl + A-9-Cc + IAAb | –64·8 ± 3·9 | –60·8 ± 4·2 | –62·4 ± 3·6 | –63·6 ± 4·5 | –63·1 ± 3·3 | –62·2 ± 3·5 | –60·8 ± 4·2 | 2·6ns |
aColeoptile segments were incubated in the indicated medium (the same as in growth experiments) for 110 min, after which a single segment was transferred into an electrophysiological chamber containing the same medium. Measurements of membrane potential (30 min) were carried out after insertion of a microelectrode into the cell and stabilization of the Em ( < 10 min) at 2 h (0 min).
bIAA was added after 2 h of segment preincubation in medium with 1 or 10 mm KCl (for the last 10 min the coleoptile segments were incubated in the electrophysiological chamber).
cA-9-C was added after 1 h of segment preincubation in medium with 1 or 10 mm KCl (for the last 10 min the coleoptile segments were incubated in the electrophysiological chamber).
nsNot statistically significant.
*Statistically significant at P < 0·05.