Table I.
Mean values of steady-state nitrate-selective microelectrode measurements in wild-type and nia1nia2 epidermal and mesophyll cells in the dark
| Compartment | Plant | Cell Type | Mean Nitrate Activity | Mean Membrane Potential |
|---|---|---|---|---|
| mm | mv | |||
| Cytoplasm | Wild type | Epidermal | 2.2 (±0.5)a | −147.0 (±15.8) |
| Mesophyll | 2.8 (±0.7) | −128.6 (±20.3) | ||
| nia1nia2 | Epidermal | 3.2 (±1.6) | −123.3 (±11.6) | |
| Mesophyll | 3.9 (±0.6) | −118.6 (±24.4) | ||
| Vacuole | Wild type | Epidermal | 35.0 (±7.1) | −99.5 (±7.8) |
| Mesophyll | 31.8 (±11.8) | −98.0 (±27.6) | ||
| nia1nia2 | Epidermal | 50.0 (*)b | −60.0 (*) | |
| Mesophyll | 32.0 (*) | −100.0 (*) | ||
| Apoplast | Wild type | 0.3 (±0.2) | – | |
| nia1nia2 | 0.7 (±0.3) | – |
a
sds shown in brackets n > 5.
b
*, No replication.