Use of permeabilised cells of Chara corallina provides a unique opportunity to study the electrical characteristics of the tonoplast whilst being able to control ionic conditions on the outside of the membrane. Current-voltage (I/V) analysis over wide voltage spans, and admittance measurements at 5 Hz showed that many permeabilised cells had a similar conductance and capacitance to the tonoplast of intact cells. Cells developed two regions of negative-slope conductance upon addition of external Cl-, which suggests the existence of potential-dependent Cl- channels in the Chara tonoplast. With Cl- concentrations similar to those expected in vivo, the resting potential was more sensitive to changes in external K+ than Cl-; however, a decrease in external K+ did not significantly alter the shape of the I/V relation.
|Original language||English (US)|
|Number of pages||14|
|Journal||Plant and Cell Physiology|
|State||Published - Jan 1 1987|
- Cl- channel
- Current-voltage (I/V)
- Membrane capacitance
- Voltage clamp.
ASJC Scopus subject areas
- Plant Science
- Cell Biology