Patch-clamp techniques were employed to study the electrical properties of vacuoles from sugar beet (Beta vulgaris) cell suspensions at physiological concentrations of cytoplasmic Ca2+. Vacuoles exposed to K+ malate revealed the activation of instantaneous and time-dependent outward currents by positive membrane potentials. Negative potentials induced only instantaneous inward currents. The time-dependent outward currents were 10 times more selective for malate than for K+ and were completely blocked by zinc. Vacuoles exposed to KCl developed instantaneous currents when polarized to positive or negative membrane potentials. The time-dependent outward channels could serve as the route for the movement of malate into the vacuole, whereas K+ could move through the time-independent inward and outward channels.
|Original language||English (US)|
|Number of pages||5|
|State||Published - Nov 1992|
ASJC Scopus subject areas
- Plant Science