Figure 3.
Electrical description of a root hair and the measurement technique. A, Electrical network of a plant cell. The symbols have their usual meanings (Horowitz and Hill, 1989). Rm and Rv are the resistances of the plasma membrane and vacuole, respectively. Cm and Cv are the capacitances. An impalement into the vacuole will measure the vacuolar and plasma membrane electrical properties in series. B, Electrical schematic of root hair electrical measurements. To isolate the vacuole electrical properties from the electrical properties of the plasma membrane, voltage clamping was performed through a double-barrel micropipette impaled into the vacuole, while the cytoplasm was held at virtual ground, relative to the vacuole.