Abstract
Because of the viscoelastic property of the cell wall and of the osmotic pressure difference between in- and out-side the plasmalemma, the tension of Characean cell wall changes as a function of the water flow across the membrane. By giving a constant sinusoidal mechanical vibration (10Hz) to the internode, and by studing the absorption rate of the vibration, the relative velocity of water flow can be estimated. Then the water conductivity, Lp, of the membrane can be figured out (with a time resolution of 0.1sec). It was found that there was no significant difference in Lp between the efflux and the influx. This confirmed that the membrane itself was not a rectifier for the water flow (non-intrinsic).
