Reversible Changes in the Hydraulic Permeability of Plant Cell Membranes

Abstract

Effects on water flux formerly attributed to changes in Lp (the coefficient of hydraulic permeability) in the classical plasmolytic studies were possibly due to changes in [alpha] (the reflection coefficient). Conditions are defined under which effects due to a fall in Lp may be distinguished from those due to a fall in [alpha]. CO2, azide, and 0.1)2 [image] chloroform decreased Lp in carrot disks and segments of sunflower hypocotyl. Higher concentrations of chloroform brought about an increase in water efflux which was associated with irreversible changes in the membrane. The effect of chloroform depended not only on concentration but on lenght of treatment. Immersion in distilled water brought about an increase in Lp. The effects of CO2, of azide, and of distilled water were reversible. In the cases of CO2 reversal was achieved within 2 minutes.