Local Ionic Environment of Plant Membranes: Effects on Membrane Functions

Abstract

Electrostatic properties of the isolated plasma membrane of maize roots were studied using the fluorescent ANS probe and microelectrophoresis of membrane vesicles. Variations of the net surface charge of membrane were obtained by adding ionic surfactants or by acidifying the medium. Parallel experiments were performed on excised roots. We showed that surface electrostatic interactions can affect major membrane functions such as ATPase activity, trans-membrane PD, and permeability to NO₃.