Production of Guard Cell Protoplasts from Onion and Tobacco

Abstract

A single intracellular microelectrode technique has been adapted to measure membrane resistance in a higher plant cell. As a direct result of the convenience of this method, which allows relatively long term recordings on a single cell, it has been found that membrane resistance increases for about 30 minutes after cell impalement in Pisum sativum L. cv. Alaska root cortical cells, although cell potential is established at a constant value in less than 2 minutes. It is proposed that these observations imply a regulating feedback loop between electrogenic pump rates and membrane potential.