| Abstract: | Clint, G. M. 1985. The investigation of stomatal ionic relationsusing guard cell protoplasts. 1. Methodology.—J exp. Bot.36: 1726–1738. A study was made of the methodology for the production and useof guard cell protoplasts in ion transport studies, with particularemphasis placed on the effects of the composition of the externalmedium on protoplast survival and performance. Addition of externalKCl to media during the production of guard cell protoplastsfrom Commelina communis L. was found to improve viability andto increase K+ content and physiological competence of the isolatedprotoplasts. Addition of low levels (20 x 10–3 mol m–3)CaCl2 increased protoplast yield and the maintenance of viabilityin long-term incubation. Ambiguities and uncertainties werefound in the application of methods commonly used for the assessmentof viability of isolated protoplasts. Poor yields (despite highpercentage recoveries) together with difficulties in the assessmentof viability were considered to pose major potential problemsin the use of guard cell protoplasts in ion transport studies. Key words: Guard cell protoplasts, ion transport, Commelina communis |
