Fluxes of86Rb+in “isolated” guard cells ofVicia fabaL.

✍ Scribed by H. M. Brindley

• Publisher: Springer-Verlag
• Year: 1990
• Tongue: English
• Weight: 914 KB
• Volume: 181
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00195898

✦ Synopsis

Steady-state 86Rb+ fluxes and contents were measured in stomatal guard cells of Vicia faba L., using "isolated" epidermal strips in which all cells other than the guard cells had been killed by a brief ultrasound treatment. Flux experiments were carried out for a range of stomatal apertures, achieved by incubation in light or dark, or on solutions containing different concentrations of RbC1 (1 30 mM). At pH 5.5 the effiux curve of 86Rb+ could be fitted to the sum of two exponential terms and it was possible to calculate compartmental contents and fluxes. The data indicate that steady-state stomatal opening is achieved by regulation of both influx and effiux. Salt accumulation was not always adequate to contribute the observed osmotic requirement for opening, and this may indicate that some other solute accounts for the discrepancy.