This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Tyerman, S. D. Articles by Steudle, E. Search for Related Content PubMed PubMed Citation Articles by Tyerman, S. D. Articles by Steudle, E. Agricola Articles by Tyerman, S. D. Articles by Steudle, E.

Articles

Determination of Solute Permeability in Chara Internodes by a Turgor Minimum Method ¹

Effects of External pH

Arbeitsgruppe Membranforschung am Institut für Medizin, Kernforschungsanlage Jülich, Postfach 1913, D-5170 Jülich, Federal Republic of Germany

The analysis of Sha'afi et al. (Sha'afi, Rich, Mickulecky, Solomon 1970 J Gen Physiol 55: 427-450) for determining solute permeability in red blood cells has been modified and applied to turgid plant cells. Following the addition of permeating solute to the external medium, a biphasic response of cell turgor can be measured with the pressure probe in isolated internodes of Chara corallina. After an initial decrease in turgor due to water flow (water phase), turgor increases due to the uptake of the solute (solute phase) until the original turgor is reattained. From the pressure/time course in the neighborhood of the minimum turgor, the permeability of the osmotic solute can be determined. The data obtained by the minimum method for rapidly permeating (ethanol, methanol) and slowly permeating (formamide, dimethylformamide) solutes are similar to those calculated from the half-time of pressure changes during the solute phase and to data obtained by other workers using radioactive tracers. The methods employing the pressure probe were applied to examine the effect of high pH (up to pH 11) on the membrane permeability. There appeared to be no effect of high pH on the permeability coefficients, reflection coefficients, and hydraulic conductivity.

¹ Supported by a grant from the Deutsche Forschungsgemeinschaft, Zi 99/8.

This article has been cited by other articles:

				Y. Kim, Q. Ye, H. Reinhardt, and E. Steudle Further quantification of the role of internal unstirred layers during the measurement of transport coefficients in giant internodes of Chara by a new stop-flow technique J. Exp. Bot., December 1, 2006; 57(15): 4133 - 4144. [Abstract] [Full Text] [PDF]

				Q. Ye, B. Wiera, and E. Steudle A cohesion/tension mechanism explains the gating of water channels (aquaporins) in Chara internodes by high concentration J. Exp. Bot., February 1, 2004; 55(396): 449 - 461. [Abstract] [Full Text] [PDF]

				T. Henzler and E. Steudle Transport and metabolic degradation of hydrogen peroxide in Chara corallina: model calculations and measurements with the pressure probe suggest transport of H2O2 across water channels J. Exp. Bot., December 1, 2000; 51(353): 2053 - 2066. [Abstract] [Full Text] [PDF]