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STIMULATION OF CHLORIDE TRANSPORT IN CHARA BY EXTERNAL PH CHANGES
Author(s) -
SMITH F. A.
Publication year - 1972
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1972.tb01269.x
Subject(s) - chemistry , biophysics , darkness , ion transporter , stimulation , chara , chloride , biochemistry , membrane , botany , biology , organic chemistry , neuroscience
S ummary Transport of Cl − into cells of Char a corallina is greatly reduced when the cells are bathed in solutions of high pH. Under these conditions there is no difference between the influx in the light and in the dark. When cells are pretreated at high pH in light and then transferred to low pH and darkness, the rate of Cl − transport is greatly stimulated. This is the reverse of the normal effect when cells are transferred from light to dark. An increase in Cl − transport is also produced by pretreatment of cells at high pH in the dark. Addition of (NH 4 ) 2 SO 4 to the solutions produces even larger stimulations of Cl − transport under these conditions. The results suggest that CI − transport is controlled by the pH gradient across the plasma‐lemma, and that the pH gradient (normally produced by metabolic processes) is altered by the treatments described above. The results are consistent with the hypothesis that charge transfer across the plasmalemma results in H + extrusion, and that Cl − is taken up in exchange for OH − . Other possible effects of pH changes on ion transport are also considered.