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The number of K(+) channels in the plasma membrane of guard cell protoplasts changes in parallel with the surface area.

Authors
Type
Published Article
Journal
Proceedings of the National Academy of Sciences of the United States of America
Publication Date
Volume
99
Issue
15
Pages
10215–10220
Identifiers
PMID: 12096192
Source
Medline
License
Unknown

Abstract

The activity of the two dominant K(+) channels in the plasma membrane of Vicia faba guard cell protoplasts was examined during pressure-driven swelling. For this purpose, the K(+) currents and the membrane capacitance (C(m)) of guard cell protoplasts were recorded in parallel. A rise in C(m), reflecting an increase of the membrane surface area, was coupled to a proportional rise in conductance of both the K(+) inward and K(+) outward rectifier. The activation kinetics of the K(+) channels were not affected during this process. The quantitative and temporal coupling of C(m) and K(+) conductance can hence be interpreted as the result of the addition of active inward and outward rectifier K(+) channels to the plasma membrane during an increase in surface area.

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