Premium
Two voltage‐dependent calcium channels co‐exist in the apical plasma membrane of Arabidopsis thaliana root hairs
Author(s) -
Miedema Henk,
Demidchik Vadim,
Véry AnneAliénor,
Bothwell John H. F.,
Brownlee Colin,
Davies Julia M.
Publication year - 2008
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.1469-8137.2008.02465.x
Subject(s) - conductance , biophysics , root hair , depolarization , membrane , chemistry , patch clamp , hyperpolarization (physics) , membrane potential , calcium , voltage dependent calcium channel , biochemistry , biology , stereochemistry , receptor , mathematics , organic chemistry , combinatorics , nuclear magnetic resonance spectroscopy , gene
Summary• Calcium (Ca 2+ )‐permeable plasma membrane ion channels are critical to root hair elongation and signalling. Arabidopsis thaliana root hair plasma membrane contains a hyperpolarization‐activated Ca 2+ channel (HACC) conductance. Here, the co‐residence of HACC with a depolarization‐activated Ca 2+ channel (DACC) conductance has been investigated. • Whole‐cell patch‐clamping of apical plasma membrane has been used to study Ca 2+ conductances and reveal the negative slope conductance typical of DACCs. Specific voltage protocols, Ba 2+ ‐permeation and inhibition by the cation channel blocker Gd 3+ have been used to identify the DACC conductance. • The Gd 3+ sensitive DACC conductance was identified in only a minority of cells. DACC activity was quickly masked by the development of the HACC conductance. However, in the period between the disappearance of the negative slope conductance and the predominance of HACC, DACC activity could still be detected. • A DACC conductance coexists with HACC in the root hair apical plasma membrane and could provide Ca 2+ influx over a wide voltage range, consistent with a role in signalling.