Genes for calcium-permeable channels in the plasma membrane of plant root cells

Biochim Biophys Acta. 2002 Aug 31;1564(2):299-309. doi: 10.1016/s0005-2736(02)00509-6.


In plant cells, Ca(2+) is required for both structural and biophysical roles. In addition, changes in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) orchestrate responses to developmental and environmental signals. In many instances, [Ca(2+)](cyt) is increased by Ca(2+) influx across the plasma membrane through ion channels. Although the electrophysiological and biochemical characteristics of Ca(2+)-permeable channels in the plasma membrane of plant cells are well known, genes encoding putative Ca(2+)-permeable channels have only recently been identified. By comparing the tissue expression patterns and electrophysiology of Ca(2+)-permeable channels in the plasma membrane of root cells with those of genes encoding candidate plasma membrane Ca(2+) channels, the genetic counterparts of specific Ca(2+)-permeable channels can be deduced. Sequence homologies and the physiology of transgenic antisense plants suggest that the Arabidopsis AtTPC1 gene encodes a depolarisation-activated Ca(2+) channel. Members of the annexin gene family are likely to encode hyperpolarisation-activated Ca(2+) channels, based on their corresponding occurrence in secretory or elongating root cells, their inhibition by La(3+) and nifedipine, and their increased activity as [Ca(2+)](cyt) is raised. Based on their electrophysiology and tissue expression patterns, AtSKOR encodes a depolarisation-activated outward-rectifying (Ca(2+)-permeable) K(+) channel (KORC) in stelar cells and AtGORK is likely to encode a KORC in the plasma membrane of other Arabidopsis root cells. Two candidate gene families, of cyclic-nucleotide gated channels (CNGC) and ionotropic glutamate receptor (GLR) homologues, are proposed as the genetic correlates of voltage-independent cation (VIC) channels.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Annexins / chemistry
  • Annexins / metabolism
  • Calcium Channels / genetics*
  • Calcium Channels / metabolism
  • Carrier Proteins / metabolism
  • Cation Transport Proteins*
  • Cations, Divalent
  • Cell Membrane / metabolism
  • Cyclic Nucleotide-Gated Cation Channels
  • Genes, Plant*
  • Ion Channels / metabolism
  • Molecular Sequence Data
  • Plant Proteins*
  • Plant Roots / cytology
  • Plant Roots / metabolism*
  • Potassium Channels / classification
  • Potassium Channels / metabolism
  • Sequence Alignment


  • Annexins
  • Calcium Channels
  • Carrier Proteins
  • Cation Transport Proteins
  • Cations, Divalent
  • Cyclic Nucleotide-Gated Cation Channels
  • Ion Channels
  • LCT1 protein, Triticum aestivum
  • Plant Proteins
  • Potassium Channels