Expression and Ca2+ dependency of plasma membrane K+ channels of tobacco suspension cells adapted to salt stress.
The expression of plasma membrane K+ channels of NaCl-adapted tobacco suspension cells and effects of extracellular Ca2+ on plasma membrane K+ channels were investigated. Reverse transcription-PCR (RT-PCR) analysis showed that expression of TORK1, which encodes a K+ channel, was much lower in NaCl-adapted cells than in NaCl-unadapted cells. The magnitude of the outward K+ currents of NaCl-adapted as well as NaCl-unadapted cells decreased with increasing extracellular Ca2+ but there is no significant difference in Ca2+ dependency of the K+ current. These analyses suggest that reduction of the number of K+ channels might cause NaCl adaptation of cells through the decrease of outward K+ currents.
Kasukabe
Naoki
N
Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Okayama, 700-8530 Japan.
Watanabe-Sugimoto
Megumi
M
Matsuoka
Ken
K
Okuma
Eiji
E
Obi
Ichiro
I
Nakamura
Yoshimasa
Y
Shimoishi
Yasuaki
Y
Murata
Yoshiyuki
Y
Kakutani
Tadaaki
T
D000222:Adaptation, Physiological; D002118:Calcium / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D014026:Nicotiana / Q000378:metabolism*
D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger; D012965:Sodium Chloride; D002118:Calcium