|
Plant Physiol, July 2000, Vol. 123, pp. 833-844
Blue Light Activates Potassium-Efflux Channels in Flexor Cells
from Samanea saman Motor Organs via Two
Mechanisms1
SuJeong
Suh,
Nava
Moran, and
Youngsook
Lee*
Department of Life Science, School of Environmental Engineering,
Pohang University of Science and Technology, Pohang, 790-784, Republic
of Korea (S.S., Y.L.); and Department of Agricultural Botany,
Faculty of Agricultural, Food and Environmental Quality Sciences, The
Hebrew University of Jerusalem, Rehovot 76100, Israel (N.M.)
Light-induced leaflet movement of Samanea saman
depends on the regulation of membrane transporters in motor cells. Blue
light (BL) stimulates leaflet opening by inducing K+
release from the flexor motor cells. To elucidate the mechanism of
K+-efflux (KD)-channel regulation by light,
flexor motor cell protoplasts were patch-clamped in a cell-attached
configuration during varying illumination. Depolarization elicited
outward currents through single open KD channels. Changes
in cell membrane potential (EM) were
estimated by applying voltage ramps and tracking the change of the
apparent reversal potential of KD-channel current. BL
shifted EM in a positive direction (i.e.
depolarized the cell) by about 10 mV. Subsequent red light pulse
followed by darkness shifted EM oppositely
(i.e. hyperpolarized the cell). The BL-induced shifts of
EM were not observed in cells pretreated
with a hydrogen-pump inhibitor, suggesting a contribution by
hydrogen-pump to the shift. BL also increased KD-channel
activity in a voltage-independent manner as reflected in the increase
of the mean net steady-state patch conductance at a depolarization of
40 mV relative to the apparent reversal potential
(G@40). G@40
increased by approximately 12 pS without a change of the single-channel conductance, possibly by increasing the probability of channel opening.
Subsequent red-light and darkness reversed the change in
G@40. Thus, K+ efflux, a
determining factor for the cell-volume decrease of flexor cells, is
regulated by BL in a dual manner via membrane potential and by an
independent signaling pathway.
1
This work was supported by the Korea Research
Foundation (grant no. BSRI-98-4435), the Basic Science Research Fund
of Pohang University of Science and Technology (to Y.L.), the
U.S.-Israel Binational Agricultural Research and Development Fund
(grant no. IS-2469-94CR), and the German-Israeli Foundation for
Scientific Research and Development (grant no. G-384.193.12/94 to
N.M.).
*
Corresponding author; e-mail ylee{at}postech.ac.kr; fax
82-562-279-2199.
© 2000 American Society of Plant Physiologists
This article has been cited by other articles:
|
|
|
|
 
X. Chen, W.-H. Lin, Y. Wang, S. Luan, and H.-W. Xue
An Inositol Polyphosphate 5-Phosphatase Functions in PHOTOTROPIN1 Signaling in Arabidopis by Altering Cytosolic Ca2+
PLANT CELL,
February 1, 2008;
20(2):
353 - 366.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Ueda and Y. Nakamura
Chemical Basis of Plant Leaf Movement
Plant Cell Physiol.,
July 1, 2007;
48(7):
900 - 907.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Yu, D. Becker, H. Levi, M. Moshelion, R. Hedrich, I. Lotan, A. Moran, U. Pick, L. Naveh, Y. Libal, et al.
Phosphorylation of SPICK2, an AKT2 channel homologue from Samanea motor cells
J. Exp. Bot.,
November 1, 2006;
57(14):
3583 - 3594.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S.-i. Inoue, T. Kinoshita, and K.-i. Shimazaki
Possible Involvement of Phototropins in Leaf Movement of Kidney Bean in Response to Blue Light
Plant Physiology,
August 1, 2005;
138(4):
1994 - 2004.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. BABOURINA, L. GODFREY, and K. VOLTCHANSKII
Changes in Ion Fluxes During Phototropic Bending of Etiolated Oat Coleoptiles
Ann. Bot.,
July 1, 2004;
94(1):
187 - 194.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. K. Azad, Y. Sawa, T. Ishikawa, and H. Shibata
Phosphorylation of Plasma Membrane Aquaporin Regulates Temperature-Dependent Opening of Tulip Petals
Plant Cell Physiol.,
May 1, 2004;
45(5):
608 - 617.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Stoelzle, T. Kagawa, M. Wada, R. Hedrich, and P. Dietrich
Blue light activates calcium-permeable channels in Arabidopsis mesophyll cells via the phototropin signaling pathway
PNAS,
February 4, 2003;
100(3):
1456 - 1461.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Okazaki
Blue Light Inactivates Plasma Membrane H+-ATPase in Pulvinar Motor Cells of Phaseolus vulgaris L.
Plant Cell Physiol.,
August 15, 2002;
43(8):
860 - 868.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Moshelion, D. Becker, A. Biela, N. Uehlein, R. Hedrich, B. Otto, H. Levi, N. Moran, and R. Kaldenhoff
Plasma Membrane Aquaporins in the Motor Cells of Samanea saman: Diurnal and Circadian Regulation
PLANT CELL,
March 1, 2002;
14(3):
727 - 739.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. Babourina, I. Newman, and S. Shabala
Blue light-induced kinetics of H+ and Ca2+ fluxes in etiolated wild-type and phototropin-mutant Arabidopsis seedlings
PNAS,
February 19, 2002;
99(4):
2433 - 2438.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Moshelion, D. Becker, K. Czempinski, B. Mueller-Roeber, B. Attali, R. Hedrich, and N. Moran
Diurnal and Circadian Regulation of Putative Potassium Channels in a Leaf Moving Organ
Plant Physiology,
February 1, 2002;
128(2):
634 - 642.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
X. Wang, K. Haga, Y. Nishizaki, and M. Iino
Blue-Light-Dependent Osmoregulation in Protoplasts of Phaseolus vulgaris Pulvini
Plant Cell Physiol.,
December 1, 2001;
42(12):
1363 - 1372.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Iino, C. Long, and X. Wang
Auxin- and Abscisic Acid-Dependent Osmoregulation in Protoplasts of Phaseolus vulgaris Pulvini
Plant Cell Physiol.,
November 1, 2001;
42(11):
1219 - 1227.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Yu, M. Moshelion, and N. Moran
Extracellular Protons Inhibit the Activity of Inward- Rectifying Potassium Channels in the Motor Cells of Samanea saman Pulvini
Plant Physiology,
November 1, 2001;
127(3):
1310 - 1322.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Moshelion and N. Moran
Potassium-Efflux Channels in Extensor and Flexor Cells of the Motor Organ of Samanea saman Are Not Identical. Effects of Cytosolic Calcium
Plant Physiology,
February 1, 2001;
125(2):
1142 - 1150.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
M. Moshelion and N. Moran
Potassium-Efflux Channels in Extensor and Flexor Cells of the Motor Organ of Samanea saman Are Not Identical. Effects of Cytosolic Calcium
Plant Physiology,
October 1, 2000;
124(2):
911 - 919.
[Abstract]
[Full Text]
|
|
|
|
|
