Demidchik, V.

Shabala, S.

Sokolik, A.

Svistunenko, D.

Yurin, V. M.

English

Электронная библиотека БГУ

Ответ растительной клетки на абиотические стрессовые воздействия
84
STRESS INDUCED PRODUCTION OF HYDROXYL RADICALS LEADS TO
ACTIVATION OF CATION CHANNEL MEDIATED K+ EFFLUX FROM PLANT
CELLS
Demidchik V. 1, Sokolik A.1, Svistunenko D.2, Shabala S.3, Yurin V.M.1
1Department of Physiology and Biochemistry of Plants, Belarusian State University,
220030, Independence Avenue 4, Minsk, Belarus, dzemidchyk@bsu.by
2Department of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ,
Colchester, Essex, United Kingdom
3School of Agricultural Science, University of Tasmania, Private Bag 54, Hobart, Tas
7001, Australia
Potassium (K+) is essential macronutrient which is directly involved in regulation of en-
zyme activities, osmotic phenomena and generation of transmembrane electrical potential.
The loss of K+ by plant cells is central to stress reactions and also observed in signalling,
development, mineral acquisition, and other physiological processes. Generation of reac-
tive oxygen species is known to accompany these processes. Here, we propose a new
mechanism of induction of K+ loss from plants cells, which is activation of K+ efflux chan-
nels by hydroxyl radicals (most chemically-active ROS and a major damaging factor under
stress conditions). Using electron paramagnetic resonance spectroscopy, we have shown
that hydroxyl radicals are produced in Arabidopsis thaliana roots in response to NaCl,
pathogen elicitors, heavy metal copper and osmotic shock. K+ efflux was induced by same
stress factors in this system (as measured by ionselective vibrating microelectrodes,
MIFETM). This efflux was sensitive to K+ channel blockers and scavengers of free radicals.
Gork1-1 plants lacking major root K+ efflux channel did not respond to stresses (via K+
efflux). Patch-clamp electrophysiological analyses showed that 16-pS K+-selective channel
was activated by hydroxyl radicals in root cell plasma membrane. This channel had slow
kinetics, was outwardly rectifying and inhibited by classical antagonists of K+ channels.
Thus, K+ efflux GORK1-1 was shown to be activated by hydroxyl radicals that are gener-
ated in stress conditions by plant cells. Phenotyping studies are now in progress to test ef-
fects of gork KO on plant stress sensitivity and productivity under stress conditions.


Stress induced production of hydroxyl radicals leads to activation of cation channel mediated K+ efflux from plant cells

http://elib.bsu.by/bitstream/123456789/33845/1/048.pdf

Stress induced production of hydroxyl radicals leads to activation of cation channel mediated K+ efflux from plant cells

Abstract

Similar works

Full text

Available Versions

Электронная библиотека БГУ