THE ROLE OF PROTON PUMP AND POTASSIUM ON PLASMA MEMBRANE IN REGULATION OF CELLULOSE
SYNTHESIS IN PLANTS
L. P. Belova, G. A. Velikanov,1 T. M. Ilyina
Kazan' Institute of Biochemistry and Biophysics, Kazan'Centre RAS, Russia;
1 e-mail: velikanov@mail.knc.ru
A study was made of the influence of two activators of plasma membrane proton pump [indole-3-acetic acid (IAA)
and fusicoccin (EC)] and of the blocker of potassium channels of outward direction [tetraethylam-monium chloride (TEA)] on
exogenous [U-14Ñ]glucose incorporation into cellulose fraction of cell wall, and on the value of plasmalemma membrane
potential. It has been shown that IAA and FC exert different influences on the intensity of [U-14Ñ]glucose
incorporation into cellulose fraction: IAA activates, while FC inhibits incorporation intensity. A conclusion is made that
differences in affects of IAA and FC on the intensity of cellulose synthesis at the plasma membrane level may be due to the
fact that the activating effect of IAA on plasma membrane proton pump involves activation of the inward direction potassium
channels, whereas that of FC, on the contrary, is associated with their blocking. Under the action of TEA, the intensity of
incorporation of radioactively labeled glucose was increased. Apparently, the role of plasma membrane in regulation of the
intensity of cellulose synthesis may be associated with not only the activity of proton pump on plasma membrane, but also the
functional condition of potassium channels of this membrane.
Key words: synthesis of cellulose, plasma membrane, proton pump, membrane potential, potassium channels
inward direction
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