Ion channels in electrical signaling in higher plants

Abstract

Electrical signals (ESs) of plants occurring under the action of various external factors play an important role in adaptation to changing environmental conditions. The generation of ESs in higher plant cells is associated with the activation of Ca2+, K+, and anion fluxes, as well as changes in the activity of plasma membrane H+-ATPase. In the present review, the molecular nature of ion channels contributing to ESs transmission in higher plants is analyzed based on the comparison of data from molecular-genetic and electrophysiological studies. Based on such characteristics of ion channels as selectivity, activation mechanism, and intracellular and tissue localization, those ion channels that meet the requirements for potential participants of ESs generation were selected from a wide variety of ion channels in higher plants. Analysis of the data of experimental studies performed on mutants with suppressed or enhanced expression of a certain channel gene revealed those channels whose activation contributes to ESs formation. The channels responsible for Ca2+ flux during ESs generation include channels of GLR family, for K+ flux - GORK, for anions - MSL. Consideration of the prospects for further studies suggests the need to combine electrophysiological and genetic approaches along with the analysis of ion concentrations in intact plants within a single study.