An anion conductance, the essential component of the hydroxyl-radical-induced ion current in plant roots
journal contributionposted on 2023-05-19, 19:40 authored by Igor Pottosin, Zepeda-Jazo, I, Bose, J, Sergey ShabalaSergey Shabala
Oxidative stress signaling is essential for plant adaptation to hostile environments. Previous studies revealed the essentiality of hydroxyl radicals (HO•)-induced activation of massive K+ efflux and a smaller Ca2+ influx as an important component of plant adaptation to a broad range of abiotic stresses. Such activation would modify membrane potential making it more negative. Contrary to these expectations, here, we provide experimental evidence that HO• induces a strong depolarization, from −130 to −70 mV, which could only be explained by a substantial HO•-induced efflux of intracellular anions. Application of Gd3+ and NPPB, non-specific blockers of cation and anion conductance, respectively, reduced HO•-induced ion fluxes instantaneously, implying a direct block of the dual conductance. The selectivity of an early instantaneous HO•-induced whole cell current fluctuated from more anionic to more cationic and vice versa, developing a higher cation selectivity at later times. The parallel electroneutral efflux of K+ and anions should underlie a substantial leak of the cellular electrolyte, which may affect the cell’s turgor and metabolic status. The physiological implications of these findings are discussed in the context of cell fate determination, and ROS and cytosolic K+ signaling.
Publication titleInternational Journal of Molecular Sciences
Department/SchoolTasmanian Institute of Agriculture (TIA)
PublisherMolecular Diversity Preservation International
Place of publicationMatthaeusstrasse 11, Basel, Switzerland, Ch-4057
Rights statementCopyright 2018 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/