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Abstract

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.

Item Type:	Article
Authors/Creators:	Pottosin, I and Zepeda-Jazo, I and Bose, J and Shabala, S
Keywords:	ion channel, membrane transport, anion conductance, electrolyte leakage, hydroxyl radical, membrane potential, MIFE, oxidative stress, patch-clamp
Journal or Publication Title:	International Journal of Molecular Sciences
Publisher:	Molecular Diversity Preservation International
ISSN:	1422-0067
DOI / ID Number:	https://doi.org/10.3390/ijms19030897
Copyright Information:	Copyright 2018 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
Related URLs:	UTAS Profile: Pottosin, I Google Scholar: Shabala, S UTAS Profile: Shabala, S
Item Statistics:	View statistics for this item

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