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Exogenously applied 24-epibrassinolide (EBL) ameliorates detrimental effects of salinity by reducing K+ efflux via depolarization-activated K+ channels

Citation

Azhar, N and Su, N and Shabala, L and Shabala, S, Exogenously applied 24-epibrassinolide (EBL) ameliorates detrimental effects of salinity by reducing K+ efflux via depolarization-activated K+ channels, Plant and Cell Physiology, 58, (4) pp. 802-810. ISSN 0032-0781 (2017) [Refereed Article]

Copyright Statement

Copyright 2017 The Authors

DOI: doi:10.1093/pcp/pcx026

Abstract

This study has investigated mechanisms conferring beneficial effects of exogenous application of 24-epibrassinolides (EBL) on plant growth and performance under saline conditions. Barley seedlings treated with 0.25 mg lK-1 EBL showed significant improvements in root hair length, shoot length, shoot fresh weight and relative water content when grown in the presence of 150mM NaCl in the growth medium. In addition, EBL treatment significantly decreased the Na+ content in both shoots (by approximately 50%) and roots. Electrophysiological experiments revealed that pre-treatment with EBL for 1 and 24 h suppressed or completely prevented the NaCl-induced K+ leak in the elongation zone of barley roots, but did not affect root sensitivity to oxidative stress. Further experiments using Arabidopsis loss-of-function gork1-1 (lacking functional depolarization-activated outward-rectifying K+ channels in the root epidermal cells) and akt1 (lacking inward-rectifying K+ uptake channel) mutants showed that NaCl-induced K+ loss in the elongation zone of roots was reduced by EBL pre-treatment 50- to 100-fold in wild-type Col-0 and akt1, but only 10-fold in the gork1-1 mutant. At the same time, EBL treatment shifted vanadate-sensitive H+ flux towards net efflux. Taken together, these data indicate that exogenous application of EBL effectively improves plant salinity tolerance by prevention of K+ loss via regulating depolarization-activated K+ channels.

Item Details

Item Type:Refereed Article
Keywords:epibrassinolide, ion transport, membrane depolarization, potassium, sodium, voltage gating
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural Crops
Objective Field:Horticultural Crops not elsewhere classified
Author:Su, N (Mrs Nana Su)
Author:Shabala, L (Dr Lana Shabala)
Author:Shabala, S (Professor Sergey Shabala)
ID Code:118202
Year Published:2017
Web of Science® Times Cited:1
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2017-07-06
Last Modified:2018-05-23
Downloads:0

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