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Na+ extrusion from the cytosol and tissue-specific Na+ sequestration in roots confer differential salt stress tolerance between durum and bread wheat


Wu, H and Shabala, L and Azzarello, E and Huang, Y and Pandolfi, C and Su, N and Wu, Q and Cai, S and Bazihizina, N and Wang, L and Zhou, M and Mancuso, S and Chen, Z and Shabala, S, Na+ extrusion from the cytosol and tissue-specific Na+ sequestration in roots confer differential salt stress tolerance between durum and bread wheat, Journal of Experimental Botany, 69, (16) pp. 3987-4001. ISSN 0022-0957 (2018) [Refereed Article]


Copyright Statement

Copyright 2018 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.1093/jxb/ery194


The progress in plant breeding for salinity stress tolerance is handicapped by the lack of understanding of the specificity of salt stress signalling and adaptation at the cellular and tissue levels. In this study, we used electrophysiological, fluorescence imaging, and real-time quantitative PCR tools to elucidate the essentiality of the cytosolic Na+ extrusion in functionally different root zones (elongation, meristem, and mature) in a large number of bread and durum wheat accessions. We show that the difference in the root’s ability for vacuolar Na+ sequestration in the mature zone may explain differential salinity stress tolerance between salt-sensitive durum and salt-tolerant bread wheat species. Bread wheat genotypes also had on average 30% higher capacity for net Na+ efflux from the root elongation zone, providing the first direct evidence for the essentiality of the root salt exclusion trait at the cellular level. At the same time, cytosolic Na+ accumulation in the root meristem was significantly higher in bread wheat, leading to the suggestion that this tissue may harbour a putative salt sensor. This hypothesis was then tested by investigating patterns of Na+ distribution and the relative expression level of several key genes related to Na+ transport in leaves in plants with intact roots and in those in which the root meristems were removed. We show that tampering with this sensing mechanism has resulted in a salt-sensitive phenotype, largely due to compromising the plant’s ability to sequester Na+ in mesophyll cell vacuoles. The implications of these findings for plant breeding for salinity stress tolerance are discussed.

Item Details

Item Type:Refereed Article
Keywords:potassium, stress, signalling, sodium
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Grains and seeds
Objective Field:Wheat
UTAS Author:Wu, H (Mr Honghong Wu)
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Su, N (Mrs Nana Su)
UTAS Author:Wu, Q (Mr Qi Wu)
UTAS Author:Bazihizina, N (Dr Nadia Bazihizina)
UTAS Author:Wang, L (Dr Lu Wang)
UTAS Author:Zhou, M (Professor Meixue Zhou)
UTAS Author:Shabala, S (Professor Sergey Shabala)
ID Code:127316
Year Published:2018
Web of Science® Times Cited:44
Deposited By:Agriculture and Food Systems
Deposited On:2018-07-20
Last Modified:2019-03-05
Downloads:68 View Download Statistics

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