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Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots


Wu, H and Shabala, L and Liu, X and Azzarello, E and Zhou, M and Pandolfi, C and Chen, Z-H and Bose, J and Mancuso, S and Shabala, S, Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots, Frontiers in Plant Science, 6 Article 71. ISSN 1664-462X (2015) [Refereed Article]


Copyright Statement

Copyright 2015 Wu, Shabala, Liu, Azzarello, Zhou, Pandolfi, Chen, Bose, Mancuso and Shabala Licensed Under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.3389/fpls.2015.00071


Salinity stress tolerance is a physiologically complex trait that is conferred by the large array of interacting mechanisms. Among these, vacuolar Na+ sequestration has always been considered as one of the key components differentiating between sensitive and tolerant species and genotypes. However, vacuolar Na+ sequestration has been rarely considered in the context of the tissue-specific expression and regulation of appropriate transporters contributing to Na+ removal from the cytosol. In this work, six bread wheat varieties contrasting in their salinity tolerance (three tolerant and three sensitive) were used to understand the essentiality of vacuolar Na+ sequestration between functionally different root tissues, and link it with the overall salinity stress tolerance in this species. Roots of 4-day old wheat seedlings were treated with 100 mM NaCl for 3 days, and then Na+ distribution between cytosol and vacuole was quantified by CoroNa Green fluorescent dye imaging. Our major observations were as follows: (1) salinity stress tolerance correlated positively with vacuolar Na+ sequestration ability in the mature root zone but not in the root apex; (2) contrary to expectations, cytosolic Na+ levels in root meristem were significantly higher in salt tolerant than sensitive group, while vacuolar Na+ levels showed an opposite trend. These results are interpreted as meristem cells playing a role of the "salt sensor;" (3) no significant difference in the vacuolar Na+ sequestration ability was found between sensitive and tolerant groups in either transition or elongation zones; (4) the overall Na+ accumulation was highest in the elongation zone, suggesting its role in osmotic adjustment and turgor maintenance required to drive root expansion growth. Overall, the reported results suggest high tissue-specificity of Na+ uptake, signaling, and sequestration in wheat roots. The implications of these findings for plant breeding for salinity stress tolerance are discussed.

Item Details

Item Type:Refereed Article
Keywords:bread wheat, cytosolic Na+, Na+ distribution, root zones, salinity stress tolerance, vacuolar Na+ sequestration
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:Barley
UTAS Author:Wu, H (Mr Honghong Wu)
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Zhou, M (Professor Meixue Zhou)
UTAS Author:Bose, J (Dr Jayakumar Bose)
UTAS Author:Shabala, S (Professor Sergey Shabala)
ID Code:100719
Year Published:2015
Web of Science® Times Cited:53
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2015-05-27
Last Modified:2017-11-02
Downloads:331 View Download Statistics

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