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Reduced tonoplast fast-activating and slow-activating channel activity is essential for conferring salinity tolerance in a facultative halophyte, quinoa

Citation

Bonales Alatorre, E and Shabala, S and Chen, Z-H and Pottosin, I, Reduced tonoplast fast-activating and slow-activating channel activity is essential for conferring salinity tolerance in a facultative halophyte, quinoa, Plant Physiology, 162, (2) pp. 940-952. ISSN 0032-0889 (2013) [Refereed Article]

Copyright Statement

Copyright 2013 American Society of Plant Biologists

DOI: doi:10.1104/pp.113.216572

Abstract

Halophyte species implement a "salt-including" strategy, sequestering significant amounts of Na+ to cell vacuoles. This requires a reduction of passive Na+ leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na+-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na+ accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na+ exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na+ sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na+, this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K+ than for Na+, and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 mM NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and saltgrown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na+ leak, thus enabling efficient sequestration of Na+ to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Summer Grains and Oilseeds
Objective Field:Summer Grains and Oilseeds not elsewhere classified
Author:Bonales Alatorre, E (Dr Edgar Bonales Alatorre)
Author:Shabala, S (Professor Sergey Shabala)
Author:Pottosin, I (Professor Igor Pottosin)
ID Code:86793
Year Published:2013
Web of Science® Times Cited:58
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2013-10-22
Last Modified:2017-11-02
Downloads:0

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