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Nax loci affect SOS1-like Na+/H+ exchanger expression and activity in wheat
Citation
Zhu, M and Shabala, L and Cuin, TA and Huang, X and Zhou, M and Munns, R and Shabala, S, Nax loci affect SOS1-like Na+/H+ exchanger expression and activity in wheat, Journal of Experimental Botany, 67, (3) pp. 835-844. ISSN 0022-0957 (2016) [Refereed Article]
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Copyright Statement
© The Author 2015. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/
Abstract
Salinity stress tolerance in durum wheat is strongly associated with a plant’s ability to control Na+ delivery to the shoot. Two loci, termed Nax1 and Nax2, were recently identified as being critical for this process and the sodium transporters HKT1;4 and HKT1;5 were identified as the respective candidate genes. These transporters retrieve Na+ from the xylem, thus limiting the rates of Na+ transport from the root to the shoot. In this work, we show that the Nax loci also affect activity and expression levels of the SOS1-like Na+/H+ exchanger in both root cortical and stelar tissues. Net Na+ efflux measured in isolated steles from salt-treated plants, using the non-invasive ion flux measuring MIFE technique, decreased
in the sequence: Tamaroi (parental line)>Nax1=Nax2>Nax1:Nax2 lines. This efflux was sensitive to amiloride (a known inhibitor of the Na+/H+ exchanger) and was mirrored by net H+ flux changes. TdSOS1 relative transcript levels were 6–10-fold lower in Nax lines compared with Tamaroi. Thus, it appears that Nax loci confer two highly complementary mechanisms, both of which contribute towards reducing the xylem Na+ content. One enhances the retrieval of Na+ back into the root stele via HKT1;4 or HKT1;5, whilst the other reduces the rate of Na+ loading into the xylem via SOS1. It is suggested that such duality plays an important adaptive role with greater versatility
for responding to a changing environment and controlling Na+ delivery to the shoot.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | wheat, salinity tolerance, HKT transporter, potassium, sequestration, sodium, xylem loading |
| Research Division: | Agricultural, Veterinary and Food Sciences |
| Research Group: | Crop and pasture production |
| Research Field: | Crop and pasture improvement (incl. selection and breeding) |
| Objective Division: | Plant Production and Plant Primary Products |
| Objective Group: | Grains and seeds |
| Objective Field: | Wheat |
| UTAS Author: | Zhu, M (Ms Min Zhu) |
| UTAS Author: | Shabala, L (Associate Professor Lana Shabala) |
| UTAS Author: | Cuin, TA (Dr Tracey Cuin) |
| UTAS Author: | Huang, X (Mr Xin Huang) |
| UTAS Author: | Zhou, M (Professor Meixue Zhou) |
| UTAS Author: | Shabala, S (Professor Sergey Shabala) |
| ID Code: | 106563 |
| Year Published: | 2016 |
| Web of Science® Times Cited: | 55 |
| Deposited By: | Tasmanian Institute of Agriculture |
| Deposited On: | 2016-02-14 |
| Last Modified: | 2017-11-06 |
| Downloads: | 139 View Download Statistics |
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