Nax loci affect SOS1-like Na\(^+\)/H\(^+\) exchanger expression and activity in wheat
Please always quote using this URN: urn:nbn:de:bvb:20-opus-190908
- 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-likeSalinity 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.…
Author: | Min Zhu, Lana Shabala, Tracey A. Cuin, Xin Huang, Meixue Zhou, Rana Munns, Sergey Shabala |
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URN: | urn:nbn:de:bvb:20-opus-190908 |
Document Type: | Journal article |
Faculties: | Fakultät für Biologie / Julius-von-Sachs-Institut für Biowissenschaften |
Language: | English |
Parent Title (English): | Journal of Experimental Botany |
Year of Completion: | 2016 |
Volume: | 67 |
Issue: | 3 |
Pagenumber: | 835-844 |
Source: | Journal of Experimental Botany (2016) 67:3, S. 835-844. https://doi.org/10.1093/jxb/erv493 |
DOI: | https://doi.org/10.1093/jxb/erv493 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
Tag: | HKT transporter; potassium; salinity stress; sequestration; sodium; xylem loading |
Release Date: | 2021/02/02 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung |