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-150236
  • 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 theSalinity 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.show moreshow less

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Metadaten
Author: Min Zhu, Lana Shabala, Tracey A Cuin, Xin Huang, Meixue Zhou, Rana Munns, Sergey Shabala
URN:urn:nbn:de:bvb:20-opus-150236
Document Type:Journal article
Faculties:Fakultät für Biologie / Theodor-Boveri-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), Vol. 67, No. 3, 835–844. DOI: 10.1093/jxb/erv493
DOI:https://doi.org/10.1093/jxb/erv493
Pubmed Id:http://www.ncbi.nlm.nih.gov/pubmed?term=PMC4737075
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 58 Pflanzen (Botanik) / 580 Pflanzen (Botanik)
Tag:HKT transporter; potassium; salinity stress; sequestration; sodium; xylem loading
Release Date:2019/01/23
Licence (German):License LogoCC BY: Creative-Commons-Lizenz: Namensnennung