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Physiological and molecular mechanisms mediating xylem Na+ loading in barley in the context of salinity stress tolerance


Zhu, M and Zhiu, M and Shabala, L and Shabala, S, Physiological and molecular mechanisms mediating xylem Na+ loading in barley in the context of salinity stress tolerance, Plant Cell and Environment, 40, (7) pp. 1009-1020. ISSN 0140-7791 (2017) [Refereed Article]

Copyright Statement

2016 John Wiley & Sons Ltd

DOI: doi:10.1111/pce.12727


Time-dependent kinetics of xylem Na+ loading was investigated using a large number of barley genotypes contrasting in their salinity tolerance. Salt-sensitive varieties were less efficient in controlling xylem Na+ loading and showed a gradual increase in the xylem Na+ content over the time. To understand underlying ionic and molecular mechanisms, net fluxes of Ca2+, K+ and Na+ were measured from the xylem parenchyma tissue in response to H2O2 and ABA; both of them associated with salinity stress signalling. Our results indicate that NADPH oxidase-mediated apoplastic H2O2 production acts upstream of the xylem Na+ loading and is causally related to ROS-inducible Ca2+ uptake systems in the root stelar tissue. It was also found that ABA regulates (directly or indirectly) the process of Na+ retrieval from the xylem and the significant reduction of Na+ and K+ fluxes induced by bumetanide are indicative of a major role of chloride cation co-transporter (CCC) on xylem ion loading. Transcript levels of HvHKT1;5_like and HvSOS1_like genes in the root stele were observed to decrease after salt stress, while there was an increase in HvSKOR_like gene, indicating that these ion transporters are involved in primary Na+/K+ movement into/out of xylem.

Item Details

Item Type:Refereed Article
Keywords:ABA; CCC transporter; H2O2; NADPH oxidase; SKOR; SOS1; xylem sodium loading
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:Zhu, M (Ms Min Zhu)
UTAS Author:Zhiu, M (Professor Meixue Zhou)
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Shabala, S (Professor Sergey Shabala)
ID Code:117709
Year Published:2017 (online first 2016)
Web of Science® Times Cited:69
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2017-06-26
Last Modified:2017-11-02

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