Research Article
Heterologous Overexpression of PeNHX3 from Populus euphratica Enhances Salt Stress Tolerance in Arabidopsis thaliana
Issue:
Volume 14, Issue 6, December 2026
Pages:
143-153
Received:
6 October 2026
Accepted:
26 October 2026
Published:
10 November 2026
DOI:
10.11648/j.ajls.20261406.11
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Abstract: The NHX-type Na+/H+ antiporters are key membrane proteins that maintain intracellular ion homeostasis under salt stress, whereas their functions in the desert tree Populus euphratica remain poorly understood. This study aimed to identify the NHX gene family in P. euphratica and to screen candidate genes for salt tolerance, and to verify the function of the screened gene through heterologous expression. Genome-wide identification, combined with analyses of gene structure, conserved motifs, physicochemical properties, and promoter cis-elements, yielded six PeNHX genes distributed on five scaffolds, all containing the Na+/H+_Exchanger domain; PeNHX1–5 clustered with the vacuolar AtNHX1–4, and PeNHX6 clustered with the endosomal AtNHX5/6. Under 300 mmol/L NaCl treatment, the expression of these genes in roots, stems, and leaves was quantified by qRT-PCR, and PeNHX3 showed the strongest induction among all members, reaching approximately 33-fold of the control level in stems at 12 h. A 35S:: PeNHX3-GFP fusion protein transiently expressed in Nicotiana benthamiana. PeNHX3-overexpression Arabidopsis lines obtained by the floral dip method exhibited significantly greater primary root length and shoot fresh weight than the wild type under 100 and 150 mmol/L NaCl. These results indicate that PeNHX3 improves salt tolerance when heterologously expressed and is a promising candidate gene for salt-tolerance breeding of woody plants.
Abstract: The NHX-type Na+/H+ antiporters are key membrane proteins that maintain intracellular ion homeostasis under salt stress, whereas their functions in the desert tree Populus euphratica remain poorly understood. This study aimed to identify the NHX gene family in P. euphratica and to screen candidate genes for salt tolerance, and to verify the functio...
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