AUTHOR=Sharma Pradeep , Mishra Shefali , Pandey Bharati , Singh Gyanendra 

TITLE=Genome-wide identification and expression analysis of the NHX gene family under salt stress in wheat (Triticum aestivum L)

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1266699

DOI=10.3389/fpls.2023.1266699

ISSN=1664-462X

ABSTRACT=<p>Salt stress affects plant growth and development, resulting in the loss of crop yield across the world, and sodium-proton antiporters (NHXs) are one of the genes known to promote salt tolerance in transgenic plants. In this study, we conducted a comprehensive genome-wide analysis and expression profile of <italic>NHX</italic> genes in wheat under salinity stress. We identified 30 <italic>TaNHX</italic> genes in wheat based on the Na<sup>+</sup>/H<sup>+</sup> exchanger domain, with all genes containing an amiloride motif except one, a known for inhibiting Na<sup>+</sup> ions in plants. Phylogenetic analysis classified these genes into three classes with subfamilies: 12 were localized in vacuoles, while 18 were in the endoplasmic reticulum and plasma membrane. Promoter analysis revealed stress-related <italic>cis</italic>-acting elements, indicating their potential role in abiotic stress tolerance. The non-synonymous (K<sub>a</sub>)/synonymous (K<sub>s</sub>) ratios highlighted that the majority of <italic>TaNHX</italic> genes experienced robust purifying selection throughout their evolutionary history. Transcriptomis data analysis and qRT-PCR demonstrated distinct expression patterns for <italic>TaNHX</italic> genes across various tissues when subjected to salt stress. Additionally, we predicted 20 different miRNA candidates targeting the identified <italic>TaNHX</italic> genes. Protein-protein interaction prediction revealed NHX6’s involvement in the SOS1 pathway, while <italic>NHX1</italic> gene exhibit proton antiporter activity. Molecular dynamics (MD) simulations were also conducted to examine the interactions of <italic>TaNHX1</italic>, <italic>TaNHX2</italic>, and <italic>TaNHX3</italic>. These results represent a significant advancement in our understanding of the molecular mechanisms governing Na<sup>+</sup> transporters. This may also offer promising avenues for future studies aimed at unraveling the intricate details of their biological roles and applications.</p>