Genome-wide identification of NHX (Na + /H + antiporter) gene family in Cucurbita L. and functional analysis of CmoNHX1 under salt stress.

Soil salinization, which is the accumulation of salt in soil, can have a negative impact on crop growth and development by creating an osmotic stress that can reduce water uptake and cause ion toxicity. The NHX gene family plays an important role in plant response to salt stress by encoding for Na/H antiporters that help regulate the transport of sodium ions across cellular membranes. In this study, we identified 26 genes in three cultivars of L., including 9 , 9 () and 8 (). The evolutionary tree splits the 21 genes into three subfamilies: the endosome (Endo) subfamily, the plasma membrane (PM) subfamily, and the vacuole (Vac) subfamily. All the genes were irregularly distributed throughout the 21 chromosomes. 26 were examined for conserved motifs and intron-exon organization. These findings suggested that the genes in the same subfamily may have similar functions while genes in other subfamilies may have functional diversity. The circular phylogenetic tree and collinearity analysis of multi-species revealed that L. had a substantially greater homology relationship than and in terms of gene homology. We initially examined the -acting elements of the 26 in order to investigate how they responded to salt stress. We discovered that the , , , , , and all had numerous ABRE and G-box -acting elements that were important to salt stress. Previous transcriptome data showed that in the mesophyll and veins of leaves, many and , such as , responded significantly to salt stress. In addition, we heterologously expressed in plants in order to further confirm the response of to salt stress. The findings demonstrated that during salt stress, that had heterologously expression was found to have decreased salt tolerance. This study offers important details that will aid in further elucidating the molecular mechanism of under salt stress.