Abstract: Using Shenqiuhong Hippophae rhamnoides as the experimental material, the gene encoding the NHX1 protein of the Na+/H+ antiporter (NHX) family was cloned, and bioinformatic analysis was performed on the Hippophae rhamnoides NHX1 protein (HrNHX1). The results indicated that the full length of the HrNHX1 gene was approximately 1 600 bp, encoding an acidic hydrophobic protein consisting of 538 amino acid residues. The molecular formula of this protein was C2754H4269N672O759S21, with a total of 8 502 atoms and a relative molecular mass of 59 637. 71. HrNHX1 belonged to a stable protein, containing 13 transmembrane domains, lacking a signal peptide, being a non-secretory protein, and containing one Na+/H+ exchanger domain characteristic of the NHX protein family. Subcellular localization analysis showed that the HrNHX1 protein was localized on the vacuolar membrane. Homology alignment analysis indicated that the HrNHX1 protein sequence had high sequence similarity with the NHX1 protein sequences of Gossypium raimondii, Gossypium hirsutum, Morus notabilis, and Hevea brasiliensis. Phylogenetic tree analysis found that the HrNHX1 protein sequence clustered on the same evolutionary branch with the NHX protein sequences of rice and wheat, which had drought resistance and salt tolerance functions, suggesting they had a close evolutionary relationship. The HrNHX1 gene played an important role in enhancing plant drought resistance and salt tolerance, and regulating the activity of its encoded HrNHX1 protein or the expression level of this gene could effectively improve plant adaptability to drought and salt stress.

Key words: shenqiuhong, Hippophae rhamnoides, HrNHX1 gene, gene cloning, bioinformatic analysis