Genome-Wide Identification of the Cation/Proton Antiporter () Gene Family and Expression Pattern Analysis Under Salt Stress in Winter Rapeseed ( L.).

The gene family regulates ionic balance and pH homeostasis in cells, significantly contributing to plant stress tolerance. In this study, a total of 63 gene family members were identified in the whole genome of L. (), and the three subfamily members were (9), (15), and (39), respectively. The members of the gene family encoded 303-1259 amino acids, with molecular weights in the range of 32,860.39~139,884.73 kDa, distributed on 10 chromosomes, and contained 17 conserved motifs, and , and the gene family members had the same molecular weights on 10 chromosomes and contain 17 conserved motifs. The and subfamilies have more exons than the subfamily. An analysis of promoter cis-acting elements in the gene showed that members of this gene family contain TC-rich, LTR, MBS, and ARE stress response elements. In addition, transcriptome analysis revealed the expression of genes in under salt stress. The selected genes were verified by RT-qPCR. By detecting the Na and K flow rates in the root and chloroplast cells of salt-tolerant and salt-sensitive varieties after salt treatment, it was found that the rate of Na and K efflux from the root and chloroplast cells of salt-sensitive varieties was significantly higher than that of salt-tolerant varieties. This investigation marks the first systematic identification of the gene family in . This study further explores its expression patterns and the efflux rates of Na and K across salt-tolerant varieties, providing a theoretical basis for understanding the role of the gene family in the salt stress response of .