Genome-wide characterization of SOS1 gene family in potato ( Solanum tuberosum ) and expression analyses under salt and hormone stress.

Salt Overly Sensitive 1 (SOS1) is one of the members of the Salt Overly Sensitive (SOS) signaling pathway and plays critical salt tolerance determinant in plants, while the characterization of the family in potato () is lacking. In this study, 37 were identified and found to be unevenly distributed across 10 chromosomes, with most of them located on the plasma membrane. Promoter analysis revealed that the majority of these genes contain abundant -elements involved in various abiotic stress responses. Tissue specific expression showed that 21 of the 37 were widely expressed in various tissues or organs of the potato. Molecular interaction network analysis suggests that 25 StSOS1s may interact with other proteins involved in potassium ion transmembrane transport, response to salt stress, and cellular processes. In addition, collinearity analysis showed that 17, 8, 1 and 5 of orthologous genes were paired with those in tomato, pepper, tobacco, and Arabidopsis, respectively. Furthermore, RT-qPCR results revealed that the expression of were significant modulated by various abiotic stresses, in particular salt and abscisic acid stress. Furthermore, subcellular localization in suggested that StSOS1-13 was located on the plasma membrane. These results extend the comprehensive overview of the gene family and set the stage for further analysis of the function of genes in SOS and hormone signaling pathways.