Salinity is one of the most important problems that adversely affect crops growth, productivity and quality worldwide. Salt Overly Sensitive 1 (SOS1) gene family plays vital roles in plant response to salt stress. Herein, we report the identification of the SOS family in wheat and the exploration of the expression profiles of SOSs under salt stress. Complete genome sequences of T. aestivum were downloaded from Ensembl plant database. Conservation and divergence of TaSOS1 family were conducted by using phylogenetic tree, gene structure and synteny distribution analysis. Expression profiles of TaSOS1s were obtained based on transcriptome and qRT-PCR analysis. Totally, 119 TaSOS1 proteins in wheat were identified at the genome-wide level and classified into three groups. Six motifs were conserved in TaSOS1 gene family. Moreover, 25 TaSOS1 genes had three copies distributing in three sub-genomes (A, B and D). A total of 32, 28 and 29 TaSOS1 genes were located on the sub-genomes A, B and D, respectively. Moreover, there were 19, 12, 6, 7, 28, 5 and 12 genes located on the three homologous of chromosomes 1, 2, 3, 4, 5, 6 and 7, respectively. Two genes were mapped to unattributed scaffolds. The duplication events analysis indicated that tandem repeats contributed to the expansion of the SOS1 family in wheat. Collinearity analysis demonstrated that segmental duplications play an important role in the expansion of SOS1 members. Chromosome 7, 5, 3, and 2 showed collinear relationship. Tissue specific expression pattern analysis revealed that 41 TaSOS1 genes expressed in various tissues, such as root, shoot, leaf, spike and grain. Transcriptomic analysis revealed that 28 and 26 genes were up- and down-regulated under salinity stress, respectively, of which 18 genes were further confirmed by RT-qPCR. The plants with high expression level of these genes displayed higher tolerance to salinity stress, stronger root system, higher Fv/Fm value and water potential. The results could be helpful for further elucidating the molecular mechanism of TaSOS1 related to salt tolerance in wheat and provide a toolkit for improving the salinity tolerance of wheat.

盐度是对全球作物生长、生产力和质量产生不利影响的最重要问题之一。Salt Overly Sensitive 1 ( SOS1 ) 基因家族在植物对盐胁迫的反应中起着至关重要的作用。在此，我们报告了小麦中SOS家族的鉴定以及盐胁迫下SOS表达谱的探索。T. aestivum的完整基因组序列从 Ensembl 植物数据库下载。通过系统发育树、基因结构和同线性分布分析，对TaSOS1家族进行了保守和分化。TaSOS1的表达谱s 是基于转录组和 qRT-PCR 分析获得的。在全基因组水平上总共鉴定了小麦中的 119 种 TaSOS1 蛋白，并将其分为三组。TaSOS1基因家族中有六个基序是保守的。此外，25 个TaSOS1基因具有三个拷贝，分布在三个亚基因组（A、B 和 D）中。共有 32、28 和 29个 TaSOS1基因分别位于亚基因组 A、B 和 D 上。1、2、3、4、5、6、7号染色体3个同源基因上分别有19、12、6、7、28、5、12个基因。两个基因被映射到未归属的支架上。重复事件分析表明串联重复有助于SOS1的扩展小麦的家庭。共线性分析表明，片段重复在SOS1成员的扩展中起着重要作用。7、5、3、2号染色体呈共线关系。组织特异性表达模式分析显示，41个TaSOS1基因在根、芽、叶、穗和籽粒等多种组织中均有表达。转录组学分析显示，盐胁迫下分别有28个和26个基因上调和下调，其中18个基因通过RT-qPCR进一步证实。这些基因高表达的植物表现出更高的盐胁迫耐受性，更强的根系，更高的Fv / Fm价值和水潜力。研究结果有助于进一步阐明TaSOS1与小麦耐盐性相关的分子机制，为提高小麦耐盐性提供工具包。