Genome-wide identification and expression analysis of wheat GS3-family genes under salt- alkali stresse

Background Soil salinization is a major abiotic stress restricting global agricultural sustainability. As an important allohexaploid staple crop, wheat has a large and complex genome, and improving its salt-alkali tolerance through functional studies of stress-related gene families is a key strategy for stress-resistant breeding. G proteins, especially the Gγ subunit encoded by GS3 homologous genes, have been proven to participate in plant growth regulation and abiotic stress responses. In several grass crops, GS3/AT1 homologs negatively regulate alkaline tolerance by affecting ROS homeostasis. However, the systematic identification and functional characteristics of the TaGS3 gene family in wheat under salt-alkali stress remain largely unclear. Result In this study, a total of six TaGS3 genes were identified from the wheat genome and renamed TaGS3-1 to TaGS3-6 . All encoded proteins contained the conserved G gamma 2 domain, were hydrophilic and unstable, and were rich in cysteine regions. These genes were unevenly distributed on six chromosomes of the A, B, and D subgenomes. Gene structure and conserved motif analysis showed high conservation among family members, with all genes containing five exons. Promoter analysis revealed abundant cis-elements related to hormone, light, and stress responses, suggesting roles in environmental adaptation. Synteny analysis detected six segmental duplication events in wheat and close homologous relationships with rice, maize, soybean, and Arabidopsis. Protein interaction prediction indicated dense interactions among TaGS3 members, consistent with functional redundancy in polyploid wheat. Expression analysis showed tissue-specific patterns in roots, stems, leaves, spikes, and grains. Under salt and alkaline stress, TaGS3-1, TaGS3-2, TaGS3-3, TaGS3-6 were generally upregulated with increasing stress concentration, while TaGS3-4, TaGS3-5 were downregulated. Subcellular localization confirmed that TaGS3-1 and TaGS3-3 were localized in the nucleus. Conclusion This study systematically identified and characterized the TaGS3 gene family in common wheat at the genome-wide level, including gene structure, chromosomal distribution, evolutionary relationships, promoter elements, and expression patterns under salt-alkali stress. The results reveal that TaGS3 genes are widely involved in wheat growth and development and respond differentially to saline-alkali stress. These findings provide candidate genes and a theoretical basis for further functional verification of TaGS3 and molecular breeding of salt-alkali-tolerant wheat varieties.