Unveiling differential expression profiles of the wheat DOG1 gene family and functional analysis of the association between TaDOG1-1 and heat stress tolerance in transgenic Arabidopsis

High temperatures can significantly impact wheat growth and grain yields during the grain-filling stage. In this study, we identified genes that respond to high-temperature stress during the grain-filling stage. We also identified and characterized 24 novel genes of the DOG1 gene family in hexaploid wheat. Motif analysis and conserved domain search revealed substantial similarities among TaDOG1 family members. Phylogenetic analysis demonstrated the evolutionary conservation of the TaDOG1 family across various plant species. Tissue-specific expression profiling indicated consistent patterns, with TaDOG1 genes predominantly expressed in stem tissues. Only TaDOG1-1 exhibited enhanced expression, particularly during hard dough and ripening stages. TaDOG1-1 and TaDOG1-7 exhibited increased expression under heat stress during the grain-filling stage, indicating their heat-responsive nature. Cis-element analysis revealed potential regulatory motifs, suggesting the involvement of TaDOG1-1 and TaDOG1-7 in stress tolerance mechanisms. Yeast two-hybrid screening revealed interacting proteins, including stress-responsive and grain development-associated proteins. To understand the biological function, we overexpressed TaDOG1-1 in Arabidopsis plants and observed enhanced thermotolerance under basal heat stress. Under heat stress, the transgenic plants exhibited increased biomass and elevated expression levels of heat-responsive genes. Furthermore, TaDOG1-1–overexpressing plants showed improved survival rates under soil heat stress, along with a greater accumulation of antioxidant enzymes in leaves. In this study, the identification and functions of the DOG1 gene family provide valuable insights for developing genetic engineering strategies aimed at improving wheat yield under high-temperature stress.