Genome Wide Identification of Sesame Dof Transcription Factors and Functional Analysis of SiDof8, SiDof10 and SiDof34 in Fatty Acid Synthesis

The Dof (DNA binding with one finger) protein is one of the unique transcription factors in plants, and it plays an important role in plant growth and stress response. Sesame is an oil-bearing crop with high oil content and rich nutrition. In this study, 34 Dof genes were identified in the sesame genome using bioinformatics technology, and their physicochemical properties, gene structure, conserved motifs, tissue-specific expression and functions in fatty acid synthesis were preliminarily analyzed. The results showed that although there were differences in sequence length, molecular weight and isoelectric point, SiDofs all contained a conservative zinc finger structure, which could be divided into three categories in phylogeny. All 34 SiDof genes contain 1–2 exons, and the conserved motifs among subfamilies are similar. Tissue-specific expression analysis showed that the expression levels of SiDof8, SiDof10 and SiDof34 were the highest in seeds 24 days after pollination. Overexpression of SiDof8, SiDof10 and SiDof34 could significantly increase the contents of C18:0, C18:1, C18:2 and C18:3, and all of them are located in the nucleus. There were Dof DNA binding elements in the promoter region of fatty acid synthesis genes. These results provide a theoretical basis for further study on the function of the sesame Dof genes and biological breeding.