[Identification of the PfDof transcription factor family in and functional analysis of in lipid synthesis].

(L.) Britt. is a characteristic oil crop rich in polyunsaturated fatty acids, particularly α-linolenic acid, which has important development and utilization value. The Dof transcription factor is one of the plant-specific transcription factor families, which is widely involved in important biological processes such as plant growth, development, and metabolic regulation. In order to explore the key Dof transcription factors involved in the oil biosynthesis and systematically analyze their regulatory mechanisms of . seeds, a total of 56 PfDof gene family members were identified from the genome and transcriptome data of . and classified into four subfamilies according to sequence characteristics. All PfDofs contained highly conserved C-C zinc finger domains, with gene duplication being the primary mechanism driving their evolution and expansion. Genes within the same subgroup exhibited similar gene structures and conserved motifs. The 56 PfDofs were predicted as unstable hydrophilic proteins, with α-helixes and random coils as their predominant structural components. The RNA-seq results revealed that 11 PfDofs exhibited differential expression during different developmental stages of . seeds. RT-qPCR was performed to further validate the expression patterns of these 11 members across various tissue samples (root, stem, leaf, and flower) of . and at different developmental stages of its seeds. The results showed that exhibited the highest expression level in seeds, which was consistent with the transcriptome data. Subcellular localization studies demonstrated that PfDof29 was localized to the nucleus and had a transcriptional activation activity. Overexpression of in resulted in a significant increase in total oil content of tobacco leaves, accompanied by reductions in starch and soluble sugar content, while the protein content remained unchanged. Additionally, the metabolic balance between saturated and unsaturated fatty acids in the transgenic tobacco leaves was altered, with a significant increase in α-linolenic acid content. The expression levels of the fatty acid desaturase genes , , and were significantly upregulated. A yeast one-hybrid assay revealed that PfDof29 could directly bind to the promoter region of , thereby regulating its expression. This study provides an initial understanding of the regulatory mechanisms of PfDof transcription factors in the synthesis and accumulation of oil in . . These findings offer new insights into the enhancement of oil content and quality of . seeds.