The Genome-Wide Identification of the Dihydroflavonol 4-Reductase (DFR) Gene Family and Its Expression Analysis in Different Fruit Coloring Stages of Strawberry.

Dihydroflavonol 4-reductase (DFR) significantly influences the modification of flower color. To explore the role of in the synthesis of strawberry anthocyanins, in this study, we downloaded the CDS sequences of the gene family from the genome database TAIR; the DFR family of forest strawberry was compared; then, a functional domain screen was performed using NCBI; the selected strawberry DFR genes were analyzed; and the expression characteristics of the family members were studied by qRT-PCR. The results showed that there are 57 members of the DFR gene family in strawberry, which are mainly expressed in the cytoplasm and chloroplast; most of them are hydrophilic proteins; and the secondary structure of the protein is mainly composed of α-helices and random coils. The analysis revealed that genes mostly contain light, hormone, abiotic stress, and meristem response elements. From the results of the qRT-PCR analysis, the relative expression of each member of the gene was significantly different, which was expressed throughout the process of fruit coloring. Most genes had the highest expression levels in the full coloring stage (S4). The expression of , , and during the S4 period was 8, 2.4, and 2.4 times higher than during the S1 period, indicating that the gene plays a key role in regulating the fruit coloration of strawberry. In the strawberry genome, 57 members of the strawberry gene family were identified. The higher the gene expression, the higher the anthocyanin content, and the gene may be the key gene in anthocyanin synthesis. Collectively, the gene is closely related to fruit coloring, which lays a foundation for further exploring the function of the gene family.