StMYB113 Promotes Anthocyanin Biosynthesis in Potato (Solanum tuberosum L.) Desiree Tubers

MYB transcription factors play a key role in anthocyanin biosynthesis. However, there are few reports on MYB transcription factors that can regulate anthocyanin biosynthesis in potato. In this study, the StMYB113 gene was isolated from potato and characterized. Transient activation experiments showed that the StMYB113 gene could promote anthocyanin biosynthesis in tobacco leaves by enhancing the expression of genes encoding anthocyanin biosynthesis-related enzymes. In addition, overexpression of the StMYB113 gene promoted anthocyanin accumulation in potato tuber skin. Furthermore, transient luciferase analysis showed that StMYB113 enhanced the promoter activities of StF3H and StDFR genes significantly. These results indicated that the StMYB113 gene could promote anthocyanin accumulation in potato tuber skin by directly activating the expression of StF3H and StDFR. The promoter activity of StMYB113 was significantly higher in light than in dark conditions, suggesting that the expression of StMYB113 is induced by light. These findings illustrate the role and regulation of the StMYB113 gene in potato anthocyanin biosynthesis and enrich the regulatory theory of potato anthocyanin biosynthesis.