Screening transcription factors of IbMYB1-4 by yeast one-hybrid assays in purple-fleshed sweet potato

The transcription factor IbMYB1 has been identified to be involved in anthocyanin biosynthesis in purple-fleshed sweet potato. However, the upstream transcription factors of PIbMYB1-4 involved in anthocyanin biosynthesis have rarely been studied. In this study, yeast one-hybrid screen was conducted in purple-fleshed sweet potato storage roots to identify upstream transcription factors of PIbMYB1-4 . Three proteins, IbERF1, IbPGP19 and IbPDC, were screened as the upstream binding proteins of PIbMYB1-4 . Yeast one-hybrid assays and luciferase reporter assays were used to verify that upstream binding proteins interacted with the promoters. The interaction between the promoters and upstream binding proteins was verified by yeast one-hybrid and luciferase reporter assays. The gene expression of upstream transcription factors, transcription factors and structural genes involved in anthocyanin biosynthesis in different root stages of purple-fleshed and white-fleshed sweet potato was analyzed by real-time PCR. IbERF1 has been identified as the upstream transcription factor of PIbMYB1 involved in anthocyanin biosynthesis in purple-fleshed sweet potato. It has been identified that IbERF1 plays an important role in anthocyanin biosynthesis in purple-fleshed sweet potato.