The ERF transcription factor ZbERF3 promotes ethylene-induced anthocyanin biosynthesis in Zanthoxylum bungeanum

Ethylene regulates fruit ripening, and in Zanthoxylum bungeanum, fruit color deepened with increasing of ethylene during fruit ripening, but the molecular mechanism of this physiological process was still unclear. In our study, through the combined analysis of transcriptome and metabolome, it was found that ethylene release was consistent with anthocyanin synthesis, and ethylene response factors (ERFs) were significantly related to anthocyanin biosynthesis during the fruit ripening of Zanthoxylum bungeanum. Ethylene treatment significantly induced fruit coloration and promoted anthocyanin synthesis and the expression of ZbERF3. Furthermore, Yeast one-hybrid assays and Luciferase reporter assays demonstrated that ZbERF3 directly bound to the promoter of ZbMYB17 and transcriptionally activated its expression. What's more, it was demonstrated that ZbMYB17 directly bound to the promoter of ZbANS, promoting anthocyanin biosynthesis. Overall, this study revealed the mechanism of ERF and MYB synergistically regulating the coloration of Z. bungeanum fruit.