Transcriptional analysis reveals that 1-methylcyclopropene treatment promotes anthocyanin synthesis in peach fruit

Anthocyanins are bioactive substances that are not only responsible for the pigmentation of various fruits, but also hold potential benefits to human health. In this study, postharvest peaches were treated with 10 ppm 1-MCP, and changes of anthocyanin biosynthesis were then revealed at transcriptional level to gain insight into the underlying molecular mechanisms. The functions of key transcription factors (TFs) were systematically analyzed. Results demonstrated that 1-MCP effectively up-regulated expression of structural genes and stimulated anthocyanin accumulation. A novel transcription factor PpbHLH135 can respond positively to 1-MCP treatment and has been noted for its remarkable gene expression and protein abundance. The transcription factor bHLH3 was also investigated in this study due to its widespread interest and attention, serving to compare the regulatory function of bHLH135 in anthocyanin synthesis, although it didn’t show a significant response to 1-MCP treatment in this study. PpbHLH3 TF showed a stronger regulatory effect on PpF3H , while PpbHLH135 was more dominant over the regulation of PpUFGT . Future genetic and molecular experimentation will elucidate whether PpbHLH135 TF, in combination with other TFs, can play a stronger regulating role in fruit pigmentation, or in other metabolic pathways.