Comparative Transcriptomic Analysis Identified the Genes Involved in Anthocyanin Accumulation in Perilla frutescens

The MYB-bHLH-WDR (MBW) complex formed by MYB transcriptional factors (TFs), bHLH TFs and WDR proteins participates in the regulation of anthocyanin biosynthesis in plants. In Perilla frutescens, the majority of the structure genes and TFs involved in anthocyanin accumulation have been isolated. However, whether the MYB TF PfMYBC05 can interact with bHLH TF PfF3G1 and regulates anthocyanin biosynthesis is unclear. Here, using two perilla cultivars with different anthocyanin levels, we first investigated the differentially expressed genes associated with anthocyanin biosynthesis, and isolated PfMYBC05 and PfF3G1 genes. Subsequently, the yeast two-hybrid (Y2H), and the coimmunoprecipitation (CoIP) confirmed the protein interaction between PfMYBC05 and PfF3G1. Moreover, transgenic Arabidopsis and tobacco plants overexpressing PfMYBC05 or PfF3G1 could not accumulate higher anthocyanin in plants; meanwhile, transient overexpression of PfMYBC05, PfF3G1, or their combination in tobacco leaves also could not induce the accumulation of anthocyanins. These results combined with the previous report demonstrated that PfF3G1 interacts with a WDR protein PfWD and is located in the nucleus; and PfWD overexpressing, but not PfF3G1 overexpressing transgenic plants, accumulates higher anthocyanins, indicating that the formation of MBW complex is required for the function of MYB TFs and bHLH TFs in perilla.