CaMYC, A Novel Transcription Factor, Regulates Anthocyanin Biosynthesis in Color-leaved Pepper (Capsicum annuum L.)

Anthocyanins are secondary metabolites derived from the general phenylpropanoid pathway and are widespread throughout the plant kingdom. Anthocyanin accumulation is regulated by transcription factors. However, little is known about the role of CaMYC from the bHLH family in pepper anthocyanin synthesis. In this study, a purple-leaved pepper (Capsicum annuum L.) was selected and subjected to light and cold stress at the seedling stage. The result showed that anthocyanin content in purple leaves was higher than in green leaves, which was related to anthocyanins synthesis. CaMYC is an important factor and may be responsible for anthocyanin synthesis. Light and cold stress can result in strong anthocyanin accumulation. CaMYC plays a key role in increasing structural gene expression, which regulates anthocyanin synthesis by the combination of CaMYB and CaWD40. Further analysis showed that CaMYC-silencing resulted in low expression of structural genes in the anthocyanin synthesis pathway, suggesting that CaMYC has a positive role in pepper anthocyanin metabolism. Our study will provide an insight for anthocyanin synthesis in pepper.