Anthocyanin Accumulation and Transcriptional Regulation of Anthocyanin Biosynthesis in Purple Pepper

Pepper (Capsicum annuum) is among
the important horticultural crops with economic value, and more and
more colorful varieties have been marketed. The purple pepper is becoming
increasingly popular on the consumer market because of its anthocyanin
richness. Here, two cyanidin-based anthocyanins were separated and
identified from peels of purple cultivars by HPLC–LC–MS.
To study the molecular mechanism of anthocyanin accumulation, the
differential expression of genes related to anthocyanin biosynthesis
was examined by qRT-PCR and RNA-Seq in peel from green and purple
cultivars. These results show that CaANT1, CaANT2, CaAN1, and CaTTG1 are involved in anthocyanin accumulation of pepper. Further investigation
suggested that CaANT1, CaANT2, CaAN1, and CaTTG1 can activate anthocyanin
accumulation via forming a new MMBW transcription complex.