Transcriptome profiles reveal new regulatory factors of anthocyanin accumulation in a novel purple-colored cherry tomato cultivar Jinling Moyu

Abstract

Anthocyanins are important secondary metabolites with high nutraceutical value. They represent the major red, purple, violet and blue pigments in higher plants but are usually not present in the fruits of domesticated tomatoes. Recently, several genes that regulate anthocyanin accumulation have been identified in wild tomatoes or mutation lines; however, whether there are other new factors involved in the regulation of anthocyanin biosynthesis is still unknown. “Jinling Moyu” (MY) is a novel purple cherry tomato that accumulates considerable anthocyanins in its ripe fruit. A transcriptome comparison analysis of MY fruits with pink and green fruit revealed that several structural genes assigned to the anthocyanin biosynthetic pathway were highly expressed in MY tomato, but all six known regulatory genes of anthocyanin accumulation in tomato fruits were rarely expressed among the samples in this study. However, four other R2R3–MYB and five other bHLH transcription factors were highly correlated with the differentially expressed structural genes in the anthocyanin pathway, indicating that these transcription factors might regulate anthocyanin biosynthesis in MY tomato. Our study will aid in understanding the complex mechanism regulating anthocyanin pigmentation in tomato fruits .