Insights into the Coloring Mechanism of Dark-Red and Yellow Fruits in Sweet Cherry through Transcriptome and Metabolome Analysis

Abstract

The color of sweet cherry fruits is an important indicator of their appearance and quality. That influences the purchasing desires of consumers. We performed a multi-omics analysis of two different colors of sweet cherry fruits (yellow “Bing Hu” and dark-red “Hong Deng” fruits). A total of 12 flavonoid differential metabolites, including hesperetin, rutin, and quercetin, and 18 differential structural genes, including PAL, CHS, FLS, and DFR, were identified. Possible key regulatory genes for the second stage of color change (from green to yellow) of “Bing Hu” sweet cherry fruits were identified as SBP, bHLH, WD40, and bZIP, which regulated the accumulation of flavonoids, including hesperetin and naringenin. In addition, the possible important roles of transcription factors, which were mainly MYB, bHLH, AP2, and WRKY, in the third stage of color change in both fruits were also identified. This study offers new insights into the changes in fruit coloration between yellow and dark-red sweet cherries, while the analysis of key metabolites and differential genes lays a molecular foundation for future color improvement and breeding programs.