PavbHLH102 functions as a positive regulator of anthocyanin biosynthesis in sweet cherry fruit by targeting multiple key genes

Abstract

Anthocyanins play a crucial role in shaping the visual appeal and nutritional quality of fruits. Previous research on anthocyanin biosynthesis in sweet cherry (Prunus avium L.) has primarily relied on single-omics approaches or focused on a limited range of metabolites, leaving the regulatory mechanisms and dynamic metabolism of anthocyanins during ripening inadequately characterized. This study integrated anthocyanin-targeted metabolomics and transcriptomics to identify key anthocyanins in sweet cherry and construct a transcriptional regulatory network for anthocyanin biosynthesis. A novel bHLH transcription factor, Prunus avium bHLH transcription factor 102 (PavbHLH102), was identified, and its role in regulating cyanidin levels was validated through overexpression and silencing experiments. Both in vitro and in vivo assays demonstrated that PavbHLH102 activates key anthocyanin biosynthetic genes, including PavF3H, PavDFR, and PavUFGT, thereby enhancing fruit coloration. Notably, PavF3′H upregulation significantly increased cyanidin accumulation. This study provides new insights into anthocyanin regulation in sweet cherry and offers valuable resources for improving fruit quality.