The regulatory network composed of phytohormones, transcription factors and non-coding RNAs is involved in the flavonoids biosynthesis of fruits

Flavonoids, abundant in the fruits, are pivotal to their growth, development, and storage. In addition, they have significant beneficial effects on human health. Consequently, research is increasingly concentrating on the regulatory mechanisms governing flavonoid biosynthesis in fruits. Phytohormones are involved in the regulation of flavonoid biosynthesis. The abscisic acid, ethylene, jasmonic acid, cytokinins, and brassinosteroids promote flavonoid biosynthesis, while auxin negatively regulates flavonoid biosynthesis. Subsequently, transcription factors from the MYB, bHLH, WRKY, NAC, and bZIP families are pivotal in regulating flavonoid biosynthesis. In addition, non-coding RNAs (microRNA and lncRNA) also participate in the regulation of flavonoids biosynthesis. MicroRNAs are generally believed to negatively regulate flavonoid metabolism in fruits, while lncRNAs have the opposite effect. Furthermore, the interactions between plant hormones, transcription factors, and non-coding RNAs in fruit flavonoid biosynthesis were analyzed. Ultimately, a foundational regulatory network for fruit flavonoid biosynthesis was hereby established.