Multi-omics explores the potential regulatory role of acetylation modification in flavonoid biosynthesis of Ginkgo biloba

Abstract Flavonoids are crucial medicinal active ingredients in Ginkgo biloba. However, the effect of protein post-translational modifications (PTMs) on flavonoid biosynthesis remains poorly explored. Lysine acetylation, a reversible PTM, plays a crucial role in metabolic regulation. This study aims to investigate the potential role of acetylation in G. biloba flavonoid biosynthesis. Through comprehensive analysis of transcriptomes, metabolomes, proteomes, and acetylated proteins in different tissues, a total of 11,788 lysine acetylation sites were identified on 4324 acetylated proteins, including 89 acetylation sites on 23 proteins. Additionally, 128 types of differentially accumulated flavonoids were identified among tissues, and a dataset of differentially expressed genes related to the flavonoid biosynthesis pathway was constructed. Twelve (CHI, C3H1, ANR, DFR, CCoAOMT1, F3H1, F3H2, CCoAOMT2, C3H2, HCT, F3’5’H, and FG2) acetylated proteins that might be involved in flavonoid biosynthesis were identified. Specifically, we found that the modification levels of CCoAOMT1 and F3’5’H sites correlated with the catalytic production of homoeriodictyol and dihydromyricetin, respectively. Inhibitors of lysine deacetylase (trichostatin A, TSA) impacted total flavonoid content in different tissues and increased flavonoid levels in G. biloba roots. Treatment with TSA revealed that expression levels of GbF3’5’H and GbCCoAOMT1 in stems and leaves aligned with total flavonoid content variations, while in roots, expression levels of GbC3H2 and GbFG2 corresponded to total flavonoid content changes. Collectively, these findings reveal for the first time the important role of acetylation in flavonoid biosynthesis.