Metabolomics integrated with transcriptomics reveals redirection of the phenylpropanoids metabolic flux in Ginkgo biloba

Ginkgo biloba is monotypic species native to China with great economic and ecological values. Leaves extract of this tree contains about 24% flavonoids, which are widely used for pharmaceutical industry. However, the flavonoids biosynthesis pathway is poorly understood in Ginkgo. In this study, we comprehensively compared the transcriptome and metabolite profiles of Ginkgo high-flavonoids mutant (ZY1) and Anlu1 (control) leaves. A total of 122 significantly changed metabolites (SCMs) and 1683 differentially expressed genes (DEGs), including 445 transcription factors, were identified in ZY1 compared with Anlu1. An integrated analysis of metabolic and transcriptomic data revealed that the abundances of some major flavonoids (especially flavone and flavonol) were most significantly increased, while other phenylpropanoid -derived products and lipids showed the most largely reduced abundances in ZY1 compared to that in Anlu1. qRT-PCR results confirmed the alterations in the expression levels of genes encoding components of pathways involved in phenylpropanoids and lipids. The redirection of metabolic flux may contribute to increased accumulation of flavonoid levels in ZY1 leaves. Our results provide valuable information for metabolic engineering of Ginkgo flavonoids biosynthesis.