Proteomic and metabolomic analyses reveal stage- and tissue- specific flavonoid accumulation in Ginkgo biloba

Abstract

Ginkgo biloba L. is rich in bioactive ingredients and thus has great economic and medicinal value. Efficient extraction and rational utilization of key flavonoid components from appropriate tissues has important practical significance, and specific strategies should be developed to improve their effective utilization. Herein, quantitative proteomics and metabolomics were deployed for the identification of protein and metabolite profiles in the leaf (collected in June and September, JL and SL, respectively), kernel and exotesta (collected in September, SK and SE, respectively). In total, 8130 known metabolites were identified, and cluster analysis proved the close relationship between the leaf groups. Venn diagrams revealed 67 differentially expressed proteins (DEPs) distributed among the different groups with SL as the control. The regulatory relationship between DEPs and differentially expressed metabolites (DEMs) of the flavonoid biosynthesis pathway in the SE vs. SL and SE vs. JL comparisons was revealed by KGML network analysis. In addition, kaempferol, kaempferol-3-O-glucoside, luteolin, quercetin, ginkgolide C, isoquercitrin, quercetin 3-galactoside, quercitrin, catechin and rutin were differentially expressed between most pairs of groups and related to the flavonoid biosynthesis pathway. Therefore, these compounds can be used as effective references when selecting appropriate plant tissues from which to extract certain bioactive components.