Transcriptome and Metabolome Analyses Reveal Differences in the Accumulation of Key Metabolites in Various Tissues of Lonicera macranthoides

TL;DR

This study explores how different parts of the Lonicera macranthoides plant accumulate various metabolites, revealing important patterns in metabolite biosynthesis.

Contribution

The study identifies tissue-specific gene and metabolite patterns in Lonicera macranthoides, highlighting key roles of flowers and fruits in saponin and flavonoid biosynthesis.

Findings

Transcriptome analysis identified 7321 differentially expressed genes across flowers, fruits, and leaves.

Flowers and fruits are key tissues for biosynthesis of hederagenin-based saponins and flavonoids.

Metabolomics revealed 4961 metabolites, with many involved in secondary metabolite pathways.

Abstract

Background: Lonicera macranthoides is a valuable traditional Chinese medicinal plant, enriched in secondary metabolites that exert significant therapeutic effects against specific diseases. However, the differences in the accumulation of key metabolites across various tissues of this plant remain poorly understood. Methods: This study analyzed the transcriptomes and metabolomes of three key tissues (flowers, leaves, and fruits) in Lonicera macranthoides. Results: Transcriptome sequencing identified 7321 differentially expressed genes (DEGs) common to flowers, fruits, and leaves. Among the top 20 KEGG pathways enriched by these DEGs, metabolic pathways and biosynthesis of secondary metabolites were prominently represented. At least 70 CYP genes and 12 UGT genes were differentially expressed, with a greater proportion of these genes being up-regulated in flowers or fruits. DEGs involved in flavonoid biosynthesis include CHI, CHS, and FLS, with most of these genes being up-regulated in fruits. Metabolomics analysis identified 4961 metabolites across the three tissues. KEGG pathway classification of these DAMs showed that a large proportion are involved in metabolic pathways and secondary metabolite biosynthesis. Conjoint analysis of the transcriptomic and metabolomic data revealed that the most significantly enriched were metabolic pathways and biosynthesis of secondary metabolites. Integrative analysis of DEGs and DAMs indicated that flowers and fruits are likely key tissues for the biosynthesis of hederagenin-based saponins, while fruits may serve as critical organs for flavonoid biosynthesis. Conclusions: This study provides novel insights into the tissue-specific differential accumulation of metabolites in Lonicera macranthoides, and lays a crucial foundation for further investigating the underlying molecular regulatory mechanisms.

Figures