Differential analysis of the main medicinal components contents and the transcriptome in the female and male Ginkgo biloba leaves

To explore the differences in the content of terpene lactones and flavonol glycosides and their main components and gene transcription between female and male Ginkgo biloba leaves.

The liquid chromatography-mass spectrometry (LC-MS) and high performance liquid chromatography-ultraviolet (HPLC-UV) were applied to determine the content of terpene lactones and flavonol glycosides in 10 female and 10 male G. biloba leaves, respectively. The transcriptome sequencing was performed on 3 female and 3 male G. biloba leaves with representative contents of terpene lactones and flavonol glycosides.

The contents of terpene lactones and flavonol glycosides and their main components in female leaves were relatively higher than those in male leaves, but only quercetin content was significantly different. Through transcriptome sequencing, a total of 288 023 696 Raw reads, and 257 059 884 Clean reads are obtained. Q30 ≥ 91.24%, GC content ≥ 45.95%, and uniquely mapped reads rate ≥ 85.04%. A total of 676 differentially expressed genes (DEGs) were identified (P < 0.05 and |log₂FC| ≥ 1), and compared with female plants, 340 DEGs were up-regulated and 336 DEGs were down-regulated in male plants. GO enrichment analysis showed that 372 DEGs were significantly enriched into 163 GO terms, including oxidation-reduction process, carbohydrate metabolic process, detoxification and catalytic activity. KEGG enrichment analysis showed that the DEGs were mainly related to metabolic pathways such as plant hormone signal transduction, plant-pathogen interaction, other glycan degradation and steroid biosynthesis. The expression of related structural genes in the synthesis pathway of ginkgo terpene lactones and flavonol glycosides was higher in female plants than in male plants, which was consistent with the trend of terpene lactones and flavonol glycosides content in female plants being higher than that in male plants.

The contents of terpene lactones and flavonol glycosides and the expression of genes related to biosynthesis pathways in G. biloba leaves of different sexes are different, female plants are slightly higher than that of male plants. This study provides a theoretical basis for the selection and breeding of excellent germplasm of G. biloba for excellent leaves based on different sexes.