Mining of key O-methyltransferase genes and UDP-glucosyltransferase genes for ginkgotoxin and ginkgotoxin-5'-glucoside synthesis based on transcriptome sequencing analysis

Ginkgo biloba seeds contain toxic ginkgotoxin (MPN) and its glucoside (MPNG), but their biosynthetic genes are poorly understood. To identify these genes, we performed multi-stage transcriptome sequencing, DEG screening, WGCNA, and enrichment analysis during seed development. MPNG accumulation predominated in mature seeds, correlating with gene expression dynamics. We identified 25 O-methyltransferase (OMT) and 40 UDP-glucosyltransferase (UGT) candidates. Among these, seven OMTs (e.g., Gb_35680, Gb_01186) and eight UGTs (e.g., Gb_34745, Gb_37494) were significantly upregulated during maturation, confirmed by qRT-PCR. WGCNA revealed four gene modules strongly correlated with MPN/MPNG accumulation, enriched in methylation, glycosylation, and secondary metabolite biosynthesis. This study integrates dynamic transcriptome and co-expression analyses to pinpoint key regulatory nodes in ginkgo toxin biosynthesis, providing novel genetic targets for developing low-toxicity cultivars through molecular breeding.