Metabolomic and transcriptomic analysis of Ginkgo biloba leaves in diverse habitats
Ginkgo biloba, an economically significant species in China, which is natural distribution across China's diverse provinces and altitudes has led to observed variations in the flavonoid content of its leaves, yet the regulatory mechanisms behind these differences are not well understood. In this study we explore the differential gene expression and metabolic signatures between five-year-old ginkgo leaves grown a in high-altitude region of Nyingchi in Tibet and those grown in a lower-altitude region of Pizhou, Jiangsu. Leaves from the two regions were subjected to metabolomic analysis, and a total of 310 differential metabolites were identified in nine categories, including flavonoids, lipids, organic acids, amino acids, and phenolic acids. The majority of primary metabolites exhibited a general reduction in concentration in ginkgo leaves sourced from high altitudes. In contrast, the contents of secondary metabolites were found to be higher than those from low altitude, with a particularly significant difference observed in flavonoid content. Additionally, transcriptome analysis detected a total of 2745 differentially expressed genes (DEGs) were identified in ginkgo leaves cultivated in two distinct regions through transcriptome analysis. Of these, 1254 were upregulated and 1491 were downregulated. In addition to the enrichment analysis revealed 32 differential genes associated with the phenylpropanoid biosynthesis pathway, genes involved in the regulation of flavonoid synthesis were identified, including 21 MYB, 17 AP2, 7 bHLH, 4 WRKY, and 3 bZIP genes. The transcriptomic and metabolomic analysis revealed that the elevated flavonoid content observed in ginkgo leaves may be the result of higher expression of flavonoid synthesis genes caused by the complex environmental factors at high altitude. The results provided new insights into the molecular mechanism of plants response to high altitude environment, and also offer insights into a scientific basis for improving the quality of ginkgo leaf production.