Genome-Wide Characterization of Phosphate Transporters Reveals Differential Regulation of Growth and Medicinal Metabolite Accumulation Under Phosphorus Deficiency in Ginkgo biloba

Ginkgo biloba L. (G. biloba) is an important medicinal tree species rich in bioactive flavonoids and terpene lactones. Phosphate transporters (PHTs) play essential roles in phosphate uptake, transport, and homeostasis; however, their characteristics and functions in G. biloba remain unclear. In this study, 21 non-redundant GbPHT genes were identified from the G. biloba genome and classified into five subfamilies, including PHT1, PHT2, PHT3, PHT4, and PHO, containing five, one, four, six, and five members, respectively. Promoter analysis revealed abundant cis-elements associated with light, hormone, and stress responses, suggesting complex regulatory patterns of GbPHT genes. To investigate the effects of phosphorus availability on growth and medicinal metabolites, G. biloba seedlings were subjected to normal phosphorus and phosphorus deficiency treatments. Phosphorus deficiency significantly inhibited root development, biomass accumulation, and photosynthetic performance. However, phosphorus deficiency markedly enhanced flavonoid accumulation in leaves and terpene lactone accumulation in roots, accompanied by increased expression of key structural genes involved in their biosynthetic pathways. Furthermore, transient overexpression of GbPHT1-1 in G. biloba leaves promoted flavonoid accumulation and upregulated flavonoid biosynthetic genes. Collectively, this study provides the first comprehensive characterization of the G. biloba PHT family and reveals that phosphorus deficiency coordinates growth restriction with enhanced medicinal secondary metabolite accumulation. These findings provide new insights into phosphorus adaptation and nutrient regulation of medicinal quality in G. biloba.