Identification and analysis of CYP450 family members in Ginkgo biloba reveals the candidate genes for terpene trilactone biosynthesis

Cytochrome P450 (CYP450), a superfamily of mono-oxygenases, participates in various physiological processes of plants. Terpene trilactones (TTLs) are unique bioactive components of Ginkgo biloba L. and have been applied in many fields including industry, medicine, and health. In this study, a total of 187 CYP450s were identified from the ginkgo genome and were divided into six clans, of which the CYP71 clan (10 subfamilies) included all A-type CYP450s, with a total of 83. The other five clans (18 subfamilies) contained 104 non-A-type CYP450s. The physicochemical properties, functional domains, conserved motifs, phylogenic relationships, gene structures, and chromosome locations of the GbCYP450s were comprehensively analyzed. The GbCYP450s had a conserved domain of FXXGXRXCXG, and each clan or subfamily had its own characteristics, indicating potential differences in their functions. A total of 114 identified differentially expressed CYP450s were identified from transcriptome sequencing. Combined with the content of TTLs, 22 CYP450s that might be involved in TTL biosynthesis were screened via correlation and weighted gene correlation network analysis. By constructing a phylogenetic tree with CYP450s involved in terpenoid biosynthesis in other plants, and 22 CYP450s had a close evolutionary relationship, which further verified our hypothesis. Additionally, the MeJA treatment could increase the content of TTLs in G. biloba, and 12 of the 22 candidate GbCYP450s contained cis-acting regulatory elements involved in methyl jasmonate (MeJA)-responsiveness, among which eight CYP450s genes were strongly induced by MeJA to up-regulate expression. This study provides a foundation for clarifying the function of CYP450s in TTL biosynthesis and the use of genetic engineering technology to increase the production of TTLs.