Pan-genome analysis and functional characterisation of the terpene synthase (TPS) gene family in five varieties of yellowhorn (Xanthoceras sorbifolium)

The terpene synthase (TPS) gene family is integral to the biosynthesis of terpenoids, which are vital for plant defence, development, and interaction with the environment. Yellowhorn (Xanthoceras sorbifolium) has gained attention for its bioactive compounds, particularly terpenoids, which have applications in pharmaceuticals, biofuels, and cosmetics. This study provides a comprehensive pan-genome-wide analysis of the TPS gene family across five yellowhorn varieties (Xg11, Xzs4, Xwf8, Xjg, and Xzg2). A total of 257 TPS genes were identified and characterised, showing diversity in their evolutionary patterns. Phylogenetic analysis revealed distinct clades corresponding to functional classes of TPS genes. Conserved domains and motifs of these genes were analysed to highlight their structural characteristics. Furthermore, expression profiling under abiotic stresses, including cold and drought, was conducted, revealing the roles of specific TPS genes in stress tolerance. Tissue-specific expression analysis demonstrated the involvement of TPS genes in key physiological processes across different plant organs. This research advances our understanding of the TPS gene family in yellowhorn, with implications for improving crop resilience and biotechnological applications.