## 4 Conclusions  
In the present study, we employed bioinformatics analysis methods and qRT-PCR experimental validation to identify 11 _OSC_ genes within the genome of _G. pentaphyllum_. We explored their physicochemical properties, conserved domains, gene structures, phylogenetic relationships, and expression levels across four geographically distinct populations. The results indicated that the _GpOSC_ genes exhibited conservation in both structure and evolutionary patterns. Notably, findings from the phylogenetic tree suggested that the genes encoding dammarenediol synthase in _G. pentaphyllum_ have undergone independent convergent evolution alongside the _DS_ genes of the _Panax_ genus. This convergence has led to the acquisition of dammarenediol synthase activity and ultimately resulted in the production of similar types of saponins across these two different plant families. Furthermore, this study identified significant variations in _OSC_ gene family expression among the four populations examined. These differences suggest that _G. pentaphyllum_ may synthesize different types of gynenosides depending on inherent genetic variations or external factors such as environmental conditions and soil composition. In summary, this study enhances our understanding of the systematic evolution of _OSC_ genes in _G. pentaphyllum_, as well as elucidating biosynthetic mechanisms underlying triterpen compounds. This is particularly significant for exploring molecular mechanisms responsible for forming dammarane-type triterpen saponins and addressing geographical differences observed within _G. pentaphyllum_. In future studies, plant genetic engineering technologies could be employed to further investigate correlations between expression differences among _GpOSC_ family members and various saponin types, providing a theoretical foundation to support advancements in saponin metabolism engineering, standardized cultivation practices, variety improvement efforts, and sustainable resource development related to _G. pentaphyllum_. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/life14121599/s1](https://www.mdpi.com/article/10.3390/life14121599/s1)]([https://www.mdpi.com/article/10.3390/life14121599/s1](https://www.mdpi.com/article/10.3390/life14121599/s1)), Figure S1: Chromosomal localization of _OSC_ gene family members of _G. pentaphyllum_; Figure S2: Tertiary structure predictions of the 11 candidate GpOSC proteins; Figure S3: Multiple sequence alignment of the eleven GpOSC proteins; Figure S4: Sequence logos of the top ten significantly enriched motifs; Figure S5: Visualization of promoter cis-element prediction of _OSC_ genes within _G. pentaphyllum_; Figure S6: Heatmap of gene expression values in different populations of _G. pentaphyllum_; Figure S7: The expression levels of four _GpOSC_ genes in four distinct populations investigated using qRT-PCR; Table S1: Informations of 84 _OSC_ genes used in phylogenetic tree analysis; Table S2: Informations of samples used in transcriptome analysis; Table S3: RNA-seq data used for transcriptome analysis; Table S4: The FPKM values of _GpOSC_ genes in 12 samples from different populations of _G. pentaphyllum_; Table S5: Primers of four GpOSC genes in _G. pentaphyllum_. Conceptualization, X.Z. and C.C. ; methodology, X.Z. and H.Y. ; software, X.Z. and H.Y. ; validation, X.Z., X.W. ([PERSON]) and C.C. ; formal analysis, X.Z. and X.W. ([PERSON]); investigation, H.Y. and X.W. ([PERSON]); resources, X.Z. ; data curation, X.Z., H.Y. and X.W. ([PERSON]); writing--original draft preparation, X.Z. ; writing--review and editing, X.W. ([PERSON]) and C.C. ; visualization, X.Z. ; supervision, X.Z. ; project administration, X.Z. and X.W. ([PERSON]); funding acquisition, X.Z., X.W. ([PERSON]) and C.C. All authors have read and agreed to the published version of the manuscript. This study was financially supported by the Project of the Science and Technology Program of Shaanxi Academy of Science (No.