Abstract: order to analyze the lupeol biosynthetic pathway in Syneilesis aconitifolia and explore its key enzyme genes, DNBSEQ sequencing platform was used to sequence the transcriptome of leaves, stems, roots and rhizomes of Syneilesis aconitifolia, and 191 541 Unigenes were obtained after de novo assembly. KEGG metabolic pathway analysis showed that 961 Unigenes were involved in the lupeol biosynthetic pathway in Syneilesis aconitifolia, of which 395 Unigenes encoded 17 key enzymes of the biosynthetic pathway. Comparing root with other tissues, 24 shared differentially expressed genes were involved in the lupeol biosynthetic pathway, encoding farnesyl diphosphate synthase (FPPS), squalene synthase (SS), squalene epoxidase (SE) and other key enzymes. Structural analysis of the key enzymes FPPS, SS and SE, showed that they all had conserved catalytic domains and substrate binding domains. This work enriched the functional gene database of Syneilesis aconitifolia, and laid a foundation for further study of the lupeol biosynthetic pathway and the function and regulation mechanism of key enzyme genes.

Key words: Syneilesis aconitifolia, transcriptome sequencing, lupeol, farnesyl diphosphate synthase, squalene synthase, squalene epoxidase