The genome analysis of Tripterygium wilfordii reveals TwCYP712K1 and TwCYP712K2 responsible for oxidation of friedelin in celastrol biosynthesis pathway

Tripterygium wilfordii is a vine used in Traditional Chinese Medicine (TCM) from the family Celastraceae. The active ingredient celastrol is a friedelane-type pentacyclic triterpenoid, with a putative role as an anti-tumor, immunosuppression, and obesity agent. Here we reported a reference genome assembly of T. wilfordii with high-quality annotation by using a hybrid sequencing strategy, which obtained a 340.12 Mb total genome size, a contig N50 reaching 3.09 Mb, 31593 structure genes, and the repeat percentage was 44.31%. Comparative evolutional analyses showed that T. wilfordii diverged from species of Malpighiales about 102.4 million years ago. In addition, we successfully anchored 91.02% sequences into 23 pseudochromosomes using Hi-C technology and the super-scaffold N50 reached 13.03 Mb. Based on integration of genome, transcriptome and metabolite analyses, as well as in vivo and in vitro enzyme assays of the two CYP450 genes, TwCYP712K1 and TwCYP712K2 the second biosynthesis step of celastrol was investigated and elucidated. Syntenic analysis revealed that TwCYP712K1 and TwCYP712K2 derived from a common ancestor. These results have provided insights into further investigating pathways for celastrol and valuable information to aid the conservation of resources and helped us reveal the evolution of Celastrales.