Functional characterization of five triterpene synthases through De-novo assembly and transcriptome analysis of Euphorbia grantii and Euphorbia tirucalli

Euphorbia grantii and Euphorbia tirucalli known to synthesize diverse triterpenes including euphol and tirucallol. These two triterpenes known to possess potent anti-cancer, anti-bacterial, and anti-fungal properties along with various other biological activities. In this study, De-novo assembly and comparative transcriptome analysis of leaf and stem tissues of E. tirucalli and E. grantii were carried out to identify thirteen triterpene synthases from 1,40,227 in correlation with the metabolic profiling. Comparative transcriptome analysis indicated that EutTTS4 and EutTTS5 genes which encodes for euphol/tirucallol and tirucallol synthase were highly expressed in leaf and stem tissue. The genes which encodes -amyrin synthase (EutTTS1) and lupeol synthase (EutTTS2) were characterized by overexpressing them in YPH499 yeast strain. We have developed using hem1 and erg7 knock yeast strain of lanosterol deficient yeast (TMBL17) and used for over expression of friedelin synthase (EutTTS3), and two novel triterpenes synthases such as euphol/tirucallol synthase (EutTTS4) and tirucallol synthase (EutTTS5). These results are very useful in large scale production of triterpenes by genomic integration of respective triterpene synthases in TMBL yeast strain developed in this study. Significance StatementWe have functionally characterized triterpene synthases from E. tirucalli and E. grantii and developed a hem1 and erg7 knock out of lanosterol deficient yeast (TMBL17) for the large-scale production of triterpene and triterpene related products.