A cycloartenol synthase from the steroidal saponin biosynthesis pathway of .

Steroidal saponins named polyphyllin are the major active components of . Cycloartenol synthase (CAS) is a key enzyme that catalyzes the formation of the sterol scaffold. In this study, we cloned a putative gene from . Heterologous expression in yeast indicated that PpCAS can convert 2,3-oxidosqualene into cycloartenol. qRT-PCR analysis showed that the expression of was highest in leaves and lowest in roots. To our best knowledge, this is the first report of the functional characterization of cycloartenol synthase from , which lays the foundation for further analysis of the biosynthesis pathway of polyphyllins.[Formula: see text].