Abstract

Steroidal saponins named polyphyllin are the major active components of Paris polyphylla. Cycloartenol synthase (CAS) is a key enzyme that catalyzes the formation of the sterol scaffold. In this study, we cloned a putative CAS gene from Paris polyphylla. Heterologous expression in yeast indicated that PpCAS can convert 2,3-oxidosqualene into cycloartenol. qRT-PCR analysis showed that the expression of PpCAS 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 Paris polyphylla, which lays the foundation for further analysis of the biosynthesis pathway of polyphyllins.

摘要

甾体皂苷名为多元茶碱是巴黎多元茶的主要活性成分。Cycloartenol合酶（CAS）是催化固醇支架形成的关键酶。在这项研究中，我们从巴黎七叶树中克隆了一个推定的CAS基因。酵母中的异源表达表明PpCAS可以将2,3-氧化角鲨烯转化为环戊烯醇。qRT-PCR分析表明，PpCAS的表达在叶中最高，在根中最低。据我们所知，这是巴黎多花中环戊烯醇合酶功能特性的首次报道，为进一步分析多花素的生物合成途径奠定了基础。