Characterization of a monoterpene synthase from Paeonia lactiflora producing α-pinene as its single product

To identify a terpene synthase that catalyzes the conversion of geranyl pyrophosphate (GPP) to α-pinene and is involved in the biosynthesis of paeoniflorin.Two new terpene synthase genes were isolated from the transcriptome data of Peaonia lactiflora. Phylogenetic analysis and sequence characterization revealed that one gene, named PlPIN, encoded a monoterpene synthase that might be involved in the biosynthesis of paeoniflorin. In vitro enzyme assay showed that, in contrast to most monoterpene synthases, PlPIN encoded an α-pinene synthase which converted GPP into α-pinene as a single product.This newly identified α-pinene synthase could be used for improving paeoniflorin accumulation by metabolic engineering or for producing α-pinene via synthetic biology.