Characterization of Guaiene Synthases from <i>Stellera chamaejasme</i> L. Flowers and Their Application in De novo Production of (−)-Rotundone in Yeast

Abstract

Four terpene synthases for the biosynthesis of volatile terpenoids were identified from the transcriptome of <i>Stellera chamaejasme</i> L. flowers, including SchTPS1, SchTPS2, SchTPS3, and SchTPS4. Their functions were characterized by synthetic biology approaches in <i>Escherichia coli</i> and in vitro enzymatic assays. SchTPS1, SchTPS2, and SchTPS3 are guaiene synthases, while SchTPS4 is an (<i>E</i>,<i>E</i>)-geranyl linalool synthase. Next, SchTPS1 and α-guaiene 2-oxidase VvSTO2 were co-expressed in <i>Saccharomyces cerevisiae</i> to reconstruct the biosynthetic pathway of (-)-rotundone, which is a unique aroma compound in fruits, vegetables, and wines. This is the first report for the construction of a (-)-rotundone-producing microbial platform.