Cloning and expression of a sesquiterpene synthase gene from Taiwania cryptomerioides

Abstract

Abstract Taiwania (Taiwania cryptomerioides Hayata) is a conifer species native to Taiwan, which is known for several bioactive secondary metabolites extracted from it. In this study, a sesquiterpene synthase (TPS) gene isolated from Taiwania was in focus. First, a pair of degenerate primers was designed for reverse transcription-polymerase chain reaction based on the total RNA extracted from the leaves of a mature tree. A DNA fragment with the conserved region of TPS gene was obtained. After 5′- and 3′-end amplification, the full-length gene was obtained, which contains an open reading frame of 1791 bp and encodes a predicted molecular mass of 70.2-kDa protein. The gene was highly expressed in young leaves, female flowers, and cones. The expression in leaves was enhanced by salicylic acid. To identify the function of TPS, the recombinant protein from Escherichia coli (Migula) Castellani & Chalmers was incubated with farnesyl diphosphate. Gas chromatography/mass spectrometry analysis and retention time as well as mass spectrum matching with authentic standards revealed that the major product of TPS is sesquiterpene α-gurjunene. The gene was, therefore, designated as Tc-Gur.