Identification of sesquiterpene synthase genes in the genome of Aquilaria sinensis and characterization of an α-humulene synthase

Abstract Sesquiterpenes are the major pharmacodynamic components of agarwood, a precious traditional Chinese medicine obtained from resinous portions Aquilaria sinensis trees that form in response to environmental stressors. To characterize sesquiterpene synthases responsible for production A. , bioinformatics analysis genome identified six new terpene synthase genes, and 16 genes were as type TPS-a phylogenetic analysis. The expression patterns eight after treatment with various hormones or hydrogen peroxide analyzed by real-time quantitative PCR. results suggest 100 μM methyl jasmonate, ethephon, ( ±)-abscisic acid could be effective short-term effectors increase while 1 mM salicylate may have long-term effects on increasing specific (e.g., As-SesTPS AsVS AsTPS12 AsTPS29 ). changes these under conditions reflected their roles during abiotic biotic stresses. Heterologous novel gene, AsTPS2 Escherichia coli produced humulene product, so is renamed AsHS1 . different ASS1, AsSesTPS, AsVS, mainly producing α -humulene. Based predicted space conformation model, small ligand molecule bind free amino bonding catalytic function enzyme, substrate farnesyl diphosphate (FPP) probably binds one side RxR motif. Arg450, Asp453, Asp454, Thr457, Glu461 NSE/DTE motif D307 D311 DDxxD found polar interaction two Mg 2+ clusters docking. -bound motifs RXR jointly directed into pocket AsHS1. Comparison tertiary structural models ASS1 showed they differed structures several positions, such surrounding secondary pocket, which lead differences products. results, biosynthetic pathways sesquiterpenes α- proposed. This study provides insights functions enriches knowledge agarwood formation.