Identifi cation of sesquiterpene synthase genes in the genome of Aquilaria sinensis and characterization of anα-humulene synthase  

作　　者：Jiadong Ran Yuan Li Xin Wen Xin Geng Xupeng Si Liping Zhang Yimian Ma Zheng Zhang 

机构地区：[1]Institute of Medicinal Plant Development,Chinese Academy of Medical Sciences and Peking Union Medical College,No.151,Malianwa North Road,Haidian,Beijing 100193,People’s Republic of China [2]Institute of Plant Protection,Chinese Academy of Agricultural Sciences,No.12,Zhongguancun South Street,Haidian,Beijing 100193,People’s Republic of China [3]Lanzhou University of Technology,No.287,Langongping Road,Qilihe District,Lanzhou 730050,Gansu,People’s Republic of China

出　　处：《Journal of Forestry Research》2023年第4期1117-1131,共15页林业研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(81773844).

摘　　要：Sesquiterpenes are the major pharmacodynamic components of agarwood,a precious traditional Chinese medicine obtained from the resinous portions of Aquilaria sinensis trees that form in response to environmental stressors.To characterize the sesquiterpene synthases responsible for sesquiterpene production in A.sinensis,a bioinformatics analysis of the genome of A.sinensis identifi ed six new terpene synthase genes,and 16 sesquiterpene synthase genes were identifi ed as type TPS-a in a phylogenetic analysis.The expression patterns for eight of the sesquiterpene synthase genes after treatment with various hormones or hydrogen peroxide were analyzed by real-time quantitative PCR.The results suggest that 100μM methyl jasmonate,ethephon,(±)-abscisic acid or hydrogen peroxide could be eff ective short-term eff ectors to increase the expression of sesquiterpene synthase genes,while 1 mM methyl salicylate may have long-term eff ects on increasing the expression of specifi c sesquiterpene synthase genes(e.g.,As-SesTPS,AsVS,AsTPS12 and AsTPS29).The expression changes in these genes under various conditions refl ected their specifi c roles during abiotic or biotic stresses.Heterologous expression of a novel A.sinensis sesquiterpene synthase gene,AsTPS2,in Escherichia coli produced a major humulene product,so AsTPS2 is renamed AsHS1.AsHS1 is diff erent from ASS1,AsSesTPS,and AsVS,for mainly producingα-humulene.Based on the predicted space conformation of the AsHS1 model,the small ligand molecule may bind to the free amino acid by hydrogen bonding for the catalytic function of the enzyme,while the substrate farnesyl diphosphate(FPP)probably binds to the free amino acid on one side of the RxR motif.Arg450,Asp453,Asp454,Thr457,and Glu461 from the NSE/DTE motif and D307 and D311 from the DDxxD motif were found to form a polar interaction with two Mg^(2+)clusters by docking.The Mg^(2+)-bound DDxxD and NSE/DTE motifs and the free RXR motif are jointly directed into the catalytic pocket of AsHS1.Comparison of the tertiary structu

关 键 词：AGARWOOD Aquilaria sinensis Sesquiterpene synthase Humulene 

分 类 号：S792.99[农业科学—林木遗传育种]