22个白木香倍半萜合酶(AsTPS)基因的健康与伤害诱导表达特性研究

Study on Background and Wound Induced Expression of 22 Sesquiterpene Synthase Genes of Aquilaria sinensis

目的:明确22个As TPS基因在健康和伤害白木香中的表达情况,筛选出催化沉香倍半萜合成的关键酶基因。方法:全断法伤害处理白木香,常规PCR和荧光定量PCR(qRT-PCR)检测基因表达情况。结果:22个As-TPS基因中,1个基因在健康和伤害白木香中均不表达;3个基因在健康白木香中不表达,但明显响应于外界伤害;18个基因在健康白木香中均有一定量表达,而伤害处理后,其中7个基因相对表达量达数千倍,11个基因虽也被诱导表达,但相对表达量仅达几十倍至几百倍。结论:21个As-TPS基因为伤害诱导型基因,其中3个是沉香倍半萜合成的关键催化酶基因;在伤害诱导后含量急剧表达上升的7个As-TPS是白木香伤害诱导结香早期倍半萜合成的重要催化酶。

Objective：TO confirm the expression mode of 22 sesquiterpene synthase in healthy and wound Aquilaria sinensis，and selected the key enzymes for catalyzing agarwood sesquiterpene synthesis.Methods：The branch of A. sinensis were treated by all broken method，the gene expression was tested by PCR and qRT-PCR.Results：1 gene expressed neither in the healthy nor wound trees.3 genes were silenced in healthey trees，but were obviously response to the external stimuli.Other 18 genes expressed in healthy samples among which 7genes expression increased rapidly and the relative expression level was thousands of times and 11 genes also were induced to express but the relative expression level was dozens to hundreds times in short time after trees were wounded.Conclusion：21 sesquiterpene synthase genes are induced-genes and catalyze synthesis of agarwood sesquiterpenes.Among of them，3 enzymes are the pivotal enzymes for catalyzing sesquiterpene synthesis and 7 enzymes are the key enzymes for sesquiterpene synthesis in early period of agarwood formation in wound A.sinensis.