Research Of Effect On Sesquiterpenoids In Aquilaria Sinensis In Vitro-culture Adventitious Root Induced By Methyl Jasmonate

Agarwood is the resinous portion of the trunk and branches of Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae), which has been used pharmaceutically as a traditional Chinese medicine treatments. A. sinensis is the unique plant sources of agarwood in China, however, eaglewood resin can be produced only when A. sinensis plant under the effect of natural or human factors. All agarwood-producing plants take a considerably long time to grow and the resinous portion is formed inside of the wood. These circumstances make the worldwide trading of agarwood is facing a serious shortage of resources. As a result, various and artificial ways to raise agarwood formation and exploration of its production mechanism will be worthy of further research as well as protect this precious wild plant resource.1 objectiveThe induction of adventitious root was obtained from in vitro-culture A. sinensis plantlets. Adventitious root was treated by MeJA to study the production of sesquiterpenoids, one of the principal compounds in the oleoresin of agarwood, and related gene expression. The chemical component analytics and transcriptome sequencing of aseptic seedling processed before and after treated by MeJA, was detected. The results comparing was performed before and after the procedure and the difference of sesquialter terpenoid was filtered. Therefore, the candidate gene of related differential expression was obtained. The compositional variation date of sesquialter terpenoid and the former was combined and analyzed synthetically. There was variation in the level of transcription of A. sinensis by MeJA inducement that was explained. What’s more, the biosynthesis of downstream sesquialter terpenoid was influenced. This research is aimed at the mechanism of producing the aquilaria agallocha roxb by A. sinensis. There were two that were the anabolic pathway of sesquialter terpenoid and the synthesis of secondary metabolism by MeJA signal transduction. It provides the references for the mechanism of A. sinensis to contribute edgeworthia chrysantha.2 Methods2.1 Adventitious root inductionAdventitious root was cultured by A. sinensis tissue as materials. The exogenous hormone, medium component, and induction time, on the effort of adventitious root induction, was mainly researched.2.2 The chemical component analytics of aseptic seedling processed by MeJAThe adventitious root treated by MeJA was the material and the chemical component was measured by GC/MS. Differences of compound were identified after compared the composition before and after processing.2.3 The analysis of aseptic seedling, processed by MeJA, under transcriptomeTreat adventitious root of A. sinensis with MeJA. The transcriptome sequencing of adventitious root was analyzed by RNA-Seq technology before and after the process. The expression tendency was analyzed after different expression genes were filtered. The transcription factor of interrelated different expression genes and metabolism of terpenoid was analyzed principally.3 Results3.1 Research on the inducement of adventitious rootThe exogenous hormone, medium component, induction time and other factor levels on the effort of adventitious root induction, was researched. The most exceptional induction condition:aseptic seedling of A. sinensis was, added into NAA 1.0mg/L that was all 1/2MS medium, put on culture medium within 7d. It was transferred to the full 1/2 ms hormone-free medium to take root by inducement. It can achieve the highest rooting rate that is more than 85% in average and the average root number was 12.8.3.2 Research on the chemical composition of adventitious root of treated with MeJAUnder the detection of HS-GC/MS and SPME-GC/MS, precursors of sesquialter terpenoid of fragrant compounds were produced after it was processed by 100μM MeJA with 72h that was α-guaiene,δ-guaiene and α-humulene.3.3 Research on the transcriptome of adventitious root by MeJAThe adventitious root of A. sinensis was processed by MeJA. The related genes expression of Terpenoid backbone biosynthesis and sesquiterpene synthase have changed significantly. In addiction, The JA signal transduction regulator of adventitious roots also presented a differential expression.4 ConclusionThe optimal condition of the tissue culture of aseptic seedling of A. sinensis induced adventitious root in this research was determined successfully. The sesquiterpene compounds of agarwood were produced after treated by MeJA. The transcriptome sequencing of adventitious root before and after the process by MeJA was analyzed. There was different expression in the regulatory gene of sesquiterpene. The changes in the genetic level in process of sesquiterpene synthase was studied and provided essential data for the further research of the mechanisms of sesquiterpene of agarwood.