Expression profiling of sesquiterpenes encoding genes in different Artemisia species

Medicinal plants have had important roles in traditional medicine since ancient times. Secondary metabolites produced in plants have many applications in medicine, pharmacology and industry. The genus Artemisia is very important due to the production of sesquiterpene Artemisinin and many other compounds. Various sesquiterpenes production is catalyzed from central intermediate farnesyl diphosphate, by sesquiterpene enzymes. In this study seven Artemisia species local to Iran were planted. Flower tissues were sampled in flowering phase, in three biological replications. The relative expression of one prenyle transferase (Farnesyl diphophate synthase) and two sesquiterpene synthases (beta-caryophyllene synthase and beta-farnesene synthase) was studied by Real-time PCR. Artemisia annua was considered as the reference species. Besides, gas chromatography-mass spectrometry (GC-MS) was applied to investigate the end products produced by each terpene synthases. The results showed that the expression of terpene synthase genes is consistent with their products obtained in GC-MS. The maximum level of expression for terpene synthase-encoding genes was achieved for A. scoparia. Moreover, the results from GC-MS indicated the highest amount of production of beta-caryophyllene and beta-farnesene in this species. It can be concluded that the biosynthesis pathways of sesquiterpenes may be regulated by its specific sesquiterpene synthase.