Isolation and Characterization of DBR۲ Gene Promoter from Iranian Artemisia annua

Artemisia annua is still the only commercial source of Artemisinin. To date, a number of biochemical and molecular studies about Artemisinin’s biosynthetic pathway have been carried out. In metabolic engineering approach, isolation and characterization of promoters leads to an understanding of which cis-acting elements are responsible for the regulation of gene expression. DBR۲ is a key enzyme in Artemisinin biosynthetic pathway. In order to allow chromosome walking beyond the ۵'-flanking region of DBR۲, two specific primers were used in combination with ۶ arbitrary primers in TAIL-PCR method. A ۶۹۶bp upstream of DBR۲ start codon was isolated and cloned. The subsequent sequence analysis using bioinformatics softwares revealed that there were several cis-acting elements such as TATA-box, CAAT-box, and MeJA-responsive element, and several W-box and light-responsive elements inside the DBR۲ promoter. These results can be helpful in understanding of artemisinin biosynthesis regulation and will facilitate metabolic engineering of the compound.

Keywords:

Artemisinin , Cis-acting element , Chromosome walking , Metabolic engineering