Sequence and expression analysis of Anethum graveolens prenyltransferase gene

Background and Aim: Furanocoumarins are produced in many plants including Apiaceae species as a class of secondary metabolites. Light-activated furanocoumarins react with pyrimidine bases especially with thymine and form cross-linkage between two strands of DNA. Therefore they show toxicity and have an important role in plant defense response against biotic and abiotic stresses by inhibiting DNA replication and transcription. According to attachment of prenyl group into the C۶ or C۸ position of precursor molecule (umbelliferone), linear furanocoumarins, like psoralen and angular furanocoumarins like angelicin would be produced, respectively. During plant-herbivore coevolution, some plants have evolved the C۸ prenylation pathway for generating angular furanocoumarins, in order to increase the toxicity of linear furanocoumarins, which is tolerated by insects. A membrane-bound prenyltransferase, which accepts two substrates: dimethylallyl diphosphate as a prenyl donor, and umbelliferone as prenyl acceptor, is responsible for this enzymatic reaction, although this enzyme has a strict preference toward C۶ prenylation. It is reported that consummation of plant extracts that contain furanocoumarins, in drug dosage, can cause some skin problems such as vitiligo, psoriasis, and even it can increase the risk of skin cancer. Here we tried to characterize the encoding gene of prenyltransferase as the key enzyme in the biosynthetic pathway of furanocoumarins, in one of the well-known herbal medicine, Anethum graveolens (common name: Dill) to decrease its side effects by engineering of this metabolic pathway in future.Methods: For our purpose, first, we designed two couple of primers (one interior and another exterior) based on the conserved sequences of other species’ aromatic prenyltransferases. The exonic and intronic regions of AgPT were elucidated by sequencing of PCR products achieved from both genomic DNA and cDNA templates. Next, the expression pattern of AgPT in different organs of root, stem and leaf under normal and UV-stress conditions was determined by qPCR.Results: Results of phylogenetic and expression analysis suggest that the isolated gene is encoding prenyltransferase in Dill.Conclusion: Altogether, we could successfully characterize the AgPT which encodes prenyl transferase in Dill.

Keywords:

furanocoumarins , prenyltransferase , Anethum graveolens , vitiligo