Since flax (Linum usitatissimum) lignans have demonstrated potential application in medicine and their role in flax is still not clear, there is a big interest in elucidating pinoresinol-lariciresinol reductase (PLR) synthesis regulation, a key enzyme in lignan biosynthesis. In the flax genome, at least two PLRs with different stereospecifity have been characterized. The corresponding genes were previously cloned in the lab and their promoters were analyzed in silico using databases. The first part of the work was aimed at determining the possible interaction of two Aradopsis thaliana MYB transcription factors (AtMYB20 and AtMYB61) with a LuPLR1 putative MYB-binding box. DNA-protein interactions have been confirmed using gel shift assay experiments. In the same way, in order to get insight into the LuPLR2 gene regulation, promoter-reporter constructs were designed using the gateway technology. Three promoter deletions were amplified and cloned upstream of a gus-gfp reporter genes for further Agrobacterium-mediated introduction into the flax genome. Linum album, a wild Iranian Linum species, could be an alternative source of cytotoxic podophyllotoxin (PTOX) to face the problem of Podophyllum supply (endangered species). The obtained in vitro hairy root cell lines (produced by A. rhizogenes transformation) show a fast growth and all produce PTOX as detected by HPLC method.