Influence of different strains of Agrobacterium rhizogenes on induction of hairy roots and lignan production in Linum tauricum ssp. tauricum

Hairy root cultures were induced from leaf explants of Linum tauricum ssp. tauricum by infection with Agrobacterium rhizogenes. Different bacterial strains of Agrobacterium rhizogenes - TR 105 and ATCC 15834 were evaluated for induction of transformed hairy roots in Linum tauricum ssp. tauricum. These different strains varied in their virulence for induction of hairy roots in this species. Acetosyringon in cultivation medium was used to increase of frequency of hairy root induction. Growth kinetics of transgenic roots indicated a similar pattern of growth, with maximum growth occurring between 17 and 20 days. The transformed nature of tissue was confirmed by the production of opines. The lignan production of different clones was found to be growth-related. The cultures produced to 2.6% of the lignan 4'-demethyl-6-methoxypodophylotoxin (4'-DM-MPTOX) and to 3.5% of the lignan 6-methoxypodophyllotoxin (6MPTOX) on a dry weight basis, which was 10 to 12 times higher than in Linum tauricum ssp. tauricum cell suspensions. Transformed cultures showed significant differences in lignan content. The highest amount of 4'-DM-MPTOX and MPTOX was found in transformed line induced by strain ATCC 15834. Rapidly growing root lines were selected to increase the efficiency of he production of lignans.