hairy roots formation in four solanaceae species by different strains of agrobacterium rhizogenes

plants are the important sources of drugs. secondary metabolites are responsible for therapeutic propertiesin plants. three compounds including (-)-hyoscyamine, its racemate atropine, and scopolamine (hyoscine) are the most famous tropane alkaloids in the solanaceae familly. nowadays, attempts to developthese alkaloids in biotechnological procedures which are principally based on the hairy root cultures using agrobacterium rhizogenes. in the present study, we showed the percent of induced hairy roots percent in the leaf and root explants of four plants from the solanaceae family (atropa belladonna l., hyoscyamus niger l., datura stramonium l. and datura metel l.), that infected with the six strains of agrobacterium rhizogenes (a4, a7, ar15834, ar9534, ar9402, and ar318). hairy roots were appeared from the leaf and roots explants on ½ms medium culture. the presence of t-dna in the supposedly transformal lines was shown by pcr. the highest transformation yield of 93% was accomplished using leaf explants of d. metel infected by ar15834 and a4 strains. one fastest growing clone of transforming d. metel roots line (induced by ar15834)was selected and the biomass of hairy and natural roots were measured and compared  after 0, 2, 4, 6, 8 and 10 days. the results showed that, the fresh and dry weight of hairy roots was 4.44 and 4.92 times higher than the weights of non-transformed roots respectively after 8- 10 days. these roots are hormone-autotrophic and have the great lateral branches. therefore, the hairy roots of d. metel and d. stramonium can be used to increase tropane alkaloids production yield in the pharmaceutical industry.