Producing a High Scopolamine Hairy Root Clone in Hyoscyamus muticus through Transformation by Agrobacterium rhizogenes

Agrobacterium rhizogenes causes hairy root disease in plants. These hairy roots are ge-netically stable and grow rapidly. Transformed hairy roots of Hyoscyamus muticus in-duced by the bacterium can produce tropane alkaloids in trace amounts of intact plant tissues. In this research, in order to compare growth and biosynthetic stability of hairy roots with wild type ones, leaf and nodal segments of the plant were inoculated with the A. rhizogenes strains A۴ and LBA۹۴۰۲. When hairy roots appeared, both the wild type and transformed roots were cultured in a liquid B۵ medium. The amounts of tropane alka-loids in both the wild type and transformed roots were measured using HPLC. The growth rates of transformed roots were stable and their dry weights were up to four times higher than those of wild type roots. Alkaloid content was the same for both transformed roots and wild type ones. However, when hairy roots underwent an autonomous dediffer-entiation and produced callus, their hyoscyamine content decreased considerably, whereas not only did their scopolamine content, not decrease, but in some cases it in-creased dramatically. A callus producing hairy root clone, produced ۲.۷۲ mg/g scopola-mine which is a significantly high record for hairy roots of H. muticus.