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 genetically stable and grow rapidly. Transformed hairy roots of Hyoscyamus muticus induced 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 A4 and LBA9402. When hairy roots appeared, both the wild type and transformed roots were cultured in a liquid B5 medium. The amounts of tropane alkaloids 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 dedifferentiation and produced callus, their hyoscyamine content decreased considerably, whereas not only did their scopolamine content, not decrease, but in some cases it increased dramatically. A callus producing hairy root clone, produced 2.72 mg/g scopolamine which is a significantly high record for hairy roots of H. muticus