TRANSFORMATION OF WITHANIA-SOMNIFERA (L) DUNAL BY AGROBACTERIUM-RHIZOGENES - INFECTIVITY AND PHYTOCHEMICAL STUDIES

Three different strains of Agrobacterium rhizogenes, namely A(4), LBA 9302 and LBA 9360 were used for infection to induce hairy root formation in W. somnifera. Strain specificity of the bacterium and frequency of transformation events were analysed. Significant differences were observed between the transformation ability of the different strains of Agrobacterium. The best response in terms of transformation ability and growth of the hairy roots was obtained with A. rhizogenes strain A(4), followed by LBA 9402, whereas LBA 9360 strain failed to induce a transformation event. The production of withanolides with special reference to withaferin A was studied through HPLC in the A(4) induced hairy root lines and their respective media at different growth phases (i.e. 4, 10 and 24 weeks). The presence of withaferin A in the media as well as in the hairy roots of 10-week-old cultures highlights the importance of the present study for the commercial prospects of this plant.