Induction of hairy roots in Gmelina arborea Roxb. and production of verbascoside in hairy roots

Seedling tissues of Gmelina arborea, a medicinally important tree species, were infected with wild type Agrobacterium rhizogenes strain ATTCC 15834, which led to the induction of hairy roots from 32% of the explants. Transgenic status of the roots was confirmed by PCR using rolB specific primers, and subsequently, by Southern analysis of the PCR products. Six transformed clones of hairy roots were established, some of which differed in their root morphology. Doubling time of the faster growing hairy root lines was about 7 days and these cultures showed about seven-fold increase in biomass at the end of 4 weeks as compared to non-transformed seedling roots. The hairy roots showed an ability to synthesize verbascoside, a phenylpropanoid glycoside of medicinal value. This is the first report on the induction of hairy roots in G. arborea.