Influence of Agrobacterium rhizogenes strains on biomass and alkaloid productivity in hairy root lines of Hyoscyamus muticus and H. albus

Abstract

Using leaf explants of in vitro grown Hyoscyamus albus and H. muticus plantlets, hairy roots were induced following inoculation with Agrobacterium rhizogenes strains A₄ and LBA-9402. The transformed roots, appearing after 14-17 days incubation on hormone-free MS medium containing 1 g/L cephalexin, were excised and maintained in the same medium. Ten randomly selected hairy root lines from each bacterial treatment of the two plant systems were compared for growth and alkaloid production in half-strength, hormone-free MS medium on 25th day of culture. A. rhizogenes strain-A₄ induced hairy root lines of both H. albus and H. muticus were comparatively faster growing than those induced by strain LBA-9402. In contrast to earlier reports, some of the hairy root lines of H. albus induced by A. rhizogenes strain A₄ were as fast growing as the hairy root lines of H. muticus. The atropine yields of A₄ induced lines of H. albus were significantly higher (3.5 fold) than the LBA-9402 induced lines. No such relationship between the bacterial strain and alkaloid productivity could, however, be obtained in case of hairy root lines of H. muticu.