title: Genetic transformation of Tylophora indica with Agrobacterium rhizogenes A4: growth and tylophorine productivity in different transformed root clones.
abstract: We have developed an efficient transformation system for Tylophora indica, an important medicinal plant in India, using Agrobacterium rhizogenes strains LBA9402 and A4 to infect excised leaf and stem explants and intact shoots at different sites. The induction of callus and transformed roots was dependent on the bacterial strain, explant type and inoculation site used. Transformed roots were induced only in explants infected with A. rhizogenes strain A4, while an optimal transformation frequency of up to 60% was obtained with intact shoots inoculated at the nodes. The presence of the left-hand transferred DNA (T(L)-DNA) in the genome of T. indica roots induced by A. rhizogenes was confirmed by PCR amplification of the rooting locus genes of A. rhizogenes. Root growth and the production of tylophorine, the major alkaloid of the plant, varied substantially among the nine root clones studied. Both parameters increased over time in liquid cultures, with maximum biomass and tylophorine accumulation occurring within 4-6 weeks of growth in fresh medium. Interestingly, in liquid culture, the culture medium also accumulated tylophorine up to concentrations of 9.78+/-0.21 mg l(-1).
authors.affiliation: Centre of Advanced Study in Cell and Chromosome Research, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700019, India.
authors.forename: Kuntal Narayan
authors.initials: KN
authors.lastname: Chaudhuri
authors.forename: Biswajit
authors.initials: B
authors.lastname: Ghosh
authors.forename: David
authors.initials: D
authors.lastname: Tepfer
authors.forename: Sumita
authors.initials: S
authors.lastname: Jha
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis*; D005818:Genetic Engineering / Q000379:methods*; D007212:Indolizines; D010616:Phenanthrenes; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012231:Rhizobium; D013997:Time Factors; D046509:Tissue Culture Techniques; D014170:Transformation, Genetic; D031110:Tylophora / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000470:Alkaloids; D007212:Indolizines; D010616:Phenanthrenes; C004218:tylophorine