title: Spontaneous plant regeneration in transformed roots and calli from Tylophora indica: Changes in morphological phenotype and tylophorine accumulation associated with transformation by Agrobacterium rhizogenes.
abstract: We examined the effects of genetic transformation by Agrobacterium rhizogenes on the production of tylophorine, a phenanthroindolizidine alkaloid, in the Indian medicinal plant, Tylophora indica. Transformed roots induced by the bacterium grew in axenic culture and produced shoots or embryogenic calli in the absence of hormone treatments. However, hormonal treatment was required to regenerate shoots in root explants of wild type control plants. Transformed plants showed morphological features typically seen in transgenic plants produced by A. rhizogenes, which include, short internodes, small and wrinkled leaves, more branches and numerous plagiotropic roots. Plants regenerated from transformed roots showed increased biomass accumulation (350-510% in the roots and 200-320% in the whole plants) and augmented tylophorine content (20-60%) in the shoots, resulting in a 160-280% increase in tylophorine production in different clones grown in vitro.
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 / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism; D007212:Indolizines / Q000032:analysis / Q000378:metabolism*; D008027:Light; D010616:Phenanthrenes / Q000032:analysis / Q000378:metabolism*; D010641:Phenotype; D018517:Plant Roots / Q000502:physiology*; D018520:Plant Shoots / Q000502:physiology; D030821:Plants, Genetically Modified; D012038:Regeneration / Q000528:radiation effects; D012231:Rhizobium / Q000378:metabolism*; D014170:Transformation, Genetic; D031110:Tylophora / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects
chemical_list: D000470:Alkaloids; D004269:DNA, Bacterial; D007212:Indolizines; D010616:Phenanthrenes; C036483:T-DNA; C004218:tylophorine