title: [In vitro culture and the Agrobacterium-mediated genetic transformation of Morinda officinalis].
abstract: OBJECTIVE
  To establish an effective system for the Agrobacterium-mediated genetic transformation of M. officinalis, for laying a foundation for the improvement of breeds and introduction of foreign objective genes.
  
  
  METHODS
  The explants used for culture were the nodular stem segments from M. officinalis. Agrobacterium tumefaciens strain was EHA101, containing vector plasmid pGA482GG. The GUS gene and NPT II gene were introduced into the plasmid.
  
  
  RESULTS
  MT basal medium with BA 1 mg.L-1 was effective to inducing the direct shoot formation, and the frequency of shoot formation was 97.8%. As BA concentrations increased, the ability of shoot formation decreased. The explants oriented with their apical ends protruding from the medium produced more shoots than when they were placed with their basal end upright or were placed horizontally. The optimal rooting medium for regenerating shoots was MT basal medium supplemented with 0.2 to 0.5 mg.L-1 NAA, and a root induction rate over 80.0% was observed. The selection pressure for kanamycin was 50 mg.L-1. Cefotaxime was used as antibiotics, and the concentration was 300 mg.L-1. After 1.5 months, 14.8% resistant shoots were emerged from the explants. Histochemical GUS assay showed that 22.2% of the resistant plants were GUS-positive.
  
  
  CONCLUSIONS
  Plant regeneration system and Agrobacterium-mediated genetic transformation have been established for M. officinalis in vitro.
authors.affiliation: College of Chinese Materia Medica, Guangzhou University of Traditional Chinese Medical and Pharmaceutical Sciences, Guangzhou 510405, Guangdong, China.
authors.forename: Hong
authors.initials: H
authors.lastname: He
authors.forename: Hong-hua
authors.initials: HH
authors.lastname: Xu
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics*; D046508:Culture Techniques; D005798:Genes, Bacterial; D032066:Morinda / Q000235:genetics / Q000254:growth & development*; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D010946:Plants, Medicinal / Q000235:genetics / Q000254:growth & development*; D014170:Transformation, Genetic