title: Efficient genetic transformation of okra (Abelmoschus esculentus (L.) Moench) and generation of insect-resistant transgenic plants expressing the cry1Ac gene.
abstract: Agrobacterium -mediated transformation system for okra using embryos was devised and the transgenic Bt plants showed resistance to the target pest, okra shoot, and fruit borer ( Earias vittella ). Okra is an important vegetable crop and progress in genetic improvement via genetic transformation has been impeded by its recalcitrant nature. In this paper, we describe a procedure using embryo explants for Agrobacterium-mediated transformation and tissue culture-based plant regeneration for efficient genetic transformation of okra. Twenty-one transgenic okra lines expressing the Bacillus thuringiensis gene cry1Ac were generated from five transformation experiments. Molecular analysis (PCR and Southern) confirmed the presence of the transgene and double-antibody sandwich ELISA analysis revealed Cry1Ac protein expression in the transgenic plants. All 21 transgenic plants were phenotypically normal and fertile. T1 generation plants from these lines were used in segregation analysis of the transgene. Ten transgenic lines were selected randomly for Southern hybridization and the results confirmed the presence of transgene integration into the genome. Normal Mendelian inheritance (3:1) of cry1Ac gene was observed in 12 lines out of the 21 T0 lines. We selected 11 transgenic lines segregating in a 3:1 ratio for the presence of one transgene for insect bioassays using larvae of fruit and shoot borer (Earias vittella). Fruit from seven transgenic lines caused 100 % larval mortality. We demonstrate an efficient transformation system for okra which will accelerate the development of transgenic okra with novel agronomically useful traits.
authors.affiliation: Mahyco Research Centre, Maharashtra Hybrid Seeds Company Ltd., P.O. Box-76, Dawalwadi, Jalna-Aurangabad Road, Jalna, 431203, Maharashtra, India.
authors.forename: M
authors.initials: M
authors.lastname: Narendran
authors.forename: Satish G
authors.initials: SG
authors.lastname: Deole
authors.forename: Satish
authors.initials: S
authors.lastname: Harkude
authors.forename: Dattatray
authors.initials: D
authors.lastname: Shirale
authors.forename: Asaram
authors.initials: A
authors.lastname: Nanote
authors.forename: Pankaj
authors.initials: P
authors.lastname: Bihani
authors.forename: Srinivas
authors.initials: S
authors.lastname: Parimi
authors.forename: Bharat R
authors.initials: BR
authors.lastname: Char
authors.forename: Usha B
authors.initials: UB
authors.lastname: Zehr
mesh_terms: D028483:Abelmoschus / Q000235:genetics* / Q000469:parasitology*; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001681:Biological Assay; D015139:Blotting, Southern; D020090:Chromosome Segregation / Q000235:genetics; D003433:Crosses, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D004731:Endotoxins / Q000235:genetics*; D006460:Hemolysin Proteins / Q000235:genetics*; D007313:Insecta / Q000502:physiology; D010572:Pest Control, Biological; D030821:Plants, Genetically Modified; D014170:Transformation, Genetic
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; C036483:T-DNA; C030956:insecticidal crystal protein, Bacillus Thuringiensis