title: Genetic transformation of Ornithogalum via particle bombardment and generation of Pectobacterium carotovorum-resistant plants.
abstract: Bacterial soft rot caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) is one of the most devastating diseases of Ornithogalum species. No effective control measures are currently available to use against this pathogen; thus, introduction of resistant genes via genetic transformation into this crop is a promising approach. Tachyplesin I, an antimicrobial peptide, has been shown to effectively control numerous pathogenic bacteria, including Pcc. In this study, liquid-grown cell clusters of Ornithogalum dubium and Ornithogalum thyrsoides were bombarded with a pCAMBIA2301 vector containing a celI leader sequence fused to a gene encoding tachyplesin I, a neomycin phosphotransferase (nptII) gene that served as a selectable marker and a β-glucuronidase (GUS) gene that served as a reporter. Selection was carried out in the dark in liquid medium containing 80mg/L kanamycin. Regeneration was executed in the light after 6-14 months depending on the cultivar. Hundreds of transgenic plantlets were produced and their identity was confirmed through GUS activity assays. PCR and RT-PCR were used to confirm the presence of the target, reporter and selection genes in the divergent lines of plantlets. The resistance of the O. dubium plants to Pcc was evaluated in vitro, following infection with a highly virulent isolate from calla lily. Although control plantlets were completely macerated within a week, 87 putative transgenic subclones displayed varying levels of disease resistance. During three growing seasons in the greenhouse, the transgenic O. dubium lines grew poorly, whereas the transgenic O. thyrsoides plants grew similarly to non-transgenic plants.
authors.affiliation: Department of Ornamental Horticulture, ARO, The Volcani Center, Derech Hamacabim 20, P.O. Box 6, Bet Dagan 50250, Israel.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lipsky
authors.affiliation: Department of Ornamental Horticulture, ARO, The Volcani Center, Derech Hamacabim 20, P.O. Box 6, Bet Dagan 50250, Israel.
authors.forename: Avner
authors.initials: A
authors.lastname: Cohen
authors.affiliation: Department of Ornamental Horticulture, ARO, The Volcani Center, Derech Hamacabim 20, P.O. Box 6, Bet Dagan 50250, Israel.
authors.forename: Aurel
authors.initials: A
authors.lastname: Ion
authors.affiliation: Department of Ornamental Horticulture, ARO, The Volcani Center, Derech Hamacabim 20, P.O. Box 6, Bet Dagan 50250, Israel. Electronic address: irisy@volcani.agri.gov.il.
authors.forename: Iris
authors.initials: I
authors.lastname: Yedidia
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D060467:Disease Resistance / Q000235:genetics; D018014:Gene Transfer Techniques; D005966:Glucuronidase; D054884:Host-Pathogen Interactions; D007612:Kanamycin; D031442:Ornithogalum / Q000235:genetics / Q000276:immunology*; D016973:Pectobacterium carotovorum / Q000502:physiology*; D010456:Peptides, Cyclic / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000276:immunology; D016133:Polymerase Chain Reaction; D014170:Transformation, Genetic; D019076:Transgenes
chemical_list: D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D010456:Peptides, Cyclic; C057636:tachyplesin peptide, Tachypleus tridentatus; D007612:Kanamycin; D005966:Glucuronidase
keywords: Flower bulbs; Ornithogalum; Particle bombardment; Pectobacterium carotovorum subsp. carotovorum; Soft rot