title: Transformation of miniature potted rose (Rosa hybrida cv. Linda) with P(                 SAG12               )-ipt gene delays leaf senescence and enhances resistance to exogenous ethylene.
abstract: KEY MESSAGE                 :                                      The P                   (                     SAG12                   )                   -ipt                    gene was transferred to miniature rose, as the first woody species, resulting in increased ethylene resistance due to specific up-regulation of the                   ipt                    gene under senescence promoting conditions.                                                                  Transgenic plants of Rosa hybrida 'Linda' were obtained via transformation with Agrobacterium tumefaciens strain harboring the binary vector pSG529(+) containing the P(                     SAG12                   )-ipt construct. A. tumefaciens strains AGL1, GV3850 and LBA4404 (containing P(35S)-INTGUS gene) were used for transformation of embryogenic callus, but transgenic shoots were obtained only when AGL1 was applied. The highest transformation frequency was 10 % and it was achieved when half MS medium was used for the dilution of overnight culture of Agrobacterium. Southern blot confirmed integration of 1-6 copies of the nptII gene into the rose genome in the tested lines. Four transgenic lines were obtained which were morphologically true-to-type and indistinguishable from Wt shoots while they were in in vitro cultures. Adventitious root induction was more difficult in transgenic shoots compared to the Wt shoots, however, one of the transgenic lines (line 6) was rooted and subsequently analyzed phenotypically. The ipt expression levels were determined in this line after exposure to exogenous ethylene (3.5 μl l(-1)) and/or darkness. Darkness resulted in twofold up-regulation of ipt expression, whereas darkness combined with ethylene caused eightfold up-regulation in line 6 compared to Wt plants. The transgenic line had significantly higher content of chlorophyll at the end of the treatment period compared to Wt plants.
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Højbakkegård Alle 9-13, 2630, Taastrup, Denmark. zakizadeh55@gmail.com
authors.forename: Hedayat
authors.initials: H
authors.lastname: Zakizadeh
authors.forename: Henrik
authors.initials: H
authors.lastname: Lütken
authors.forename: Sridevy
authors.initials: S
authors.lastname: Sriskandarajah
authors.forename: Margrethe
authors.initials: M
authors.lastname: Serek
authors.forename: Renate
authors.initials: R
authors.lastname: Müller
mesh_terms: D016960:Agrobacterium tumefaciens; D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D016922:Cellular Senescence; D002734:Chlorophyll / Q000032:analysis; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D003583:Cytokinins / Q000494:pharmacology; D003624:Darkness; D005030:Ethylenes / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D058439:Plant Somatic Embryogenesis Techniques; D030821:Plants, Genetically Modified; D027826:Rosa / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D014170:Transformation, Genetic; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D005030:Ethylenes; D010937:Plant Growth Regulators; D002734:Chlorophyll; C036216:ethylene; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase; C402082:SAG12 protein, Arabidopsis; D003546:Cysteine Endopeptidases