title: Engineering fire blight resistance into the apple cultivar 'Gala' using the FB_MR5 CC-NBS-LRR resistance gene of Malus × robusta 5.
abstract: The fire blight susceptible apple cultivar Malus × domestica Borkh. cv. 'Gala' was transformed with the candidate fire blight resistance gene FB_MR5 originating from the crab apple accession Malus × robusta 5 (Mr5). A total of five different transgenic lines were obtained. All transgenic lines were shown to be stably transformed and originate from different transgenic events. The transgenic lines express the FB_MR5 either driven by the constitutive CaMV 35S promoter and the ocs terminator or by its native promoter and terminator sequences. Phenotyping experiments were performed with Mr5-virulent and Mr5-avirulent strains of Erwinia amylovora, the causal agent of fire blight. Significantly less disease symptoms were detected on transgenic lines after inoculation with two different Mr5-avirulent E. amylovora strains, while significantly more shoot necrosis was observed after inoculation with the Mr5-virulent mutant strain ZYRKD3_1. The results of these experiments demonstrated the ability of a single gene isolated from the native gene pool of apple to protect a susceptible cultivar from fire blight. Furthermore, this gene is confirmed to be the resistance determinant of Mr5 as the transformed lines undergo the same gene-for-gene interaction in the host-pathogen relationship Mr5-E. amylovora.
authors.affiliation: Plant Pathology, Institute of Integrative Biology (IBZ), ETH Zürich, Zürich, Switzerland.
authors.forename: Giovanni A L
authors.initials: GA
authors.lastname: Broggini
authors.forename: Thomas
authors.initials: T
authors.lastname: Wöhner
authors.forename: Johannes
authors.initials: J
authors.lastname: Fahrentrapp
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Kost
authors.forename: Henryk
authors.initials: H
authors.lastname: Flachowsky
authors.forename: Andreas
authors.initials: A
authors.lastname: Peil
authors.forename: Maria-Viola
authors.initials: MV
authors.lastname: Hanke
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter
authors.forename: Andrea
authors.initials: A
authors.lastname: Patocchi
authors.forename: Cesare
authors.initials: C
authors.lastname: Gessler
mesh_terms: D003433:Crosses, Genetic; D060467:Disease Resistance / Q000276:immunology*; D044084:Erwinia amylovora / Q000472:pathogenicity / Q000502:physiology*; D017343:Genes, Plant; D005818:Genetic Engineering / Q000379:methods*; D027845:Malus / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014774:Virulence
keywords: Erwinia amylovora; GMO; Gene-for-gene