title: Identification of differentially expressed genes in Malus domestica after application of the non-pathogenic bacterium Pseudomonas fluorescens Bk3 to the phyllosphere.
abstract: Biological control of plant diseases by the application of antagonistic micro-organisms to the plant phyllosphere is only marginally understood. Suppression subtractive hybridization (SSH) was used for the identification of genes expressed after application of the non-pathogenic bacterium Pseudomonas fluorescens Bk3 to the phyllosphere of the apple scab-susceptible cultivar Malus domestica cv. Holsteiner Cox. In total, 157 expressed sequence tag (EST) clones were obtained. The sequencing of 113 ESTs which have a significantly elevated transcript level and the comparison of the obtained sequences with databases revealed similarities to different classes of pathogenesis-related proteins, for example, RNase-like PR10 protein and endochitinase, or similarities to proteins expressed under stress conditions that could have a protective function, for example, a germin-like protein, glutathione S-transferase, thioredoxin-like proteins, and heat shock proteins. In addition, several transcripts were identified that code for proteins which have a crucial role at different stages of pathogen recognition and in signalling pathways or an as yet unknown function in plant defence. The results show that a number of transcripts encoding proteins/enzymes which are known to be up-regulated after pathogen infection are also up-regulated after the application of a non-pathogenic bacterium to a M. domestica cultivar. The expression of these proteins might increase the plant resistance towards pathogen infection and damage.
authors.affiliation: Leibniz University of Hannover, Institute of Botany, Herrenhäuserstr. 2, D-30419 Hannover, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Kürkcüoglu
authors.forename: Juliana
authors.initials: J
authors.lastname: Degenhardt
authors.forename: Julia
authors.initials: J
authors.lastname: Lensing
authors.forename: Abdul Nasser
authors.initials: AN
authors.lastname: Al-Masri
authors.forename: Achim E
authors.initials: AE
authors.lastname: Gau
mesh_terms: D015152:Blotting, Northern; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate / Q000235:genetics; D027845:Malus / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D009693:Nucleic Acid Hybridization; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000382:microbiology*; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011551:Pseudomonas fluorescens / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger