title: Transcriptome profiling in hybrid poplar following interactions with Melampsora rust fungi.
abstract: In natural conditions, plants are subjected to a combination of biotic stresses and often have to cope with simultaneous pathogen infections. In this report, we aim to understand the global transcriptional response of hybrid poplar NM6 (Populus nigra x P. maximowiczii) to infection by two biotrophic Melampsora fungi, Melampsora larici-populina and M. medusae f. sp. deltoidae. These pathogens triggered different responses after inoculation of poplar leaves. Transcript profiling using the GeneChip Poplar Genome Array revealed a total of 416 differentially expressed transcripts whose expression level was > or = twofold relative to controls. Interestingly, approximately half of the differentially expressed genes in infected leaves showed altered expression following interaction with either of the Melampsora spp. We also infected poplar leaves simultaneously with both Melampsora spp. to investigate potential interaction between the responses to the individual pathogens during a mixed infection. For this mixed inoculation, the number of differentially expressed transcripts increased to 648 and our analysis showed that infection with both fungi also induced a common set of genes. The genes induced after Melampsora spp. infection were mainly related to primary and secondary metabolic processes, cell-wall reinforcement and lignification, defense and stress-related mechanisms, and signal perception and transduction.
authors.affiliation: Natural Resources Canada, Canadien Forest Service, Laurentian Forestry Centre, Sainte-Foy, Quebec, Canada.
authors.forename: Aïda
authors.initials: A
authors.lastname: Azaiez
authors.forename: Brian
authors.initials: B
authors.lastname: Boyle
authors.forename: Valérie
authors.initials: V
authors.lastname: Levée
authors.forename: Armand
authors.initials: A
authors.lastname: Séguin
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000890:Anti-Infective Agents / Q000378:metabolism; D001487:Basidiomycota / Q000502:physiology*; D002473:Cell Wall / Q000235:genetics; D002678:Chimera / Q000378:metabolism*; D002999:Clone Cells; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D020411:Oligonucleotide Array Sequence Analysis; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology*; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D016133:Polymerase Chain Reaction; D032107:Populus / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D015203:Reproducibility of Results; D015398:Signal Transduction
chemical_list: D018528:ATP-Binding Cassette Transporters; D000890:Anti-Infective Agents