title: A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature.
abstract: BACKGROUND
  The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG), which is considered sensitive to A. brassicicola.
  
  
  RESULTS
  We show that the interaction has the characteristics of a compatible one, with expanding rather than limited lesions. To ask whether DiG is merely more sensitive to the pathogen or, rather, interacts in distinct manner, we identified genes whose regulation differs between Col-0 and DiG challenged with A. brassicicola. Suppression subtractive hybridization was used to identify differentially expressed genes, and their expression was verified using semi-quantitative PCR. We also tested a set of known defense-related genes for differential regulation in the two plant-pathogen interactions. Several known pathogenesis-related (PR) genes are up-regulated in both interactions. PR1, and a monooxygenase gene identified in this study, MO1, are preferentially up-regulated in the compatible interaction. In contrast, GLIP1, which encodes a secreted lipase, and DIOX1, a pathogen-response related dioxygenase, are preferentially up-regulated in the incompatible interaction.
  
  
  CONCLUSIONS
  The results show that DiG is not only more susceptible, but demonstrate that its interaction with A. brassicicola has a specific transcriptional signature.
authors.affiliation: Department of Biology, Israel Institute of Technology, Technion, Haifa, Israel. titirtua@gmail.com
authors.forename: Arup K
authors.initials: AK
authors.lastname: Mukherjee
authors.forename: Sophie
authors.initials: S
authors.lastname: Lev
authors.forename: Shimon
authors.initials: S
authors.lastname: Gepstein
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Horwitz
mesh_terms: D000528:Alternaria / Q000472:pathogenicity*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D010935:Plant Diseases / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D005819:Genetic Markers; D018749:RNA, Plant