title: Pathogen-regulated genes in wheat isogenic lines differing in resistance to brown rust Puccinia triticina.
abstract: BACKGROUND
  Inoculation of wheat plants with Puccinia triticina (Pt) spores activates a wide range of host responses. Compatible Pt interaction with susceptible Thatcher plants supports all stages of the pathogen life cycle. Incompatible interaction with TcLr9 activates defense responses including oxidative burst and micronecrotic reactions associated with the pathogen's infection structures and leads to complete termination of pathogen development. These two contrasting host-pathogen interactions were a foundation for transcriptome analysis of incompatible wheat-Pt interaction.
  
  
  METHODS
  A suppression subtractive hybridization (SSH) library was constructed using cDNA from pathogen-inoculated susceptible Thatcher and resistant TcLr9 isogenic lines. cDNA represented steps of wheat-brown rust interactions: spore germination, haustorium mother cell (HMC) formation and micronecrotic reactions. All ESTs were clustered and validated by similarity search to wheat genome using BLASTn and sim4db tools. qRT-PCR was used to determine transcript levels of selected ESTs after inoculation in both lines.
  
  
  CONCLUSIONS
  Out of 793 isolated cDNA clones, 183 were classified into 152 contigs. 89 cDNA clones and encoded proteins were functionally annotated and assigned to 5 Gene Ontology categories: catalytic activity 48 clones (54 %), binding 32 clones (36 %), transporter activity 6 clones (7 %), structural molecule activity 2 clones (2 %) and molecular transducer activity 1 clone (1 %). Detailed expression profiles of 8 selected clones were analyzed using the same plant-pathogen system. The strongest induction after pathogen infection and the biggest differences between resistant and susceptible interactions were detected for clones encoding wall-associated kinase (GenBank accession number JG969003), receptor with leucine-rich repeat domain (JG968955), putative serine/threonine protein kinase (JG968944), calcium-mediated signaling protein (JG968925) and 14-3-3 protein (JG968969).
  
  
  CONCLUSIONS
  The SSH library represents transcripts regulated by pathogen infection during compatible and incompatible interactions of wheat with P. triticina. Annotation of selected clones confirms their putative roles in successive steps of plant-pathogen interactions. The transcripts can be categorized as defense-related due to their involvement in either basal defense or resistance through an R-gene mediated reaction. The possible involvement of selected clones in pathogen recognition and pathogen-induced signaling as well as resistance mechanisms such as cell wall enforcement, oxidative burst and micronecrotic reactions is discussed.
authors.affiliation: Department of Genetic Engineering, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. m.dmochowska@ihar.edu.pl.
authors.forename: Marta
authors.initials: M
authors.lastname: Dmochowska-Boguta
authors.affiliation: Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland. Sylwia.Alaba@amu.edu.pl.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Alaba
authors.affiliation: Department of Genetic Engineering, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. y.yanushevska@ihar.edu.pl.
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Yanushevska
authors.affiliation: Department of Genetic Engineering, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. u.piechota@ihar.edu.pl.
authors.forename: Urszula
authors.initials: U
authors.lastname: Piechota
authors.affiliation: Department of Genetic Engineering, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. tucholska1982@gmail.com.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Lasota
authors.affiliation: Department of Functional Genomics, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. a.orczyk@ihar.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Nadolska-Orczyk
authors.affiliation: Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland. wmk@amu.edu.pl.
authors.forename: Wojciech M
authors.initials: WM
authors.lastname: Karlowski
authors.affiliation: Department of Genetic Engineering, Plant Breeding and Acclimatization, Institute - National Research Institute, Radzikow, 05-870, Blonie, Poland. w.orczyk@ihar.edu.pl.
authors.forename: Waclaw
authors.initials: W
authors.lastname: Orczyk
mesh_terms: D001487:Basidiomycota / Q000235:genetics*; D019295:Computational Biology / Q000379:methods; D060467:Disease Resistance / Q000235:genetics*; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D054884:Host-Pathogen Interactions; D008954:Models, Biological; D058977:Molecular Sequence Annotation; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology*; D013997:Time Factors; D014908:Triticum / Q000382:microbiology*