title: Comparative analysis of plant immune receptor architectures uncovers host proteins likely targeted by pathogens.
abstract: BACKGROUND
  Plants deploy immune receptors to detect pathogen-derived molecules and initiate defense responses. Intracellular plant immune receptors called nucleotide-binding leucine-rich repeat (NLR) proteins contain a central nucleotide-binding (NB) domain followed by a series of leucine-rich repeats (LRRs), and are key initiators of plant defense responses. However, recent studies demonstrated that NLRs with non-canonical domain architectures play an important role in plant immunity. These composite immune receptors are thought to arise from fusions between NLRs and additional domains that serve as "baits" for the pathogen-derived effector proteins, thus enabling pathogen recognition. Several names have been proposed to describe these proteins, including "integrated decoys" and "integrated sensors". We adopt and argue for "integrated domains" or NLR-IDs, which describes the product of the fusion without assigning a universal mode of action.
  
  
  RESULTS
  We have scanned available plant genome sequences for the full spectrum of NLR-IDs to evaluate the diversity of integrations of potential sensor/decoy domains across flowering plants, including 19 crop species. We manually curated wheat and brassicas and experimentally validated a subset of NLR-IDs in wild and cultivated wheat varieties. We have examined NLR fusions that occur in multiple plant families and identified that some domains show re-occurring integration across lineages. Domains fused to NLRs overlap with previously identified pathogen targets confirming that they act as baits for the pathogen. While some of the integrated domains have been previously implicated in disease resistance, others provide new targets for engineering durable resistance to plant pathogens.
  
  
  CONCLUSIONS
  We have built a robust reproducible pipeline for detecting variable domain architectures in plant immune receptors across species. We hypothesize that NLR-IDs that we revealed provide clues to the host proteins targeted by pathogens, and that this information can be deployed to discover new sources of disease resistance.
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.|Division of Plant and Microbial Sciences, School of Biosciences, University of Exeter, Exeter, UK.
authors.forename: Panagiotis F
authors.initials: PF
authors.lastname: Sarris
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.
authors.forename: Volkan
authors.initials: V
authors.lastname: Cevik
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.
authors.forename: Gulay
authors.initials: G
authors.lastname: Dagdas
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.
authors.forename: Jonathan D G
authors.initials: JD
authors.lastname: Jones
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, UK. Ksenia.Krasileva@tgac.ac.uk.|The Genome Analysis Centre, Norwich Research Park, Norwich, UK. Ksenia.Krasileva@tgac.ac.uk.
authors.forename: Ksenia V
authors.initials: KV
authors.lastname: Krasileva
mesh_terms: D000595:Amino Acid Sequence; D060467:Disease Resistance; D050939:Gene Fusion; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D010944:Plants / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D017434:Protein Structure, Tertiary; D014908:Triticum / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000382:microbiology
chemical_list: D010940:Plant Proteins