title: The receptor-like kinase SERK3/BAK1 is required for basal resistance against the late blight pathogen phytophthora infestans in Nicotiana benthamiana.
abstract: BACKGROUND
  The filamentous oomycete plant pathogen Phytophthora infestans causes late blight, an economically important disease, on members of the nightshade family (Solanaceae), such as the crop plants potato and tomato. The related plant Nicotiana benthamiana is a model system to study plant-pathogen interactions, and the susceptibility of N. benthamiana to Phytophthora species varies from susceptible to resistant. Little is known about the extent to which plant basal immunity, mediated by membrane receptors that recognise conserved pathogen-associated molecular patterns (PAMPs), contributes to P. infestans resistance.
  
  
  RESULTS
  We found that different species of Phytophthora have varying degrees of virulence on N. benthamiana ranging from avirulence (incompatible interaction) to moderate virulence through to full aggressiveness. The leucine-rich repeat receptor-like kinase (LRR-RLK) BAK1/SERK3 is a major modulator of PAMP-triggered immunity (PTI) in Arabidopsis thaliana and N. benthamiana. We cloned two NbSerk3 homologs, NbSerk3A and NbSerk3B, from N. benthamiana based on sequence similarity to the A. thaliana gene. N. benthamiana plants silenced for NbSerk3 showed markedly enhanced susceptibility to P. infestans infection but were not altered in resistance to Phytophthora mirabilis, a sister species of P. infestans that specializes on a different host plant. Furthermore, silencing of NbSerk3 reduced the cell death response triggered by the INF1, a secreted P. infestans protein with features of PAMPs.
  
  
  CONCLUSIONS
  We demonstrated that N. benthamiana NbSERK3 significantly contributes to resistance to P. infestans and regulates the immune responses triggered by the P. infestans PAMP protein INF1. In the future, the identification of novel surface receptors that associate with NbSERK3A and/or NbSERK3B should lead to the identification of new receptors that mediate recognition of oomycete PAMPs, such as INF1.
authors.affiliation: The Sainsbury Laboratory, John Innes Centre, Norwich, United Kingdom.
authors.forename: Angela
authors.initials: A
authors.lastname: Chaparro-Garcia
authors.forename: Rachael C
authors.initials: RC
authors.lastname: Wilkinson
authors.forename: Selena
authors.initials: S
authors.lastname: Gimenez-Ibanez
authors.forename: Kim
authors.initials: K
authors.lastname: Findlay
authors.forename: Michael D
authors.initials: MD
authors.lastname: Coffey
authors.forename: Cyril
authors.initials: C
authors.lastname: Zipfel
authors.forename: John P
authors.initials: JP
authors.lastname: Rathjen
authors.forename: Sophien
authors.initials: S
authors.lastname: Kamoun
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schornack
mesh_terms: D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D055750:Phytophthora infestans / Q000276:immunology*; D010935:Plant Diseases / Q000276:immunology / Q000469:parasitology; D057865:Plant Immunity; D017346:Protein Serine-Threonine Kinases / Q000276:immunology*; D014026:Nicotiana / Q000201:enzymology / Q000276:immunology / Q000469:parasitology*
chemical_list: D017346:Protein Serine-Threonine Kinases