title: Expanded functions for a family of plant intracellular immune receptors beyond specific recognition of pathogen effectors.
abstract: Plants and animals deploy intracellular immune receptors that perceive specific pathogen effector proteins and microbial products delivered into the host cell. We demonstrate that the ADR1 family of Arabidopsis nucleotide-binding leucine-rich repeat (NB-LRR) receptors regulates accumulation of the defense hormone salicylic acid during three different types of immune response: (i) ADRs are required as "helper NB-LRRs" to transduce signals downstream of specific NB-LRR receptor activation during effector-triggered immunity; (ii) ADRs are required for basal defense against virulent pathogens; and (iii) ADRs regulate microbial-associated molecular pattern-dependent salicylic acid accumulation induced by infection with a disarmed pathogen. Remarkably, these functions do not require an intact P-loop motif for at least one ADR1 family member. Our results suggest that some NB-LRR proteins can serve additional functions beyond canonical, P-loop-dependent activation by specific virulence effectors, extending analogies between intracellular innate immune receptor function from plants and animals.
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Vera
authors.initials: V
authors.lastname: Bonardi
authors.forename: Saijun
authors.initials: S
authors.lastname: Tang
authors.forename: Anna
authors.initials: A
authors.lastname: Stallmann
authors.forename: Melinda
authors.initials: M
authors.lastname: Roberts
authors.forename: Karen
authors.initials: K
authors.lastname: Cherkis
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Dangl
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology; D016923:Cell Death; D011971:Receptors, Immunologic / Q000502:physiology*; D016897:Respiratory Burst; D015398:Signal Transduction
chemical_list: D011971:Receptors, Immunologic