Premium
Structurally distinct Arabidopsis thaliana NLR immune receptors recognize tandem WY domains of an oomycete effector
Author(s) -
Goritschnig Sandra,
Steinbrenner Adam D.,
Grunwald Derrick J.,
Staskawicz Brian J.
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13823
Subject(s) - biology , arabidopsis , genetics , computational biology , arabidopsis thaliana , effector , evolutionary biology , gene , microbiology and biotechnology , mutant
Summary Nucleotide‐binding leucine‐rich repeat ( NB ‐ LRR , or NLR ) receptors mediate pathogen recognition. The Arabidopsis thaliana NLR RPP 1 recognizes the tandem WY ‐domain effector ATR 1 from the oomycete Hyaloperonospora arabidopsidis through direct association with C‐terminal LRR s. We isolated and characterized homologous NLR genes RPP 1‐EstA and RPP 1‐ZdrA from two Arabidopsis ecotypes, Estland (Est‐1) and Zdarec (Zdr‐1), responsible for recognizing a novel spectrum of ATR 1 alleles. RPP 1‐EstA and ‐ZdrA encode nearly identical NLR s that are phylogenetically distinct from known immunity‐activating RPP 1 homologs and possess greatly expanded LRR domains. Site‐directed mutagenesis and truncation analysis of ATR 1 suggests that these homologs recognize a novel surface of the 2 nd WY domain of ATR 1, partially specified by a C‐terminal region of the LRR domain. Synteny comparison with RPP 1 loci involved in hybrid incompatibility suggests that these functions evolved independently. Closely related RPP 1 homologs have diversified their recognition spectra through LRR expansion and sequence variation, allowing them to detect multiple surfaces of the same pathogen effector. Engineering NLR receptor specificity may require a similar combination of repeat expansion and tailored amino acid variation.