RPW8/HR repeats control NLR activation in Arabidopsis thaliana.

RPW8/HR repeats control NLR activation in Arabidopsis thaliana.

Blog Article

In many plant species, conflicts between divergent elements of the immune system, especially nucleotide-binding oligomerization domain-like receptors (NLR), can lead to hybrid necrosis.Here, we report deleterious allele-specific interactions between an NLR and a non-NLR gene cluster, resulting in not one, but multiple hybrid necrosis cases in Arabidopsis thaliana.The NLR cluster is RESISTANCE TO PERONOSPORA PARASITICA 7 (RPP7), which can confer strain-specific resistance to oomycetes.The non-NLR cluster is Crochet Supplies RESISTANCE TO POWDERY MILDEW 8 (RPW8) / HOMOLOG OF RPW8 (HR), which can confer broad-spectrum resistance to both fungi and oomycetes.RPW8/HR proteins contain at the N-terminus a potential transmembrane domain, followed by a specific coiled-coil (CC) domain that is similar to a domain found in pore-forming toxins MLKL and HET-S from mammals and fungi.

C-terminal to the CC domain is a variable number of 21- or 14-amino acid repeats, reminiscent of regulatory 21-amino acid repeats in fungal HET-S.The number of repeats in different RPW8/HR proteins along with the Bone Broth sequence of a short C-terminal tail predicts their ability to activate immunity in combination with specific RPP7 partners.Whether a larger or smaller number of repeats is more dangerous depends on the specific RPW8/HR autoimmune risk variant.