Matching NLR Immune Receptors to Autoimmunity in camta3 Mutants Using Antimorphic NLR Alleles

Publication date: 12 April 2017
Source:Cell Host & Microbe, Volume 21, Issue 4
Author(s): Signe Lolle, Christiaan Greeff, Klaus Petersen, Milena Roux, Michael Krogh Jensen, Simon Bressendorff, Eleazar Rodriguez, Kenneth Sømark, John Mundy, Morten Petersen
To establish infection, pathogens deploy effectors to modify or remove host proteins. Plant immune receptors with nucleotide-binding, leucine-rich repeat domains (NLRs) detect these modifications and trigger immunity. Plant NLRs thus guard host "guardees." A corollary is that autoimmunity may result from inappropriate NLR activation because mutations in plant guardees could trigger corresponding NLR guards. To explore these hypotheses, we expressed 108 dominant-negative (DN) Arabidopsis NLRs in various lesion mimic mutants, including camta3, which exhibits autoimmunity. CAMTA3 was previously described as a negative regulator of immunity, and we find that autoimmunity in camta3 is fully suppressed by expressing DNs of two NLRs, DSC1 and DSC2. Additionally, expression of either NLR triggers cell death that can be suppressed by CAMTA3 expression. These findings support a model in which DSC1 and DSC2 guard CAMTA3, and they suggest that other negative regulators of immunity may similarly represent guardees.

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Teaser

NLRs detect pathogen-induced modifications in plant proteins, triggering immunity. Lolle et al. express dominant-negative NLRs (DN-NLRs) and screen for suppressed autoimmunity in various mutants. DN-NLRs for DSC1 and DSC2 suppress autoimmunity in a camta3 mutant, a putative negative regulator of immunity, suggesting that autoimmunity results from detection of modified self.


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