NLR singletons, pairs and networks: evolution, assembly and regulation of the intracellular immunoreceptor circuitry of plants

Now published in Current Opinion in Plant Biology, 50:121-131.

NLRs are modular plant and animal proteins that are intracellular sensors of pathogen-associated molecules that trigger a potent broad-spectrum immune reaction known as the hypersensitive response. An emerging paradigm is that plant NLRs form immune signalling networks with varying degrees of complexity. NLRs may have evolved from multifunctional singleton receptors, which combine pathogen detection (sensor activity) and immune signalling (helper or executor activity) into a single protein, to functionally specialized interconnected receptor pairs and networks. In this article, we highlight some of the recent advances in plant NLR biology by discussing models of NLR evolution, NLR complex formation, and how NLR (mis)regulation modulates immunity and autoimmunity. Multidisciplinary approaches are required to dissect the evolution, assembly and regulation of the immune receptor circuitry of plants.

Highlights:

• NLRs may have evolved from singletons to pairs and networks.
• Assembly of immunoreceptor complexes is associated with NLR activation.
• NLR (mis)regulation modulates immunity and autoimmunity.