Professor Mark Banfield, JIC
Engineering a plant immune receptor to extend pathogen perception
Plant NLR immune receptors (nucleotide-binding domain and leucine-rich repeat receptors) can mediate effective disease resistance in many of the solanaceous and cereal crops that feed the world. These NLRs survey the intracellular environment for the signatures of non-self, typically the presence and/or activity of translocated pathogen effector proteins. They typically contain three domains, but the prevalence of non-canonical domains is increasingly being realised. These integrated domains (NLR-IDs) are thought to act as traps or baits to directly detect effectors, but little is known about how they function and generate a response.
Rice provides the major source of calories for greater than half the world’s population. But rice blast disease, caused by the fungus Magnaporthe oryzae, generates significant pre-harvest yield loss. We have been studying how immunity-related signalling is mediated by the rice NLR Pik, in response to an effector from the rice blast pathogen. Pik contains an integrated heavy metal associated (HMA) domain that directly binds effectors. Both the rice blast effector and the Pik NLR exists as an allelic series in nature with differential binding specificities. We are using both in vitro and in vivo approaches to understand the molecular basis of specificity, with the ultimate aim of engineering these NLR receptors for enhanced and/or extended pathogen recognition.