PT  - JOURNAL ARTICLE
AU  - Paul C. Bailey
AU  - Gulay Dagdas
AU  - Erin Baggs
AU  - Wilfried Haerty
AU  - Ksenia V. Krasileva
TI  - Immune receptors with exogenous domain fusions form evolutionary hotspots in grass genomes
AID  - 10.1101/100834
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 100834
4099  - http://biorxiv.org/content/early/2017/01/20/100834.short
4100  - http://biorxiv.org/content/early/2017/01/20/100834.full
AB  - Understanding evolution of plant immunity is necessary to inform rational approaches for genetic control of plant diseases. The plant immune system is innate, encoded in the germline, yet plants are capable of recognizing diverse rapidly evolving pathogens. Plant immune receptors (NLRs) can gain pathogen recognition through point mutation, recombination of recognition domains with other receptors, and through acquisition of novel ‘integrated’ protein domains. The exact molecular pathways that shape immune repertoire including new domain integration remain unknown. Here, we describe a non-uniform distribution of integrated domains among NLR subfamilies in grasses and identify genomic hotspots that demonstrate rapid expansion of NLR gene fusions. We show that just one clade in the Poaceae is responsible for the majority of unique integration events. Based on these observations we propose a model for the expansion of integrated domain repertoires that involves a flexible NLR ‘acceptor’ that is capable of fusion to diverse domains derived across the genome. The identification of a subclass of NLRs that is naturally adapted to new domain integration can inform biotechnological approaches for generating synthetic receptors with novel pathogen ‘traps’.