Tandem Repeat Evolution of the Leucine-Rich Repeat Domain in Plant Innate Immune Receptors

The leucine-rich repeat (LRR) domain is responsible for effector binding in intracellular plant immune receptors. LRR’s are known to undergo tandem duplications, deletions, and insertions, but existing work has not been able to analyze these mutations in detail. We develop a method to detect tandem repeat mutations in evolutionary time. Applying the method to the model plant organism Arabidopsis Thaliana, we uncovered higher rates of tandem mutations in receptors responsible for direct binding to pathogen effectors.