The glutamate receptor‐like GLR2.7 modulates insect egg‐induced defense responses in Arabidopsis

Summary Upon perception of insect eggs, Arabidopsis thaliana activates a generic immune response that culminates in cell death (hypersensitive‐like response (HR‐like)). While this response can subsequently impact egg survival, the molecular mechanisms are poorly understood. Through a genome‐wide association study (GWAS), we identified the amino acid‐gated calcium channel GLUTAMATE‐LIKE RECEPTOR2.7 (GLR2.7) as an important gene controlling the extent of HR‐like and accumulation of salicylic acid (SA) in response to egg extract of Pieris brassicae . Analysis of natural polymorphisms showed that two major haplotypes segregate at the species‐wide level and suggests that balancing selection acts at this locus. Insect oviposition triggered a long‐lasting localized cytosolic calcium accumulation that depended on GLR2.7 and was linked with egg‐associated glutamate (Glu). We propose that Glu‐activated GLR2.7 is involved in egg perception and early immune responses.