A plant immune receptor mediates tritrophic interactions by linking caterpillar detection to predator recruitment

Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine

Plants deploy direct and indirect defenses in response to insect herbivory. The specific antiherbivore responses involve cell surface immune receptors that recognize herbivore-associated molecular patterns (HAMPs), yet the ecological relevance of this molecular interplay in natural settings remains unexplored. Here, we demonstrate with laboratory and field experimentation in Mexico that the inceptin receptor (INR) in the leaves of common bean orchestrates a tritrophic interaction upon recognition of inceptin, a HAMP in caterpillar oral secretions. Near-isogenic lines with a naturally occurring null mutation in INR revealed that inceptin recognition does not only amplify the wound response but activates an herbivore-specific immune pathway to trigger the emission of a distinctive volatile blend that recruits predatory wasps to effectively remove caterpillars from the plants. These findings provide a definitive molecular-to-ecological link, revealing how a single immune receptor mediates ecologically relevant plant-insect-predator interactions in nature. A plant receptor detects caterpillar attack and triggers emission of chemical cues to attract predatory wasps. teaser