A plant surface receptor for sensing insect herbivory

Herbivory, the feeding on living plant parts by animals, is a fundamental ecosystem process affecting both global autotroph biomass production in natural habitats and crop production in agricultural settings (1). Invasions by herbivorous insects are an ancient threat to food security as evidenced, for example, by their inclusion as one of the 10 Biblical plagues. Insect pests remain a major threat to the world’s food security both in terms of regular annual crop loss as well as periodic catastrophic losses such as those caused by locust swarms that have repeatedly swept over large parts of East Africa (2). Modern integrated pest management strategies comprise mechanical methods (barriers, traps, tillage), the use of synthetic insecticides, the application of biological control agents (pest-parasitizing insects, insecticidal nematodes), and molecular marker-based breeding strategies (3). Biotechnological transfer of insect resistance traits holds great potential for the production of crops with enhanced pest resilience. This strategy requires a detailed understanding of mechanisms underlying insect pest recognition in host plants, which until recently, was lacking. In PNAS, Steinbrenner et al. (4) reveal the molecular identity of a plant immune receptor sensing herbivory-inflicted host tissue damage. Plants employ a germline-encoded innate immune system to combat microbial infections and insect pest invasions (5, 6). This surveillance system is activated upon sensing patterns of danger derived either from the infectious agent or from the host plant itself. Immunogenic microbial surface signatures are referred to as pathogen-associated molecular patterns (PAMPs). In analogy to PAMPs, plant defense-stimulating compounds found in saliva, oral secretions (OSs), or frass of plant-chewing (caterpillars, beetles) or sucking (mites, … [↵][1]1To whom correspondence may be addressed. Email: nuernberger{at}uni-tuebingen.de. [1]: #xref-corresp-1-1