Beans use an immune receptor to call in airstrikes on caterpillars

Key points

• For decades, scientists have understood that plants can release volatile organic compounds—essentially airborne chemical signals—to attract the natural enemies of the things that eat them, like caterpillars.
• What we didn’t know was exactly how a plant translates the physical act of being eaten into a specific, predator-summoning distress signal.
• “[One] thing we didn’t know is how the plant detects the caterpillar in the first place,” says Adam Steinbrenner, a biologist at the University of Washington.
• Now, after years of experimenting with common bean plants in the lab and in the agricultural fields of Oaxaca, Mexico, Steinbrenner’s team pinpointed a single immune receptor that orchestrates its anti-caterpillar defense system.
• Drooling caterpillars When an herbivorous insect like a caterpillar feeds on a plant, it introduces its saliva straight into the plant’s damaged tissues.