Plant-infecting bacteria have a surprisingly direct way of taking over crops. Instead of slowly breaking down defenses, many of them inject proteins straight into plant cells, effectively hijacking the system from the inside.

For decades, scientists have tried to understand one particularly important group of these proteins, known as AvrE/DspE. These molecules are used by pathogens that attack a wide range of crops, including rice, tomatoes, apples, and pears. They are responsible for diseases such as bacterial speck, brown spot, and the devastating fire blight that can wipe out entire orchards.