Scientists say they have identified a protein that causes zombielike behavior in plants.

Certain crops are vulnerable to parasites that take control of their hosts’ behavior, forcing them to act in the intruder’s interest. (The same is true in some animal species: Spiders in Costa Rica infected by a parasitic wasp, for example, will abandon their own web and build one better suited to the wasp.)

The phenomenon occurs in flowering plants that have been infected by a pathogen transmitted by the tiny insects called leafhoppers. Rather than grow petals or stamens, infected plants will produce green, leaflike structures. This benefits the leafhoppers, which can eat the leaflike growths, but it prevents the plants from reproducing.

“It is like a living death for the plant,” said Saskia A. Hogenhout, a biologist at the John Innes Center in England and an author of the study, which appears in the journal PLOS Biology. Affected crops can include grapes, coconuts and rapeseed.

By sequencing the genome of the pathogen, researchers identified a protein, SAP54, that causes the plants to produce the leaf tissue rather than their intended flowers. To become active, SAP54 interacts with a family of plant proteins known as RAD23.