Why a parasitic vine can’t take a bite out of tomatoes

Like botanical vampires, dodder plants (Cuscuta sp.) suck the life out of crops around the world.  But tomatoes (Solanum lycopersicum) are mysteriously immune to the parasitic vine’s attacks.

To figure out how they do it, a research team from England and Germany hit tomatoes and three other plant species with C. reflexa extract in the lab. Tomatoes totally overreacted, producing stress hormones to protect themselves from the parasite, while the other plants failed to mount a defense.

This suggests that tomatoes treat the dodder like a virus, taking cues from parasite proteins as a warning system, the team writes July 28 in Science. This sensitivity traces to a receptor that senses the presence of a small protein released by dodder plants.

This probably isn’t the only defense option. Some wild tomato species can fend off dodder even though they’re missing the gene behind the receptor, the researchers note. Still, the findings could prove useful in protecting other crops from vampiric vines through genetic engineering.