Parasitic plants employ a genetic "language" to talk to the plants they've chosen as hosts, possibly to trick them into lowering their defenses, scientists report.
Such "vampire" plants can tap into the host, transporting RNA -- the translator of DNA, which is the plant's blueprint -- between them and their chosen victim, they say.
Plant expert Jim Westwood of Virginia Tech studied how one such parasitic plant known as a dodder or strangleweed attacks a host plant, wrapping its tendrils around its victim and then using a probe to tap into the host's stems and drain fluids.
A significant amount of so-called messenger RNA moves between both parasite and victim, Westwood and his research colleagues reported in the journal Science.
It had been believed that messenger RNA, also known as mRNA, was too fragile and short-lived to be transferred between two different species.
However, Westwood and his research colleagues discovered that thousands of mRNA molecules were exchanged between the strangleweed and its host, creating a communication exchange between both of the plants.
"The discovery of this novel form of inter-organism communication shows that this is happening a lot more than any one has previously realized," Westwood, a professor of plant pathology and physiology, said. "Now that we have found that they are sharing all this information, the next question is, 'What exactly are they telling each other?'"
A large number of plant species can mount chemical defenses against "vampire" plants, so the strangleweed might be using the RNA communication in an attempt to get the host plant to lower such chemical defenses, the researchers wrote.
If that's true, Westwood said, then that knowledge could possibly be turned against the parasite, exposing an "Achilles heel."
Understanding what's going on when a parasitic plant latches on to a host, and perhaps blocking that RNA communication, may lead to increases in major food crops globally by defeating the parasitic plants that target them, researcher Julie Scholes at Britain's University of Sheffield says.
"Parasitic plants such as witchweed and broomrape are serious problems for legumes and other crops that help feed some of the poorest regions in Africa and elsewhere," she said.
The findings have significant inferences for the possibility of creating new control strategies involving disrupting the RNA information parasites may be using to "reprogram" their victims, she said.
The next stage of the research will be an attempt to discover exactly what the exchanged mRNA is saying to each of the plants involved in a parasitic relationship, Westwood says.
