Parasitic plant uses RNA-based communication technique
Jim Westwood, a scientist who works at Virginia Tech, may have discovered a new way that plants communicate with each other. His findings may also explain better how to combat weeds that weaken food crops in some poor nations.
Westwood's study was published in the journal Science on August 15.
"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 said. "Now that we have found that they are sharing all this information, the next question is, 'What exactly are they telling each other?'"
Westwood studied one parasitic weed, dodder. He studied how dodder latches on to two sample host plants: Arabidopsis and tomatoes. Dodder uses a protuberance known as a haustorium to break into the host plant, absorbing vital nutrients and moisture.
In one of Westwood's previous studies, he discovered that when a parasitic weed attaches itself to a new host plant, the two plants transfer RNA. RNA is a molecule that is used to convey DNA. This new study posits that in this exchange, the plants also exchange mRNA, a molecule which gives cells instructions based on DNA. Scientists previously thought that mRNA was not stable enough to be transferred between species, but Westwood's findings seem to say the opposite.
Thousands of mRNA molecules are shared between a parasitic weed and the host plant when the parasite attaches itself, letting the two plants communicate openly with each other.
Westwood plans to conduct a new study to try to figure out what the mRNA molecules the parasitic plant feeds into the host plant are saying. They may be telling the host plant to shut off its defenses so the parasitic plant has an easier opening, Westwood theorizes.
This knowledge could open up scientists to helping world hunger immensely by protecting crops in countries around the world from parasites.
"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," said Julie Scholes, a professor at the University of Sheffield in the U.K. "In addition to shedding new light on host-parasite communication, Westwood's findings have exciting implications for the design of novel control strategies based on disrupting the mRNA information that the parasite uses to reprogram the host."
Westwood said that he is excited to see how this information could be applied to save plants from parasitic weeds.
"The beauty of this discovery is that this mRNA could be the Achilles hill for parasites," Westwood said. "This is all really exciting because there are so many potential implications surrounding this new information."