UNIVERSITY PARK, Pa. -- Sneaky parasitic weeds may be able to steal genes from the plants they are attacking and then use those genes against the host plant, according to a team of scientists.
In a study, researchers detected 52 incidences of the nonsexual transfer of DNA -- known as horizontal gene transfer, or HGT -- from a host plant to members of a parasitic plant family known as the broomrapes, said Claude dePamphilis, professor of biology, Penn State. The transferred genes then became functional in the parasitic species. Although considered rare in plants and other complex species, HGT may thus occur in some parasitic plants, an insight that could lead to better methods of controlling parasitic plants that threaten agriculture, he added.
"These parasitic plants that we study from the broomrape family include some of the world's most devastating agricultural weeds," said dePamphilis. "The HGT discovery is really part of our effort to try to better understand how parasitic plants work and how we can better control them. Our hope is that we can use this information to find the best strategies to generate, or breed, resistant host plants."
The researchers, who released their findings today (Oct. 24) in the current issue of Proceedings of the National Academy of Sciences, suggest that the transfer could boost the parasitic plant's ability to invade their hosts and overcome defenses the host creates to try to ward off attacks. HGT may also help reduce the risk of infection for the parasites.
While horizontal gene transfers in less complex species, such as bacteria, are common, most evolution in more complex organisms is driven by the sexual exchange of DNA, along with mutation and natural selection. However, the researchers suggest that the close feeding connections of parasitic plants with their hosts may increase the chances of intact genes traveling from the host to the parasite's genome where it can quickly become functional.