From "The Blade Plus", Swainsboro Georgia, October 2, 2006
Scientists engineer rootknot nematode resistance
Abstracted and modified from an article by Stephanie Schupska,
University of Georgia
University of Georgia distinguished research professor in plant pathology, Richard Hussey, and his research team have found a way to halt the damage caused by one of the world's most destructive groups of plant pathogens.
Root-knot nematodes (Meloidogyne spp.) attack nearly every food and fiber crop grown, about 2,000 plant species in all. The nematode invades plant roots, and by feeding on the roots' cells, they cause the roots to grow large galls, or knots, damaging the crop and reducing its yields.
Working with assistant research scientist Guozhong Huang and research technician Rex Allen, Hussey discovered how to make plants resistant to root-knot nematode infection. Eric Davis at North Carolina State University and Thomas Baum at Iowa State University also collaborated on the research.
The discovery "has the potential to revolutionize root-knot resistance in all crops," Hussey said. Because root- knot nematode resistance doesn't come naturally in most crops, Hussey's group bioengineered their own. The results of the study were published Sept. 26 in the journal, Proceedings of the National Academy of Sciences.
Using a technique called RNA interference (RNAi), the researchers have effectively turned the nematode's biology against itself. They genetically modified Arabidopsis, a model plant, to produce double-stranded RNA to knock out the specific parasitism gene in the nematode when it feeds on the plant roots. Note that the 2006 Nobel Prize in Physiology and Medicine was awarded to scientists Andrew Fire and Craig Mello for their discovery of RNAi using Caenorhabditis elegans as a model system.
"Our results of in-plant RNA interference silencing of a parasitism gene in root-knot nematodes provides a way to development crops with broad resistance to this destructive pathogen," Hussey said. "Equally important, our approach makes available a strategy for developing root-knot-nematode-resistant crops for which natural resistance genes do not exist."