Wheat streak mosaic virus is good for something after all.
The yield-robbing viral infection, carried by wheat curl mites and transferred when leaves brush against one another in the wind, has limited the growth of winter wheat acres in Western Canada. But the virus’s ability to infect so efficiently gave scientists in Nebraska some ideas about how to use it to their advantage in the laboratory.
Once the virus has set up shop in an infected plant, it forces that plant’s own cells to begin manufacturing duplicate viral copies of itself.
Read Also
Research looks to control flea beetles with RNAi
A Vancouver agri-tech company wants to give canola growers another weapon in the never-ending battle against flea beetles.
Drake Stenger, a scientist with the United States Department of Agriculture’s research service at the University of Nebraska in Lincoln, has harnessed the disease’s ability to infect and control cell multiplication. Instead of making the cereal sick, the virus carries foreign genes into the growing plant, which then begins to express them in its own tissue.
“This gives plant breeders the ability to make a rapid assessment of the effect of a foreign gene in a plant,” said Stenger.
“We can tell in two weeks whether we are on the right track. Before it took up to eight months.”
This genetic transformation is not stable, doesn’t result in modified genetic offspring and doesn’t work particularly well when trying to modify protein or other seed-based characteristics.
“It works better when looking at whole plant systems,” said Stenger. “If you are trying to evaluate which gene gave you the best insect resistance for instance, you would know much more rapidly, and then you could begin the conventional process of creating a transgenic plant, knowing you already had the best gene.”
The conventional method of adding genes to a plant involves inserting the target gene into a mass of plant cells called a callus, from which a plant can be grown. That process takes six to nine months.
“We still need to make the DNA we need. That takes just as long. Once we have the gene we want, we still have to engineer the plant the way we always have. This just makes selection of the genes faster,” said Stenger.
The USDA has already licensed the technology to some plant breeders, but says it is too early to expect reportable results using the virus transfer system.
The researchers hope the system may someday provide the information they need to stop the wheat streak virus itself. In Nebraska, they are examining ways of creating cereal plants that block certain proteins that are necessary for the virus to multiply.
