University of California Riverside scientists have solved a 20-year-old genetics puzzle that could help protect wheat, barley, and other crops from the devastating infection of Brome Mosaic virus. This virus primarily affects grasses such as wheat and barley, and occasionally affects soybeans as well.

According to Ayala Rao, professor of plant pathology and microbiology, who has been studying Brome Mosaic virus for decades, the genetic material of Brome Mosaic virus is divided into three particles that until now were impossible to tell apart. Inside each of the particles is a strand of RNA, the genetic material that controls the production of proteins. The proteins perform different tasks, some of which cause stunted growth, lesions, and ultimately the death of infected host plants.

Through a genetic engineering technique, the research team led by Rao disabled the pathogenic aspects of the virus and infused the viral genes with a host plant. They were able to isolate the viral particles in the plants and determine their structure. With one of the particles is fully mapped, it became clear that the first two particles are more stable than the third.
"Once we alter the stability, we can manipulate how RNA gets released into the plants," Rao said. "We can make the third particle more stable, so it doesn't release RNA and the infection gets delayed."
[news.ucr.edu]