Video: AgriLife Today
Scientists at Texas A&M AgriLife Research have created a cocktail of bacteria-destroying viruses that can prevent or stop a disease that ravages vineyards.
The discovery could provide significant help to the multimillion-dollar wine industry in the United States. Pierce’s disease can cause a vineyard to die within months after infection.
In a study published in the academic journal PLOS-ONE, the researchers identify four bacteriophages that specifically target Xylella fastidiosa, the bacterium that causes Pierce’s disease. A bacteriophage, or phage, is a virus that attacks bacteria.
Xylella fastidiosa is native to the United States and causes disease in many plants including grapevines, oaks, peaches, almonds, coffee and citrus, according to Carlos Gonzalez, a professor of plant pathology and microbiology as well as an AgriLife Research plant pathologist.
“We have imported most of our grapevines from Europe,” Gonzalez said. “The pathogen and the host – in this case the grapevine – did not co-evolve. That made the grapevines susceptible.”
The bacteria infect wine grapes via an insect known as the glassy-winged sharpshooter. When the insect feeds on a plant, the bacteria are transmitted into the plant where they travel throughout the xylem vessels, infecting as they go.
“Instead of feeding on the leaves of a plant, the glassy-winged sharpshooter feeds on the cane of a grapevine and therefore spreads the bacterium much more efficiently,” Gonzalez said.
Based on this information, Gonzales and his colleagues created a phage “cocktail” containing four candidate viruses, each chosen for its physical and genetic characteristics.
The researchers then inoculated grapevines inside a greenhouse. The team experimented with applying the phage cocktail both before and after the plants had been infected with Xylella fastidiosa.
They found that the cocktail worked both to prevent infection and to arrest the disease after infection.
The team conducted their research at the Center for Phage Technology in College Station. Private funding for the project came from Otsuka Pharmaceutical Co. Ltd. and Ridge Vineyards.