Researchers Focus in on Solutions for Zebra Chip Disease

Texas A&M AgriLife Research scientists are working on a new research project to fight plant diseases transmitted by psyllids — particularly zebra chip disease. Funded by a $682,500 grant from USDA’s National Institute of Food and Agriculture, this three-year project will investigate the mechanisms through which the bacterial pathogen Candidatus Liberibacter solanacearum affects plant and insect immune systems, leading to agricultural losses.

The findings by researchers in the Texas A&M College of Agriculture and Life Sciences could help potato growers significantly reduce pesticide dependency and enhance sustainable agricultural practices.

“The economic impact of diseases like zebra chip in potatoes has been enormous for Texas and other potato-producing states, especially in the Pacific Northwest,” says principal investigator Julien Levy. “The only management system in place right now is applying pesticides to limit the spread of the disease by insects. Our research project aims to identify long-term solutions that help producers and the environment.”

Tackling Zebra Chip

With zebra chip disease, bacteria establish an infection that disrupts plants’ nutrient transport systems — whether it be tomatoes or, most notably, potatoes. Frying infected potatoes to make chips produces dark stripes, which give the disease its name. In the past, if even a single potato in a batch was found to have zebra chip, the entire lot had to be thrown out.

“This disease has resulted in massive economic losses,” says Cecilia Tamborindeguy, Texas A&M AgriLife Professor. “Although pesticide use has kept the disease somewhat under control, it’s not a sustainable solution, especially with rising production costs and other environmental concerns.”

In response, Levy and Tamborindeguy will be conducting a parallel study of plant and insect immune systems, as the bacteria must bypass both to spread infections. In particular, they’ll be investigating proteins the bacteria use to weaken the plant hosts’ defenses, as well as how those proteins could be blocked.

“The idea behind the project is to identify those proteins from the bacteria that are blocking the defense, and then we may be able to support the plant’s defense against the bacteria,” Levy adds.

While Levy leads investigations into the interactions between the bacteria and the plant, Tamborindeguy will be looking into the interactions between the bacteria and the psyllid responsible for spreading it.

“We have shown that the presence of the pathogen is also bad for the insect,” she says. “The bacteria are able to disrupt defenses at different stages in the life cycle and in different hosts. If we can improve both the insect and plant’s defense against the pathogen, it would provide an additional layer of protection.”

For more, continue reading at agrilifetoday.tamu.edu.