Researchers at the University of Idaho are working to introduce genes from a plant in the nightshade family into potatoes in order to develop spuds that are resistance to harmful nematodes, a Sept. 21 news release said.
The genes are from the plant, called litchi tomato, which has a natural resistance to several species of cyst and root-knot nematodes. The release noted nematode cysts remain viable in fields for more than a decade, and can be found down to three feet deep in soil.
The team at U of I lead by nematologist and plant pathologist Louise-Marie Dandurand, have been working for several years studying a range of possibilities for using litchi tomato as a tool to avert nematode-related yield losses in potatoes. The release said litchi tomato has been planted as a “trap crop” in the program to eradicate pale cyst nematode (PCN). When planted in fields infested with PCN, litchi tomato stimulates cysts to hatch in the absence of a viable host, causing them to starve.
The release noted Dandurand also has a post-doctoral researcher seeking to identify chemicals in litchi tomato that harm or kill nematodes. The chemicals that prove effective could be refined and applied directly to fields as a pesticide.
Allan Caplan, associate professor in U of I’s Department of Plant Sciences, and Fangming Xiao, a professor in the department, are working to identify the genes in litchi tomato that are specifically expressed when nematodes attack the plant
“We found at least 277 genes that got turned on,” Caplan said in the release. “We think not all of them are necessary. We have to make educated guesses of which to try first, and it’s really a matter of trial and error. We’re pretty certain some of these are going to have a big effect but we can’t say with certainty which ones they’re going to be.”
The two have turned over some of the genes they suspect may be directly involved in killing nematodes to Joseph Kuhl, associate professor in the Department of Plant Sciences, who used biotechnology to introduce them into a red-skinned potato variety, Desiree, last summer. Desiree was chosen because it’s relatively easy to transform through genetic modification, the release said.
Xiao created some biotech potatoes using litchi tomato genes last fall, and Caplan is set to introduce additional litchi tomato genes into potatoes this summer. The release noted all their growing, infecting and analysis is taking place in closed growth chambers.
By first using genetic engineering to find the pathway through which litchi tomato protects itself, Caplan believes researchers may later be able to change gene expression to protect potatoes from nematodes through laboratory methods that aren’t considered to be genetic modifications.