Kansas State University researcher begins quest for new virus-resistant plant technology

Kansas State University plant pathologist David Cook is working to develop a technology that would target DNA and RNA viruses in farm crops.

A Kansas State University researcher is setting off on an ambitious quest to develop a technology that would provide greater resistance to viruses and pathogens in common farm crops.

David Cook, an assistant professor in plant pathology, has received just under $1 million from the Defense Advanced Research Projects Agency (DARPA) to pursue an idea that would target viruses through their ribonucleic acid, or RNA.

In biological terms, RNA is the delivery mechanism for deoxyribonucleic acid, or DNA, which contains the genetic 'blueprint' of a living organism.

DARPA is the research arm of the U.S. Department of Defense, located in the Defense Sciences Office. Cook said the group has been funding more projects in biology and agriculture recently, with an eye on protecting the country from acts of bioterrorism and related threats.

Viruses come in different forms, with some storing their information in the form of RNA and others in the form of DNA (deoxyribonucleic acid). Current methods to combat these viruses using plant resistance take significant amounts of time and many viruses change to avoid control.

“We think we can develop a novel approach to target both DNA and RNA viruses,” Cook said of his idea to develop the technology. “It should be quicker and allow us to create plants that are resistant to many viruses. And we are thinking of ways to mitigate virus evolution to make the system last a bit longer.”

Most viruses are hardy little fellows. Once they encounter resistance, they’re smart enough to find a way around the resistance, constantly changing in order to survive. For plant scientists, that creates an ever-present challenge to build new forms of resistance.

Cook’s three-year project will use a well-known technology called the clustered regularly interspersed short palindromic repeats, or simply CRISPR technology.

“The CRISPR system was discovered in the late ‘80s, but it has really exploded in the last 5-10 years, sometimes called the ‘CRISPR Craze,’” Cook said. “The idea of using these systems to edit DNA has been rapidly moving. Somebody changed the system to target RNA in humans, and that’s one of the things that got me thinking about its use for plants.

“I looked into how they did it, and it’s not feasible in plants and the way we would want to use it. But it got me thinking that this would be really powerful technology and we could certainly use it for plant improvement. There are a lot of technological challenges that have to be dealt with to make it work.”

Cook and his team will begin trials immediately using the model plant, Nicotiana benthamiana, which will allow them to rapidly test the technology numerous times.

“We have our ideas of what’s going to work,” Cook said. “We’ll test it in a system against a couple of RNA and DNA viruses that represent important viral pathogens, and go from there.”

If it goes well, Cook said a short-term goal is to introduce the technology into soybeans in about three years: “The goal is that in three years we could have an economically important crop, where this system is in there and providing resistance to a couple of viruses,” he said.

“We’re trying to make quick technical progression to show that we can do this in diverse plants. This would clearly be a success if we could deliver this in a couple of years.”

The resulting varieties would be classified as genetically modified organisms, so Cook noted that they will undergo intense regulatory scrutiny before they would be made available for farmers’ fields.

“With minor modifications this technology could be put into any plant to protect against any virus,” Cook said. “That would certainly be the long-term goal.”

Aside from providing resistance to RNA viruses, Cook thinks it is possible to use CRISPR to find ways to improve a plant’s observable characteristics, such as its shape or height.

“We may be able to control many plant phenotypes using our new approach,” he said. “A long-term goal is to have these two systems working in the plant – viral resistance and controlling plant genes – and that these systems could even sort of talk to each other.”

He added: “Science is about incremental progress. It’s clearly a big task, but we’ll try to break it down into small tasks.”