Biotech News


Gene editing made simple

Feb 17, 2017

Plant breeders look to gains new tool may bring

CHICAGO — She could explain it using a graphic of a strand of DNA, with its complicated chains of hard-to-pronounce parts. But for Dr. Juliet Marshall, a pathologist and an agronomist at the University of Idaho, a familiar nursery rhyme would do.

“Baa baa, black sheep, have you any wool? Yes, sir, yes, sir, three bags full. One for my master, one for my dame — and there comes CRISPR-CAS9, we’re going to cut it right there. Take out that ‘a’ and guess what happens? We’ve just shifted it. You’ve now forgot what those last two sentences were. But it’s still all there if you look at it,” Marshall said.

She was explaining the basics of how gene editing and the CRISPR-CAS9 process works to “edit,” or insert, cut out and replace genes to achieve different results.“We have a very targeted spot, we know what that gene is going to be used to develop, say susceptibility, a specific recognition model in the plant. We can target that spot and cut it out,” she said.

Marshall, along with representatives and members of the American Seed Trade Association, are working with gene editing to edit out and edit in traits and qualities in plants and beyond.

Long-form, CRISPR is Clustered Regularly Interspaced Short Palindromic Repeats. Cas9 is a nuclease that is used with another element to “cut” a cell’s genome and allow the editing, consisting of the addition of or deletion of specific genes.

Hot Issue

Gene editing is the hot topic for scientists in fields ranging from agriculture to medicine.

In agriculture, the technology holds promise for doing everything from fighting potentially devastating crop diseases to improving the flavor and yield of vegetables. But for the industry involved in using the technology, making sure that it and the crops it’s used in will be accepted around the globe is a priority.

“It’s a challenge from the beginning. A lot of people are not very knowledgeable about breeding or genetics. They have concerns about it, whether it’s in plant science or food or health. How we address that is going to be key,” said Andy Lavigne, president and CEO of ASTA.

The work being done with CRISPR-Cas9 extends beyond U.S. borders.

Jerry Flint, vice president of industry affairs and regulatory for DuPont Pioneer, said his company has entered into a collaboration with the International Wheat and Maize Improvement Center, based in Mexico.\ “This collaboration agreement will allow us to work very closely to help address some of the needs we have in developing countries. One of the first targets we are going to work on is maize lethal necrosis disease, a very devastating disease in Africa that can cause significant yield loss to growers,” Flint said.

“One of the things that we do is look at the plant genetics that already exist and see how we can deploy those in the latest varieties we have,” Flint said.

For Marshall, who works with wheat and barley, gene editing could be the key to finding a way to build resistance to fusarium head blight and a common and devastating side effect — vomitoxin.

Finding a way to edit resistance into wheat and barley varieties and thus control vomitoxin could prevent crop losses and resulting food waste.

“We’re seeing this vomitoxin show up in a lot of our grain. We’re seeing large levels of this toxin. I’ve seen over 25 parts per million in durum wheat in Idaho that had to be thrown away,” Marshall said.“We can edit a protein to not recognize that pathogen toxin so now we have prevented that toxin from starting the infection process and it slows down the disease. That’s where I think CRISPR-CAS can be very helpful,” she said.

Marshall emphasized that GMO wheat and GMO barley does not exist, but even without genetically modified wheat or barley, the gene editing solution still could be used to control fusarium head blight and vomitoxin.

“We can use the techniques to understand the process and use gene editing to reduce the impacts,” Marshall said.

Breeding Tool

She sees it as a way to make changes that are relatively small but important to plant breeding.“We can make rapid progress with small, but effective changes. We don’t have to do the introduction of novel genes. We don’t have to introduce novel genes at all,” she said.

Along with the science end of the process, Flint said the seed industry and companies are working to make sure the consuming public has a better understanding of the process and how it can impact scientific arenas, from medicine to food crops.

“One of the things we’re doing as we’re developing the products in our pipeline is to reach out to stakeholders, listen to them, understand some of the questions that they’re asking and try to figure out a way that we can have a productive dialogue around the tools that we’re trying to deploy and the benefits, but also understanding in terms of the tremendous opportunity this provides for plant breeders,” Flint said.

By Jeannine Otto, AgriNews Publications