The tools of biotechnology have been used in crop development for more than three decades. And while transgenic crops may have gotten the public's attention in the beginning, plant breeders saw other benefits — including marker-assisted breeding. But the latest tool that will allow plant breeders to reach new crop production is gene editing, and Syngenta is incorporating that new tech into its development programs.
Recently, the company announced it has signed a nonexclusive intellectual property license with the Broad Institute of the Massachusetts Institute of Technology and Harvard University to use a key tool for gene editing – CRISPR-Cas9. But Michiel van Lookeren Campagne, head of global seeds research at Syngenta, says that the company has been using gene editing techniques since 2010.
"It may sound strange, but the technology to edit has been around — but it has also been very expensive," van Lookeren Campagne says. "With CRISPR-Cas9, the tech has become much easier, faster and less expensive. The tool has made gene editing accessible for everybody."
He explained that before CRISPR-Cas9 came along, a single genome edit might cost $1 million, but with the new tool it can be done for as little as $20,000 per edit.
"And this is a very precise and predictable tool for plant breeders," van Lookeren Campagne says.
Genome editing is different from what many think of for crop biotech. In more "traditional" biotech, biologists work to insert genetic material into a plant's genome, often from other sources such as soil bacteria. With gene editing, a breeder can very precisely go into a plant genome and cut out unneeded DNA, or make small edits to resident plant genes to build crop productivity.
Advancing plant breeding
"We've used genetic modification and marker technology as a tool; genome editing is just a new tool in our tool kit," van Lookeren Campagne says. "It allows us to do things like we used to do with traditional breeding, only much faster and more efficiently."
For example, traditionally, if a breeder wanted a desirable trait in a plant, that meant cross-breeding plants to bring the new trait into an elite crop. However, getting desirable traits often means bringing along some extra "baggage" — green snap for corn, or susceptibility to lodging — that will have to be bred back out. That boosts the number of breeding iterations, and lengthens the development time.
"That cross comes with extra DNA around the key trait you were looking for, and breeders work hard to break that linkage. With genome editing you can just delete that stuff away, and clean it up," van Lookeren Campagne says. "[Genome editing] will drive the gain in yield. Right now it's about 1% per year in corn, but I think editing will accelerate that."
This is high-level work on the DNA of the plant, but as van Lookeren Campagne says, this is nothing more than a traditional breeder does — but it's faster. Regulators are also looking at genome editing in the same way — as long as it’s a final product that could be achieved by more traditional methods, regulators aren't going to require extra steps to bring the product to market.
But gene editing isn't a panacea, because some efforts are more complicated. Take yield, for example. Under its Good Growth Plan, Syngenta has set a goal to improve productivity of crops 20% by 2020. This goal will measure progress using all traits and technologies available to Syngenta, and gene editing will help. Yet, improving yield at a trait level is a challenge.
"We don't know what the common components of yield or drought tolerance are," van Lookeren Campagne says. "We need to better understand the precise biology of yield common in germplasm."
Essentially, the next challenge is about gaining biological knowledge, which is advancing rapidly. For example, it's technically possible to edit a crop genome to become tolerant to a specific herbicide, but more needs to be known. Van Lookeren Campagne makes an interesting observation on that score: "If you think about it, weeds that were killed by a herbicide also get resistance to that herbicide," he says. "That was through natural evolution using genes in the plant; you could mimic that through gene editing to create herbicide tolerance."