Genetic technologies rooted and ready to sprout

Reading Time: 4 minutes

Biotechnology advancements are promising to reshape agriculture as the full potential of tools such as RNAi and gene editing gain acceptance.

The full potential of mRNA to speed up vaccine development leapt to the forefront during the fight to contain the pandemic, but it’s biotechnological cousin RNAi has been quietly gaining momentum in food and agriculture for years.

Despite its use, RNAi (the i stands for interference) is now being overshadowed by the new technique of gene editing.

Both will likely have their uses in products that will be used on farms in the future.

Why it matters: Regulatory updates, and clear communication from the scientific community are required for the potential of RNAi and gene editing to be realized in Canada.

RNAi selection is the essential core of all traditional crop breeding, says Ian Affleck, vice-president of plant biotechnology with CropLife Canada. Indeed, our ancestors’ selection for useful or preferable traits reinforcing specific parts of a plant’s genetic code was just a more rudimentary way of manipulating RNA.

In modern times, RNAi as a potentially revolutionary biotechnology has been on the radar since the mid-1990s. Like many technologies, it has taken decades to get it to a place of practical use.

“It’s in the last five to 10 years where we’ve really started to be able to leverage its capabilities,” says Affleck. High profile examples like the Arctic Apple — a slow-browning variety created by increasing the number of browning-preventing genes — are few and far between.

But there are less publicized cases. A notable example is the development of RNAi sprays, where the applied product only harms plants, pests, or pathogens with a specific sequence.

RNAi and gene editing are both likely to provide products for farms.
photo: iStock/Getty Images

Unique genes within pigweed, for example, could be directly targeted in a spray application, leaving everything else unharmed. Such an approach, says Affleck, offers “incredibly precise pest control options.”

Alexandra Sébastien, an ecologist, researcher and post-doctoral fellow at the University of Guelph and University of British Columbia, also says RNAi-targeting sprays have significant potential. The ability to target individual insect pests, for example, means control without harming beneficials like honeybees.

RNAi sprays break down quickly in the field as well.

“I would argue this is a benefit as it does not accumulate in the field,” she says. “It’s long enough to have an effect, and short enough not to affect the environment.”

RNAi sprays could also be very affordable, particularly if the substance used as a delivery mechanism is cheap to produce (such as yeast). Savings could be passed to multiple levels of the value chain. Such alternatives could even allow farmers to grow crops not resistant to certain pests, but achieve results similar to those in a resistant, transgenic variety.

There is increasing resistance to biotechnology traits, such as Bt, which is in much of the corn planted in Ontario.

However gene editing is threatening to steal the show.

Whatever the promise of RNAi, the onset of gene editing has in many ways delegated it to the inner pages of yesterday’s paper.

Gene editing is even more precise, says Affleck, likening it to parts of the world where residents went directly from no means of telecommunication to cellphones. It marked a significant technological jump past older, hard-wired telecommunications infrastructure, the proverbial RNAi, which served the same purpose, though less efficiently.

Though only recently emerging onto the scientific scene, gene editing initiatives abound around the globe — from high oleic soybeans and high-fibre wheat, to sweeter and more shelf-stable vegetables.

Notable Canadian examples include efforts at producing high-oil and high-protein canola, the latter of which is receiving millions in support from the Protein Industries Supercluster and other partners.

But Sébastien reiterates RNAi technologies still have some positives not necessarily shared by gene editing.

Because RNAi relates to genetic information en route to becoming proteins, controlling that process in the environment does not involve making a genetic change. By consequence, that means no new proteins are created. Proteins are what can cause adverse reactions in some people.

Gene editing, however, does change the genome, and thus can generate new proteins depending on the developer’s goals.

Though not necessarily a problem, Sébastien says the potential effects of those new proteins need to be considered.

Canadian regulations slow to adapt

In countries such as the United States and Australia, gene editing has been accepted with no additional oversight requirements provided changes made to an organism could have also been made via conventional breeding.

Affleck says Europe is the exception. There, an ongoing legal and political debate rages between how current laws classify the technology, and how (or if) changes can be made.

In Canada, the status of gene editing remains elusive. Because all plant breeding falls under federal regulation in Canada, changes need to come from Health Canada and the Canadian Food Inspection Agency. Efforts to modernize plant breeding oversight and policies are currently ongoing, with a public consultation period set to open in the coming few months.

“It requires modernization and this is our opportunity to catch up to the rest of the world,” says Affleck. “Canadian farmers need access to the same varieties as their competitors around the world do.”

While some gene-edited crops are sure to generate significant attention in and outside agricultural circles, Affleck believes the more incremental improvement of existing varieties, as done by Canada’s plant breeders using both RNAi and gene editing, will have a significant impact on the farm.

“The compound interest of being able to breed for those standard breeding objectives… when they have that tool that gets 10 per cent more powdery mildew resistance, for example,” he says, also highlighting the opportunity to fill very specific niche markets as an opportunity.

At a higher level, Sébastien believes researchers need to put more effort into public outreach and communication.

RNAi, gene editing, and genomics in general are complex subjects and differences between each are not widely understood, she says.