Building Better Blueprints, One Gene at a Time

The Potential of Genome Editing for Agriculture

It fills me with tremendous optimism to see with increasing frequency new articles and research papers about the potential scientific breakthroughs of genome editing. What draws me to these pieces is the great promise that this innovation holds for researchers to solve previously unsolvable problems, like treating incurable and fatal genetic diseases, modifying human immune cells to kill cancer cells, and even curbing the spread of Malaria, which still kills 627,000 people each year. In agriculture too, we are expanding our understanding as to how genome-editing could help tackle the critical agronomic and sustainability challenges we face. Today plant scientists are using the technology to design plant varieties for better yields, improved resilience to extreme weather conditions, increased resistance to diseases and pests, reduced need for fertilizer or boosted nutritional value, to name just a few examples. All of these innovations would be a win for both people and the planet.

Yet despite this promise, the successful application of genome editing hinges on its acceptance by society.  As the world urgently seeks new ways to ensure the supply of safe, healthy and affordable food – made more precarious by the COVID-19 pandemic, the war in Ukraine and the effects of climate change – I am encouraged by the increased interest in the potential of genome-editing for agriculture. However, it also concerns me that the scientific community still isn’t doing enough to help the public understand exactly what this technology does, why it’s something to celebrate instead of fear, and why scientists, like me, are so excited about it.

This article is my attempt to do that.

That Time I Built a House…

When I was in my early twenties, I built a house. And I don’t mean that I hired a contractor to build a house, or picked out a floorplan in a new neighborhood development – I mean that I literally drew the blueprints and, with the help of two family members, built the entire house from the ground up.

 
This is where I should probably remind you that I’m a plant scientist, not a carpenter or construction worker. The biggest thing I’d “constructed” before the house was probably my sixth-grade science fair project when I built a detailed model of the entire cellular respiratory pathway using only my sister’s college biology textbook as a reference.

Fast forward about ten years to when I won a government lottery for one of a few properties at a new lakeside development in Manitoba, Canada, where I’m originally from. I only had to pay $350 for the land—so taking it was a no-brainer, but the catch was that I had to build a house on it within five years.

I was still in graduate school at the time—needless to say, I couldn’t afford to hire professionals to build the house for me. So, I did what any other financially-challenged, but technically-minded college student would do: I went to the University of Wisconsin library, studied all the construction books I could find in the engineering section, drew the architectural plans for my house, and miraculously, got them approved.

Then, over the course of a few summers, my dad, brother-in-law and I brought this dream to reality. Our construction process was slow but precise. I was the reader and translator of the blueprints, cutting each board or tile to the correct measurements. Then I gave detailed instructions to my “crew,” telling them exactly where each piece needed to go. And eventually, we ended up with a pretty impressive 1,400-square-foot lake cottage that my family still uses to this day.

Everything hinges on the blueprint

DNA can’t do it all alone; it relies on molecules called Messenger RNA (mRNA) to deliver the instructions for building each protein to the parts of the cells that make them. In my house-building analogy, I was like the Messenger RNA, reading the blueprints and delivering specific instructions for building each piece of the house (or protein) to my crew, which then carried out the orders.

Now consider this: what if there was a defect in the blueprint for the house? If we followed those instructions anyway, the defect would be built into the house—which could later lead to structural problems, ranging from minor to catastrophic, depending on which part the defect involved. 

But – if I was able to pinpoint the defect in the blueprint, I could take an eraser and pencil to fix the mistake (or use scissors to snip out the faulty section and replace it), then deliver those new instructions, and my crew would build the flawless version of the house.

On the other hand, if I wanted to add a feature to improve the house design mid-construction, like adding a window or moving a wall, I could do the same thing: update the blueprints and deliver the improved instructions to the building crew. It’s important to remember that, relative to the size and complexity of the blueprint, these changes are small and precise. The house as a whole will still stand as it would have before, with one or two targeted improvements having been made.

This “fine-tuning” is what genome-editing tools are now enabling scientists to do; to develop plants with improved characteristics faster, more precisely and efficiently than ever before. And helping farmers to grow better crops to meet the needs of a growing world while reducing the environmental burden of agriculture is, I believe, certainly worth getting excited about. 

Genome editing vs. genetically modified organisms (GMOs) 

Genome editing does not introduce DNA from a different species (unlike genetically modified organisms or GMOs which transfer a desirable trait from one species to another). Changes brought about through genome editing are therefore comparable to those that might occur through natural selection or through selective breeding. Therefore, regulators in much of the Americas, Australia, Japan and India have either defined genome editing to be exempt from GMO regulations or are evaluating product candidates on a case-by-case basis—a rational, science-based approach that I agree with. Keep in mind that all new plant varieties still go through years of field trialing and safety testing before they are made available to farmers to grow. 

 
Often, I am asked if genome-edited seed products will replace the GMO seeds available to farmers today. Here I go back to my construction story and consider building my house in a warmer climate. In a “genome-editing scenario,” I could edit the blueprint and redraw the structure to have thicker walls, more insulation, and properly positioned windows to mitigate the effects of high air temperatures and help keep the house comfortable on hot days. But if I really wanted the house to be cooler, I would need to “genetically modify” the blueprint to include an air-conditioning unit—an external “trait” not included in the home’s original design. So sometimes there are limits as to what we can do to improve a plant by just editing its native DNA sequence, and I foresee a continued need for both types of technology to meet the world’s agricultural challenges.

Designing a house in the digital age

If I won the same lottery today as all those years ago, chances are that I would not be spending hours in a library pouring over books and drawing up the plans for my future house, as I did back then. Instead, I would fire up my computer and use special software to design it based on my pre-requisites. Artificial Intelligence would offer enhancements to my idea of a perfect house using insights and predictions about the land, positioning and surroundings to propose the best possible blueprint in terms of efficiency, safety and sustainability, for example.