One of the biggest challenges has been delivering the CRISPR components into seeds. And in a newly minted lab at the IGI, plant scientist Myeong-Je Cho is trying to figure out how to use CRISPR on plant seeds, including those from the cacao tree, which is hobbled by a disease that threatens livelihoods in the developing world. Before joining IGI in 2016, Cho worked at the ag corporation DuPont Pioneer. IGI hired him because of his approach to using CRISPR on seeds.
Past techniques inserted CRISPR into cells using Agrobacterium, a bacteria that can also carry the location for the scissors to cut. But that method is still transgenic. Cho’s approach puts CRISPR directly into cells. Staskawicz says it’s a significant advance.
To demonstrate, Cho grabs a scalpel and dissects a tiny flower. Donning a white lab coat, he cozies up to his weapon of choice: a gene gun. There’s no pistol grip or trigger; it’s just a tiny box that holds a petri dish full of plant embryos. Instead of bullets, the gun shoots hundreds of thousands of gold particles coated in CRISPR components. He fires and — pop! — they splatter like a shotgun blast. The particles penetrate the plant cells inches below, delivering CRISPR.
“If you look at it under a microscope, there are many, many holes,” Cho says.
The technique relies on a remarkable capability of plant cells called totipotency. In humans, only stem cells have the ability to become any body part. But for plants, each and every cell can form everything.
“A single cell has the potential to become a whole plant,” Cho says.
If Cho can make CRISPR work on cacao and other plants, the new crops will keep the same properties as their parents — the refined product of thousands of years of breeding — but exclude the genes that make the crops susceptible to disease. After he’s done with the gene gun, Cho shows off sparkling white refrigerator-sized incubators full of petri dishes. Inside each perfectly stacked container is a clump of what looks like pre-chewed food. Many sport little green shoots that’ll grow up to be genetically modified broccoli, rice, wheat, cacao, pepper and tomato. Each is part of IGI’s efforts to fix one crop problem or another.
“The technology is robust, and it’s simple,” Staskawicz says. “A lot of people can do it, and you don’t need fancy equipment.”
Most of us don’t think about it, but we eat GMO foods every day. Almost all American-grown corn and soybeans come from genetically modified seed. The two crops are used as sweeteners and fillers in an amazing array of processed foods.
Wheel your cart around a supermarket, and you’ll push past aisles of GMO foods, such as breads, cereals and crackers, as well as yogurt, milk and meat. Even cheese is made from genetically engineered rennet — the enzyme that curdles milk — instead of traditional rennet from animal stomachs.
But not long after engineered corn and soybeans hit the market in the mid-’90s, the term GMO got tangled together with concerns about pesticides and patented seeds. And there’s good reason for that. The first wave of genetically engineered foods was all about farmers’ needs (like crops that withstand pesticides and net higher yields) and corporate profits (from selling those pesticides).