"You're capitalizing on the same motivations that breeders have always had. They need genetic variability if they're going to make progress on solving a problem like disease resistance. If the variability exists in the plants of that species somewhere, they can use traditional plant breeding and combine those genes with genes their varieties already have and make improvements. But what if there is no genetically controlled resistance to that disease or that insect? Traditional plant breeding is stuck at that point. There's nothing that the breeder can do to overcome that challenge. And that's where genetic engineering has its biggest advantage.
"In genetic engineering, you can actually take a gene from any species and integrate it into the genetic information molecule that the plant already has. So, you're adding new genetic variation. The key is that that gene needs to be able to control the characteristic that is a challenge to the plant breeder, or more importantly a challenge to the farmer who's going to grow those crop varieties
"Actually there are two methods that are used. One uses a naturally occurring genetic engineer. There's a microbe that is called 'Agrobacterium.' Okay, so another microbe in our story. This microbe is a soil bacterium. Most of the time it lives a pretty sedate life degrading dead plant parts. But if it happens to live close to a wounded plant, it changes its life style. It will find itself inside the wound, and it senses that it's near a plant. And then it mobilizes some of its own DNA to insert into the plant cells and take over the metabolism of those plants So, scientists were studying that, and they said, 'You know, this bacteria is amazing. It can genetically engineer plants.' And then somebody had the idea, 'What if we take all those genes out of this bacteria, this agrobacterium, that cause disease and we just put in genes that we want the plant to have? Will it still introduce those genes into the plant?' And sure enough, it did So now, this naturally occurring genetic engineer can be used to introduce genes that we want to introduce into all of our major crop plants corn, rice, even wheat. You can use this naturally occurring genetic engineer.
"Now, a part of the story is that it took about two decades of research to get it to work on corn. Meanwhile scientists had some other ideas. So one scientist said, 'What if I just shoot the DNA into cells that are on a Petri dish? I know I can grow corn cells that are on a Petri dish and get little corn plants to clonally propagate from those cells. What if I shoot them with little gold particles, so the gold doesn't kill the cell. But if I coat DNA on those gold particles and shoot it in, then maybe I'll get DNA in the cell that can be incorporated permanently into the corn's chromosome.' And guess what? That worked.
"So, can you imagine if you were the first person that heard this idea from your fellow scientist? What would you have said? 'You're crazy!' But it worked. And so, that's called the 'gene gun.' It was not predictable science in terms of how often they would get plants from this that would express these genes and keep them in their chromosome. But with trial and error, which has always been a part of plant breeding, they were able to find lines that worked."