Here's one of them stuck on a petri dish with no hormones (photo: right). You can see it's just growing. (By the way, there must be some technical term for holes that have been punched out with a hole punch?!) Now you add hormones to the cells (photo:left) and you can see roots developing and eventually flowers will come out. That's really quite remarkable! All we really need to do is to get some DNA from the resistance gene into those cells and eventually if we get those cells generated into a plant, that gene will be in the germline of the plant -- namely the flower part, the pollen and the egg.
Incorporating the New DNA
There are two ways to accomplish this. The method depends on plant type. One way is to introduce a cloned resistance gene into a bacterium called Agrobacterium tumefaciens that normally infects plant cells. In the process of infection, the bacterium will inject the DNA for the resistance gene into the plant cell's chromosomes, if you're lucky.
The other way, for more recalcitrant plants is to use a plant gun which literally shoots bullets covered with the recombinant clone DNA. They pierce the outside cellular wall of the plants, get inside the nucleus and again insert into the chromosome of the plant cells. Don't go out and buy one of these immediately -- they are not your typical Saturday Night Special!
  
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Winding Your Way Through DNA Resource Book Index
