Transgenesis is a technique in plant breeding that involves the incorporation of foreign DNA into a plant; this DNA can theoretically come from any source, but largely in commercial varieties comes from other plants, bacteria, or viruses. This form of plant breeding remains very controversial, and is largely unaccepted in most of the world most notably in Europe. Commercially transgenesis is mostly used to give plants virus resistance, insect resistance, or herbicide tolerance and mostly in commodity crops like maize, soybeans, and cotton.
How does transgenesis work? Scientists start by identifying a gene of interest. Next this gene is isolated (cloned) from the donor organism and modified to work in plants. This gene is then introduced into a plant by agrobacterium-mediated plant transformation or biolistic transformation. Once incorporated into the plant’s DNA, the new gene will be able to confer the new beneficial quality to the plant. This technique achieves plant lines that would not be able to be made by conventional breeding and is therefore largely considered unnatural.