PBS has a nice list of genetic modifications to four different plants. First on the list is the antifreeze gene from a fish that was inserted into a tomato. The tomato was infected with a bacteria that had the gene in a genetically engineered plasmid. The PBS site also discusses Bt Corn, which produces it’s own pesticide, Golden Rice, which produces it’s own beta-carotene, and the herbicide resistant Roundup Ready Soybeans.