<P> DNA transfers naturally between organisms . Several natural mechanisms allow gene flow across species . These occur in nature on a large scale--for example, it is one mechanism for the development of antibiotic resistance in bacteria . This is facilitated by transposons, retrotransposons, proviruses and other mobile genetic elements that naturally translocate DNA to new loci in a genome . Movement occurs over an evolutionary time scale . </P> <P> The introduction of foreign germplasm into crops has been achieved by traditional crop breeders by overcoming species barriers . A hybrid cereal grain was created in 1875, by crossing wheat and rye . Since then important traits including dwarfing genes and rust resistance have been introduced . Plant tissue culture and deliberate mutations have enabled humans to alter the makeup of plant genomes . </P> <P> The first genetically modified crop plant was produced in 1982, an antibiotic - resistant tobacco plant . The first field trials occurred in France and the USA in 1986, when tobacco plants were engineered for herbicide resistance . In 1987, Plant Genetic Systems (Ghent, Belgium), founded by Marc Van Montagu and Jeff Schell, was the first company to genetically engineer insect - resistant (tobacco) plants by incorporating genes that produced insecticidal proteins from Bacillus thuringiensis (Bt). </P> <P> The People's Republic of China was the first country to allow commercialized transgenic plants, introducing a virus - resistant tobacco in 1992, which was withdrawn in 1997 . The first genetically modified crop approved for sale in the U.S., in 1994, was the FlavrSavr tomato . It had a longer shelf life, because it took longer to soften after ripening . In 1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil, making it the first commercially genetically engineered crop marketed in Europe . </P>

When was the first genetically modified plant produced in a laboratory