But biotechnology's most novel contribution will probably be in adding alien genes to the rice gene pool through genetic engineering. Genetic engineering also allows the re-introduction of rice genes that have been extracted and modified to give altered properties. Such gene transfers are impossible with conventional breeding methods. Further, genetic engineering allows introducing one or two well-characterized genes at a time. There is no need for the extensive backcrossing done in conventional hybridization to remove undesirable genes.
Several methods are now available to transfer genes into rice.
So far, the protoplast system, and biolistic and Agrobacterium -mediated gene transfer are noteworthy. All three methods have produced fertile transgenic rice. Protoplasts are plant cells freed of their cell wall by enzymatic digestion. Protoplasts can uptake foreign DNA after treatment with polyethyleneglycol, a neutral polymer, or application of an electric current in a process known as electroporation. In the biolistic method, also known as particle bombardment, DNA associated with tiny gold particles is shot into cells with a burst of high pressure.