The tumor-inducing plasmids of the bacteria Agrobacterium tumefaciens infects plants and results to unregulated growth of the plant. However, the avirulent form of the bacterium is used to develop the transgenic plant. By introducing desired gene into the transposable region of the bacterium plasmid, the bacterium is infected in plants cells and the gene in traduced and integrated into the embryonic plant cells. The cells develop into a genetically modified plant.