A leaf can be cut and then exposed to Agrobacterium tumefaciens which has been genetically engineered to include a recombinant plasmid. The bacteria infects the leaf cells and the leaf can be exposed to antibiotics that will kill cells which do not have the new genes.The transgenic cells will form a clump called a callus which will eventually grow roots and shoots if placed on a nutrient medium. The plantlets can then be transferred to pots and then to the soil where they grow into adult plants.