Agrobacterium-mediated Plant Transformation

The most widely used method for the introduction of new genes into plants is based on the natural DNA transfer capacity of Agrobacterium tumefaciens.

Agrobacterium tumefaciens is a soil-borne bacterium. Like Rhizobium, the nitrogen-fixing bacterial genus, Agrobacterium has developed a way of living and deriving nourishment from plant tissues. However, unlike Rhizobium, Agrobacterium is a parasite and provides no benefit to the plant that it colonises. Instead, it causes Crown Gall disease as shown in the above picture a Crown gall formation on a stem of a tomato plant. A. tumefaciens has been used extensively for genetic engineering of plants. This is achieved by engineering selected genes into the T-DNA of the bacterial plasmid in laboratory conditions so that they become integrated into the plant chromosomes when the T-DNA is transferred.