Agrobacterium tumefaciens

A bacterium that causes crown gall disease in some plants. The bacterium characteristically infects a wound, and incorporates a segment of Ti plasmid DNA into the host genome. This DNA causes the host cell to grow into a tumour-like structure that synthesizes specific opines that only the pathogen can metabolize. This DNA -transfer mechanism is exploited in the genetic engineering of plants. See: T-DNA.

A gram-negative, rod-shaped flagellated bacterium responsible for crown gall tumor in plants. Following infection, the TI plasmid from the bacterium becomes integrated into the host plant's DNA, and the presence of the bacterium is no longer necessary for the continued growth of the cell. This bacterium is now used to deliberately transfer genetic material into plants through biotechnology.