Agrobacterium

Agrobacterium is a genus of Gram-negative bacteria established by H. J. Conn that uses horizontal gene transfer to cause tumors in plants. Agrobacterium tumefaciens is the most commonly studied species in this genus. Agrobacterium is well known for its ability to transfer DNA between itself and plants, and for this reason it has become an important tool for genetic engineering.

The Agrobacterium genus is quite heterogeneous. Recent taxonomic studies have reclassified all of the Agrobacterium species into new genera, such as Ruegeria, Pseudorhodobacter and Stappia, but most species have been reclassified as Rhizobium species.