Agrobacterium tumefaciens - Gram-negative, rod prokaryote (bacterium)
Copyright 2008 Dennis Kunkel Microscopy, Inc.
Caption: Agrobacterium tumefaciens - Gram-negative, plant pathogen, rod bacterium. Agrobacterium tumefaciens is an alphaproteobacteria from the family Rhizobiaceae and is known to cause tumors in plants. It causes crown gall disease (formation of tumors disease) in over 140 species of dicot plants. A. tumefaciens is a serious pathogen of grape vines, stone fruits, nut trees, sugar beets, horse radish and rhubarb. Agrobacterium spp. can transfer DNA between itself and plants and thus has become an important tool for genetic manipulation (genetic engineering). Most Agrobacterium spp. have plasmids that they can be inject into plant cells at wound sites. This plasmid DNA is designed to integrate into the chromosomes of the infected plant's cellular DNA. DNA transfer from Agrobacterium tumefaciens to eukaryotic plant cells is the only known example of interkingdom DNA transfer. Magnification*: x3,000 Type: SEM
*(Magnifications are based on a 35mm slide image of 24mm in the narrow dimension.)