Allorhizobium vitis  Allorhizobium vitis is a plant pathogen that infects grapevines. The species is best known for causing a tumor known as crown gall disease. One of the virulent strains, "A. vitis" S4, is responsible both for crown gall on grapevines and for inducing a hypersensitive response in other plant species. Grapevines that have been affected by crown gall disease produce fewer grapes than unaffected plants. Though not all strains of "A. vitis" are tumorigenic, most strains can damage plant hosts. "A. vitis" shares many genetic and morphological characteristics with several "Agrobacterium" species, including "A. tumefaciens". The two species have overlapping host ranges, and both "A. vitis" and "A. tumefaciens" may reduce the yield of infected crops. For this reason, research on "A. vitis" focuses on transmission and methods of control. "A. vitis" is a Gram-negative bacterium with a thin peptidoglycan layer in its cell wall. The species is aerobic and mesophilic, with individual cells that are rod-shaped and motile. On culture, colonies are round, white, and translucent. The presence of "A. vitis" has been confirmed in Germany, France, Austria, Hungary, South Africa, and the United States. Crown gall disease outbreaks in Europe and North America in the mid-1980s have been linked to "A. vitis", and the species has continued to survive in those regions. Additionally, a survey conducted in China from 2003-2009 identified strains of "A. vitis" on blighted banana plants. The genome of "A. vitis" consists of two circular chromosomes and five plasmids. It is 6.32 Mb long and encodes 5549 proteins. Four rRNA operons have been identified. Tumorigenic strains contain a Ti plasmid (pTi). Ti plasmids in galls produce various opines that are then secreted from the gall. In a vitis, pTi codes for octopine and/or cucumopine. Tumorigenic strains also contain a plasmid that allows the bacterium to utilize tartrate. "A. vitis" was formerly referred to as "Agrobacterium" biovar III. Originally, the species included only biovar III strains found in grape hosts.