Agrobacterium tumefaciens
Agrobacterium tumefaciens is the causal agent of crown gall disease (the formation of tumours) in over 140 species of eudicots. It is a rod-shaped, Gram-negative soil bacterium. Symptoms are caused by the insertion of a small segment of DNA (known as T-DNA, for 'transfer DNA', not to be confused with tRNA that transfers amino acids during protein synthesis), from a plasmid into the plant cell, which is incorporated at a semi-random location into the plant genome. Plant genomes can be engineered by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors.
| Agrobacterium tumefaciens | |
|---|---|
| Agrobacterium tumefaciens attaching itself to a carrot cell | |
| Scientific classification | |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Alphaproteobacteria |
| Order: | Hyphomicrobiales |
| Family: | Rhizobiaceae |
| Genus: | Agrobacterium |
| Species: | A. tumefaciens |
| Binomial name | |
| Agrobacterium tumefaciens (Smith and Townsend 1907) Conn 1942 (Approved Lists 1980) | |
| Type strain | |
| ATCC 4720 | |
| Synonyms | |
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Homotypic synonyms
Heterotypic synonyms
Agrobacterium radiobacter (Beijerinck and van Delden 1902) Conn 1942 (Approved Lists 1980) is NOT a synonym. The two used to be synonimized on the basis of an unjustified type strain change in the Approved Lists of 1980, now reverted. | |
Agrobacterium tumefaciens is an Alphaproteobacterium of the family Rhizobiaceae, which includes the nitrogen-fixing legume symbionts. Unlike the nitrogen-fixing symbionts, tumor-producing Agrobacterium species are pathogenic and do not benefit the plant. The wide variety of plants affected by Agrobacterium makes it of great concern to the agriculture industry.
Economically, A. tumefaciens is a serious pathogen of walnuts, grape vines, stone fruits, nut trees, sugar beets, horse radish, and rhubarb, and the persistent nature of the tumors or galls caused by the disease make it particularly harmful for perennial crops.
Agrobacterium tumefaciens grows optimally at 28 °C (82 °F). The doubling time can range from 2.5–4h depending on the media, culture format, and level of aeration. At temperatures above 30 °C (86 °F), A. tumefaciens begins to experience heat shock which is likely to result in errors in cell division.