Agrobacterium
Scientific classification
Kingdom: Bacteria Phylum: Proteobacteria Class: Alpha Proteobacteria Order: Rhizobiales Family: Rhizobiaceae Genus: Agrobacterium
Species
Agrobacterium tumefaciens Agrobacterium rhizogenes Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Orders Alpha Proteobacteria    Caulobacterales - e. ... Orders Alpha Proteobacteria    Caulobacterales - e. ... Families Aurantimonadaceae Bartonellaceae Beijerinckiaceae Bradyrhizobiaceae Brucellaceae Hyphomicrobiaceae Methylobacteriaceae Methylocystaceae Phyllobacteriaceae Rhizobiaceae Rhodobiaceae The Rhizobiales are an order of alpha proteobacteria. ... Genera Agrobacterium Rhizobium Sinorhizobium Ensifer The Rhizobiaceae are a family of proteobacteria, including many (but not all) species of rhizobia as well as plant parasites like Agrobacterium. ... Binomial name Agrobacterium tumefaciens Smith & Townsend, 1907 Agrobacterium tumefaciens is a species of bacteria that causes tumors (commonly known as galls or crown galls) in dicots (Smith et al. ... Binomial name Agrobacterium rhizogenes (Riker et al. ...

áAgrobacterium is a genus of bacteria that causes 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 plant improvement by genetic engineering. For other uses of the word, please see Genus (disambiguation). ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... Binomial name Agrobacterium tumefaciens Smith & Townsend, 1907 Agrobacterium tumefaciens is a species of bacteria that causes tumors (commonly known as galls or crown galls) in dicots (Smith et al. ... In biology, a species is one of the basic units of biodiversity. ... The structure of part of a DNA double helix Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living organisms. ... Plant breeding has been practiced for thousands of years. ... An iconic image of genetic engineering; this autoluminograph from 1986 of a glowing transgenic tobacco plant bearing the luciferase gene, illustrating the possibilities of genetic engineering. ...

Taxonomic note: The Agrobacterium genus is quite heterogeneous. Recent taxonomic studies have reclassified all of the Agrobacterium species in to new genera, such as Ruegeria, Pseudorhodobacter and Stappia, but most species have been reclassified as Rhizobium species. Look up Heterogeneous in Wiktionary, the free dictionary. ... Look up taxonomy in Wiktionary, the free dictionary. ... Species Ruegeria algicola Ruegeria atlantica Ruegeria gelatinovorans The Ruegeria are proteobacteria, that previously were known as the marine Agrobacterium before they were reclassified in 1998. ... Rhizobia (from the Greek words Riza = Root and Bios = Life) are soil bacteria that fix nitrogen (diazotrophy) after becoming established inside root nodules of legumes (Fabaceae). ...

Agrobacterium as a plant pathogen

The large growths on these roots are galls induced by Agrobacterium sp.

A. tumefaciens causes crown-gall disease in plants. The disease is characterised by a tumour like growth or gall on the infected plant, often at the junction between the root and the shoot. Tumors are incited by the transfer of a DNA (T-DNA) segment from the bacterial tumour-inducing (Ti) plasmid. The closely related species, A. rhizogenes, induces root tumors, and carries the distinct Ri (root-inducing) plasmid. Although the taxonomy of Agrobacterium is currently under revision it can be generalised that 3 biovars exist within the genus, A. tumefaciens or biovar 1, A. rhizogenes or biovar 2, and A. vitis or biovar 3. Strains within biovars 1 and 2 are known to be able to harbour either a Ti or Ri-plasmid, whilst strains of biovar 3, generally restricted to grapevines, can harbour a Ti-plasmid. Non-Agrobacterium strains have been isolated from environmental samples which harbour a Ri-plasmid whilst laboratory studies have shown that non-Agrobacterium strains can also harbour a Ti-plasmid. Many environmental strains of Agrobacterium do not possess either a Ti or Ri-plasmid. These strains are avirulent. Agrobacterium tumefaciens causes gall fomration on roots. ... Agrobacterium tumefaciens causes gall fomration on roots. ... Kalanchoë infected with crown-gall using Agrobacterium tumefaciens. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... Kalanchoë infected with crown-gall using Agrobacterium tumefaciens. ... Figure 1: Schematic drawing of a bacterium with plasmids enclosed. ... Figure 1: Schematic drawing of a bacterium with plasmids enclosed. ...

The plasmid T-DNA is integrated semi-randomly into the genome of the host cell (Francis and Spiker, 2005. Plant Journal. 41(3): 464.), and the virulence (vir) genes on the T-DNA are expressed, causing the formation of a gall. The T-DNA carries genes for the biosynthetic enzymes for the production of unusual amino acids, typically octopine or nopaline. It also carries genes for the biosyntheis of the plant hormones, auxin and cytokinins. By altering the hormone balance in the plant cell, the division of those cells cannot be controlled by the plant, and tumors form. The ratio of auxin to cytokinin produced by the tumor genes determines the morphology of the tumor (root-like, disorganized or shoot-like). In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Phenylalanine is one of the standard amino acids. ... Plant hormones (or plant growth regulators, or PGRs) are internally secreted chemicals in plants that are used for regulating their growth. ... IAA appears to be the most active Auxin in plant growth. ... Cytokinins are a class of plant growth substances (plant hormones) active in promoting cell division. ...

Agrobacterium in biotechnology

The ability of Agrobacterium to transfer genes to plants has been exploited for genetic engineering for plant improvement. A modified Ti or Ri plasmid can be used. The plasmid is 'disarmed' by deletion of the tumor inducing genes, the only essential parts of the T-DNA are its two small (25 base pair) border repeats, at least one of which is needed for plant transformation. Marc Van Montagu and Jozef Schell at the University of Ghent (Belgium) discovered the gene transfer mechanism between Agrobacterium and plants, which resulted in the development of methods to alter Agrobacterium into an efficient delivery system for gene engineering in plants. A team of researchers led by Dr Mary-Dell Chilton were the first to demonstrate that the virulence genes could be removed without adversely affecting the ability of Agrobacterium to insert its own DNA into the plant genome (1983). For other meanings of this term, see gene (disambiguation). ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... An iconic image of genetic engineering; this autoluminograph from 1986 of a glowing transgenic tobacco plant bearing the luciferase gene, illustrating the possibilities of genetic engineering. ... Plant breeding has been practiced for thousands of years. ... Marc Van Montagu is a Belgian molecular biologist. ... Jozef Schell (Antwerp, 20 July 1935 - Brussels, 17 April 2003) was a Belgian molecular biologist. ... Ghent University (in Dutch, Universiteit Gent, abbreviated UGent) is one of the two large Flemish universities. ... Mary-Dell Chilton is a key founder of modern plant biotechnology. ...

The genes to be introduced into the plant are cloned into the T-DNA region of the disarmed plasmid, together with a selectable marker (such as antibiotic resistance) to enable selection for plants that have been successfully transformed. Plants are grown on media containing antibiotic following transformation, and those that do not have the T-DNA integrated into their genome will die. An alternative method is agroinfiltration. Figure 1: Schematic drawing of a bacterium with plasmids enclosed. ... Agroinfiltration is a method in plant biology to induce transient expression of genes in a plant or to produce a desired protein. ...

Plant (S. chacoense) transformed using Agrobacterium. Transformed cells start forming calluses on the side the leaf pieces

Transformation with Agrobacterium can be achieved in two ways. Protoplasts, or leaf-discs can be incubated with the Agrobacterium and whole plants regenerated using plant tissue culture. A common transformation protocol for Arabidopsis is the floral-dip method: the flowers are dipped in an Agrobacterium culture, and the bacterium transforms the germline cells that make the female gametes. The seeds can then be screened for antibiotic resistance (or another marker of interest), and plants that have not integrated the plasmid DNA will die. Image File history File links Download high-resolution version (869x717, 120 KB) I (seb951) took this image. ... Image File history File links Download high-resolution version (869x717, 120 KB) I (seb951) took this image. ... Species See text. ... Transformation is the genetic alteration of a cell resulting from the introduction, uptake and expression of foreign genetic material (DNA or RNA). ... Initially protoplast (in Greek: proton = first and platho = mould) referred to the first organized body of a species this meaning is similar to the non-biological definition, the first from from which all subsequent forms are derived. ... Plant tissue culture, also called micropropagation, is a practice used to propagate plants under sterile conditions, often to produce clones of a plant. ... Binomial name Arabidopsis thaliana (L.) Heynh. ... Germline is a word used in biology and genetics. ... Gametes (in Greek: γαμέτες) —also known as sex cells, germ cells, or spores—are the specialized cells that come together during fertilization (conception) in organisms that reproduce sexually. ... A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ...

Agrobacterium does not infect all plant species, but there are several other effective techniques for plant transformation including the gene gun. The gene gun is a device for injecting cells with genetic information, originally designed for plant transformation. ...

See also

• Agroinfiltration
• Marc Van Montagu

Agroinfiltration is a method in plant biology to induce transient expression of genes in a plant or to produce a desired protein. ... Marc Van Montagu is a Belgian molecular biologist. ...

External links

• Current taxonomy of Agrobacterium species, and new Rhizobium names
• Agrobacteria is used as gene ferry - Transfer of genetic information to other bacteria?