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''Agrobacterium rhizogenes'' (updated scientific name: ''Rhizobium rhizogenes'')〔Young J.M., Kuykendall L.D., Martínez-Romero E., Kerr A. and Sawada H. 2001. A revision of ''Rhizobium'' Frank 1889, with an emended description of the genus, and the inclusion of all species of ''Agrobacterium'' Conn 1942 and ''Allorhizobium undicola'' de Lajudie et al. 1998 as new combinations: ''Rhizobium radiobacter'', ''R. rhizogenes'', ''R. rubi'', ''R. undicola'' and ''R. vitis''. ''International Journal of Systematic and Evolutionary Microbiology'', 51:89-103〕 is a Gram negative soil bacterium that produces hairy root disease in dicotyledonous plants. ''A. rhizogenes'' induces the formation of proliferative multi-branched adventitious roots at the site of infection; so called 'hairy roots' 〔 Chilton MD, Tepfer D, Petit A, David C, Casse Delbart FT. ''Agrobacterium rhizogenes'' insert T-DNA into the genome of the host plant root cells. nature. 1982; 295:432-4〕 In the rhizosphere, plants may suffer from wounds by soil pathogens or other sources. This leads to the secretion of phenolic compounds like acetosyringone which have chemotactic effects that attract the bacteria. Under such conditions, certain bacterial genes are turned on leading to the transfer of its T-DNA from its root inducing plasmid (Ri plasmid) into the plant through the wound. After integration and expression, ''in vitro'' or under natural conditions, the hairy root phenotype is observed, which typically includes overdevelopment of a root system that is not completely geotropic, and altered (wrinkled) leaf morphology, if leaves are present.〔Cardarelli M, Mariotti D, Pomponi M, Spanò L, Capone I, Costantino P. 1987. "''Agrobacterium rhizogenes'' T-DNA genes capable of inducing hairy root phenotype". ''Molecular and General Genetics'' 209(3):475-480.〕 Bacterial genes may be retained within the plant. The hairy roots are grown ''in vitro'' in bioreactors to study their soil interaction with other pathogens like fungi and nematodes. This technique has also led to the commercial production of certain metabolic compounds that the plant is known to secrete, especially in regard to the medicinal plants that are difficult to cultivate in sufficient quantities by other means. The root cultures are also used for genetic engineering. == References == 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Agrobacterium rhizogenes」の詳細全文を読む スポンサード リンク
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