The Rhizobium--legume symbiosis

Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character
J E BeringerD A Hopwood


The rhizobia are soil microorganisms that can interact with leguminous plants to form root nodules within which conditions are favourable for bacterial nitrogen fixation. Legumes allow the development of very large rhizobial populations in the vicinity of their roots. Infections and nodule formation require the specific recognition of host and Rhizobium, probably mediated by plant lectins. Penetration of the host by a compatible Rhizobium species usually provokes host root cell division to form the nodule, and a process of differentiation by both partners then ensues. In most cases the rhizobia alter morphologically to form bacteroids, which are usually larger than the free-living bacteria and have altered cell walls. At all stages during infection, the bacteria are bounded by host cell plasmalemma. The enzyme nitrogenase is synthesized by the bacteria and, if leghaemoglobin is present, nitrogen fixation will occur. Leghaemoglobin is a product of the symbiotic interaction, since the globin is produced by the plant while the haem is synthesized by the bacteria. In the intracellular habitat the bacteria are dependent upon the plant for supplies of energy and the bacteroids, in particular, appear to differentiate so that they are ...Continue Reading


Jan 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·P J MurphyJ Schell
Aug 6, 2008·Acta Crystallographica. Section F, Structural Biology and Crystallization Communications·Tomomi FujiiYasuo Hata
Apr 27, 2002·Applied and Environmental Microbiology·Ranjeet K TokalaM J Morra
Oct 27, 1999·Proceedings of the National Academy of Sciences of the United States of America·D A PhillipsH Volpin
Sep 25, 2016·Microbiological Research·Bhagya IyerShalini Rajkumar
Jan 1, 1983·Nutrition Reviews·C D Earl, F M Ausubel
Feb 1, 1996·Medical Hypotheses·A P Kozlov
Dec 22, 2017·International Journal of Molecular Sciences·Irina V LeppyanenElena A Dolgikh
Jan 1, 1997·Critical Reviews in Microbiology·A Hochman

Related Concepts

Nitrogen Fixation
Rhizobium species
Regulation of Biological Process
Cell Division