Leguminosae root nodules

The biosynthesis of amino acids first requires access to a nitrogen source. In 1888, Hermann Hellriegel (1831-1895) and Hermann Wilfarth (1853-1904) discovered the process of nitrogen fixation by nodular bacteria in the root nodules of the Leguminosae. [26]... 

So far, the most extensively studied N.f. system is the symbiotic association between members of the Leguminosae and Rhizobium the legume often chosen for these studies is Glycine max (soybean). Infection of the plant roots by virulent Rhizobia leads to the formation of root nodules which have the capacity to fix nitrogen. The Rhizobia living free in the soil do not fix nitrogen. Under laboratory conditiorrs however, pure cultures of Rhizobium will fix nitro-... 

Newcombe W, Peterson R L 1979 The occurrence and ontogeny of transfer cells associated with lateral roots and root nodules in Leguminosae. Can J Bot 57 2583-2602... 

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