Legume nodule development

Abstract

The Fabaceae comprise the third largest family of higher plants, and numerous legume species are spread worldwide in a variety of climates from the artic circle to the tropics. Many legumes obtain their nitrogen sources via a symbiotic interaction with nitrogen-fixing rhizobia and are therefore important natural fertilizers and pioneer plants on eroded soils. Moreover, some legumes have protein-rich seeds, making them essential for food and feed. Medicago truncatula and Lotus japonicus are the model species for legume research as well as for nodulation, the process that results in the symbiotic organs, the nodules, in which the rhizobia reside for nitrogen fixation. Via biotechnological tools such as genome analysis, bioinformatics, mutagenesis, transcriptomics, proteomics and metabolomics, researchers are investigating the molecular and biological principles of the nodulation process. These studies will ultimately lead to the improvement of existing symbioses and eventually to the extension of the process to non-nodulating crops. In this chapter, an overview is given of the current knowledge of the nodulation process in the model legumes. © 2010 Springer-Verlag Berlin Heidelberg.