Importance des composés phénoliques dans les interactions entre plantes et microorganismes: Exemple des relations Rhizobium/légumineuses

Abstract

Summary: Induction by Rhizobium bacteria of symbiotic nitrogen-fixing root nodules on legume plants is a host-specific process. The use of a reporter gene, whose transcription can be detected easily by assaying for ß-galactosidase activity allowed quickly description of inducers in seed extracts and root exudates of various legumes. The transcription of nodulation (nod) genes in the symbiotic bacteria is induced by particular flavonoid signals, mainly flavones and isoflavones. The amounts, the diversity and the activity of the flavonoids interacting with products from nodD genes determine specificity and intensity of the nodulation. Flavonoids are molecules active at low concentrations and their technological use open new field to control plant-microbe interactions in the rhizosphere. © 1996, Taylor & Francis Group, LLC.