Biological nitrogen fixation in non-legume plants

• Published in: Annals of botany Vol. 111; no. 5; pp. 743 - 767
• Main Authors: Santi, Carole, Bogusz, Didier, Franche, Claudine
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.05.2013
• Subjects: biodiversity; crops; Crops, Agricultural - microbiology; Crops, Agricultural - physiology; Cyanobacteria; Cyanobacteria - metabolism; endophytes; Endophytes - physiology; Frankia; host plants; Infections; INVITED REVIEW; Legumes; Microbiology; Nitrogen Fixation; nitrogen-fixing bacteria; Nodules; phylogeny; plant growth; Plant interaction; Plant roots; Plant Roots - microbiology; Plant Roots - physiology; Plants; symbionts; Symbiosis; Symbiosis - physiology
• ISSN: 0305-7364; 1095-8290
• DOI: 10.1093/aob/mct048

BackgroundNitrogen is an essential nutrient in plant growth. The ability of a plant to supply all or part of its requirements from biological nitrogen fixation (BNF) thanks to interactions with endosymbiotic, associative and endophytic symbionts, confers a great competitive advantage over non-nitrogen-fixing plants.ScopeBecause BNF in legumes is well documented, this review focuses on BNF in non-legume plants. Despite the phylogenic and ecological diversity among diazotrophic bacteria and their hosts, tightly regulated communication is always necessary between the microorganisms and the host plant to achieve a successful interaction. Ongoing research efforts to improve knowledge of the molecular mechanisms underlying these original relationships and some common strategies leading to a successful relationship between the nitrogen-fixing microorganisms and their hosts are presented.ConclusionsUnderstanding the molecular mechanism of BNF outside the legume–rhizobium symbiosis could have important agronomic implications and enable the use of N-fertilizers to be reduced or even avoided. Indeed, in the short term, improved understanding could lead to more sustainable exploitation of the biodiversity of nitrogen-fixing organisms and, in the longer term, to the transfer of endosymbiotic nitrogen-fixation capacities to major non-legume crops.