Molecular basis of symbiosis between Rhizobium and legumes

  title={Molecular basis of symbiosis between Rhizobium and legumes},
  author={Christoph Freiberg and R{\'e}my Fellay and Amos Bairoch and William John Broughton and Andr{\'e} Rosenthal and Xavier Perret},
Access to mineral nitrogen often limits plant growth, and so symbiotic relationships have evolved between plants and a variety of nitrogen-fixing organisms. These associations are responsible for reducing 120 million tonnes of atmospheric nitrogen to ammonia each year. In agriculture, independence from nitrogenous fertilizers expands crop production and minimizes pollution ot water tables, lakes and rivers. Here we present the complete nucleotide sequence and gene complement of the plasmid from… 
Nitrogen-fixing bacteria associated with leguminous and non-leguminous plants
A wide diversity of nitrogen-fixing bacterial species belonging to most phyla of the Bacteria domain have the capacity to colonize the rhizosphere and to interact with plants.
Genomics insights into symbiotic nitrogen fixation.
The Composite Genome of the Legume Symbiont Sinorhizobium meliloti
The annotated DNA sequence of the α-proteobacteriumSinorhizobium meliloti, the symbiont of alfalfa, is presented, indicating that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution.
Complete sequence of a Rhizobium plasmid carrying genes necessary for symbiotic association with the plant host
The complete sequencing of the symbiotic plasmid pNGR234a from Rhizobium species NGR234(1) is reported, revealing not only putative new symbiotic genes but also possible mechanisms for evolution and lateral dispersal of symbiotic nitrogen-fixing abilities among rhizobia.
Legumes Symbioses: Absence of Nod Genes in Photosynthetic Bradyrhizobia
It is shown by complete genome sequencing of two symbiotic, photosynthetic, Bradyrhizobium strains, BTAi1 and ORS278, that canonical nodABC genes and typical lipochito-oligosaccharidic Nod factors are not required for symbiosis in some legumes.
Synthetic Plasmids to Challenge Symbiotic Nitrogen Fixation Between Rhizobia and Legumes
The major molecular mechanisms involved in the development of proficient nodules are reviewed and a framework for assembling a subset of symbiotic loci into small synthetic plasmids capable of converting soil bacteria into beneficial plant symbionts is described.
Genealogy of legume-Rhizobium symbioses.
Legume Symbiotic Interaction from Gene to Whole Plant
Nodule inception NIN proteins are crucial for nodulation organogenesis through the activation of target proteins, and the response of rhizobia and plants to environmental stress and their strategy to adapt stress is reviewed.
Legumes and Nitrogen Fixation: Physiological, Molecular, Evolutionary Perspectives, and Applications
In order to meet the ever growing food, feed, and biofuel demand, there has been an increasing dependence on intensive agriculture that may lead to the deterioration of soil quality and require the production of nitrogen fertilizers at the expense of nonrenewable fossil fuels.
Symbiotic nitrogen fixation research in the postgenomics era
The stage is set for a renaissance in symbiosis research, which will provide new insight into the complex molecular interplay that underpins symbiotic nitrogen fixation, and how functional genomics might contribute to this renaissance.


Ecological genetics of Rhizobium meliloti: symbiotic plasmid transfer in the Medicago sativa rhizosphere
Interspecific transfer of pJB5JI generated symbiotically proficient transconjugants of WL113, demonstrating that a mechanism exists for genetic flux in indigenous R. meliloti populations in response to selection pressure provided by the host legume.
Two C4-dicarboxylate transport systems in Rhizobium sp. NGR234: rhizobial dicarboxylate transport is essential for nitrogen fixation in tropical legume symbioses.
This phenotype was found for tested host plants of NGR234 with either determinate- or indeterminate-type nodules, confirming for the first time that symbiosis-specific uptake of dicarboxylates is a prerequisite for nitrogen fixation in tropical legume symbioses.
Organization of host‐inducible transcripts on the symbiotic plasmid of Rhizobium sp. NGR234
In a systematic approach to identify genes involved in the early steps of the legume—Rhizobium symbiosis, we studied transcription patterns of symbiotic plasmid‐borne loci. A competitive
Genetic regulation of nitrogen fixation in rhizobia.
Although the involvement of FixLJ and FixK in nifA regulation is remarkably different in the three rhizobial species discussed here, they constitute a regulatory cascade that uniformly controls the expression of genes (fixNOQP) encoding a distinct cytochrome oxidase complex probably required for bacterial respiration under low-oxygen conditions.
Elaboration of flavonoid-induced proteins by the nitrogen-fixing soybean symbiont Rhizobium fredii is regulated by both nodD1 and nodD2, and is dependent on the cultivar-specificity locus, nolXWBTUV
It is shown that secretion of SR proteins by this organism has an absolute dependence on the regulatory gene nodD1, nodD2 and nolXWBTUV, and their potential role in symbiosis is strengthened by the discovery that their accumulation depends on these genes.
Canonical ordered cosmid library of the symbiotic plasmid of Rhizobium species NGR234.
A full overlapping collection of cosmids was derived from a total genomic library and sequences homologous to nodE, nodG, nodP, and nodQ have been assigned to another autonomously replicating element in Rhizobium species NGR234.
Plant-Microbe Interactions
Current concepts in the use of introduced bacteria for biological disease control: mechanisms and antifungal metabolites and Linda S. Thomashow and David M. Weller.
Nodulating strains of Rhizobium loti arise through chromosomal symbiotic gene transfer in the environment.
The results suggest that the diverse strains arose by transfer of chromosomal symbiotic genes from ICMP3153 to nonsymbiotic rhizobia in the environment.
Plasmid-linked nif and "nod" genes in fast-growing rhizobia that nodulate Glycine max, Psophocarpus tetragonolobus, and Vigna unguiculata.
Confirmation that the nod genes detected by homology were responsible for nodulation were obtained by introducing the mobilization functions of RP(4) (together with Tn5) and selecting transconjugants resistant to kanamycin and neomycin was obtained.
Identification of Rhizobium plasmid sequences involved in recognition of Psophocarpus, Vigna, and other legumes
Three non-overlapping sets of cosmids were found that conferred upon a slow-growing Rhizobium species, as well as on R. loti and R. meliloti, the ability to nodulate Psophocarpus and Vigna, thus pointing to the existence of three sets of host-specificity genes.