A century after the discovery of rhizobia, first Beta-proteobacteria species (beta-rhizobia) were isolated from legume nodules in South Africa and America. Since then, numerous belonging to Burkholderiaceae family have been isolated. The presence a highly branching lineage nodulation genes beta-rhizobia suggests long symbiotic history. In this review, we focus on beta-rhizobial genus Paraburkho...

Rhizobium ecuadorense CNPSo 671(T) was isolated from a common bean nodule in Ecuador. The draft genome brings novelty about indigenous rhizobial species in centers of genetic diversity of the legume.

Fluctuations in numbers of Rhizobium leguminosarum biovar trifolii and its bacteriophages in two fields with different soil types were followed during a 17-month period in 1981 and 1982. Mean levels of both phage and rhizobia varied significantly (P < 0.05) on different occasions, with rhizobial levels varying from 1.6 x 10 to 2.0 x 10 cell per g of soil and phage from 0 to 1.7 x 10 PFU/g of so...

The aim of this study was to characterize rhizobial isolates from Cratylia mollis Mart. ex Benth, Calliandra depauperata Benth. and Mimosa tenuiflora (Willd.) Poir. by means of rhizobial colonies morphology and restriction analysis of the 16S ribosomal gene (16S rDNA-ARDRA). Nodules were collected in the field and from plants cultivated in a greenhouse experiment using Caatinga soil samples. Si...

background and objectives: nitrogen fixation is a biological process, which provides atmospheric nitrogen in usable form for plants, and satisfies the plants n requirement and can replace chemical fertilizers in high proportion. on the other hand, calcareous and high ph soils have usually small amounts of nutrients in available forms and use of plant growth promoting rhizobacteria can increase ...

Flavonoids are crucial signaling molecules in the symbiosis between legumes and their nitrogen-fixing symbionts, the rhizobia. The primary function of flavonoids in the interaction is to induce transcription of the genes for biosynthesis of the rhizobial signaling molecules called Nod factors, which are perceived by the plant to allow symbiotic infection of the root. Many legumes produce specif...

Root symbioses with arbuscular mycorrhizal fungi and rhizobial bacteria share a common signaling pathway in legumes. Among the common symbiosis genes are CASTOR and POLLUX, the twin homologous genes in Lotus japonicus that encode putative ion channel proteins. Here, we show that the orthologs of CASTOR and POLLUX are ubiquitously present and highly conserved in both legumes and nonlegumes. Usin...

Mutualisms are thought to be destabilized by exploitative mutants that receive benefits from partners without reciprocation. Nonetheless, there is surprisingly little evidence for the spread of exploitation in mutualist populations. In particular mutualisms, non-beneficial partners are commonplace and this raises the question of whether exploitation is invading as an adaptive strategy. Here, we...