∗Corresponding author. E-mail: [email protected] Abbreviations: AGP, Arabinogalactan protein; GPI-anchor, Glycosylphosphatidylinositol lipid anchor; HRGP, Hydroxyproline-rich glycoprotein; IT, Infection thread; NF, Nod-factor (Lipochitin oligosaccharide); LPS, lipolysaccharide; PRP, proline-rich protein; UDP, uridine diphosphate Colonization of host cells by rhizobium bacteria involves th...

Three strains of aerobic chemoorganotrophic naphthalene-degrading bacteria (designated TSY03b(T), TSY04, and TSW01) isolated from sediment of a polychlorinated-dioxin-transforming microcosm were characterized. These strains had Gram-negative-stained, rod-shaped cells measuring 0.6‒0.9 μm in width and 1.2‒3.0 μm in length and were motile by means of peritrichous flagella. Naphthalene was utilize...

High soil temperatures in tropical areas limit nodulation and dinitrogen fixation by strains of Rhizobium. Several heat-tolerant bean-nodulating Rhizobium strains have been isolated previously. However, the basis of their resistance to heat remains unknown. In this study, we compared the effects of heat on symbiotic nitrogen fixation, cell survival, amino acid uptake, and protein synthesis in a...

A quantitative method was developed to measure the binding of fluorescent-labeled lentil (Lens esculenta Moench), pea (Pisum sativum L.), broad bean (Vicia faba L.), and jackbean (Canavalia ensiformis L., DC.) lectins to various Rhizobium strains. Lentil lectin bound to three of the five Rhizobium leguminosarum strains tested. The number of lentil lectin molecules bound per R. leguminosarum 128...

Strains of Rhizobium etli, Rhizobium meliloti, and Rhizobium tropici decreased their capacity to grow after successive subcultures in minimal medium, with a pattern characteristic for each species. During the growth of R. etli CE 3 in minimal medium (MM), a fermentation-like response was apparent: the O2 content was reduced and, simultaneously, organic acids and amino acids were excreted and po...

Concatenated sequence analysis with 16S rRNA, rpoB and fusA genes identified a bacterial strain (IRBG74) isolated from root nodules of the aquatic legume Sesbania cannabina as a close relative of the plant pathogen Rhizobium radiobacter (syn. Agrobacterium tumefaciens). However, DNA:DNA hybridization with R. radiobacter, R. rubi, R. vitis and R. huautlense gave only 44%, 5%, 8% and 8% similarit...

Symbiosis between leguminous plants and soil bacteria, commonly referred to as rhizobia, is of considerable economic importance, in low input sustainable agriculture, agroforestry and land reclamation, besides being eco-friendly. In the era of development and commercialization of bioinoculant technology for sustainable agriculture development, rhizobial inoculants have been targetted as potenti...

Research in the field of Rhizobium-legume symbiosis faces a new challenge: integrate the wealth of information generated by genomic projects. The goal: apprehend the complexity of the molecular mechanisms involved in symbiotic associations. At the time of writing, the genomes of three micro-symbionts (Bradyrhizobium japonicum, Mesorhizobium loti and Sinorhizobium meliloti) have been sequenced, ...

Non-nodulating Agrobacterium-like strains identified among root nodule isolates of common bean were labeled with gusA, a reporter gene encoding beta-glucuronidase (GUS). Bean plants were then co-inoculated with an infective Rhizobium strain and labeled transconjugants of Agrobacterium-like strains. Blue staining of nodules showed that Agrobacterium-like strains were able to colonize these symbi...

Several mechanisms are expected to rapidly rid mutualisms of genetic variation in partner quality. Variation for mutualist quality, however, appears to be widespread. We used a model legume-rhizobium mutualism to test for evidence that context-dependent selection may maintain variation in partner quality. In a greenhouse experiment using 10 natural populations of Medicago truncatula and two str...