NodMl-V(C(18:1), Me, Cb, AcFuc) is a major component of lipo-chitin oligosaccharides (LCOs), or Nod factors, produced by Mesorhizobium loti. The presence of a 4-O-acetylated fucosyl residue (AcFuc) at the reducing end has been thought to be essential for symbiotic interactions with the compatible host plant, Lotus japonicus. We generated an M. loti mutant in which the nolL gene is disrupted; no...

In many legumes, including Lotus japonicus and Medicago truncatula, susceptible root hairs are the primary sites for the initial signal perception and physical contact between the host plant and the compatible nitrogen-fixing bacteria that leads to the initiation of root invasion and nodule organogenesis. However, diverse mechanisms of nodulation have been described in a variety of legume speci...

In legume-rhizobia symbiosis, the nodule number is controlled to ensure optimal growth of the host. In Lotus japonicus, the nodule number has been considered to be tightly regulated by host-derived phytohormones and glycopeptides. However, we have discovered a symbiont-derived phytohormonal regulation of nodule number in Mesorhizobium loti. In this study, we found that M. loti synthesized gibbe...

Mesorhizobium loti is the microsymbiont of Lotus species, including the model legume L. japonicus. M. loti differs from other rhizobia in that it contains two copies of the key nitrogen fixation regulatory gene nifA, nifA1 and nifA2, both of which are located on the symbiosis island ICEMlSym(R7A). M. loti R7A also contains two rpoN genes, rpoN1 located on the chromosome outside of ICEMlSym(R7A)...

Rhizobium loti strains NZP2037 and NZP2213 were each found to contain a single large plasmid: pRlo2037a (240 MDal) and pRlo2213a (120 MDal), respectively. Plasmid DNA present in crude cell lysates of each strain and purified pRlo2037a DNA did not hybridize with pID1, a recombinant plasmid containing part of the nitrogen fixation (nif) region of R. meliloti, indicating that nif genes were not pr...

Global viewing of protein-protein interactions (PPIs) is a useful way to assign biological roles to large numbers of proteins predicted by complete genome sequence. Here, we systematically analyzed PPIs in the nitrogen-fixing soil bacterium Mesorhizobium loti using a modified high-throughput yeast two-hybrid system. The aims of this study are primarily on the providing functional clues to M. lo...

Mechanisms underlying nodulation factor signaling downstream of the nodulation factor receptors (NFRs) have not been fully characterized. In this study, clathrin heavy chain1 (CHC1) was shown to interact with the Rho-Like GTPase ROP6, an interaction partner of NFR5 in Lotus japonicus. The CHC1 gene was found to be expressed constitutively in all plant tissues and induced in Mesorhizobium loti-i...

The unicellular green alga Lobomonas rostrata requires an external supply of vitamin B12 (cobalamin) for growth, which it can obtain in stable laboratory cultures from the soil bacterium Mesorhizobium loti in exchange for photosynthate. We investigated changes in protein expression in the alga that allow it to engage in this mutualism. We used quantitative isobaric tagging (iTRAQ) proteomics to...

Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO(2) to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti, the microsymbiont of the model legume Lotus japonicus, possesses on the symbiosis island a gene (msi040) encoding an alpha-type CA homologue, annotated as CAA1. In the present wo...