Synthesis of chitin oligosaccharides by NodC is the first committed step in the biosynthesis of rhizobial lipochitin oligosaccharides (LCOs). The distribution of oligosaccharide chain lengths in LCOs differs between various Rhizobium species. We expressed the cloned nodC genes of Rhizobium meliloti, R. leguminosarum bv. viciae, and R. loti in Escherichia coli. The in vivo activities of the vari...

Exopolysaccharides (EPS) are produced by a wide assortment of bacteria including plant pathogens and rhizobial symbionts. Rhizobium meliloti mutants defective in EPS production fail to invade alfalfa nodules. Production of EPS in R. meliloti is likely controlled at several levels. We have characterized a new gene of this regulatory circuit. syrA was identified by its ability to confer mucoid co...

The response of pea (Pisum sativum cv. Avola) to arbuscular micorrizal fungi (AM) species Glomus mosseae and Glomus intraradices and Rhizobium leguminosarum bv. Viciae, strain D293 regarding growth, nodulation and nitrogen fixing activity was studied. Pea plants (Pisum sativum cv. Avola) were grown in a glasshouse until flowering stage (35 days) in 4 kg plastic pots using leached cinnamonic for...

DNA sequencing of the nodIJ region from Rhizobium leguminosarum biovar trifolii revealed the nodT gene immediately downstream of nodJ. DNA hybridizations using a nodT-specific probe showed that nodT is present in several R. leguminosarum strains. Interestingly, a flavonoid-inducible nodT gene homologue in R. leguminosarum bv. viciae is not in the nodABCIJ operon but is located downstream of nod...

An investigation was carried out to determine the genetic structure in soil populations of Rhizobium leguminosarum bv. trifolii and viciae at each of two Oregon sites (A and C) that were 1 km apart. Although the soils were similar, the plant communities were quite different because grazing by domestic animals had been allowed (site A) or prevented (site C). Analysis of allelic variation at 13 e...

A system for studying the in vivo activity of Rhizobium NodC protein in Escherichia coli has been developed. Using thin-layer chromatography, high-performance liquid chromatography, and mass spectrometry, we show that in this system R. leguminosarum bv. viciae NodC protein directs the synthesis of chitinpentaose, chitintetraose, chitintriose, and two as yet unidentified modified chitin oligosac...

Rhizobium leguminosarum bv. viciae RCAM1026 is a strain first isolated in 1964 from nodules of "Ramensky 77" cultivar of garden pea (Pisum sativum L.) now routinely used as a model strain in inoculation experiments on pea. Assembly with SPAdes yielded 133 contigs longer then 200 bp (N50 = 202,321, GC% = 60.84). Resulting annotated genome is 7,248,686 bp encoding 6792 genes.

Transgenic alfalfa (Medicago sativa L. cv Regen) roots carrying genes encoding soybean lectin or pea (Pisum sativum) seed lectin (PSL) were inoculated with Bradyrhizobium japonicum or Rhizobium leguminosarum bv viciae, respectively, and their responses were compared with those of comparably inoculated control plants. We found that nodule-like structures formed on alfalfa roots only when the rhi...

Sciences, University of East Anglia, Norwich NR4 7TJ, UK 2 School of Biological Analysis of the nodulation characteristics of transposon-induced mutants of Rhizobium leguminosarum bv. viciae revealed that nodO and the closely-linked rhi genes contribute t o nodulation of peas (Pisum sativum) and the vetch Vicia hirsuta. Although mutation of nodO alone had no significant effect on nodulation of ...