Sequence genome analysis of two photosynthetic Bradyrhizobium sp. strains (ORS278 and BTAi1) revealed that these bacteria use a Nod Factor (NF)-independent process to establish a symbiotic interaction with legumes belonging to the Aeschynomene genus. In order to identify the bacterial genes involved during this new symbiotic process, a large Tn5 mutant library (25,248 mutants) of the model strain ORS278 was screened for clones symbiotically deficient on Aeschynomene indica or Aeschynomene sensitiva (Giraud et al. 2007).

NewNodBradyDB integrates:

• The complete genome sequence of the photosynthetic Bradyrhizobium strains (ORS278 and BTAi1),
• A library of 295 mutants altered in Nodule development (Ndv^-) or in nitrogen fixation (Fix^-).

This webpage provides easy access to a database (RhizoScope) that allow users to:

• view each genome simultaneously with the syntheny maps of other rhizobial genomes,
• access the results of the bioinformatics methods used for manual gene annotation,
• determine for any gene if mutants have been selected, how many times, in which position(s), and what are the symbiotic characteristics of the mutants (pictures of the nodules, growth rate and nitrogenase activity),
• perform queries using BLAST or keywords and export the results in various file formats (EMBL, GenBank, tab-delimited files that can be easily browsed in Excel) etc.

Publication:

• Legumes symbioses: absence of Nod genes in photosynthetic bradyrhizobia. Science 316:1307-12.

For further queries or to request a mutant please contact Dr. Eric Giraud.