Quantitative time-course proteome analysis of Mesorhizobium loti during nodule maturation.

Rhizobia are nitrogen-fixing bacteria that establish a symbiotic relationship with leguminous plants. To understand the mechanism by which rhizobia alter their metabolism to establish successful nitrogen-fixing symbiotic relationship with hosts, Lotus japonicus were inoculated with Mesorhizobium loti. Bacteroids were isolated from nodules harvested at 2weeks (the early stage of nodule development), and at 3 and 4weeks (the intermediate stage of nodule development) post-inoculation.

Disclosure of the differences of Mesorhizobium loti under the free-living and symbiotic conditions by comparative proteome analysis without bacteroid isolation.

Background: Rhizobia are symbiotic nitrogen-fixing soil bacteria that show a symbiotic relationship with their host legume. Rhizobia have 2 different physiological conditions: a free-living condition in soil, and a symbiotic nitrogen-fixing condition in the nodule. The lifestyle of rhizobia remains largely unknown, although genome and transcriptome analyses have been carried out.