Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

International Committee on systematics of prokaryotes : Subcommittee on the taxonomy of rhizobia and agrobacteria minutes of the closed meeting by videoconference, 17 july 2019

International Committee on Systematics of Prokaryotes : Subcommittee on the Taxonomy of Rhizobia and Agrobacteria Minutes, Videoconference, , -Minutes of the closed meeting of the ICSP Subcommittee on the Taxonomy of Rhizobia and Agrobacteria held by videoconference on 17 July 2019, and list of recent specie

Evaluation of AFLP for the grouping of Bradyrhizobium strains

In recent years we have characterized 250 Bradyrhizobium strains, mainly from Senegal, using several taxonomic techniques i.e. numerical taxonomy of phenotypic features, Biolog system, SDS-PAGE of total cellular proteins, AS rDNA RFLP and sequence analyses, 16S-23S rDNA intergenic gone spacer RFLP and sequence analyses, AFLP, DNA:DNA hybridizations. Here we evaluate the taxonomic resolving power of those techniques by comparing the results obtained on various subsets of the same strains. We conclude that AFLP is a useful method for an initial grouping of Bradyrhizobium strains and provides infraspecific information. However, from a limited comparison, it appears that the less labor-intensive 16S-23S rDNA intergenic gene spacer analysis gives similar results and may provide additional information on deeper groupings