Phylogeny of the Rhizobium-Allorhizobium-Agrobacterium clade supports the delineation of Neorhizobium gen. nov

Seyed Abdollah Mousavi; Janina Österman; Niklas Wahlberg; Xavier Nesme; Céline Lavire; Ludovic Vial; Lars Paulin; Philippe de Lajudie; Kristina Lindström

doi:10.1016/j.syapm.2013.12.007

Phylogeny of the Rhizobium-Allorhizobium-Agrobacterium clade supports the delineation of Neorhizobium gen. nov

Syst Appl Microbiol. 2014 May;37(3):208-15. doi: 10.1016/j.syapm.2013.12.007. Epub 2014 Feb 24.

Authors

Seyed Abdollah Mousavi¹, Janina Österman², Niklas Wahlberg³, Xavier Nesme⁴, Céline Lavire⁴, Ludovic Vial⁴, Lars Paulin⁵, Philippe de Lajudie⁶, Kristina Lindström⁷

Affiliations

¹ University of Helsinki, Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, Biocentre 1, Viikinkaari 9, P.O. Box 56, Helsinki FIN-00014, Finland. Electronic address: seyed.mousavi@helsinki.fi.
² University of Helsinki, Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, Biocentre 1, Viikinkaari 9, P.O. Box 56, Helsinki FIN-00014, Finland.
³ University of Turku, Laboratory of Genetics, Department of Biology, 20014 Turku, Finland.
⁴ University of Lyon, Université Lyon1, Ecologie Microbienne, UMR CNRS 5557/USC INRA 1364, 16 rue R. Dubois, F-69622 Villeurbanne Cedex, France.
⁵ University of Helsinki, Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, Viikinkaari 4, P.O. Box 56, Helsinki FIN-00014, Finland.
⁶ IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes, Campus de Baillarguet TA A-82/J, 34398 Montpellier Cédex 5, France.
⁷ University of Helsinki, Division of Microbiology and Biotechnology, Department of Food and Environmental Sciences, Biocentre 1, Viikinkaari 9, P.O. Box 56, Helsinki FIN-00014, Finland; University of Helsinki, Department of Environmental Sciences, Viikinkaari 2a, P.O. Box 65, Helsinki FIN-00014, Finland.

PMID: 24581678
DOI: 10.1016/j.syapm.2013.12.007

Abstract

The genera Agrobacterium, Allorhizobium, and Rhizobium belong to the family Rhizobiaceae. However, the placement of a phytopathogenic group of bacteria, the genus Agrobacterium, among the nitrogen-fixing bacteria and the unclear position of Rhizobium galegae have caused controversy in previous taxonomic studies. To resolve uncertainties in the taxonomy and nomenclature within this family, the phylogenetic relationships of generic members of Rhizobiaceae were studied, but with particular emphasis on the taxa included in Agrobacterium and the "R. galegae complex" (R. galegae and related taxa), using multilocus sequence analysis (MLSA) of six protein-coding housekeeping genes among 114 rhizobial and agrobacterial taxa. The results showed that R. galegae, R. vignae, R. huautlense, and R. alkalisoli formed a separate clade that clearly represented a new genus, for which the name Neorhizobium is proposed. Agrobacterium was shown to represent a separate cluster of mainly pathogenic taxa of the family Rhizobiaceae. A. vitis grouped with Allorhizobium, distinct from Agrobacterium, and should be reclassified as Allorhizobium vitis, whereas Rhizobium rhizogenes was considered to be the proper name for former Agrobacterium rhizogenes. This phylogenetic study further indicated that the taxonomic status of several taxa could be resolved by the creation of more novel genera.

Keywords: Agrobacterium; Allorhizobium; Housekeeping genes; MLSA; Rhizobium galegae.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Genes, Bacterial*
Multilocus Sequence Typing
Phylogeny*
Rhizobiaceae / classification*
Rhizobiaceae / genetics*