title: Bradyrhizobium canariense sp. nov., an acid-tolerant endosymbiont that nodulates endemic genistoid legumes (Papilionoideae: Genisteae) from the Canary Islands, along with Bradyrhizobium japonicum bv. genistearum, Bradyrhizobium genospecies alpha and Bradyrhizobium genospecies beta.
abstract: Highly diverse Bradyrhizobium strains nodulate genistoid legumes (brooms) in the Canary Islands, Morocco, Spain and the Americas. Phylogenetic analyses of ITS, atpD, glnII and recA sequences revealed that these isolates represent at least four distinct evolutionary lineages within the genus, namely Bradyrhizobium japonicum and three unnamed genospecies. DNA-DNA hybridization experiments confirmed that one of the latter represents a new taxonomic species for which the name Bradyrhizobium canariense is proposed. B. canariense populations experience homologous recombination at housekeeping loci, but are sexually isolated from sympatric B. japonicum bv. genistearum strains in soils of the Canary Islands. B. canariense strains are highly acid-tolerant, nodulate diverse legumes in the tribes Genisteae and Loteae, but not Glycine species, whereas acid-sensitive B. japonicum soybean isolates such as USDA 6(T) and USDA 110 do not nodulate genistoid legumes. Based on host-range experiments and phylogenetic analyses of symbiotic nifH and nodC sequences, the biovarieties genistearum and glycinearum for the genistoid legume and soybean isolates, respectively, were proposed. B. canariense bv. genistearum strains display an overlapped host range with B. japonicum bv. genistearum isolates, both sharing monophyletic nifH and nodC alleles, possibly due to the lateral transfer of a conjugative chromosomal symbiotic island across species. B. canariense is the sister species of B. japonicum, as inferred from a maximum-likelihood Bradyrhizobium species phylogeny estimated from congruent glnII+recA sequence partitions, which resolves eight species clades. In addition to the currently described species, this phylogeny uncovered the novel Bradyrhizobium genospecies alpha and beta and the photosynthetic strains as independent evolutionary lineages. The type strain for B. canariense is BTA-1(T) (=ATCC BAA-1002(T)=LMG 22265(T)=CFNE 1008(T)).
authors.affiliation: FB Biologie, FG für Zellbiologie und Angewandte Botanik, Philipps Universität Marburg, Karl von Frisch Str., D-35032 Marburg, Germany.|Centro de Ciencias Genómicas, UNAM, Av. Universidad s/n, Col. Chamilpa, CP 62210, AP. 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Pablo
authors.initials: P
authors.lastname: Vinuesa
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
authors.forename: Milagros
authors.initials: M
authors.lastname: León-Barrios
authors.affiliation: Centro de Ciencias Genómicas, UNAM, Av. Universidad s/n, Col. Chamilpa, CP 62210, AP. 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Silva
authors.affiliation: Laboratorium voor Microbiologie, Vakgroep Biochemie, Fysiologie en Microbiologie. Universiteit Gent K.L., Ledeganckstraat 35, B-9000 Gent, Belgium.
authors.forename: Anne
authors.initials: A
authors.lastname: Willems
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
authors.forename: Adriana
authors.initials: A
authors.lastname: Jarabo-Lorenzo
authors.affiliation: Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pérez-Galdona
authors.affiliation: FB Biologie, FG für Zellbiologie und Angewandte Botanik, Philipps Universität Marburg, Karl von Frisch Str., D-35032 Marburg, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Werner
authors.affiliation: Centro de Ciencias Genómicas, UNAM, Av. Universidad s/n, Col. Chamilpa, CP 62210, AP. 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Martínez-Romero
mesh_terms: D001426:Bacterial Proteins; D020369:Bradyrhizobium / Q000145:classification* / Q000187:drug effects / Q000254:growth & development; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D019143:Evolution, Molecular; D007887:Fabaceae / Q000145:classification / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010088:Oxidoreductases / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013030:Spain; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D021903:DNA, Ribosomal Spacer; D010088:Oxidoreductases; C029130:nitrogenase reductase; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales