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.
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)).
Vinuesa
Pablo
P
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.
León-Barrios
Milagros
M
Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
Silva
Claudia
C
Centro de Ciencias Genómicas, UNAM, Av. Universidad s/n, Col. Chamilpa, CP 62210, AP. 565-A, Cuernavaca, Morelos, Mexico.
Willems
Anne
A
Laboratorium voor Microbiologie, Vakgroep Biochemie, Fysiologie en Microbiologie. Universiteit Gent K.L., Ledeganckstraat 35, B-9000 Gent, Belgium.
Jarabo-Lorenzo
Adriana
A
Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
Pérez-Galdona
Ricardo
R
Departamento de Microbiología, Facultad de Farmacia, Universidad de La Laguna, Avda Astrofísico Sánchez s/n, La Laguna, Spain.
Werner
Dietrich
D
FB Biologie, FG für Zellbiologie und Angewandte Botanik, Philipps Universität Marburg, Karl von Frisch Str., D-35032 Marburg, Germany.
Martínez-Romero
Esperanza
E
Centro de Ciencias Genómicas, UNAM, Av. Universidad s/n, Col. Chamilpa, CP 62210, AP. 565-A, Cuernavaca, Morelos, Mexico.
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
D001426:Bacterial Proteins; D021903:DNA, Ribosomal Spacer; D010088:Oxidoreductases; C029130:nitrogenase reductase; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales