title: Multilocus sequence analysis supports the taxonomic position of Astragalus glycyphyllos symbionts based on DNA-DNA hybridization.
abstract: In this study, the phylogenetic relationship and taxonomic status of six strains, representing different phenons and genomic groups of Astragalus glycyphyllos symbionts, originating from Poland, were established by comparative analysis of five concatenated housekeeping gene sequences (atpD, dnaK, glnA, recA and rpoB), DNA-DNA hybridization and total DNA G+C content. Maximum-likelihood phylogenetic analysis of combined atpD, dnaK, glnA, recA and rpoB sequence data placed the studied bacteria into the clade comprising the genus Mesorhizobium. In the core gene phylograms, four A. glycyphyllos nodule isolates (AG1, AG7, AG15 and AG27) formed a cluster common with Mesorhizobium ciceri, whereas the two other A. glycyphyllos symbionts (AG17 and AG22) were grouped together with Mesorhizobium amorphae and M. septentrionale. The species position of the studied bacteria was clarified by DNA-DNA hybridization. The DNA-DNA relatedness between isolates AG1, AG7, AG15 and AG27 and reference strain M. ciceri USDA 3383T was 76.4-84.2%, and all these A. glycyphyllos nodulators were defined as members of the genomospecies M. ciceri. DNA-DNA relatedness for isolates AG17 and AG22 and the reference strain M. amorphae ICMP 15022T was 77.5 and 80.1%, respectively. We propose that the nodule isolates AG17 and AG22 belong to the genomic species M. amorphae. Additionally, it was found that the total DNA G+C content of the six test A. glycyphyllos symbionts was 59.4-62.1 mol%, within the range for species of the genus Mesorhizobium.
authors.affiliation: Department of Veterinary Microbiology, University of Life Sciences, 13 Akademicka st., 20-950 Lublin, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Gnat
authors.affiliation: Department of Genetics and Microbiology, University of Maria Curie-Sklodowska, 19 Akademicka st., 20-033 Lublin, Poland.
authors.forename: Wanda
authors.initials: W
authors.lastname: Małek
authors.affiliation: Department of Genetics and Evolution, University of Bialystok, 1J Ciolkowskiego st., 15-245 Bialystok, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Oleńska
authors.affiliation: Department of Genetics and Microbiology, University of Maria Curie-Sklodowska, 19 Akademicka st., 20-033 Lublin, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Wdowiak-Wróbel
authors.affiliation: Department of Genetics and Microbiology, University of Maria Curie-Sklodowska, 19 Akademicka st., 20-033 Lublin, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Kalita
authors.affiliation: Department of Biochemistry, University of Maria Curie-Sklodowska, 19 Akademicka st., 20-033 Lublin, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Rogalski
authors.affiliation: Department of Genetics and Microbiology, University of Maria Curie-Sklodowska, 19 Akademicka st., 20-033 Lublin, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Wójcik
mesh_terms: D027883:Astragalus Plant / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D059128:Mesorhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D011044:Poland; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D053204:Root Nodules, Plant / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S