Department of Genetics and Microbiology, M. Curie-Sklodowska University, Lublin, Poland.
Department of Genetics and Microbiology, M. Curie-Sklodowska University, Lublin, Poland.
Syst Appl Microbiol. 2020 Mar;43(2):126056. doi: 10.1016/j.syapm.2020.126056. Epub 2020 Jan 22.
In this study, the diversity and the phylogenetic relationships of bacteria isolated from root nodules of Chamaecytisus ruthenicus growing in Poland were investigated using ERIC-PCR fingerprinting and by multilocus sequence analysis (MLSA). Two major clusters comprising 13 and 3 isolates were detected which 16S rRNA gene sequencing identified as Bradyrhizobium and Phyllobacterium. The results of phylogenetic analysis of individual and concatenated atpD, gyrB and recA gene sequences showed that the studied strains may represent novel species in the genera Bradyrhizobium and Phyllobacterium. In the phylogenetic tree based on the atpD-gyrB-recA concatemers, Bradyrhizobium isolates were split into two groups closely related to Bradyrhizobium algeriense STM89 and Bradyrhizobium valentinum LmjM3. The genus Phyllobacterium isolates formed a separate cluster close to Phyllobacterium ifriqiyense LMG27887 in the atpD-gyrB-recA phylogram. Analysis of symbiotic gene sequences (nodC, nodZ, nifD, and nifH) showed that the Bradyrhizobium isolates were most closely related to Bradyrhizobium algeriense STM89, Bradyrhizobium valentinum LmjM3 and Bradyrhizobium retamae Ro19 belonging to symbiovar retamae. This is the first report on the occurrence of members of symbiovar retamae from outside the Mediterranean region. No symbiosis related genes were amplified from Phyllobacterium strains, which were also unable to induce nodules on C. ruthenicus roots. Based on these findings Phyllobacterium isolates can be regarded as endophytic bacteria inhabitating root nodules of C. ruthenicus.
在这项研究中，使用 ERIC-PCR 指纹图谱和多位点序列分析（MLSA）研究了生长在波兰的 Ruthenicus 根瘤菌分离细菌的多样性和系统发育关系。检测到由 13 个和 3 个分离株组成的两个主要聚类，16S rRNA 基因测序将其鉴定为 Bradyrhizobium 和 Phyllobacterium。个别和串联 atpD、gyrB 和 recA 基因序列的系统发育分析结果表明，所研究的菌株可能代表 Bradyrhizobium 和 Phyllobacterium 属中的新种。基于 atpD-gyrB-recA 串联序列的系统发育树中，Bradyrhizobium 分离株分为两组，与 Algeriense STM89 和 Valentinum LmjM3 密切相关。Phyllobacterium 属分离株在 atpD-gyrB-recA 系统发育树中形成一个单独的聚类，与 Ifriqiyense LMG27887 密切相关。共生基因序列（nodC、nodZ、nifD 和 nifH）分析表明，Bradyrhizobium 分离株与 Algeriense STM89、Valentinum LmjM3 和 Retamae Ro19 密切相关，它们属于 retamae 共生体。这是地中海以外地区首次报道 retamae 共生体成员的发生。从 Phyllobacterium 菌株中扩增不出共生相关基因，它们也不能在 Ruthenicus 根上诱导结瘤。基于这些发现，Phyllobacterium 分离株可以被视为 Ruthenicus 根瘤的内生细菌。
