The ftsA gene as a molecular marker for phylogenetic studies in Bradyrhizobium and identification of Bradyrhizobium japonicum

Abstract

The use of ftsA gene sequences for taxonomic studies of the genus Bradyrhizobium bacteria was assessed. The ftsA gene codes for an actin-like protein involved in prokaryotic cell division. Up to now, this gene has not been used as a phylogenetic marker for analysis of bacteria establishing root nodule symbiosis with Fabaceae plants. In this study, the ftsA gene sequences obtained for bradyrhizobia forming N 2 fixing symbiosis with four Genisteae tribe plants growing in Poland and most of the type strains of the genus Bradyrhizobium species were analyzed and evaluated as molecular markers for phylogenetic studies of these bacteria for the first time. The ftsA gene sequences of all bradyrhizobial strains with completely or partially sequenced genomes, available in the GenBank database, were also included into the analysis. The phylogeny of the ftsA gene was compared to the phylogenies of other chromosomal genes commonly used in the studies of Bradyrhizobium bacteria. The results showed that the phylogenies of ftsA and the core genes recA and glnII were congruent, making the ftsA gene useful as a phylogenetic marker. Analysis of the ftsA gene sequences revealed a single-nucleotide polymorphism unique to Bradyrhizobium japonicum strains, and the potential use of this SNP for identification of this species was discussed. Electronic supplementary material The online version of this article (10.1007/s13353-018-0479-9) contains supplementary material, which is available to authorized users.

A Genomotaxonomy View of the Bradyrhizobium Genus

“…For this, markers such as recA, glnII, atpD , dnaK, gyrB , and rpoB , have been frequently used to characterize bradyrhizobial species and strains (Vinuesa et al, 2005b; Rivas et al, 2009; Delamuta et al, 2012). Novel markers such as ftsA gene provide congruent phylogenies to those derived from recA and glnII gene sequences (Kalita and Malek, 2019). Bradyrhizobium diversity knowledge has expanded recently with studies from native legumes in Africa (Gronemeyer et al, 2017; Jaiswal and Dakora, 2019; Puozaa et al, 2019), from Brazilian and Indian Chamaecrista (Santos et al, 2017; Rathi et al, 2018), from threatened native species in Brazil (Fonseca et al, 2012), from Genisteae plants in Poland (Kalita and Malek, 2017), indigenous trees in China (Yao et al, 2015) as examples.…”