Host-dependent symbiotic efficiency of Rhizobium leguminosarum bv. trifolii strains isolated from nodules of Trifolium rubens

Abstract

Trifolium rubens L., commonly known as the red feather clover, is capable of symbiotic interactions with rhizobia. Up to now, no specific symbionts of T. rubens and their symbiotic compatibility with Trifolium spp. have been described. We characterized the genomic diversity of T. rubens symbionts by analyses of plasmid profiles and BOX–PCR. The phylogeny of T. rubens isolates was inferred based on the nucleotide sequences of 16S rRNA and two core genes (atpD, recA). The nodC phylogeny allowed classification of rhizobia nodulating T. rubens as Rhizobium leguminosarum symbiovar trifolii (Rlt). The symbiotic efficiency of the Rlt isolates was determined on four clover species: T. rubens, T. pratense, T. repens and T. resupinatum. We determined that Rlt strains formed mostly inefficient symbiosis with their native host plant T. rubens and weakly effective (sub-optimal) symbiosis with T. repens and T. pratense. The same Rlt strains were fully compatible in the symbiosis with T. resupinatum. T. rubens did not exhibit strict selectivity in regard to the symbionts and rhizobia closely related to Rhizobium grahamii, Rhizobium galegae and Agrobacterium radiobacter, which did not nodulate Trifolium spp., were found amongst T. rubens nodule isolates.Electronic supplementary materialThe online version of this article (doi:10.1007/s10482-017-0922-7) contains supplementary material, which is available to authorized users.

Plant transcriptome analysis reveals specific molecular interactions between alfalfa and its rhizobial symbionts below the species level

“…The observed noneffective (O), inhibitory (I) and effective (E) intraspecies interactions can thus be explained by the equilibrium between the energy cost of N 2 -fixation and mineral nitrogen acquisition [38]. Moreover, our results of SDW-based bio-typing are generally consistent with previous reports in regards to the use of plant dry matter biomass for evaluating symbiotic efficiency [35,39,40]. It is thus critically important to inoculate compatible rhizobial strains when a specific alfalfa cultivar is cultivated in agriculture.…”

“…The symbiotic efficiency is an estimate of host growth promotion and is normally associated with enhanced plant SDW [34,35]. Here, we show that the SDWbased symbiotic efficiency of E. meliloti strains varied greatly across the five alfalfa cultivars.…”

Phototrophic Co-cultures From Extreme Environments: Community Structure and Potential Value for Fundamental and Applied Research

“…OTU000042 (classified as Rhizobium leguminosarum ), OTU000045 (classified as Acetobacteraceae ), and OTU000072 (classified as Cyanobacteria ), were the next most abundant OTUs, recruiting 17.1, 16.3, and 5.5% of the reads generated from FECB22, respectively. Rhizobium leguminosarum is a well-studied α-proteobacterium capable of N 2 -fixation and “rhizobia” have been suggested repeatedly to facilitate more sustainable agricultural practices through their symbiosis with legumes, reducing the need for nitrogen fertilizer ( Marek-Kozaczuk et al, 2017 ). It remains to be seen if OTU000042 provides N 2 to the other organisms in this co-culture or if it consumes all of the fixed N 2 itself.…”

Phototrophic co-cultures from extreme environments: community structure and potential value for fundamental and applied research

“…OTU000042 (classified as Rhizobium leguminosarum ), OTU000045 (classified as Acetobacteraceae ), and OTU000072 (classified as Cyanobacteria ), were the next most abundant OTUs, recruiting 17.1%, 16.3%, and 5.5% of the reads generated from FECB22 respectively. Rhizobium leguminosarum is a well-studied α-proteobacterium capable of N 2 -fixation and “rhizobia” have been suggested repeatedly to facilitate more sustainable agricultural practices through their symbiosis with legumes, reducing the need for nitrogen fertilizer 58 . It remains to be seen if OTU000042 provides N 2 to the other organisms in this co-culture or if it consumes all of the fixed N 2 itself.…”