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CRISPR-Cas adaptive immunity systems of prokaryotes have been identified in 42% of bacteria and 85% of archaea [1] and are actively used in genetic engineering. However, in nitrogen-fixing nodule bacteria required for agriculture, these systems are very poorly characterized. Therefore, in this study, we evaluated the diversity of CRISPR-Cas systems in the genomes of 39 isolates of alfalfa nodule bacteria Sinorhizobium meliloti recovered from soil samples from Kazakhstan and Turkmenistan, which belong to the Centra...

Nodule bacteria increase the resistance of host plants to abiotic stress factors; however, the role of the genetic potential of rhizobia in the formation of productive salt-tolerant plant-microbial symbiosis remains underestimated. The aim of the study was to evaluate the pool of genes responsible for the salt tolerance of the alfalfa microsymbiont, Sinorhizobium meliloti, using the DNA microarray technique, phenotype microarray (PM), NGS and NNGS-technologies and genome mining (antismash 5.0). As a result of the ...

Sinorhizobium meliloti are agriculturally valuable species of soil bacteria that form nitrogen-fixing symbiosis with alfalfa plants. Global climate changes lead to an increase of agricultural areas subjected to salinity. Current knowledge about about high-salt stress impact on soil saprophitic root nodulated microsymbionts of legumes is weakly studied and rhizobia gene pool responsible for salt tolerance are fragment and far from clear. An increase of bacteria nonspecific resistance (immune status) to unfavorable ...

The effectiveness of rhizobia-legume symbiotic interaction is under the genetic control of macro- and microsymbionts. Both symbionts exhibit high level of genome/genome specificity interaction which is reflected by symbiotrophic indices vary significantly. Virulence and plant dry mass increasing are indices widely used in order to reveal well matched rhizobia strain and variety of legume host plant for practice demand. The aim of the research was to study how allelic polymorphism of symbiotically significant genes...

Soil saprophytic nitrogen-fixing nodule bacteria (rhizobia) of the Sinorhizobium meliloti species are formed symbiosis with alfalfa and can also be a host of bacteriophages. Rhizobia have a symbiotic and saprophytic life phase?s cycle. Nodules formed by rhizobia on alfalfa roots are destroyed at the end of the growing season and bacteria surviving in nodule threads and did not transformed into bacteroids are released into the soil microbiome. The last is enriched in bacteriophages, which can significantly decrease...

Currently, CRISPR/Cas systems are actively studied bacterial systems, due to the possibilitpossibility to apply them for targeted editing of eukaryotic genomes. CRISPR/Cas systems are belonged to adaptive immun immune system of bacteria and archaea acting against invading mobile genetic elements (MGEs: bacteriophages and integrative conjugative elements ). Curre Currently CRISPR/Cas systems were detected in genomes of 75% of known archaea and 36 % of bacteria strains . However, there are still quite less knowledge...

Nodule bacteria (rhizobia) forming nitrogen-fixing symbiosis with legumes have a multicomponent genome represented by chromosome and a number of plasmids of different sizes. Genes related to symbiotic activity of Sinorhizobium meliloti are located predominantly on two megaplasmids SMa and SMb (1.35 and 1.68 Mb, correspondingly). Genomes at about 80% of native rhizobia nodulating alfalfa contained cryptic plasmids with sizes varied from 7 up to 450 kb. Functional role of this class of plasmids remained unclear up t...