Lavina A.M., Khakimova L.R., Matniyazov R.T., Vershinina Z.R., Baymiev A.Kh.
THE OBTAINING OF THE RECOMBINANT STRAINS OF RHIZOBIA CARRYING AN EXTRA COPY OF GENES PSSA AND ROSR LABELED WITH FLUORESCENT PROTEIN GFP ^{[№ 9 ' 2017]}
The establishment of specific symbiotic relationships between rhizobia and leguminous plants is a complex process that requires the exchange of signaling intermediary molecules between both partners. The flavonoids, secreted by the roots of leguminous plants, induce rhizobium expression of nodule-forming genes — Nod-factors. Synthesis of Nod factors is necessary, but not sufficient for the morphogenesis of effective nitrogen fixing nodules. Since no less important factor in the formation of nodules is the synthesis of rhizobacteria exopolysaccharides (EPS), which play a decisive role in the symbiotic interactions of nodule bacteria with leguminous plants. In addition, in free-living cells, rhizobia EPSs are responsible for attachment to abiotic and biotic surfaces and for the formation of biofilms that ensure the adaptation of bacteria to changing environmental conditions. Currently, the formation of biofilms by rhizobia and the relationship of this process with effective nodule formation is being intensively studied. Special attention should be paid to the rosR gene, which encodes the transcriptional regulator involved in EPS biosynthesis, as well as the pssA gene responsible for initiating the process of EPS biosynthesis in rhizobia.
To study the genes responsible for the synthesis of EPS in the context of their impact on the formation of biofilms by rhizobia, in particular in artificial symbiotic systems, where colonization of plant roots plays an important role, it is necessary to visualize the interaction of nitrogen fixing bacteria with plant roots. In view of this, the aim of this work was to obtain recombinant rhizobial strains labeled with fluorescent protein GFP by the pssA and rosR genes. To do this, a genetically engineered construct containing the fluorescent protein gene GFP was used, which serves to visualize the interaction of rhizobia with plant roots. Cloning of pssA and rosR genes into plasmid pJB658GFP, transformation of rhizobium with this construct, microscopic examination of the obtained recombinant strains was carried out.
It has been shown that recombinant rhizobial strains with an additional copy of the pssA or rosR gene are characterized by a large mismatch of the cell walls, compared to wild strains, which indicates their high production of exopolysaccharides and, as a consequence, indicates an increase in the competitiveness of the strains.

Khakimova L.R., Serbaeva E.R., Lavina A.M., Vershinina Z.R., Baymiev A.Kh.
GROWTH-STIMULATING ACTIVITY OF BACTERIA RHIZOBIUM LEGUMINOSARUM, SELECTED FROM LEGUMINOUS PLANTS OF THE SOUTH URAL ^{[№ 9 ' 2017]}
One of the promising methods for the developmrntally-oriented farming is the use of PGPR microorganisms. They can act as an effective growth promoter and, as a result, plant productivity by improving mineral nutrition and protecting against phytopathogens. One of the most important and promising groups of PGPR are the nodule bacteria of the genus Rhizobium, which are widely used in agriculture as associative microsymbionts for nonleguminous economically significant cultures.
The strains R. leguminosarum LSy10 (D18), LVe13 (Inz 2008), PVu5 isolated from legumes of the South Urals were tested on the growth-stimulating activityon seeds of cucumber and physalis plants. It has been shown that the strains R. leguminosarum LSy10 (D18), LVe13 (Inz 2008), PVu5 have growth-stimulating activity and can be used as biofertilizers for physalis and cucumber in the concentration of 107cfu / ml and 105cfu / ml. In addition, it was found that all strains have antagonistic activity against the phytopathogenic fungus F. solani and have a positive effect on plant growth.
Thus, these strains can be used as biofertilizers to protect useful crops from phytopathogenic fungi, as well as to improve plant growth.