Creation of an inducible vector system based on the rhizobia nodA gene promoter

Abstract

Background: The possibility of changing the properties of rhizobial bacteria by giving them the ability to regulate the expression of additionally introduced genes into them is an urgent task both for fundamental science and for applied agrobiology, since this will make it possible to obtain microsymbionts with desired properties. An expression construct using the rhizobia regulatory system was created in this work. The rhizobia nodD gene encodes a regulatory protein that, in the presence of plant inducers, flavonoids, activates the transcription of nod-genes involved in the early stages of the formation of legume-rhizobium symbiosis.
 Materials and methods: A vector construct containing the nodD gene from Rhizobium leguminosarum bv. trifoli under the regulation of its own promoter and the gfp gene under the regulation of the nodA gene promoter from the same rhizobia was obtained. Neorhizobium galegae CIAM 0702 were transformed with the vector construct.
 Results: It has been shown that in recombinant strains synthetic flavonoids are capable of inducing expression of gfp gene to varying degrees.
 Conclusion: In the future, the results can be used to obtain rhizosphere microorganisms with a controlled synthesis of growth-stimulating and protective substances.

Effects of Pseudomonas sp. OBA 2.4.1 on Growth and Tolerance to Cadmium Stress in Pisum sativum L.

“…OBA 2.4.1 was isolated from the rhizosphere of the Oxytropis baschkiriensis by homogenizing soil samples in a sterile LB medium (Bacto Tryptone, 1%; yeast extract, 0.55; NaCl, 0.5%; agar, 1%), with further subculture and growth at 28°C [ 23 ]. DNA from the bacteria was isolated by cell lysis in 1% Triton X100 and 1% Chelex100 suspension [ 24 ].…”