The Influence of Azotobacter vinelandii IMV B-7076 on the Buckwheat Development and Exometabolite Composition in the Root Zone

During the growth and development of plants, a large quantity of root exudates is released into the rhizosphere, forming a microbiome capable of stimulating plant growth and productivity. The application of microbial preparations will be the cornerstone of soil improvement and obtaining high-quality plant products. The aim of this study was to determine the influence of Azotobacter vinelandii IMV B-7076, a component of the highly effective complex bacterial preparation Azogran, on the buckwheat development and exometabolite composition in the root zone. Methods. The effect of azotobacter on the growth of buckwheat plants and their exometabolite synthesis was investigated during a 14-day cultivation period in a Farreus medium under phytotron conditions. The content of photosynthetic pigments in plant leaves was determined using spectrophotometric methods. The protein content in the medium was determined by the Bradford method, carbohydrates by their interaction with phenol and sulfuric acid, and phenols by the Folin-Chokalteu reagent. Results. It was found that the cultivation of buckwheat in a medium with azotobacter significantly stimulated the growth activity of plants and the content of chlorophyll a in their leaves. Under these conditions, the content of chlorophyll b and carotenoids in buckwheat leaves increased less noticeably. During the 14-day cultivation of plants in a medium containing 107 CFU/mL of these bacteria, the protein content increased by 110.4% compared to the control, phenolic compounds by 48.8%, and carbohydrates by 266.4%. Conclusions. Azotobacter vinelandii IMV B-7076 noticeably improves the growth of buckwheat, increases the concentration of exometabolites in the medium during hydroponic cultivation.