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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. [ABSTRACT FROM AUTHOR]

The problem of increasing the yield of cultivated plants attracts the attention of specialists and prompts scientists to study viral plant diseases as one of the causes of significant crop losses. A virus is an endogenous parasite that, having entered plant cells, uses the functions of cell organoids and biosystems for its reproduction, which leads to plant disease and a decrease in their productivity. One of the promising approaches to reducing viral damage to plants is the use of microbial antiviral preparations. The complex bacterial preparation Azogran, developed at the Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine, is based on the interaction of phosphate-mobilizing bacteria Bacillus subtilis IMV B-7023, nitrogen-fixing bacteria Azotobacter vinelandii IMV B-7076, and clay mineral -- bentonite. Phosphate-mobilizing bacteria and nitrogen-fixing bacteria significantly improve the growth and development of plants, essentially increasing the yield of agricultural crops. However, the effect of Azogran on the development and yield of potato plants infected with the X-virus has not been sufficiently studied. Taking this into account, the aim of the work was to study the effect of the complex bacterial preparation Azogran on the growth, some physiological and biochemical properties, and productivity of potato plants, uninfected and infected by the potato virus X. Methods. Microbiological (obtaining the bacterial preparation Azogran, used in granular form (0.25 g)), virological (isolation of potato virus X, inoculation of plants with potato virus X), serological (testing for the presence or absence of the virus), biochemical (determination of chlorophylls a, b and carotenoids), spectrophotometric, and statistical analysis. Results. In the conducted experiments, the Azogran was used in granular form in the amount of one and two granules. The effectiveness of the use of the preparation, which stimulates the intensive growth of plants of two varieties of potatoes (early variety Spokusa and medium variety Diva), which leads to an increase in their yield, is shown. The positive effect of Azogran was observed on the development of both infected and non-infected plants. It was found that when two granules of the preparation were applied, the yield of potatoes of the Diva variety increased by 27.02%, and the yield of potatoes of the Spokusa variety under the same conditions increased by 29.46%. A similar effect of Azogran was observed on plants infected with the estabpotato virus X, only to a lesser extent: in the Diva variety, the yield was 16.3% higher compared to the control (control -- plants not infected by the virus), and in the Spokusa variety it was higher by 22.59%. When studying the content of chlorophylls a and b and carotenoids in virus-infected potato plants, it was established that the content of chlorophylls at different stages of virus infection was different, but the content of chlorophylls and carotenoids was higher in plants bacterized with Azogran. Conclusions. The complex bacterial preparation Azogran has a positive effect on the development of uninfected and infected plants, reducing the harmfulness of viral infections and contributing to the increase in potato productivity. Azogran can be successfully used in crop production to increase the quality and quantity of crop yields. [ABSTRACT FROM AUTHOR]

At the present stage of development of plant virology the study of molecular mechanisms of regulation, translation and replication of viral RNA is of great interest. Potato virus X (PVX) RNA in viral particles is not available for in vitro translation, but acquires the ability to be translated as a result of shell protein phosphorylation. The aim of our study was to investigate the conditions of phosphorylation of the PVX coat protein in in vitro and in vivo systems, as well as the effect of EDTA and CaCl2 on the phosphorylation in vitro. Methods. The PVX coat protein was obtained by the guanidine chloride method. The kinase activity of PVX protein in vitro was determined in a standard reaction mixture containing Mn2+ ions, 0.8 mM EDTA, and 2 micro Ci 32P ATP (3000 Ci/mM). Phosphorylation of the protein in vivo was carried out by immersing Datura stramonium leaves with symptoms of PVX infection in water containing К3PO432P. After isolation of PVX from the leaves, the viral coat protein was fractionated by SDS-PAAG electrophoresis. Fractions of the protein were transferred from the gel by contact manner on a nitrocellulose filter. The PVX coat protein was detected by immunoblotting using immunoglobulins to PVX coat protein and rabbit antibodies labeled with peroxidase. The inclusion of labeled phosphorus in the PVX protein was detected by radioautography. Results. The PVX coat protein was phosphorylated in vitro in a standard incubation medium containing (gamma-32P) ATP. In contrast, the PVX coat protein cannot be phosphorylated in the same conditions in the presence of (alpha-32P) ATP. In vivo phosphorylated PVX coat protein was detected by exposing nitrocellulose filter with immunoblot on X-ray film. Additionally, it was found that the presence of 10 mm EDTA and 10 mm CaCl2 inhibited the process of the PVX coat protein phosphorylation in vitro. Conclusions. The coat protein of potato virus X is able to phosphorylate in vitro and in vivo systems. The terminal ATP phosphate plays a major role in the phosphorylation of the PVX coat protein. The presence of EDTA and Ca2+ influences on the process of protein phosphorylation in vitro. These agents are able to inhibit the process of phosphorylation of the PVX coat protein. Thus, the phenomenon of phosphorylation of the PVX coat protein apparently indicates about its participation in the regulation of the virus reproduction in the infected cell. [ABSTRACT FROM AUTHOR]