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0INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" _25-26 SEPTEMBER, 2024_
Na+/Ca+2-INDUCED STRESS MITIGATION BY BIO-ORGANIC TREATMENT IS A KEY FACTOR IN ORGANIC COTTON PRODUCTION IN SALT-AFFECTED SOILS
1Bakhtiyor A. Rasulov, 2Mohichehra A. Pattaeva, 3Makhammadjon G. Kosimov
1'2'3Laboratory of Biotechnology and Nanotechnology, Institute of Genetics and Plant Experimental Biology, Uzbekistan Academy of Sciences 12"BIOAZOT-N" LTD, 111226, Kybray District, Tashkent Province, Uzbekistan https://doi.org/10.5281/zenodo.13836952
One of the main abiotic pressures endangering global sustainable crop production is salinity stress. By 2050, it is anticipated that approximately half of all agricultural lands worldwide will be damaged by salinity [1]. The physiological, biochemical, and molecular characteristics of plants are adversely affected by salinity stress in a variety of ways, which decreases not only soil fertility but also crop productivity. Reduced nutrient mobilization, hormonal imbalance, the production of reactive oxygen species (ROS), ionic toxicity, and osmotic stress are all contributing factors to poor plant development under salinity stress [2, 3]. Agricultural land becomes salinized primarily as a result of salt buildup in the soil, particularly sodium (Na+) and chloride (Cl-) ions [2, 4].
The research aimed to investigate the role of exopolysaccharide (EPS) of a diazotrophic bacterial strain Azotobacter chroococcum XH2018.
It is important to bear in mind that for evaluation of Na+ removal, it must be taken those amounts of EPS, which is formed in the presence of Na+ cations. A. chroococcum XH2018 was cultivated in the presence of different concentrations of NaCl, taken as a salinity model.
After the third day of cultivation of A. chroococcum XH2018 in 2% NaCl, the formed EPS removed 11740.752 mg/L Na+, whereas from 1.0% NaCl - 5624.52 mg/L Na+ (Table 1).
However, the Na+-binding-capacity of exocellular proteins of A. chroococcum XH2018 was lower than that of EPS. For instance, from 2% NaCl supplemented Ashby medium the exocellular proteins of the strain removed 7229.135 mg/L Na+ after the third day of cultivation, whereas from 1.0% NaCl - 3184.497 mg/L (Table 1). Na+-binding-capacity of EPS and exocellular proteins totaled 18969.887 mg/L (11740.752+7229.135) Na+ from 2% NaCl supplemented Ashby medium.
Increasing NaCl concentration, as expected, negatively affected the formation of soluble exocellular proteins (Table 2). Therefore, the Na+-binding-capacity of exocellular proteins was low.
Table 1. Na+-binding-capacity of biomaterials of A. chroococcum XH2018 in different NaCl
concentrations
Samples* Amount of removed Na+ (mg/L)
AzEPS-BF1+AzPr1 7521.87
AzEPS-BF2+AzPr2 8809.017
AzEPS-BF3+AzPr3 13369.143
AzEPS-BF4+AzPr4 18969.887
*AzEPS-BF1, AzEPS-BF2, AzEPS-BF3, and AzEPS-BF4 are EPS of A. chroococcum XH2018, produced in different concentrations of NaCl, from 0 to 2%. AzPr1, AzPr2, AzPr3, and AzPr4 are the extracellular proteins of A. chroococcum XH2018, produced in different concentrations of NaCl, from 0 to 2%.
INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" 25-26 SEPTEMBER, 2024
Table 2. Formation of exocellular proteins by A. chroococcum XH2018 in different NaCl
concentrations
Samples* Amount of exocellular proteins, |ig/mg NaCl concentration, (%)
AzPr1 428.5 0
AzPr2 218.1 0.5
AzPr3 184.3 1.0
AzPr4 161.3 1.5
AzPr5 158.7 2.0
*AzPr1, AzPr2, AzPr3, AzPr4, and AzPr5 are the exocellular proteins of A. chroococcum XH2018, produced in different concentrations of NaCl, from 0 to 2%.
It can be concluded that EPS of A. chroococcum XH2018 can be used as a salt-mitigating
agent in the salt-affected soils.
REFERENCES
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