Optimization of Potassium Supply under Osmotic Stress Mitigates Oxidative Damage in Barley

Potassium (K) is the most abundant cation in plants, playing an important role in osmoregulation. Little is known about the effect of genotypic variation in the tolerance to osmotic stress under different K treatments in barley. In this study, we measured the interactive effects of osmotic stress and K supply on growth and stress responses of two barley cultivars (Hordeum vulgare L.) and monitored reactive oxygen species (ROS) along with enzymatic antioxidant activity and their respective gene expression level. The selected cultivars (cv. Milford and cv. Sahin-91Sahin-91) were exposed to osmotic stress (−0.7 MPa) induced by polyethylene glycol 6000 (PEG) under low (0.04 mM) and adequate (0.8 mM) K levels in the nutrient solution. Leaf samples were collected and analyzed for levels of K, ROS, kinetic activity of antioxidants enzymes and expression levels of respective genes during the stress period. The results showed that optimal K supply under osmotic stress significantly decreases ROS production and adjusts antioxidant activity, leading to the reduction of oxidative stress in the studied plants. The cultivar Milford had a lower ROS level and a better tolerance to stress compared to the cultivar Sahin-91. We conclude that optimized K supply is of great importance in mitigating ROS-related damage induced by osmotic stress, specifically in drought-sensitive barley cultivars.

Features of the immune response of the organism of the experementel animals to the exposure of the detergents based on anionic surfactans designed for the care of children’s tableware

Objective: We assessed the impact of the detergents, based on anionic surfactants, for the care of the children’s tableware on the indicators of the immune system of the experimental animals. Materials and methods: The effect of aqueous solutions of Alionka, Karapuz, Ushastyi Nian, Frosch Baby detergents on the indicators of the immune system was performed in the experiment with guinea pigs during 21 days. We determined the number of T- and B-lymphocytes, the number of neutrophilic granulocytes and active phagocytes; studied the reaction of the precipitation of circulating immune complexes with a solution of polyethylene glycol 6000. We used the methods of statistical processing of the results of medico-biological research. Results: The obtained results showed that the epicutaneous impact of all studied detergents for the care of children’s tableware could cause the immunomodulatory effects in the organism of guinea pigs. Changes in the largest number of the indicators of the immune system, which affected all links, were observed when exposed to Ushastyi Nian detergent. The least pronounced changes of the immunity were observed when exposed to the Frosch Baby detergent and they concerned only the indices of nonspecific resistance of the organism. The revealed inhibition of the functional activity of neutrophilic granulocytes, which was observed in animals of all experimental groups, may indicate a decrease in the protective functions of the organism of guinea pigs.

PENGARUH PENAMBAHAN POLIETILEN GLIKOL 6000 PADA TABLET IBUPROFEN DISPERSI PADAT TERHADAP ABSORBSI IBUPROFEN SECARA IN SITU

Drug absorption can be decided by various methods, namely in vitro methods, in situ methods, and in vivo methods. The in situ method is a procedure that is very close to the in vivo method. The aim of this study was to identify the effect of accumulation of polyethylene glycol 6000 (PEG 6000) on solid dispersion of ibuprofen tablets on the in-situ absorption of the drug. This research was conducted through an experiment to determine the effect of adding polyethylene glycol 6000 to the absorption of ibuprofen in situ by flowing the solution from solid dispersion ibuprofen tablets, solutions from generic ibuprofen tablets and standard ibuprofen solutions. The solid dispersion system was carried out by melting ibuprofen and polyethylene glycol 6000 in a ratio of 1:05. The drug solution was flowed through the lumen of the small intestine of male rats. Unabsorbed ibuprofen was measured by an ultraviolet spectrophotometer at a wavelength of 225.5 nm. Next, the absorbed level of ibuprofen was calculated. The results showed that ibuprofen from solid dispersion tablets was absorbed more than ibuprofen from generic tablets and standard ibuprofen. It can be concluded that polyethylene glycol 6000 has an effect on the absorption of ibuprofen in situ.

Multi-Step Cellular and Tissue Selection of Soybean for Resistance to Osmotic Stress Using Peg 6000 Invitro Conditions

Cell and tissue selection in vitro allows targeted selection of the desired traits under severe selective conditions at the level of individual cells and tissues. On the basis of multistage cell and tissue selection with the use of a selective agent - neutral osmotic polyethylene glycol 6000 in increasing concentrations -5%, 10%, 15%, 20% of the final volume of the nutrient medium, callus of the Zhansaya soybean variety that are stably resistant to osmotic stress have been obtained. Regeneration from callus was noted only in8.3 % of the planted callus 6 soybean regenerants plants resistant to osmotic stress were obtained from callus.

Potential Screening of Indigenous Drought Stress Tolerant Bacteria for Plant Growth Promotion (PGP) Traits: An In-vitro Study

Aims: The study aims to formulate relevant microbial consortia against drought stress mitigation with potential drought stress tolerant bacterial isolates by polyethylene glycol 6000 (PEG 6000) different moisture stress levels to mitigate the drought stress which can finally helpful to increase plant and soil health under adverse stress conditions. Study Design: Source of rhizosphere soil samples from groundnut drought prone areas of Andhra Pradesh. Place and Duration of Study: Department of Agricultural Microbiology, Advanced Post Graduate Centre, Acharya N.G Ranga Agricultural University, Lam, Guntur, 522 034, between June 2017 and July 2020. Methodology: Isolated strains were also tested for further drought stress screening by polyethylene glycol 6000 In-vitro screening was done for different plant growth promotion activities i.e. phosphate solubilization, IAA production, ammonia production, ACC deaminase activity, HCN production and catalase. HCN production, catalase positive, colony morphology, Gram staining and biochemical tests. Results: Fifty-one efficient bacterial isolates were obtained from drought prone rhizosphere soils of groundnut. Isolated strains were also tested for further drought stress screening by polyethylene glycol 6000 at 0% (-0.05 MPa), 10% (-0.65 MPa), 20% (-1.57 MPa), 30% (-2.17 MPa) and 40% (-2.70 MPa). Thirty-seven bacterial isolates were further found to have an enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity which improved plant growth during stress conditions. The In-vitro screening was done for different plant growth promotion activities, twelve bacterial isolates were positive for phosphate solubilization. IAA production was shown by almost all the bacterial isolates. Three isolates were positive for ammonia production. Two isolates were positive for HCN production and all the isolates were found to be catalase positive. Seven isolates were showing maximum plant growth promotion activities and further identified based on colony morphology, Gram staining and biochemical tests. Conclusion: This study suggests that 51 bacterial isolates exhibited the highest tolerance to moisture stress under In-vitro, these are screened and considered as potential isolates against plant growth promoting characteristics. Plant growth promoting bacteria that can modulate physiological response for water shortage, enhanced water or nutrient uptake and transpiration, induction of plant growth hormone signaling and increased antioxidase activity and photosynthetic rate thereby ensuring plant survival under such stressful conditions. In regard to isolates having PGP properties from the research work presented could be studied further under In-vitro and in vivo conditions from different soils with several crops for confirming their use as bio inoculants.

Osmopriming, antioxidative action, and thermal stress in sunflower seeds with different vigor levels

The osmopriming technique can reduce the period between sowing and the emergence of seedlings in the field, as well as favor seed performance under stress conditions. This study aimed to evaluate the effect of osmopriming on the physiological performance and antioxidative enzymatic activity of sunflower seeds with different vigor levels and exposed to thermal stress. Three sunflower seed lots of the cultivar Hélio 250 were used. Initially, the seeds were evaluated by germination and vigor tests to characterize the lots. Subsequently, they were primed in a polyethylene glycol 6000 solution at -2.0 MPa and 15 °C for 8 h. Then, the primed and unprimed seeds were tested for physiological quality (germination, first germination count, percentage and emergence speed index of seedlings, and seedling dry matter) and determination of the activity of the enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POX) under three temperatures: 15 °C (sub-optimal), 25 °C (optimal), and 35 °C (supra-optimal). The physiological tests allowed classifying lots 1, 2, and 3 into three different vigor levels, i.e., high, medium, and low, respectively. Osmopriming favored the performance of sunflower seeds in terms of germination and vigor at all the analyzed temperatures. This effect was more pronounced in lots of lower physiological quality at sub-optimal and supra-optimal temperatures. Sub-and supra-optimal temperatures led to a reduction in the physiological performance of seeds, mainly in less vigorous lots. In general, osmopriming favored an increase in the activity of the enzymes SOD, CAT, POX, and APX, mainly in low vigor seeds exposed to sub and supra-optimal temperatures. Osmopriming of sunflower seeds in PEG 6000 at -2.0 MPa for 8 hours is efficient to improve the performance of less vigorous lots under stress due to the sub- and supra-optimal temperatures, favoring an increase in the activity of enzymes of the antioxidative system.

Effect of water stress induced by polyethylene glycol 6000 on the somatic embryos conversion into whole plantlets in cocoa (Theobroma cacao L.)

Rainfall scarcity due to climate change is a major constraint that limits cocoa productivity in Côte d'Ivoire. This work aims to regenerate cocoa plants tolerant to water stress using in vitro methods. Staminode and petal explants of the genotypes C1, C9, C14, C15, C16, C18 and C20 were used to produce somatic embryos through two methods. Firstly, somatic embryos were induced under stressfull conditions on media containing different concentrations of polyethylene glycol (PEG) 6000 (0; 25; 50; 75; 100 and 125 g/l) and secondly; under non-stressed conditions. Somatic embryos were placed on a conversion medium in the same stress condition. The number of regenerants decreased with the increase in the concentration of PEG with all genotypes. Only genotypes C1 and C15 regenerated plantlets under water stress conditions. The sensitive genotypes C9, C14, C16, C18 and C20 have not developed plantlets on media containing PEG. The plantlets produced under water deficit conditions exhibited a reduction in stem length and leaves number and an increase in length or offset of the high number of roots. The survival rate of regenerants during acclimatization was higher on the sandsubstrate. The selected genotypes could be used in an improvement program of cocoa production.Keywords: Climate change; plant regeneration; genotype; tolerance; drought; in vitro

Characterization and Function of the 1-Deoxy-D-xylose-5-Phosphate Synthase (DXS) Gene Related to Terpenoid Synthesis in Pinus massoniana

In the methyl-D-erythritol-4-phosphate (MEP) pathway, 1-deoxy-D-xylose-5-phosphate synthase (DXS) is considered the key enzyme for the biosynthesis of terpenoids. In this study, PmDXS (MK970590) was isolated from Pinus massoniana. Bioinformatics analysis revealed homology of MK970590 with DXS proteins from other species. Relative expression analysis suggested that PmDXS expression was higher in roots than in other plant parts, and the treatment of P. massoniana seedlings with mechanical injury via 15% polyethylene glycol 6000, 10 mM H2O2, 50 μM ethephon (ETH), 10 mM methyl jasmonate (MeJA), and 1 mM salicylic acid (SA) resulted in an increased expression of PmDXS. pET28a-PmDXS was expressed in Escherichia coli TransB (DE3) cells, and stress analysis showed that the recombinant protein was involved in resistance to NaCl and drought stresses. The subcellular localization of PmDXS was in the chloroplast. We also cloned a full-length 1024 bp PmDXS promoter. GUS expression was observed in Nicotiana benthamiana roots, stems, and leaves. PmDXS overexpression significantly increased carotenoid, chlorophyll a, and chlorophyll b contents and DXS enzyme activity, suggesting that DXS is important in isoprenoid biosynthesis. This study provides a theoretical basis for molecular breeding for terpene synthesis regulation and resistance.