Water-soluble Protein Content Research Articles

Identification of QTLs and candidate genes for water-soluble protein content in soybean seeds

Soybean represents a vital source of premium plant-based proteins for human nutrition. Importantly, the level of water-soluble protein (WSP) is crucial for determining the overall quality and nutritional value of such crops. Enhancing WSP levels in soybean plants is a high-priority goal in crop improvement. This study aimed to elucidate the genetic basis of WSP content in soybean seeds by identifying quantitative trait loci (QTLs) and set the foundation for subsequent gene cloning and functional analysis. Using 180 F10 recombinant inbred lines generated by crossing the high-protein soybean cultivar JiDou 12 with the wild variety Ye 9, our researcher team mapped the QTLs influencing protein levels, integrating Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and gene expression profiling to identify candidate genes. During the 2020 and 2022 growing seasons, a standard bell-shaped distribution of protein content trait data was observed in these soybean lines. Eight QTLs affecting protein content were found across eight chromosomes, with LOD scores ranging from 2.59 to 7.30, explaining 4.15–11.74% of the phenotypic variance. Notably, two QTLs were newly discovered, one with a elite allele at qWSPC-15 from Ye 9. The major QTL, qWSPC-19, on chromosome 19 was stable across conditions and contained genes involved in nitrogen metabolism, amino acid biosynthesis, and signaling. Two genes from this QTL, Glyma.19G185700 and Glyma.19G186000, exhibited distinct expression patterns at maturity, highlighting the influence of these genes on protein content. This research revealed eight QTLs for WSP content in soybean seeds and proposed a gene for the key QTL qWSPC-19, laying groundwork for gene isolation and enhanced soybean breeding through the use of molecular markers. These insights are instrumental for developing protein-rich soybean cultivars.

Sea Bass Fish Head Broth Treated by Thermo-Ultrasonication: Improving the Nutritional Properties and Emulsion Stability.

This work investigated the underlying mechanism of thermo-ultrasonic treatment to improve the nutritional properties and emulsion stability of sea bass fish head broth. The effects of ultrasonication on the processing of fish broth were compared with boiling water treatment. The nutritional properties of fish broth mainly include protein, fat, total sugar, 5'-nucleotide and free amino acid content. To achieve a similar effect of nutrient extraction, the thermo-ultrasonic treatment required a shorter time (30 min) than boiling water (120 min). The water-soluble protein, fat and total sugar contents were at their maximum at 120 min of the thermo-ultrasonic treatment. In particular, the fat content increased with the time of thermo-ultrasonic treatment from 0.58% to 2.70%. The emulsion structure of the fish soup was characterized by measuring its color and particle size, using optical microscopy and confocal laser scanning microscopy, and determining its storage stability. Thermo-ultrasonic treatment reduced the particle size of the fish broth emulsion and the fat globules became smaller and more homogeneous. Ultrasonication not only accelerated the nutritional and flavor content of the fish head broth, but also reduced the particle size and enhanced the stability of the emulsified system of the fish broth. The fish head tissue was more severely disrupted by the cavitation effect of an ultrasound, and nutrients migrated more and faster. This was mainly due to the cavitation and mechanical breaking force of the ultrasound on the fish head tissue and the fat globules of the fish broth. Altogether, these findings suggest that the thermo-ultrasonic treatment technique is useful for processing nutrient-rich, storage-stable and ready-to-eat fish head broth.

К вопросу оценки качества сырья из каспийской атерины (Atherina boyeri caspia (Risso, 1810))

The purpose of this work was to establish the informative value of methods of structural analysis of biological fluids in determining the prospects of using atherina (Atherina boyeri caspia (Risso, 1810)) as a source of dietary protein in aquaculture. For the first time, solid-phase structures of atherina muscle homogenates were studied. It is known that the solid phase of biological fluids formed under conditions of wedge-shaped dehydration is a visualization of biochemical processes occurring in an organism or organ. The study of the morphological picture of a dried drop (facies) makes it possible to establish associative links between the features of the structuring of the studied liquid and its composition, as well as to determine the nature of the impact of environmental factors on a living system. The results of the study made it possible to establish the main type of homogenate facies and its morphological parameters, which indicate the consistency of biochemical processes and the presence of high-grade protein in the muscle tissue of the Caspian atherina, caught both in the spring and autumn seasons. The size and weight parameters of fish, the content of water-soluble protein in muscle tissue are characterized. For the first time, a comparative analysis of the level of water-soluble protein and solid-phase structures of muscle homogenates of Caspian atherina caught in different seasons in the coastal waters of Dagestan was carried out. Atherina is a food component for many fish living in the Caspian Sea. It was determined that in October, the content of muscle water-soluble protein in atherina tended to increase relative to March. During the feeding period, the accumulated part of the protein components turns into lipid components, which accumulate intensively, therefore, there are no significant seasonal differences in the content of water-soluble protein. It has been established that the biochemical processes occurring in muscle tissues are reflected in the solid-phase structures of biological fluids formed under conditions of wedge-shaped dehydration. The obtained results of the trend towards an increase in water-soluble muscle proteins in the body and an increase in the population in recent years indicate the importance of the use of Caspian atherina in the quality of live feed at fish farms.

Effect of Neutral and Acidic Protease Processing Intervals on Optimising Nutritional Value and Enhancing Physico-Chemical Properties of Oat Drink.

This study aimed to maximise the content of water-soluble protein (WSP) and β-glucan (BG) in oat drink (OD) products by optimising the duration of treatment with neutral (NP) and acidic (AP) proteases. Additionally, it investigated the correlation between changes in the OD's nutritional profile and its rheological and sensory properties. After initial treatment with α-amylase, the OD samples were divided into two groups, i.e., one treated with NP and the other with AP for 30, 60, 120, and 180 min. The samples were then analysed for their WSP and BG contents. Samples with an optimised treatment duration were evaluated for their rheological and sensory properties. The OD sample treated with AP for 60 min exhibited the highest β-glucan (0.52 g/100 mL) and WSP (1.56 g/100 mL) contents, improved storage stability, and the lowest sedimentation rate (2.13%/h), compared to the control OD sample. However, sensorially, this sample was characterised by a sticky, gluey mouthfeel and was less acceptable as a drinkable product. This study demonstrated the potential effect of protease treatment on enhancing the nutritional value and stability of OD products, although further studies are necessary to improve the sensory properties of these drinks.

Physiological and biochemical studies of young sterlet sturgeon (Acipenser ruthenus L.) in the lower reaches of the Volga river

In conditions of a decrease in the number of rolled sturgeon larvae in the lower reaches of the Volga River, an urgent issue is the study of the physiological and biochemical parameters of the fish organism. The purpose of this work is to conduct physiological and biochemical studies of juvenile sterlet (Acipenser ruthenus L, 1758). The study of fish was carried out using the methods of classical histology and biochemistry. The degree of damage to the gills and liver was assessed on a scale from 1 to 5 points. The content of total lipids and water-soluble protein in the muscle tissue of sterlet fingerlings was studied as biochemical parameters. The morphological picture of the gills of 80% of the fish corresponded to a weakly pronounced character of changes (2 points), while in others it was characterized by the presence of a borderline state between weakly pronounced changes and moderate injuries (2–3 points). Six types of disorders were found in the gills: hyperplasia of the respiratory epithelium of lamellae, dilation of the blood vessel of the filament, goblet-shaped swellings of the apical part of the filament, invasions, expansion of the apical part of the lamellae, proliferation of connective tissue of lamellae. In the liver of 80% of fish, a borderline state was recorded between mild changes and moderate damage (2–3 points), in 13.3% of individuals the liver had mild damage (2 points), in 6.7% there were medium damage (3 points). Four types of disorders were found in the liver of juvenile sterlet: fullness of the liver capillaries, pronounced venous fullness, cavities, capillary dilation. In the muscle tissue of fingerlings, the concentrations of total lipids were in the range of 1.39–5.28%, and water-soluble protein — 45.59–57.97 mg/g. The study of the physiological and biochemical parameters of juvenile sturgeon in the lower reaches of the Volga River is very important for the biology of the species and monitoring the natural reproduction of these valuable fish species.

Use of turbidimetry for determination of heat treatment intensity applied at pasteurization of milk

Express methods for estimating the intensity of heat treatment of milk are necessary in industry and in research work. For this reason, there are many ways to measure this parameter, which are based on different physical principles, including turbidimetric methods. The Harland & Ashworth turbidimetric method has been developed for a long time, however, due to its high reliability and ease of implementation, it is still used in practice. However, this method has a drawback: it takes a long time to perform the analysis. In this regard, the aim of the work is to develop an express method for evaluating the thermal class of milk based on the principle of measuring the concentration of soluble whey proteins. The result is achieved through the use of a turbidimetric measurement method with optimized sample preparation parameters and parameters for measuring the optical density of a suspension of protein aggregates. The method is implemented as follows. The milk sample is mixed with 0.1 N acetate buffer (pH 4.6) in a ratio that allows to obtain a concentration of soluble milk whey proteins from 0.05% to 0.1%. Recommended dilution coefficients: 1:3 for samples of ultra-pasteurized milk and pasteurized milk with high heat treatment intensity; 1:7 for samples of pasteurized milk with low heat treatment intensity and 1:14 for raw milk samples. The solution is filtered on a membrane filter with a pore size of 0.45 microns. The resulting filtrate is mixed with 24% trichloroacetic acid (TCA) in a 1:1 ratio to coagulate soluble whey proteins and form protein aggregates. After holding for 5–10 minutes, the optical density of the suspension of protein aggregates is measured at a wavelength of 650 nm. The content of water-soluble whey proteins in the sample can be calculated according to the calibration curve. The developed method allows to obtain the measurement result in less time than the Harland & Ashworth turbidimetric method.

Морфофизиологические и биохимические исследования каспийской атерины (Atherina boyeri caspia Risso, 1810)

The article highlights physiological and biochemical parameters of atherina (Atherina boyeri caspia Risso, 1810) in the Middle Caspian Sea at various stages of the annual cycle. The state of the fish organism was studied in the period from February to October 2022, which characterized the pre-spawning, spawning and feeding periods. The size-weight and age parameters of atherina were determined. The concentration of the main reserve substances of the fish body - total lipids and water-soluble protein – was analyzed in the muscles of the atherina. In the pre-spawning period and at the beginning of spawning of females, the level of morphological changes in the gonads was studied. There were no found significant differences in the content of total lipids and water-soluble protein in the muscles of males and females. Patterns of changes in the amount of muscle water-soluble proteins and total lipids were recorded in the entire sample of the Caspian atherina during the pre-spawning period and at the beginning of spawning. This is typical for portioned spawning fish, in which the energy expenditure of the body is directed to the formation, maturation of gonads, the removal of sexual products and the maturation of the next portions during the spawning period. In September-October, that is, already at the stage of feeding, a multidirectional character in lipid and protein metabolism was noted in the body of atherina. According to the results of histological examination, the beginning of spawning in atherina was noted in April. Mature oocytes with resorption at an average level of 30-31% were recorded in the ovaries of portioned spawning atherina in February-April, which characterized the adaptive mechanisms of the organism in the conditions of this habitat. In September, there was a significantly positive (p < 0.05) statistical correlation between the concentration of total muscle lipids and the mass of fish (r = +0.47), which characterized a positive energy balance in the body, so necessary for the next stages of life.

Standardization of Golden Sea Cucumber (Stichopus hermanii) Extracts from Pelapis Island, Kayong Regency, West Kalimantan

Stichopus hermanii can be used as a medicinal material, a source of animal protein, and wound healing medicine products. Extracts as raw materials for products must go through a standardization process to ensure pharmaceutical reproducibility, a therapeutic quality, and to ensure a consistent and uniform final composition. The purpose of this research was to determine the test results of the standardization parameters of Stichopus hermanii extract from Pelapis Island, West Kalimantan as raw material for wound healing herbal medicinal preparations. Preparation of extracts using the maceration method with 96% ethanol. The extract was standardized with specific parameters, including organoleptic, water and ethanol soluble content, phytochemical screening, and protein content, and non-specific parameters, including drying shrinkage, water content, ash content, and acid insoluble ash content. The test results obtained were a water-soluble content of 61.89%, ethanol-soluble content of 41.81%, protein content of 7.62%, drying shrinkage of 38.81%, water content of 20.58%, ash content of 37.95%, and acid insoluble ash content of 2.07%.

Investigation of the physiological state of the Caspian common sprat in spring

The aim of the work was to assess the physiological state of the common sprat in the spring period near the Dagestan coast of the Caspian Sea. The study of individuals was carried out according to a set of biological indicators. The mass, length were determined, and the Fulton fatness coefficient was calculated. The stages of maturity of fish gonads were determined, the morpho-functional state of gonads and gills was assessed by histological methods. The content of total lipids and water-soluble protein were analyzed in the muscles. In March, females were predominantly marked III stage of gonad maturity, in April — IV stage of gonad maturity. In the spring period, diffuse resorption of mature oocytes was recorded at an average level of 27–28%. In males, IV–V, VI–V stages of testicular maturity were recorded. In April, a decrease in the content of total lipids and the Fulton fatness coefficient (p < 0.05) was registered relative to March, which is associated with the expenditure of the body’s energy on the maturation of gonads in portion-spawning common sprat. The concentration of water-soluble protein in sprat muscles in March and April was comparable. Local vascular disorders and the presence of mucosal cells were recorded in the structure of the gills. The revealed morphological disorders characterized the adaptive capabilities of the organ to the external influences of the habitat. According to the results of the studies conducted in the spring of 2022, the physiological condition of the Caspian common sprat was satisfactory. The results obtained are of great importance for predicting the development of the fishery for this species near the Dagestan coast of the Caspian Sea.

Изменчивость биохимических признаков Pinus sylvestris (Pinaceae) при адаптации форм в условиях избыточного увлажнения

Conifers are characterized by a certain degree of individual variability in the content of stress metabolites, which can be caused by genotypic variations or divergence in the growth conditions of individual trees. The purpose of the study is to evaluate the variation of biochemical traits of Scots pine, which are different in the color of male strobilus, during adaptation to the conditions of constant excessive moisture in the soil of the northern taiga. The dynamics of metabolic parameters of Pinus sylvestris L. were investigated in shrubsphagnum pine stands on marshy upland soils at the mouth of the Northern Dvina River (northern taiga subzone). From July to November 2018, needle samples from shoots were collected from 10 pine trees of each of the male strobilus types, differentiated by color. The contents of photosynthetic pigments, anthocyanins, ascorbic acid, proline, water-soluble proteins, and pH were measured under laboratory conditions. The synthesis of chlorophyll in the needles in the current year of formation decreased in trees of both forms during the dry summer period. A favorable temperature in the autumn period could promote an extension of photosynthetic pigment accumulation, which might negatively affect tree preparation for overwintering. There were no significant differences between f. erythranthera Sanio and f. sulfuranthera Kozubow in the needle content of chlorophyll and carotenoids, anthocyanins, ascorbic acid, free proline, water-soluble proteins, or pH. The similarities in the adaptation of the trees to the constant excessive soil moisture in northern taiga conditions were revealed. The seasonal factor had a considerable impact on the dynamics of biochemical parameters. Ascorbic acid, proline, and anthocyanin were more actively accumulated in the needles throughout the summer due to the high air temperature, resulting in an increase in antioxidant activity and the development of protective mechanisms aimed at reducing oxidative stress. The increase in water-soluble protein content in needles from October to November is one of the cryoprotective mechanisms of the trees for the winter period. Individual differences in ascorbic acid and proline contents in yellow microspore-bearing pine needles at the establishment of minus temperatures in November were considerably higher than in red microspore-bearing pine needles. This is regarded as the norm of the reaction for different types of trees to the influence of negative temperatures. For citation: Tarkhanov S.N., Pinaevskaya E.A., Aganina Y.E., Pakhov A.S. Variability of Biochemical Properties During Adaptation of Pinus sylvestris (Pinaceae) Forms to Excessive Moisture Conditions. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 58–75. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-58-75

Isolation and identification of protease-producing Bacillus amyloliquefaciens LX-6 and its application in the solid fermentation of soybean meal.

Soybean meal (SM) is considered an ideal substitute for fish meal; however, its application is mainly limited because of its antigen proteins, glycinin and β-conglycinin. To improve the value of SM in the aquaculture industry, we employed an aerobic bacterial strain (LX-6) with protease activity of 1,390.6 ± 12.5 U/mL. This strain was isolated from soil samples and identified as Bacillus amyloliquefaciens based on morphological and physiological biochemical characteristics and 16S rDNA gene sequence analyses. Subsequently, we quantified the extent of glycinin and β-conglycinin degradation and the total protein and water-soluble protein content after SM fermentation with B. amyloliquefaciens LX-6. At 24h of fermentation, the macromolecular antigen proteins of SM were almost completely degraded; the maximum degradation rates of glycinin and β-conglycinin reached 77.9% and 57.1%, respectively. Accordingly, not only did the concentration of water-soluble proteins increase from 5.74% to 44.45% after 48h of fermentation but so did the concentrations of total protein and amino acids compared to those of unfermented SM. Field emission scanning electron microscopy revealed that the LX-6 strain gradually disrupted the surface structure of SM during the fermentation process. In addition, B. amyloliquefaciens LX-6 exhibited broad-spectrum antagonistic activity and a wide pH tolerance, suggesting its application in SM fermentation for fish meal replacement.

Screening and Identification of a Strain with Protease and Phytase Activities and Its Application in Soybean Meal Fermentation.

The aims of the study were to degrade the anti-nutritional factors (ANFs) such as phytic acid, glycinin, and β-conglycinin and improve the values of soybean meal (SBM). Firstly, in this study, a strain PY-4B which exhibited the best enzymatic activities of protease (403.3 ± 17.8 U/mL) and phytase (62.9 ± 2.9 U/mL) was isolated and screened among the isolates. Based on the analysis of physiological and biochemical characteristics and 16S rDNA sequence, the strain PY-4B was identified and named as Pseudomonas PY-4B. Next, Pseudomonas PY-4B was applied to fermentation of SBM. The results showed that the contents of glycinin and β-conglycinin were decreased by 57-63%, and the phytic acid was remarkably degraded by 62.5% due to the fermentation of SBM by Pseudomonas PY-4B. The degradation of glycinin and β-conglycinin resulted in increase of contents of water-soluble proteins and amino acids in fermented SBM. Moreover, Pseudomonas PY-4B exhibited no hemolytic activity and slight inhibitory effect on the growth of pathogen Staphylococcus aureus and the wide range of pH tolerance (3 to 9). In summary, our study indicates that isolated strain Pseudomonas PY-4B is a safe and applicable strain and has the ability to effectively degrade the ANFs (phytic acid, glycinin, and β-conglycinin) in SBM by fermentation.

ZALEZNO ˙ S´ C MI ˛EDZY WYBRANYMI CECHAMI JAKO ´ SCIOWYMI WIEPRZOWEGO MI ˛E ´ SNIA ´ LONGISSIMUS A ZAWARTOSCI ˛A W NIM BIAŁEK ROZPUSZCZALNYCH W WODZIE

This study comprised 136 meat samples (m. longissimus lumborum) from 136 pork carcasses of six-month-old crossbred porkers derived from ♀ (Polish Large White×Polish Landrace)×♂ (Duroc×Pietrain), with an average carcass weight of 85.8 ± 8.5 kg, slaughtered on an industrial processing line. The pH1, pH24, pH48, WHC, colour parameters (L*, a*, b*), moisture content, crude protein, intramuscular fat, and water-soluble protein content were determined. Significantly high correlation coefficients between the proportion of water-soluble proteins in meat and crude protein and pH48, WHC, and lightness (L*) were recorded, with pH48 (measured in water extracts of meat) having the greatest effect on the proportion of water-soluble protein fractions in the meat and crude protein. In contrast, the basic chemical composition of the meat, i.e. moisture, crude protein, and intramuscular fat content, had no significant effect on the levels of water-soluble proteins. The results indicate that water-soluble proteins are a useful indicator of the quality of pork longissimus muscle.

Zn Supplementation Mitigates Drought Effects on Cotton by Improving Photosynthetic Performance and Antioxidant Defense Mechanisms.

Drought is recognized as a paramount threat to sustainable agricultural productivity. This threat has grown more severe in the age of global climate change. As a result, finding a long-term solution to increase plants' tolerance to drought stress has been a key research focus. Applications of chemicals such as zinc (Zn) may provide a simpler, less time-consuming, and effective technique for boosting the plant's resilience to drought. The present study gathers persuasive evidence on the potential roles of zinc sulphate (ZnSO4·7H2O; 1.0 g Kg-1 soil) and zinc oxide (ZnO; 1.0 g Kg-1 soil) in promoting tolerance of cotton plants exposed to drought at the first square stage, by exploring various physiological, morphological, and biochemical features. Soil supplementation of ZnSO4 or ZnO to cotton plants improved their shoot biomass, root dry weight, leaf area, photosynthetic performance, and water-use efficiency under drought stress. Zn application further reduced the drought-induced accumulations of H2O2 and malondialdehyde, and electrolyte leakage in stressed plants. Antioxidant assays revealed that Zn supplements, particularly ZnSO4, reduced reactive oxygen species (ROS) accumulation by increasing the activities of a range of ROS quenchers, such as catalase, ascorbate peroxidase, glutathione S-transferase, and guaiacol peroxidase, to protect the plants against ROS-induced oxidative damage during drought stress. Increased leaf relative water contents along with increased water-soluble protein contents may indicate the role of Zn in improving the plant's water status under water-deficient conditions. The results of the current study also suggested that, in general, ZnSO4 supplementation more effectively increased cotton drought tolerance than ZnO supplementation, thereby suggesting ZnSO4 as a potential chemical to curtail drought-induced detrimental effects in water-limited soil conditions.

Physicochemical properties of grass carp surimi as affected by pH and NaCl concentration during washing

ABSTRACT The objective of this study was to investigate the effects of various pHs and NaCl concentrations on physicochemical properties of surimi from grass carp during washing. Surimi protein recovery was higher with 0.25% and 0.5% NaCl at the pH 5 or 7 than that with other pHs and NaCl concentrations, while the highest recovery was obtained with 0.25% NaCl at the pH 7. It decreased protein recovery and salt-soluble protein of surimi as NaCl increased by more than 1.0% during washing. The water-soluble protein content was significantly higher at the pH 3 than at other pHs, while the SDS-PAGE of surimi protein exhibited intense sarcoplasmic protein bands at the pH 3. There were significantly fewer hydrophobic groups of actomyosin treated with 0.25% NaCl at the pH 5 or 7 than that with other pHs and NaCl concentrations in washing solution. The α-helix of actomyosin was increased with the increase of NaCl during washing. In general, the washing with 0.25%−0.5% NaCl at the pH 5–7 could significantly increase the yield of surimi from grass carp.

Effect of Acetic Acid Pretreatment on Hydro-extraction of Water-Soluble Collagen from Skin of Alaska Pollock (<I>Theragra chalcogramma</I>)

Highlight Research The optimal condition for production of water-soluble collagen from Alaska pollock fish skin was the pretreatment with 0.15 M acetic acid followed by hydro-extraction at 40oC with 150 rpm for two hours. Higher acetic acid concentration at a pretreatment step enhanced the higher yield of water-soluble collagen via hydro-extraction process. Hydro-extraction was an environmentally friendly method for converting Alaska pollock fish skin to water-soluble collagen. Alaska pollock fish skin could be used as an alternative source for collagen production. Abstract To date, there is no information on skin of Alaska Pollock (Theragra chalcogramma) being used as a source for collagen. In order to produce water-soluble collagen from the skin of Alaska Pollock, a process known as hydro-extraction is utilized. This technique does not need a long extraction time or a large amount of chemical reagent. The purpose of this study was to investigate the effect of acetic acid pretreatment on hydro-extraction of water-soluble collagen from Alaska Pollock skin. The skin samples were pretreated using acetic acid at different concentrations (0.01 M; 0.05 M; 0.1 M, 0.15 M) for two hours at chilling temperature. The pretreated skin samples were further processed to produce water-soluble collagen using the hydroxy-extraction method. The obtained collagen was analyzed for proximate compositions, yield, and amino acids compositions with high performance liquid chromatography. It was found that the proximate compositions of the collagen products, specifically the protein content (75%) and fat content (1%), met the requirements of the Indonesian National Standard (SNI 8076:2014). The collagen yield ranged from 2.6 to 3.13%. The predominate amino acids in collagen were glycine, arginine, proline, glutamic acid, serine, and alanine. Pretreatment of skin sample with 0.15 M acetic acid resulted in the highest yield of water-soluble collagen (3.13%) and protein content (91.13%). The skin of Alaska Pollock fish could be used as an alternative raw material to produce water-soluble collagen for medical, pharmacy or food processing applications.

Melatonin improves drought stress tolerance of pepper (Capsicum annuum) plants via upregulating nitrogen metabolism.

While ameliorating effects of melatonin (MT) on abiotic stress tolerance in plants are widely reported, the mechanism that underlies this process remains elusive. This work investigated mechanisms by which MT improved drought tolerance in pepper (Capsicum annuum ) plants. A foliar spray of 0.1mM MT treatment was applied to plants grown at 80% and 40% of full field capacity for 3days. Drought stress caused a significant decrease in plant dry weight, relative water content, leaf water potential, PSII efficiency (F v /F m ratio), chlorophyll, soluble protein, leaf and root nitrogen content. Drought increased hydrogen peroxide, malondialdehyde (MDA), nitrate, ammonium, free amino acids, soluble sugars, proline and glycine betaine. Drought also increased peroxidase (POD), glutathione S-transferase (GST) and catalase (CAT) activities, electrolyte leakage (EL) and methylglyoxal (MG). MT pre-treatment reduced oxidative stress and improved nitrogen metabolism by activating various enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthetase (GOGAT) and glutamine dehydrogenase (GDH) activities. It also activated enzymes related to the glyoxalase system (Gly I and Gly II) and decreased NO3 - , NH4 + and free amino acid content. Our study suggests a cost-effective and sustainable solution to improve crop productivity in water-limited conditions, by enhancing plant growth, photosynthesis and nitrogen content.

Determination of the Effect of Salt Stress on Germination, Biochemical and Antioxidant Defense Systems in Linas Safflower Seeds

In this study, the germination and early seedling growth, biochemical and antioxidant enzyme activities (CAT, SOD, POD, and APX) of one-year, broad-leaved Linas safflower belonging to the Compositeae family were investigated at different salt concentrations (0, 50, 100, 150 and 200 mM). With increasing salt concentration, a 68.83% decrease in seedling length, 71% in stem length, 34% in germination rate, and 77% in fresh plant weight were determined. In addition, total phenolic content (267%), total flavonoid content (904%), CAT (462%), SOD (56%), POD (100%), and APX (381%) antioxidant enzyme activities were increased in parallel with the salt concentration. In addition, it was determined that as the salt stress increased, the water-soluble protein content decreased by 48%. In the study, it was determined that the seeds were relatively resistant to 100, 150, and 200 mM NaCl salt concentrations, and germination continued. As a result, it has been understood once again that our country has been feeling a negative impact lately, and the determination of alternative plants for growing oily plants has gained more importance in these days. Safflower, which is one of these plants, is a strategically important species both in terms of its oil content and being a source of biodiesel. This study carried out in this context will be a resource for our farmers regarding future studies on safflower seeds and which salt concentrations can be used for cultivation.

Does Dietary Lipid Level Affect the Quality of Triploid Rainbow Trout and How Should It Be Assessed?

Organoleptic properties and nutritional value are the most important characteristics of fish fillet quality, which can be determined by a series of quality evaluation indexes and closely related to fish nutrition. Systematic organoleptic and nutritional quality evaluation indexes consisting of 139 indexes for physical properties and chemical compositions of triploid rainbow trout were established. Besides, effects of dietary lipid levels (6.6%, 14.8%, 22.8% and 29.4%) on the quality of triploid rainbow trout were analyzed in the study. The main results showed that, for fillet appearance quality, fish fed diets with lipid levels above 22.8% had higher fillet thickness and redness but lower gutted yield and fillet yield (p < 0.05). For fillet texture, fish fed the diet with a 6.6% lipid level had the highest fillet hardness (5.59 N) and lowest adhesiveness (1.98 mJ) (p < 0.05), which could be related to lipid, glycogen, water soluble protein and collagen contents of the fish fillet. For fillet odor, the odor intensity of “green, fatty and fishy” significantly increased with the increase of the dietary lipid level (from 1400 to 2773 ng/g muscle; p < 0.05), which was related to the degradation of n-6 and n-9 fatty acids. For fillet taste, a high lipid diet (≥22.8%) could increase the umami taste compounds contents (from 114 to 261 mg/100 g muscle) but decrease the bitterness and sourness taste compounds contents (from 127 to 106 mg/100 g muscle and from 1468 to 1075 mg/100 g muscle, respectively) (p < 0.05). For nutritional value, a high lipid diet could increase the lipid nutrition level (such as the content of long chain polyunsaturated fatty acids increased from 3.47 to 4.41 g/kg muscle) but decease tryptophan and selenium content (from 2.48 to 1.60 g/kg muscle and from 0.17 to 0.11 g/kg muscle, respectively). In total, a high lipid diet could improve the quality of triploid rainbow trout. The minimum dietary lipid level for triploid rainbow trout should be 22.8% to keep the better organoleptic and nutritional quality.

ВЛИЯНИЕ МЕДИ В СУБЛЕТАЛЬНЫХ КОНЦЕНТРАЦИЯХ И ТЕРМАЛЬНОГО СТРЕССА НА ФИЗИОЛОГО-БИОХИМИЧЕСКИЕ ПОКАЗАТЕЛИ МОЛОДИ ПЛОТВЫ RUTILUS RUTILUS

The effects of 7- and 14-day exposure to water-dissolved Cu at sublethal concentrations 0.01 and 0.1 mg/L and subsequent increase in water temperature at a rate of 8°C/h on intestinal proteolytic activity (PA) and amylolytic activity (AA), as well as brain acetylcholinesterase (AChE) activity and water-soluble protein (WSP) content in juvenile roach Rutilus rutilus have been in vivo studied. Additionally, the values of upper sublethal temperature were determined by the critical thermal maximum (CTM) method. The average values of the CTM (27.5°C) did not differ in fish of control (exposure to 0 μg/L Cu) and Cu-exposed groups. After Cu exposure AA was 22–34% lower, PA was 57–64% lower at Cu concentration 0.01 mg/L, but 27–35% higher at Cu concentration 0.1 mg/L. Subsequent temperature stress did not change the response of proteinases and glycosidases to Cu. An increase in water temperature decreased AA by 21%, AChE activity by 24% in fish of the control group; but increased PA by 32%. AChE activity was 24–28% lower than the control after exposure to Cu (0.1 mg/L and short-term thermal load increased the inhibitory effect of Cu. An increase of WSP content by 36–58% was revealed only after 7 days of exposure to Cu, while temperature stress did not change of the effect. In general, Cu at concentrations found in the aquatic environment can reduce the activity of digestive hydrolases in the intestines of juvenile roach, reducing the rate of assimilation of protein and carbohydrate food components. Inhibition of brain AChE activity is enhanced by subsequent temperature stress. No significant differences were noticed in CTM values in fish of control and Cu-exposed group. The results obtained are important in assessing the environmental risks of chronic exposure to Cu in the zones of thermal pollution of water bodies.