Higher Superoxide Dismutase Activity Research Articles

PbrWRKY70 increases pear (Pyrus bretschneideri Rehd) black spot disease tolerance by negatively regulating ethylene synthesis via PbrERF1B-2

Various pear plant cultivars exhibit diverse abilities to resist pear black spot disease (BSD), while the precise molecular mechanisms of resistance against pear BSD remain unclear. This study proposed a profound expression of a WRKY gene, namely PbrWRKY70, derived from Pyrus bretschneideri Rehd, within a BSD-resistant pear cultivar. Comparative analysis against the wild-type revealed that the overexpression of PbrWRKY70 engendered augmented BSD resistance of transgenic Arabidopsis thaliana and pear calli. Notably, the transgenic plants exhibited higher activities of superoxide dismutase and peroxidase, along with an elevated capacity to counteract superoxide anions via increased anti-O2-. Additionally, these plants displayed diminished lesion diameter, as well as reduced levels of hydrogen peroxide, malondialdehyde and 1-aminocyclopropane-1-carboxylic acid (ACC) contents. We subsequently demonstrated that PbrWRKY70 selectively bound to the promoter region of ethylene-responsive transcription factor 1B-2 (PbrERF1B-2), a potential negative regulator of ACC, thereby downregulating the expression of ACC synthase gene (PbrACS3). Consequently, we confirmed that PbrWRKY70 could enhance pear resistance against BSD by reducing ethylene production via modulation of the PbrERF1B-2-PbrACS3 pathway. This study established the pivotal relationship among PbrWRKY70, ethylene synthesis and pear BSD resistance, fostering the development of novel BSD-resistant cultivars. Furthermore, this breakthrough holds the potential to enhance pear fruit yield and optimize storage and processing during the later stages of fruit maturation.

Genome-wide identification and analysis of glyceraldehyde-3-phosphate dehydrogenase family reveals the role of GmGAPDH14 to improve salt tolerance in soybean (Glycine max L.).

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential key enzyme in the glycolytic pathway and plays an important role in stress responses. Although GAPDH family genes have been found in different plant species, the determination of their gene family analysis and their functional roles in soybean are still unknown. In this study, gene sequence and expression data were obtained using online tools, and systematic evolution, expression profile analysis, and qRT-PCR analysis were conducted. Here a total of 16 GmGAPDH genes were identified on nine chromosomes, which were classified into three clusters. Additionally, all GmGAPDH genes harbor two highly conserved domains, including Gp_dh_N (PF00044) and Gp_dh_C (PF02800). The qRTPCR analysis also showed that most GmGAPDH genes significantly responded to multiple abiotic stresses, including NaHCO3, polyethylene glycol, cold, and salt. Among them, GmGAPDH14 was extraordinarily induced by salt stress. The GmGAPDH14 gene was cloned and overexpressed through soybean hair roots. The overexpressed transgenic soybean plants of the GmGAPDH14 gene have also shown better growth than that of control plants. Moreover, the overexpressed transgenic plants of GmGAPDH14 gene had higher activities of superoxide dismutase but lower malonaldehyde (MDA) content than those of control plants under salt stress. Meanwhile, a total of four haplotypes were found for the GmGAPDH14 gene, and haplotypes 2, 3, and 4 were beneficial for the tolerance of soybean to salt stress. These results suggest that the GmGAPDH14 gene might be involved in the process of soybean tolerance to salt stress. The results of this study will be valuable in understanding the role of GAPDH genes in the abiotic stress response of soybean.

UJI AKTIVITAS ENZIM SUPEROKSIDA DISMUTASE (SOD) EKSTRAK DAUN SALAM (Syzygium polyanthum) DENGAN METODE WATER SOLUBLE TETRAZOLIUM SALT-1 (WST-1)

Free radicals can cause various kinds of degenerative diseases and skin aging. Free radicals can be neutralized with an enzymatic antioxidant, namely superoxide dismutase (SOD). One of the plants that has high SOD activity is salam (Syzygium polyanthum). The aim of this study was to determine the activity of the crude SOD extract of bay leaves precipitated with ammonium sulfate salt at various concentrations of 25, 50, 75%. The study began with plant determination, enzyme extraction, precipitation of enzyme extracts with ammonium sulfate concentrations of 25, 50, 75%, measurement of total protein content and SOD activity test using the WST-1 method to calculate the percent inhibition. The results were statistically analyzed using one way ANOVA. The results showed that the total protein content of the crude extract of SOD and the results of precipitation with ammonium sulfate 25, 50, and 75% respectively were 9.38; 6.36; 8.50; and 11.6 mg/mL. Meanwhile, the percentage inhibition values were 73.13; 34.33; 65.67; and 80.59%. The highest SOD activity was obtained in the crude extract of the enzyme precipitated with 75% ammonium sulfate salt, which was 80.59%.

Combination of soy protein isolate and calcium chloride inhibits browning and maintains quality of fresh-cut peaches

Fresh-cut fruits are often more perishable and exhibit browning shortly after pulp is cut and exposed to natural atmosphere. In this study, fresh-cut peaches were treated with distilled water (control), 20 g L-1 soy protein isolate (SPI), 10 g L-1 calcium chloride (CaCl2) or 20 g L-1 soy protein isolate + 10 g L-1 calcium chloride (20 g L-1 SPI + 1.0 g L-1 CaCl2), respectively, and then stored at 0°C to assess the protective effects of these treatments on the qualities and the antioxidative system of fresh-cut peaches. The result showed that firmness, colour(∆E*) and soluble solid content (SSC) in fresh-cut peaches treated with 20 g L -1 SPI + 10 g L-1 CaCl2 were higher than control. Compared with other treatments, treatment with 20 g L-1 SPI + 10 g L-1 CaCl2 2 significantly decreased weight loss rate, bacterial growth, respiratory rate and ethylene emission of fresh-cut peaches. Treatment with 20 g L-1 SPI + 10 g L-1 CaCl2 also inhibited increase in browning degree, production of reactive oxygen species, malonaldehyde and total phenols, and maintained higher activities of superoxide dismutase and catalase, whereas inhibited the activities of peroxidase and polyphenol oxidase. These results suggest that treatment with 20 g L-1 SPI + 10 g L-1 CaCl2 enhanced antioxidant activities of fresh-cut peaches, inhibited browning, and was more effective in maintaining the quality of fresh cut peaches. Keywords: Edible coating; Ethylene emission; Phenolic contents; Respiration rate; Active oxygen species

Halotolerant plant growth-promoting bacteria, Bacillus pumilus, modulates water status, chlorophyll fluorescence kinetics and antioxidant balance in salt and/or arsenic-exposed wheat

Seed priming is an effective and novel technique and the use of eco-friendly biological agents improves the physiological functioning in the vegetative stage of plants. This procedure ensures productivity and acquired stress resilience in plants against adverse conditions without contaminating the environment. Though the mechanisms of bio-priming-triggered alterations have been widely explained under induvial stress conditions, the interaction of combined stress conditions on the defense system and the functionality of photosynthetic apparatus in the vegetative stage after the inoculation to seeds has not been fully elucidated. After Bacillus pumilus inoculation to wheat seeds (Triticum aestivum), three-week-old plants were hydroponically exposed to the alone and combination of salt (100 mM NaCl) and 200 μM sodium arsenate (Na2HAsO4·7H2O, As) for 72 h. Salinity and As pollutant resulted in a decline in growth, water content, gas exchange parameters, fluorescence kinetics and performance of photosystem II (PSII). On the other hand, the seed inoculation against stress provided the alleviation of relative growth rate (RGR), relative water content (RWC) and chlorophyll fluorescence. Since there was no effective antioxidant capacity, As and/or salinity caused the induction of H2O2 accumulation and thiobarbituric acid reactive substances content (TBARS) in wheat . The inoculated seedlings had a high activity of superoxide dismutase (SOD) under stress. B. pumilis decreased the NaCl-induced toxic H2O2 levels by increasing peroxidase (POX) and enzymes/non-enzymes related to ascorbate-glutathione (AsA-GSH) cycle. In the presence of As exposure, the inoculated plants exhibited an induction in CAT activity. On the other hand, for H2O2 scavenging, the improvement in the AsA-GSH cycle was observed in bacterium priming plants plus the combined stress treatment. Since B. pumilus inoculation reduced H2O2 levels against all stress treatments, lipid peroxidation subsequently decreased in wheat leaves. The findings obtained from our study explained that the seed inoculation with B. pumilus provided an activation in the defense system and protection in growth, water status, and gas exchange regulation in wheat plants against the combination of salt and As.

Effects of cannabidiol on growth performance, appetite, antioxidant capacity and liver inflammatory gene expression of juvenile large yellow croaker (Larmichthys crocea) fed diets with high soybean oil level

This study evaluated the effects of cannabidiol (CBD) on growth performance, appetite, antioxidant capacity and liver inflammatory gene expression in juvenile large yellow croaker (Larmichthys crocea) fed diets with fish oil replaced by soybean oil. Six iso‑nitrogenous and isolipidic diets were formulated with fish oil (FO, the standard diet compared with the control only), soybean oil (SO, the control) and SO supplemented with 25, 50, 100 and 250 mg/kg CBD. After 9-week feeding, with the increase of CBD supplementation in SO diet, the growth performance (final body weight, specific growth rate and feed intake) and the intestinal digestive enzyme activities (amylase, lipase and trypsin) showed a significantly quadratic trend of variation and the maximum were observed in the fish fed SO diets with 100 mg/kg CBD. Correlation analysis showed that 100 mg/kg CBD supplemented in the SO diet could promote appetite of fish by inhibiting the mRNA expression of pro-opiomelanocortin in hypothalamus. The activities of aspartate transaminase and alanine transaminase and total protein level in the serum of fish showed a significantly quadratic trend with the supplementation of CBD increasing in SO diets, and the lower were observed in fish fed SO diets with CBD. Compared with the control, 25, 50, 100 and 250 mg/kg CBD supplemented in SO diets increased peroxidase activity and total antioxidant capacity and decreased malondialdehyde content in the liver of fish, and the highest superoxide dismutase activity was observed in fish fed SO diets with 100 mg/kg CBD. Moreover, fish fed SO diets with 100 and 250 mg/kg CBD had lower mRNA expression of tumor necrosis factor α, interleukin-1β, interleukin-6 and cyclooxygenase-2 in liver of fish compared with the control. In conclusion, 100 mg/kg CBD supplemented in diets with high SO level improved the growth performance and appetite in large yellow croaker. Simultaneously, the supplementation of 100 and 250 mg/kg CBD could promote antioxidant capacity and inhibit the inflammatory gene expression in liver of large yellow croaker fed diets with the high SO level. The optimal supplementation of CBD in diets with high SO level is recommended at 100 mg/kg for large yellow croaker.

Jujubae Fructus alleviates intestinal injury caused by toxic medicinals in Shizao Decoction based on correlation between intestinal flora and host metabolism

Genkwa Fols, Kansui Radix, and Euphorbiae Pekinensis Radix in Shizao Decoction(SZD) are toxic to intestinal tract. Jujubae Fructus in this prescription can alleviate the toxicity, but the mechanism is still unclear. Therefore, this study aims to explore the mechanism. To be specific, 40 normal Sprague-Dawley(SD) rats were classified into the normal group, high-dose and low-dose SZD groups, and high-dose and low-dose SZD without Jujubae Fructus(SZD-JF) groups. The SZD groups were given(ig) SZD, while SZD-JF groups received the decoction without Jujubae Fructus. The variation of body weight and spleen index were recorded. The patho-logical changes of intestinal tissue were observed based on hematoxylin and eosin(HE) staining. The content of malondialdehyde(MDA) and glutathione(GSH) and activity of superoxide dismutase(SOD) in intestinal tissue were measured to evaluate the intestinal injury. Fresh feces of rats were collected to detect intestinal flora structure by 16S ribosomal RNA gene(16S rDNA) sequencing technology. The content of fecal short chain fatty acids and fecal metabolites was determined by gas chromatography-mass spectrometer(GC-MS) and liquid chromatography-mass spectrometer ultra-fast liquid chromatography-quadrupole-time-of-flight mass spectrometer(UFLC-Q-TOF-MS), separately. Spearman's correlation analysis was employed to analyze the differential bacteria genera and differential metabolites. RESULTS:: showed that high-dose and low-dose SZD-JF groups had high content of MDA in intestinal tissue, low GSH content and SOD activity, short intestinal villi(P<0.05), low diversity and abundance of intestinal flora, variation in the intestinal flora structure, and low content of short chain fatty acids(P<0.05) compared with the normal group. Compared with high-dose and low-dose SZD-JF groups, high-dose and low-dose SZD groups displayed low content of MDA in intestinal tissue, high GSH content and SOD activity, recovery of the length of intestinal villi, increased abundance and diversity of intestinal flora, alleviation of dysbacteria, and recovery of the content of short chain fatty acids(P<0.05). According to the variation of intestinal flora and fecal metabolites after the addition of Jujubae Fructus, 6 differential bacterial genera(Lactobacillus, Butyricimonas, Clostridia＿UCG-014, Prevotella, Escherichia-Shigella, Alistipes),4 differential short chain fatty acids(such as acetic acid, propionic acid, butyric acid, valeric acid) and 18 differential metabolites(such as urolithin A, lithocholic acid, and creatinine) were screened out. Beneficial bacteria such as Lactobacillus were in positive correlation with butyric acid and urolithin A(P<0.05). The pathogenic bacteria such as Escherichia-Shigella were in negative correlation with propionic acid and urolithin A(P<0.05). In summary, SZD-JF caused obvious intestinal injury to normal rats, which could lead to intestinal flora disorder. The addition of Jujubae Fructus can alleviate the disorder and relieve the injury by regulating intestinal flora and the metabolites. This study discusses the effect of Jujubae Fructus in relieving the intestinal injury caused by SZD and the mechanism from the perspective of intestinal flora-host metabolism, which is expected to serve as a reference for clinical application of this prescription.

Pregnancy Rates Associated with Oxidative Stress after Estrus Synchronization of Bulgarian Murrah Buffaloes in Breeding and Non-Breeding Season

Background: The current study aims to measure the effect of oxidative stress on the pregnancy rates of Bulgarian Murrah buffaloes during the breeding and non-breeding season.
 Methods: The study group consisted of 24 mature buffaloes more than 40 days after parturition. The following parameters were measured: Reactive Oxygen Species (ROS) products, Ascorbate radicals, Malondialdehyde (MDA), Nitric Oxide (NO), Super Oxide Dismutase (SOD), Glutathione peroxidase (GSH-Px), Protein Carbonyl Content (PPC), and total Nitric oxide. The Presynch/Ovsynch protocol was used for estrus synchronization.
 Results: A statistically significant increase in ROS products were measured in blood serum during the breeding season compared with the non-breeding season. The highest levels measured were in non-pregnant buffaloes during the breeding season. High levels of oxidative stress were registered due to low SOD activity in buffaloes during the breeding season compared to SOD activity during the non-breeding season. The highest SOD activity was observed in non-pregnant buffaloes during the summer season. The lowest GSH-Px levels were observed in non-pregnant buffaloes during both study periods. During the breeding season, concentrations of total NO and PPC were elevated.
 Conclusion: Comparing the obtained results for oxidative stress and antioxidant activity concerning pregnancy rate depending on the season showed that pregnancy in buffaloes during the breeding season was realized at higher values of NO and SOD. Increased oxidative stress was observed, resulting in a statistically significant increase in serum ROS products, as well as decreased SOD activity in buffaloes during the breeding season.

Dietary α-ketoglutarate alleviates glycinin and β-conglycinin induced damage in the intestine of mirror carp (Cyprinus carpio).

This study investigated the glycinin and β-conglycinin induced intestinal damage and α-ketoglutarate alleviating the damage of glycinin and β-conglycinin in intestine. Carp were randomly divided into six dietary groups: containing fish meal (FM) as the protein source, soybean meal (SM), glycinin (FMG), β-conglycinin (FMc), glycinin+1.0% α-ketoglutarate (AKG) (FMGA), β-conglycinin+1.0% AKG (FMcA). The intestines were collected on 7th, and the hepatopancreas and intestines were collected on 56th. Fish treated with SM and FMc displayed reduced weight gain, specific growth rate, and protein efficiency. On 56th day, Fish fed on SM, FMG and FMc presented lower superoxide dismutase (SOD) activities. FMGA and FMcA had higher SOD activity than those fed on the FMG and FMc, respectively. In intestine, fish fed on the SM diets collected on 7th presented upregulated the expression of transforming growth factor beta (TGFβ1), AMP-activated protein kinase beta (AMPKβ), AMPKγ, and acetyl-CoA carboxylase (ACC). Fish fed FMG presented upregulated expression of tumor necrosis factor alpha (TNF-α), caspase9, and AMPKγ, while downregulated the expression of claudin7 and AMPKα. FMc group presented upregulated expression of TGFβ1, caspase3, caspase8, and ACC. Fish fed FMGA showed upregulated expression of TGFβ1, claudin3c, claudin7, while downregulating the expression of TNF-α and AMPKγ when compared to fish fed FMG diet. FMcA upregulated the expression of TGFβ1, claudin3c than fed on the FMc. In intestine, the villus height and mucosal thickness of the proximal intestine (PI) and the distal intestine (DI) were decreased and crypt depth of the PI and mid intestine (MI) were increased in SM, FMG and FMc. In addition, fish fed on SM, FMG and FMc presented lower citrate synthase (CS), isocitrate dehydrogenase (ICD), α-ketoglutarate dehydrogenase complex (α-KGDHC) Na+/K+-ATPase activity in DI. FMGA had higher CS, ICD, α-KGDHC, and Na+/K+-ATPase activity in PI and MI than those fed on the FMG. FMcA had higher Na+/K+-ATPase activity in MI. In conclusion, dietary soybean meal destroys the intestine's health, the adverse effects are related to the presence of β-conglycinin and glycinin, especially glycinin. AKG may regulate intestinal energy via tricarboxylic acid cycle, thereby alleviating the damage intestinal morphology caused by the dietary soybean antigen proteins.

Impacts of ZnO nanoparticles and dissolved zinc (ZnSO4) on low temperature induced responses of wheat

Nanoparticles (NPs), due to their specific physical and chemical properties, can cause benefits and risks once they are released into the environment. Consideration of nano-specific impacts of nanomaterials is essential for the safe design of NPs applications. In the present study, the effects of ZnO NPs and ZnSO4 application on low temperature-induced responses was investigated in two wheat cultivars (Triticum aestivum L. spring cultivar Sivand and the winter cultivar Pishgam). Seedlings were grown in a Johnson nutrient solution and then exposed to the uptake solution containing zinc (Zn) from two sources of ZnSO4 and ZnO NPs and subjected to temperature treatments by incubating them in the dark at +25, +9, and −4 °C for 18 h. Our results indicate that ZnO NPs and ZnSO4 did not show the same effects on wheat cultivars at freezing temperature. The ZnO NPs led to an increase in malondialdehyde (MDA) content, higher electrolyte leakage, and intensified the freezing effects compared to ZnSO4 and Zn-free treatments, in Sivand. At optimum temperature, root MDA content and electrolyte leakage index (ELI) was greater in Sivand plants compared to Pishgam. The differences indicate that the two cultivars differ in their responses to ZnO NPs application and low temperatures. In general, Sivand reacted more sensitively to the ZnO NPs treatment compared to ZnSO4. Freezing temperature resulted in higher activity of superoxide dismutase (SOD), MDA content and ELI in both wheat cultivars. In Sivand, with regard to the activity of SOD, MDA content and ELI, ZnO NPs cause effects different from that of ZnSO4, which indicates that ZnO NPs used under the current experimental conditions because nano-specific risks under low temperatures.

Elucidating microalgae-mediated metabolism for sulfadiazine removal mechanism and transformation pathways

Sulfadiazine (SDZ) as a typical sulfonamide antibiotic is commonly detected in wastewater, and its removal mechanism and transformation pathways in microalgae-mediated system remain unclear. In this study, the SDZ removal through hydrolysis, photodegradation, and biodegradation by Chlorella pyrenoidosa was investigated. Higher superoxide dismutase activity and biochemical components accumulation were obtained under SDZ stress. The SDZ removal efficiencies at different initial concentrations were 65.9–67.6%, and the removal rate followed pseudo first-order kinetic model. Batch tests and HPLC-MS/MS analyses suggested that biodegradation and photodegradation through the reactions of amine group oxidation, ring opening, hydroxylation, and the cleavage of S–N, C–N, C–S bond were dominant removal mechanisms and pathways. Characteristics of transformation products were evaluated to analyze their environmental impacts. High-value products of lipid, carbohydrate, and protein in microalgae biomass presented economic potential of microalgae-mediated metabolism for SDZ removal. The findings of this study broadened the knowledge for the microalgae self-protection from SDZ stress and provided a deep insight into SDZ removal mechanism and transformation pathways.

Intermittent stepwise cooling and warming ameliorate chilling injury and improve quality in postharvest ‘Guifei’ mango fruit

Chilling injury (CI) has been a major factor restricting the commercial distribution of mango fruit. In this study, an innovative technology termed intermittent stepwise cooling and stepwise warming (ICW) was employed to investigate its effect on CI in mango fruit by evaluating ripening- and cold tolerance-related parameters. Results showed that ICW exposure maintained normal ripening in mango fruit during refrigeration at 5 °C and subsequent shelf storage at 20 °C, as manifested by increased ethylene production and respiration rate and accelerated changes in softening, color, soluble solid content, titratable acidity and chlorophyll and carotenoid contents. ICW inhibited increases in electrolyte leakage rate (ELR) and production of reactive oxygen species (O2−. And H2O2) and malondialdehyde (MDA). ICW resulted in higher activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), while promoting more accumulation of total phenolics, flavonoids, ascorbic acid and glutathione. In addition, the expressions of genes (MiICE1, MiCBF1 and MiCOR413) encoding cold-responsive factors were upregulated in response to ICW. These physio-biochemical changes conferred by ICW contributed to enhanced cold tolerance and reduced CI in mango fruit. The results indicate that ICW application could be a potential strategy for postharvest refrigeration of ‘Guifei’ mango fruit.

Increased Efficiency of a Functional SOD Mimic Achieved with Pyridine Modification on a Pyclen-Based Copper(II) Complex.

A series of Cu(II) complexes with the formula [CuRPyN3]2+ varying in substitution on the pyridine ring were investigated as superoxide dismutase (SOD) mimics to identify the most efficient reaction rates produced by a synthetic, water-soluble copper-based SOD mimic reported to date. The resulting Cu(II) complexes were characterized by X-ray diffraction analysis, UV-visible spectroscopy, cyclic voltammetry, and metal-binding (log β) affinities. Unique to this approach, the modifications to the pyridine ring of the PyN3 parent system tune the redox potential while exhibiting high binding stabilities without changing the coordination environment of the metal complex within the PyN3 family of ligands. We were able to adjust in parallel the binding stability and the SOD activity without compromising on either through simple modification of the pyridine ring on the ligand system. This goldilocks effect of high metal stabilities and high SOD activity reveals the potential of this system to be explored in therapeutics. These results serve as a guide for factors that can be modified in metal complexes using pyridine substitutions for PyN3, which can be incorporated into a range of applications moving forward.

The Associations between Bone Mineral Density and Oxidative Stress Biomarkers in Postmenopausal Women.

Oxidative stress plays an essential role in bone health among postmenopausal women. This study aimed to compare the oxidative stress biomarkers among postmenopausal women aged 50-65 years with normal bone mineral density, osteopenia, and osteoporosis. In this observational study, 120 women with normal bone mineral density, 82 with osteopenia, and 86 with osteoporosis were selected based on the densitometry data obtained from the dual-energy X-ray absorptiometry method. The serum total antioxidant capacity (TAC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) levels were measured using biochemical methods. A binary logistic regression model adjusted for confounders was used to estimate the risk of osteopenia and osteoporosis. The P-value of <0.05 was considered statistically significant. There were significant differences between the three groups in age, menopausal age, body mass index, and education (P<0.05). According to the binary logistic regression model, higher SOD activity and serum TAC levels were associated with a lower risk of osteoporosis (adjusted odds ratio [aOR], 0.991; 95% confidence intervals [CI], 0.986 to 0.996; and aOR, 0.373; 95% CI, 0.141 to 0.986, respectively). MDA was a significant risk factor for osteopenia in postmenopausal women (aOR, 1.702; 95% CI, 1.125 to 2.576). Higher SOD activity and serum TAC levels in the studied postmenopausal women were associated with a significantly lower risk of osteoporosis. Moreover, the risk of osteopenia increased significantly with higher serum MDA levels.

Overexpression of a Fragaria vesca 1R-MYB Transcription Factor Gene (FvMYB114) Increases Salt and Cold Tolerance in Arabidopsis thaliana

The MYB (v-MYB avian myeloblastosis viral oncogene homolog) transcription factor (TF) family has numerous members with complex and diverse functions, which play an indispensable role in regulating the response of plants to stress. In this study, a new 1R-MYB TF gene was obtained from Fragaria vesca (a diploid strawberry) by cloning technology and given a new name, FvMYB114. According to the subcellular localization results, FvMYB114 protein was a nuclear localization protein. Overexpression of FvMYB114 greatly enhanced the adaptability and tolerance of Arabidopsis thaliana to salt and low temperature. Under salt and cold stress, the transgenic plants had greater proline and chlorophyll contents and higher activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) than the wild-type (WT) and unloaded-line (UL) A. thaliana. However, malondialdehyde (MDA) was higher in the WT and UL lines. These results suggested that FvMYB114 may be involved in regulating the response of A. thaliana to salt stress and cold stress. FvMYB114 can also promote the expression of genes, such as the genes AtSOS1/3, AtNHX1 and AtLEA3 related to salt stress and the genes AtCCA1, AtCOR4 and AtCBF1/3 related to cold stress, further improving the tolerance of transgenic plants to salt and cold stress.

Effects and Mechanism of the Mycelial Culture Temperature on the Growth and Development of Pleurotus ostreatus (Jacq.) P. Kumm

Pleurotus ostreatus (Jacq.) P. Kumm is the second most cultivated edible mushroom worldwide. Temperature is one of the main environmental factors affecting the growth and fructification of mushrooms. However, the effects of ambient temperature on the growth, development, and production of bag-cultured P. ostreatus are still unclear. In this study, eight ambient temperatures (15 °C, 18 °C, 20 °C, 22 °C, 25 °C, 28 °C, 30 °C, and 32 °C) were used to cultivate P. ostreatus mycelia with cottonseed hull as substrate. Then, the agronomic traits and the activities of substrate-degrading and antioxidant enzymes were determined. The mycelial growth and fructification of P. ostreatus differed significantly under different temperatures, and 22 °C was the optimum temperature for mycelial culture when we comprehensively analyzed all the agronomic traits. The mycelial growth rate and the biological efficiency under 22 °C were 0.56 cm/d and 99.53%, respectively. Furthermore, there were also significant differences in the activities of substrate-degrading enzymes and antioxidant enzymes under different ambient temperatures. The highest activities of lignocellulose-degrading enzymes (laccase, xylanase, and cellulase), amylase, and proteinase at the vegetative growth stage occurred at 15–22 °C, 20–22 °C, and 22–30 °C, respectively. The highest activities of superoxide dismutase, peroxidase, and catalase at the vegetative growth stage occurred at 28–30 °C. This study provides a reference temperature for bag-cultured P. ostreatus.

Tolerance mechanisms to aluminum in popcorn inbred lines involving aluminum compartmentalization and ascorbate-glutathione redox pathway.

Inbred line 11-133 of popcorn showed the lowest apoplast Al and total Al concentrations and Al-lumogallion complex, associated with a more efficient antioxidant system, mainly due to glutathione metabolism. Popcorn (Zea mays L. var. everta) is largely intended for human consumption. About 40% of the world's arable soils are acidic. In soils acidic, aluminum (Al) ionizes producing the trivalent cation, which is highly toxic to plants. Hence, this work aimed to: (1) evaluate the Al toxicity sites and its effect on the structure of the root tips, (2) quantify Al concentrations in the apoplast and symplast of the roots, and (3) to elucidate the modulation on the activity of antioxidant enzymes and metabolites of the ascorbate-glutathione cycle in two popcorn inbred lines (ILs) 11-133 and 11-60, classified as tolerant and sensitive to this metal, respectively. Aluminum toxicity did not affect the shoot growth; however, there was a yellowing of the oldest leaf blade only in 11-60. The better performance of 11-133 is related to lower apoplastic and total Al concentrations and Al accumulation in the root associated with a lower fluorescence of Al-lumogallion complex at the root tip, indicating the presence of mechanisms of chelation with this metal. Consequently, this IL showed less change in root morphoanatomy and lower reactive oxygen species and malondialdehyde content, which are associated with a more efficient enzymatic and non-enzymatic system, mainly due to the higher content of the glutathione metabolite and the higher activities of superoxide dismutase, monodehydroascorbate reductase, dehydroascorbate reductase, γ-glutamylcysteine synthetase, and glutathione peroxidase enzymes. Thus, these findings illustrated above indicate how internal mechanisms of detoxification respond to Al in popcorn, which can be used as tolerance biomarkers.

Elevated level of chilling tolerance in cucumber fruit was obtained by β-aminobutyric acid via the regulation of antioxidative response and metabolism of energy, proline and unsaturated fatty acid

• BABA treatment enhances the chilling tolerance in cucumber fruit. • BABA application improved the antioxidant capacity of harvested cucumber fruit. • BABA-treated fruit exhibited higher level of energy status. • BABA promoted proline accumulation and maintained higher level of UFA contents. This experimental study was conducted to investigate the effects of β-aminobutyric acid (BABA) on chilling injury in cold-stored cucumber fruit. Results showed that BABA decreased the development of chilling injury in cucumber fruit. BABA-treated fruit exhibited elevated antioxidant ability, indicated by high activities of superoxide dismutase (SOD) and catalase (CAT) and low levels of hydrogen peroxide and superoxide anion. BABA treatment maintained a high level of energy status by promoting the activities and genes expression of H + -ATPase, Ca 2+ -ATPase, succinate dehydrogenase (SDH) and cytochrome C oxidase (CCO). Increased enzymes activities and genes expression of Δ 1 -pyrroline-5-carboxylate synthase (PCS) and ornithine-δ-aminotransferase (OAT) and depressed enzyme activity and gene expression of proline dehydrogenase (PDH) in BABA-treated cucumber collectively promoted the accumulation of proline. Furthermore, BABA treatment delayed the decreasing trend of unsaturated fatty acid content in cucumber. Thus, BABA is effective in enhancing chilling tolerance in cucumber fruit possibly by improving the antioxidant ability and adjusting the metabolism of energy, proline and unsaturated fatty acids.

Antioxidant activity of environmental lactic acid bacteria strains isolated from organic raw fermented meat products

The aim of the research was to evaluate the antioxidant activity of 23 LAB strains isolated from raw fermented meat products. The methodology was based on in vitro tests in which the ability of antioxidants to deactivate free radicals was used. The greatest ability to scavenge the DPPH radicals was observed in Pediococcus pentosaceus KL14 and KL10, to scavenge ABTS radicals was in Pd. pentosaceus KL11 and KL14. The highest activity of superoxide dismutase (SOD) was found in Pd. pentosaceus BAL6 and BAL3. The Pd. pentosaceus BAL6, KL14 strains were able to produce H2O2. The highest resistance to superoxide anions was found in Pd. pentosaceus KL14 whereas the hydroxyl radicals was observed in Lactiplantibacillus plantarum SCH1 and Pd. pentosaceus BAL6. All of the strains were catalase-negative. The resistance to H2O2 was observed in Pd. pentosaceus KL14 and BAL5. Furthermore, the highest antioxidant activity was found in strains Pediococcus pentosaceus KL14, BAL6 and Lactiplantibacillus plantarum SCH1. Moreover, we identified 15 strains of LAB with high antioxidant activity comparable to probiotic L. rhamnosus GG. The use of natural antioxidant activity can be used in meat processing to limit the use of chemical antioxidants.

НУТРИЦЕВТИЧЕСКИЕ ПОКАЗАТЕЛИ БАКТЕРИОЦИНПРОДУЦИРУЮЩИХ ЛАКТОКОККОВ ДЛЯ СОЗДАНИЯ ФЕРМЕНТИРОВАННЫХ ФУНКЦИОНАЛЬНЫХ ПРОДУКТОВ

The article presents data on nutraceutical indicators, including antimicrobial and superoxidase activities of strains of Lactococcus lactis subsp. lactis, to create functional products. The addition of free amino acids (alanine, glutamic acid, serine, tyrosine, and tryptophan) to the medium enhanced the antimicrobial effect of recombinant strains F-116 and F-119 on food and raw material contaminant strains to varying degrees. The effect of isoleucine is most effective, which contributed to an increase in the inhibitory activity of the F-116 strain on Staphylococcus aureus up to 32,1% and on Escherichia coli up to 84%, which was not observed in the F-119 strain. The bactericidal effect of the recombinant strain F-119 on Escherichia coli increased when serine was added to the medium from 1900 to 2550 units/ml (according to chloramphenicol), i.e. by 34%, tryptophan - by 37% and tyrosine - by 55%. With the addition of glutamic acid for 15 hours of cultivation, the fungicidal activity on Aspergillus niger increased only in strain F-116 from 2600 to 3300 units/ml (according to nystatin), which amounted to 27%, on Candida albicans up to 40%. Tyrosine increased the activity of strain F-119 on Candida albicans to . 25%, and tryptophan – 26%. The strains had high superoxide dismutase activity (27,02–30 U/mg of protein). SOD was 5–6 times higher in recombinant strains compared to the SOD activity of parental strains 729 and 1605.