Lower Catalase Activity Research Articles

Influence of 50 Hz electromagnetic frequency on oxidative stress and morphological characteristics in mosquito-borne filariasis Culex pipiens

• The larvae of Culex pipiens were exposed to EMF frequency (50 Hz). • The biochemical and morphological changes in Culex pipiens were estimated. • The larval body weight and total protein in EMF treated groups were significantly decreased compared to control. • Antioxidant enzymes activity in EMF treated groups were decreased significantly compared to the control. • Both 500 & 1000 mT caused distinct malformations to the larval body parts. The electromagnetic field (EMF) is a vital issue in research, but its use as an alternative technique for insect management is still in its beginnings. The study aimed to evaluate the effects of exposure to the electromagnetic field on the biochemical analysis and morphological characteristics in Culex pipiens . Therefore, the third instar larvae were exposed to EMF frequency (50 Hz) at different intensities (250, 500, 1000 mT) for 1 h during four successive days. After end exposure to EMF, the biochemical analysis, oxidative stress parameters, body weight, and morphological features were investigated. The results showed that larval body weight and total protein content were decreased significantly in all treated groups compared to controls. The total lipid content significantly decreased at 500 & 1000 mT exposure, while the treatment group exposed to EMF at 250 mT was not statistically different compared to control. At a high intensity of EMF 1000 mT all oxidative stress parameters; catalase (CAT) and Glutathione S-transferase (GST) activity and lipid peroxidation level (MDA) were decreased significantly compared to the control. On the other hand, at a low intensity (250 mT), CAT and GST activity was significantly increased, while MDA content was not statistically changed. Scanning electron microscopy showed that both 500 & 1000 mT caused distinct malformations to the larval body parts, mouthparts, thorax and abdomen with last abdominal structures. In conclusion, the results demonstrated that EMF exposure is a considerable stress factor that affects oxidative state and morphological features in mosquitoes and give hope that EMF will be used as an alternative method for Culex pipiens vector control.

Overexpression of a Bcl-2-associated athanogene SlBAG9 negatively regulates high-temperature response in tomato

The Bcl-2-associated athanogene (BAG) gene is a multi-functional family of co-chaperones regulator, modulating plant stress response. Our previous study revealed that the SlBAG9 of tomato (Solanum lycopersicum) had the higher expression level induced by high-temperature (HT) at the transcriptional and protein levels, but its biological function was still unclear. Here, we conducted an in-depth analysis of SlBAG9. SlBAG9 protein was not located in the mitochondria but in the cytoplasm and nucleus. Many cis-acting elements involved in plant stress and hormone responses were located in the promoter regions of SlBAG9 including heat-shock element (HSE1). The β-glucuronidase (GUS) histochemical analysis showed that SlBAG9 promoter could drive GUS gene expression in transiently transformed Nicotiana tabacum leaves under non-inducing condition and HSE1 is critical for HT-induced GUS activity under HT. The transcription of SlBAG9 was expressed in different organs and was regulated by HT, cold, drought, and salt stresses as well as exogenous abscisic acid (ABA) and H2O2. To further elucidate SlBAG9 function in response to HT, the transgenic tomato plants overexpressing SlBAG9 were developed. Compared to the wild-type plants, SlBAG9-overexpressing plants exhibited more sensitivity to HT stress, reflected by the burning symptoms, the degradation of chlorophyll, and the reduction of photosynthetic rates. Additionally, SlBAG9-overexpressing lines showed higher accumulation of lipid peroxidation production (MDA) and H2O2, but lower activities of superoxide dismutase, catalase, and peroxidase. Therefore, it is speculated that SlBAG9 plays a negative role in thermotolerance probably by inhibition of antioxidant enzyme system leading to the oxidative damage, consequently aggravating the HT-caused injury phenotype.

ROS-Scavengers, Osmoprotectants and Violaxanthin De-Epoxidation in Salt-Stressed Arabidopsis thaliana with Different Tocopherol Composition.

To determine the role of α- and γ-tocopherol (TC), this study compared the response to salt stress (200 mM NaCl) in wild type (WT) Arabidopsis thaliana (L.) Heynh. And its two mutants: (1) totally TC-deficient vte1; (2) vte4 accumulating γ-TC instead of α-TC; and (3) tmt transgenic line overaccumulating α-TC. Raman spectra revealed that salt-exposed α-TC accumulating plants were more flexible in regulating chlorophyll, carotenoid and polysaccharide levels than TC deficient mutants, while the plants overaccumulating γ-TC had the lowest levels of these biocompounds. Tocopherol composition and NaCl concentration affected xanthophyll cycle by changing the rate of violaxanthin de-epoxidation and zeaxanthin formation. NaCl treated plants with altered TC composition accumulated less oligosaccharides than WT plants. α-TC deficient plants increased their oligosaccharide levels and reduced maltose amount, while excessive accumulation of α-TC corresponded with enhanced amounts of maltose. Salt-stressed TC-deficient mutants and tmt transgenic line exhibited greater proline levels than WT plants, lower chlorogenic acid levels, and lower activity of catalase and peroxidases. α-TC accumulating plants produced more methylated proline- and glycine- betaines, and showed greater activity of superoxide dismutase than γ-TC deficient plants. Under salt stress, α-TC demonstrated a stronger regulatory effect on carbon- and nitrogen-related metabolites reorganization and modulation of antioxidant patterns than γ-TC. This suggested different links of α- and γ-TCs with various metabolic pathways via various functions and metabolic loops.

Pelleting with superabsorbent, chitosan, and phosphorus fertilizer as a new method to improve growth, yield, and physiological attributes of potato mini-tuber

Seed pelleting is a technique of covering seeds with adhesive agents to improve seed performance and plant establishment while reducing production costs. To evaluate the responses of potato superelite minitubers to different pelleting treatments both qualitatively and quantitatively, a 2-year experiment was conducted based on randomized complete block design with three replications in Mohaghegh Ardabili University, Ardabil, Iran during 2018 and 2019. Experimental treatments included 17 different combinations of zeolite (ZE) or cocopeat (CO) fillers, coating (SC) or soil application (SS) of triple superphosphate, superabsorbent polymer (SP), and chitosan (CH). The results showed a significant effect of pelleting on yield, physiological, and qualitative traits. The highest fresh and dry tuber weight belonged to SS + ZE treatment, which showed 50.6 and 49.0% increase compared to the control treatment (without pelleting), respectively. Pelleting minitubers by ZE + SS had the highest fresh tuber and biological yield (23.6 and 28.0 ton.ha-1, respectively), which showed an increase of 61.0 and 59.2%, compared to the no pelleting treatment. Most pelleting treatments increased the leaf proline content and activity of the antioxidant enzymes. The highest peroxidase activity and lowest catalase activity (16.1 and 29.6 U.mg protein-1.min, respectively) were observed in the CO+SC+CH treatment. Co-application of ZE, SC, and SP resulted in the highest protein, nitrate, and starch content. In addition, minituber pelleting with ZE+SS+SP increased methionine content significantly by 31.51% compared to the control. In general, the co-application of triple superphosphate, SP, and ZE increased the tuber yield and quality traits. Finally, the use of CH with these compounds resulted in improving physiological characteristics.

Homocysteine in Schizophrenia: Independent Pathogenetic Factor with Prooxidant Activity or Integral Marker of Other Biochemical Disturbances?

A wide range of studies have demonstrated that hyperhomocysteinemia is associated with the risk of schizophrenia, but currently available assumptions about the direct involvement of homocysteine (Hcy) in the pathogenesis of schizophrenia are hypothetical. It is possible that in vivo Hcy is only a marker of folate metabolism disturbances (which are involved in methylation processes) and is not a pathogenetic factor per se. Only one study has been conducted in which associations of hyperhomocysteinemia with oxidative stress in schizophrenia (oxidative damage to protein and lipids) have been found, and it has been suggested that the oxidative stress may be induced by the elevated Hcy in schizophrenic patients. But the authors did not study the level of reduced glutathione (GSH), as well as possible causes of hyperhomocysteinemia—disturbances of folate metabolism. The aim of this work is to analyze the association of Hcy levels with the following: (1) redox markers in schizophrenia GSH, markers of oxidative damage of proteins and lipids, and the activity of antioxidant enzymes in blood serum; (2) with the level of folate and cobalamin (В12); and (3) with clinical features of schizophrenia measured using the Positive and Negative Syndrome Scale (PANSS). 50 patients with schizophrenia and 36 healthy volunteers, matched by sex and age, were examined. Hcy in patients is higher than in healthy subjects (p = 0.0041), and this may be due to the lower folate level in patients (p = 0.0072). In patients, negative correlation was found between the level of Hcy both with the level of folate (ρ = −0.38, p = 0.0063) and with the level of B12 (ρ = −0.36, p = 0.0082). At the same time, patients showed higher levels of oxidative modification of serum proteins (p = 0.00046) and lower catalase (CAT) activity (p = 0.014). However, Hcy is not associated with the studied markers of oxidative stress in patients. In the group of patients with an increased level of Hcy (>10 μmol/l, n = 42) compared with other patients (n = 8), some negative symptoms (PANSS) were statistically significantly more pronounced: difficulty in abstract thinking (N5, p = 0.019), lack of spontaneity and flow in conversation (N6, p = 0.022), stereotyped thinking (N7, p = 0.013), and motor retardation (G7, p = 0.050). Thus, in patients with schizophrenia, hyperhomocysteinemia caused by deficiency of folate and B12 is confirmed and can be considered a marker of disturbances of vitamin metabolism. The redox imbalance is probably not directly related to hyperhomocysteinemia and is hypothetically caused by other pathological processes or by an indirect effect of Hcy, for example, on the enzymatic antioxidant defence system (CAT activity), which requires further exploration. Further study of the role of Hcy in the pathogenesis of schizophrenia is relevant, since the proportion of patients with hyperhomocysteinemia is high and correlations of its level with negative symptoms of schizophrenia are noted.

Feed deprivation over 16 days followed by refeeding until 75 days fails to elicit full compensation of Procambarus clarkii

A 75-day experiment was conducted with 6 different feeding regimes to evaluate compensatory responses in growth, physiological state, and muscle biochemical composition of juvenile Procambarus clarkii (1.37 ± 0.03 g). P. clarkii were deprived of feed for 0 day (control group), 2 (treatment 2), 4 (treatment 3), 8 (treatment 4), 16 (treatment 5), and 24 days (treatment 6) before being fed daily until day 75. Each feeding regime was tested in 10 replicate tanks with four crayfish in each tank. The growth (survival, SGRw, FCR, feeding rate, moulting frequency, HSI, PI, growth trajectory analysed using schnute model), digestive enzymes (trypsin and lipase), energy reserves and metabolites (alkaline phosphatase, total protein, total cholesterol, triglyceride, aspartate transaminase, and pyruvate kinase), antioxidant enzymes (superoxide dismutase, catalase, and malondialdehyde), and muscle biochemical composition (crude protein, crude lipid, ash, and moisture) were evaluated every 25 days. Results showed that P. clarkii in treatments 3 and 4 had similar growth as those in the control group but higher feeding rates at the end of the experiment, indicating that full compensatory growth occurred, while crayfish in treatments 5 and 6 only showed partial compensation. No compensation was observed in treatment 2. Furthermore, P. clarkii in treatment 4 had better feed utilisation efficiency, with a significantly lower FCR than those in other groups. The feed-deprivation period significantly influenced the physiological state of P. clarkii, with significantly lower values of variables of energy reserves and metabolites observed in treatments 5 and 6, except for alkaline phosphatase. Furthermore, P. clarkii in treatment 6 had significantly lower catalase activity but higher trypsin activity and malondialdehyde content than those in other groups. Muscle biochemical composition analysis revealed that P. clarkii in treatments 5 and 6 had significantly lower crude protein and lipid contents than other groups. The physiological state and muscle biochemical composition of crayfish varied over time (days 25, 50, and 75), with markedly increased activities or contents of total cholesterol, triglycerides, aspartate transaminase, catalase, crude protein and crude lipid observed in all treatments except the control group at the end of the experiment. Collectively, these results demonstrate that long-term feed deprivation (16 and 24 days) could only elicit partial compensation in growth, physiological state, and muscle biochemical composition of P. clarkii, while feed deprivation for 4 and 8 days followed by refeeding until day 75 could effectively trigger full compensation, particularly with respect to improve feed utilisation efficiency.

Comparison of Growth Performance, Carotenoid Content, and Temperature Tolerance of Two-Colored Strains of the Red Claw Crayfish Cherax quadricarinatus

The color of aquatic animals plays an important role in consumer acceptability and perceived quality. In a previous study, a red claw crayfish Cherax quadricarinatus strain with steady and hereditary shell color of blue was selected. To evaluate the potential value of this strain in crayfish culture, the growth performance, carotenoid content, and temperature tolerance of two crayfish strains (shell color; blue and blue-green) were conducted. After the 56-day rearing period, blue crayfish showed higher feed intake and growth rate, but lower survival than blue-green crayfish. Astaxanthin was the main pigment observed in the carapace of both strains, and the content of astaxanthin in blue crayfish was 18.62 mg/kg of wet weight, which was significantly lower than that of astaxanthin in blue-green crayfish (83.23 mg/kg of wet weight). The 7-day survival of two crayfish strains less than 34°C was 100%, and blue-green crayfish showed stronger tolerance to high water temperature exposure (35°C–38°C) than blue crayfish. Furthermore, after high temperature stress, lower activities of superoxide dismutase and catalase, and higher malondialdehyde in the hepatopancreases of blue crayfish were observed than those in blue-green crayfish. This study provides important information for future breeding programs for the red claw crayfish.

Prophylaxis of microelementosis in rabbits using a mixture of glauconite, succinic, humic and fulvic acids and minerals

Impaired metabolism of mineral substances in the conditions of industrial rabbit breeding may cause decrease in increment of live mass, reduction of immunity, mass morbidity and death of animals. In our experiment, we studied the efficiency of using a mineral mixture to prevent the disorders in the metabolism of rabbits according to changes in morphologic, biochemical parameters and antioxidant status of blood, chemical composition of blood plasma and increments in body weight compared to the control group of animals. For the studies, we formed four groups of white New Zealand rabbits, each comprising six individuals aged 70 days with mean body weight equaling 1.99 kg. In group I, the rabbits received an aqueous form of a mixture of glauconite, succinic acid, humic and fulvic acids and lactates of zinc, manganese, cuprum, cobalt and iron with water, rabbits of group II were given a dry form of a mixture of glauconite, succinic acid, humic and fulvic acids and lactates of zinc, manganese, cuprum, cobalt and iron with fodder, and the rabbits of group III were intramuscularly injected with butanol fraction of humic acids. The experiment lasted for 21 days. The results of the experiment indicate that the most effective prophylaxis of malfunctions of mineral metabolism in white New Zealand rabbits aged 70–95 was dry mixture of glauconite, succinic acid, humic and fulvic acids and lactates of zinc, manganese, cuprum, cobalt and iron with fodder (group II), which was given once a day for 21-day period. We determined a positive effect of biologically active supplement on the parameters of hematopoiesis(1.25 times significantly higher level of hemoglobin and 1.14 times higher number of erythrocytes), metabolism of proteins (1.54 times significantly higher content of albumins), mineral substances (significantly higher content of inorganic phosphorus – by 1.17 times, calcium by 2.18 times, manganese by 1.39 times, zinc by 1.50 times, iron by 1.39 times and cuprum by 1.49 times), functional condition of the liver (2.04 times lower activity of gamma-glutamyltransferase), the state of the antioxidant system (lowest catalase activity) and energy of rabbits’ growth (1.20-fold increment in body weight). The results of our study indicate that using a dry form of the mixture of glauconite, succinic acid, humic and fulvic acids and lactates of zinc, manganese, cuprum, cobalt and iron with fodder is an efficient method of preventing malfunctioning of mineral metabolism in rabbits.

Pretreatment of seeds with hydrogen peroxide improves deep-sowing tolerance of wheat seedlings

Drought is a prevalent natural factor limiting crop production in arid regions across the world. To overcome this limitation, seeds are sown much deeper to boost germination by soil moisture produced by underground water. Seed pretreatment can effectively induce deep-sowing tolerance in plants. In the present study, we evaluated whether H2O2 pretreatment of seeds can initiate metabolic changes and lead to improved deep-sowing tolerance in wheat. Pretreatment with 0.05 μM H2O2 promoted first internode elongation by 13% in the deep-sowing tolerant wheat cultivar “Tir” and by 32% in the sensitive cultivar “Kıraç-66” under deep-sowing conditions, whereas internode elongation was inhibited by diphenyleneiodonium chloride. In contrast to Tir seedlings, H2O2 levels in the first internode of Kıraç-66 seedlings increased under deep-sowing condition in the H2O2-treated group compared to controls. Moreover, these seedlings had significantly lower catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX) activities but higher NADPH oxidase (NOX) and superoxide dismutase (SOD) activities under the same conditions, which consequently induced greater H2O2 accumulation. Contrary to Tir, both total glutathione and glutathione S-transferase (GST) activity decreased in Kıraç-66 after deep-sowing at 10 cm. However, H2O2 treatment increased the total glutathione amounts and the activities of glutathione-related enzymes (except GST and GPX) in the first internode of Kıraç-66. Taken together, these data support that H2O2 acts as a signaling molecule in the activation of antioxidant enzymes (specifically NOX, SOD, and CAT), regulation of both glutathione-related enzymes and total glutathione content, and upregulation of the cell wall-loosening protein gene TaEXPB23.

ANTIOXIDATIVE ENZYMES ACTIVITY OF Chlorella vulgaris (UMT-M1) IN RESPONSE TO IC50 OF Pb2+ AND Hg2+

Heavy metals accumulation in aquatic bodies will lead to many deleterious effects on organisms living in them. Furthermore, some organisms can accumulate metals and this will eventually reach the primary consumers. The application of microalgae as remediator and indicator of metals pollution has become an increasing interest to scientists. In this study, we reported on the defence responses of a marine microalga, Chlorella vulgaris (UMT-M1) against Pb2+ and Hg2+ in terms of three antioxidative enzymes activity: superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). The activity of the enzymes was measured in alga treated with 5.7 mg/L PbCl2 and 0.18 mg/L Hg(NO3)2. These two concentrations were the IC50 values calculated using probit analysis. It was observed that Pb2+ and Hg2+ triggered a different strategy in counterattacking the metal’s effects. While a significant induction of SOD and CAT activity was evident in alga treated with both metals, APX activity was significantly inhibited in Pb2+-treated alga but was stimulated by more than 4-fold from the control in Hg2+-treated alga. Higher SOD activity was observed in Pb2+- compared to Hg2+-treated alga. However, lower CAT activity was observed in Pb2+- compared to Hg2+-treated alga. Also, a significant reduction in total soluble protein (TSP) content was observed in alga treated with Hg2+. Pb2+, on the other hand, significantly increased the production of TSP. The changes observed in the antioxidative enzymes activity and TSP content in this alga are good potentials to be used as biomarkers for metal’s bioindication tool.

PagERF16 of Populus Promotes Lateral Root Proliferation and Sensitizes to Salt Stress.

The aggravation of soil salinization limits the growth and development of plants. The AP2/ERF transcription factors (TFs) have been identified and play essential roles in plant development and stress response processes. In this study, the function of PagERF16 was detected using the overexpressing (OX) and RNAi transgenic poplar 84K hybrids. Plant growth, stomatal conductance, antioxidant enzymes activity, and PagERF16 co-expressed TFs were analyzed using morphological, physiological, and molecular methods. OX showed a more robust lateral root system with a bigger diameter and volume compared to the wild-type plants (WT). Physiological parameters indicated the bigger stomatal aperture and lower stomatal density of OX along with the lower Catalase (CAT) activity and higher malondialdehyde (MDA) content contributed to the salt sensitivity. The plant height and rooting rate of OX and RNAi were significantly worse compared to WT. Other than that, the morphology and physiology of RNAi plants were similar to WTs, suggesting that the function of PagERF16 may be redundant with other TFs. Our results indicate that when PagERF16 expression is either too high or too low, poplar growth and rooting is negatively affected. In addition, a downstream target TF, NAC45, involved in Auxin biosynthesis, was identified and PagERF16 could directly bind to its promoter to negatively regulate its expression. These results shed new light on the function of ERF TFs in plant root growth and salt stress tolerance.

Role of Local Biofertilizer in Enhancing the Oxidative Stress Defence Systems of Date Palm Seedling (Phoenix dactylifera) against Abiotic Stress

Among the abiotic stresses, drought is the first environmental stress responsible for a decrease in agricultural production worldwide; it affects plants in various ways, including slowing down plant growth and disrupting its general physiology. Arbuscular mycorrhizal symbiosis and plant growth-promoting rhizobacteria (PGPR) are considered to be the bioameliorators of the plant’s resistance to water stress. The present study investigated the effects of inoculation with arbuscular mycorrhizal fungi (AMF) and PGPR on the water status and antioxidant enzyme activities of date palm seedlings grown under water stress conditions. The parameters related to the plant’s water status were significantly ( p < 0.05 ) higher in the plants treated with mycorrhizae and mycorrhizae + bacteria compared with their respective controls, especially under water stress conditions. The maximum proline content was obtained in plants inoculated with the AMF species and PGPR (combined) under severe water stress conditions reaching a value of 2.588 ± 0.034 in 25% field capacity, compared with 0.978 ± 0.024 for the control. In addition, the inoculated seedlings showed notably lower activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and glutathione S-transferase (GST) in response to severe water stress compared with nonmycorrhizal seedling. Overall, the arbuscular mycorrhizal symbiosis and PGPR bacteria inoculation could be promising methods to enhance date palm resistance against oxidative stress.

Hypothyroidism induces oxidative stress and DNA damage in breast.

Breast cancer and thyroid dysfunctions have been associated for decades. Although many studies suggest a biological correlation, the mechanisms linking these two pathologies have not been elucidated. Reactive oxygen species (ROS) can oxidize lipids, proteins, and DNA molecules and may promote tumor initiation. Hence, we aimed at evaluating the mammary redox balance and genomic instability in a model of experimental hypothyroidism. Female Wistar rats were treated with 0.03% methimazole for 7 or 21 days to evaluate ROS generation, antioxidant enzyme activities, and oxidative stress biomarkers, as well as genomic instability. After 7 days, lower catalase, GPX, and DUOX activities were detected in the breast of hypothyroid group compared to the control while the levels of 4-hydroxynonenal (HNE) were higher. In addition, hypothyroid group showed an increase in γH2Ax/H2Ax ratio. Twenty-one days hypothyroid group had increased catalase and SOD activities, without significant differences between groups in the levels of oxidative stress biomarkers and DNA damage. TSH-treated MCF10A cells showed a higher extracellular, intracellular, and mitochondrial ROS production. Additionally, greater DNA damage was observed in these cells, demonstrated by a higher comet tail DNA percentage and increased 53BP1 foci. Finally, we found that TSH treatment was not able to alter cell viability. The Genome Cancer Atlas (TGCA) data showed that high TSHR expression is associated with more invasive breast cancer types. In conclusion, we demonstrate that oxidative stress and DNA damage in breast are early events of experimental hypothyroidism. Moreover, high TSH levels induce oxidative stress and genomic instability in mammary cells.

Surfactant-enhanced treatment of oil-contaminated Arctic tundra soil: Ecotoxicological assessment

During 2018–2019 summer expeditions to the Yamal peninsula, we collected tundra gley soil samples at the oil-contaminated sites. The contamination level was determined by fluorimetry and was ranged from 30 to 107 g/kg. The soil quality was evaluated by its enzymatic activity; the low catalase activity of the soils confirmed the presumed slow soil natural attenuation and the need for land remediation. The oil-contained and background samples were ex-situ treated with the aqueous solutions of non-ionic BOK-6 and anionic AddiMax PV01 synthetic surfactants. The treatment efficiency reached 71 ± 2% and 97 ± 3% in the experimental design with BOK-6 and AddiMax PV01, respectively. We derived the ecotoxicity endpoints for the surfactant solutions, using infusoria Paramecium caudatum Ehrenberg and higher plants Raphanus sativus L. and Avena sativa L. The protozoan mortality was studied and resulted in LC 50 − 24 values << 0.1 mg/L and 339 mg/L for BOK-6 and AddiMax PV01, respectively. Both surfactant solutions and surfactant residues in soil showed the inhibition potential towards higher plants. BOK-6, with a strong relation to its chemical and ecotoxic profile, completely inhibited seed germination in the treated soil. The less ecotoxic surfactant AddiMax PV01 inhibited plant growth by 38% compared to control. The treatment increased ecotoxicity and dehydrogenase activity and further lowered the catalase activity of the background soil, and, therefore, the surfactant residues migrating to the non-contaminated territories should be controlled. By this study, we show the efficiency of the surfactant-enhanced remediation of arctic soils, but the associated environmental risks must be addressed. • Ex-situ treatment of oil-contaminated tundra gley soil reached 69%–99% efficiency. • Enzymes activity indicated slow natural attenuation potential of arctic soil. • Residues of toxic surfactant could cause greater ecotoxic effect than contamination. • Surfactants residues inhibited biological activity of non-contaminated arctic soil.

Evaluation of the mitigation efficacy of a yeast cell wall extract toward deoxynivalenol contaminated diet fed to turbot (Scophthalmus maximus)

Deoxynivalenol (DON) is one of the most common mycotoxins in animal feed worldwide and causes significant threats to the animal health. Increased use of plant ingredients in aquaculture feeds increased the risk of mycotoxin contamination. To evaluate the effects of dietary deoxynivalenol (DON) on growth performance, immune response and intestinal health of turbot and the mitigation efficacy of yeast cell wall extract (YCWE) toward DON, nine isonitrogenous and isolipidic diets were formulated: Diet 1 (control): No DON added; Diets 2–5 or Diets 6–9: 0.5 or 3.0 mg added DON/kg diet + 0%, 0.1%, 0.2%, or 0.4% YCWE, respectively. Results showed that Diet 6 (3 mg/kg DON, 0% YCWE) significantly decreased weight gain, specific growth rate and feed efficiency ratio of fish and reduced immunoglobulin M and complement 4 concentrations in serum. Fish fed Diet 6 presented morphological alterations, lower activity of superoxide dismutase, catalase and total antioxidant capacity but higher malondialdehyde content, lower claudin-4 and occludin expression but higher interleukin-1β expression in intestine. Besides, Diet 6 decreased the abundance of potential helpful bacteria but increased the abundance of potential pathogens in intestine. While, dietary YCWE, especially Diet 8 (3 mg/kg DON, 0.2% YCWE) and 9 (3 mg/kg DON, 0.4% YCWE), markedly improved growth performance and immune response and enhanced the intestinal health of turbot. In conclusion, dietary YCWE could mitigate the toxic effects induced by DON in turbot, and could be used as an effective strategy to control DON contamination in fish feed.

GhWRKY46 from upland cotton positively regulates the drought and salt stress responses in plant

Cotton (Upland Cotton) is one of the major fiber crops in the world. Drought and salinity, as abiotic stress factors, dramatically affect the cotton yield, However, the response processes of cotton to drought and salt stress is still not very clear. Previously, the gene GhWRKY46, encoding WRKY transcription factor protein, was identified to possibly be associated with drought and salt pressure. In present study, the function of GhWRKY46 has been investigated in Arabidopsis and cotton. The transcription factor properties of GhWRKY46 were confirmed by its location in the nucleus and transcriptional activation activity in yeast. Overexpression of GhWRKY46 enhanced tolerance to salt and drought in Arabidopsis, conferring higher survival rates, chlorophyll contents, and biomasses in the overexpression lines under drought stress. Additionally, overexpression of GhWRKY46 enhanced the expression of the stress-related genes AtRD22, AtCBL10, and AtCPK3 in the transgenic Arabidopsis. Silencing of GhWRKY46 in cotton by virus-induced gene silencing resulted in higher sensibilities to salt stress and malondialdehyde contents, as well as lower activities of catalase and peroxidase compared with the control; this further confirmed previous results. Our results demonstrated that GhWRKY46 positively regulates the responses to drought and salt stresses, probably by enhancing the expression of stress-related genes.

Defense Responses in the Interactions between Medicinal Plants from Lamiaceae Family and the Two-Spotted Spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)

This study aimed to determine the effects of plant species on the biological parameters of Tetranychus urticae Koch and the time of mite infestation on plant physiology in Ocimum basilicum L., Melissa officinalis L. and Salvia officinalis L. Mite infestation induced various levels of oxidative stress depending on plant species and the duration of infestation. Host plants affected T. urticae life table parameters. The low level of susceptibility was characteristic of S. officinalis, which appeared to be the least infected plant species and reduced mites demographic parameters. Infested leaves of S. officinalis contained elevated levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) compared to control. In addition, higher membrane lipid peroxidation and higher activity of guaiacol peroxidase (GPX) and lower activity of catalase (CAT) were recorded with a longer mite infestation. In contrast, O. basilicum appeared to be a suitable host on which T. urticae could develop and increase in number. In basil leaves, increasing levels of hydrogen peroxide and MDA with elevated GPX activity and strongly decreased catalase activity were recorded. Knowledge of the differences in mite susceptibility of the tested medicinal plants described in this study has the potential to be applied in breeding strategies and integrated T. urticae pest management in medicinal plant cultivations.

Evaluation of probiotic potential of Bacillus strains on growth performance and physiological responses in Penaeus vannamei

This study was conducted to exhibit the effectiveness of four different Bacillus sp., that is Bacillus subtilis, B. megaterium, B. cereus and B. infantis on growth performance and physiological response in Penaeus vannamei. Experimental diets were identical in all the aspects except Bacillus incorporation: control (basal diet without probiotic) and four treatment diets T1 (basal diet + B. subtilis), T2 (basal diet + B. megaterium), T3 (basal diet + B. cereus) and T4 (basal diet + B. infantis). Each diet was fed at 10% of animal body weight, four times in a day and reared for 6 weeks in triplicate tanks. Among the treatments, final weight (0.97 ± 0.06 g), weight gain (0.94 ± 0.06 g), specific growth rate (7.88 ± 0.18%/day) and survival rate (64.66 ± 4.16%) were significantly higher in B. subtilis-treated group. Interestingly, in digestive enzyme activities, protease (3.57 ± 0.42 U/mg protein), lipase (747.83 ± 139.03 U/mg protein) and amylase (7.53 ± 1.27 U/mg protein) were higher in B. subtilis-supplemented diet fed group compared with other treatments. However, cellulase (246.83 ± 29.77 U/mg protein) activity was greater in group received B. megaterium. Significantly lower activities of superoxide dismutase, phenoloxidase and catalase were found in B. subtilis incorporated diet fed group. Hence, the study revealed that B. subtilis improves the growth performance and digestive enzyme activities. This proved the versatility of B. subtilis as a probiotic in shrimp farming practices. However, further exploration is required to commercialize the B. subtilis before recommending its application in aquaculture.

The relationship between morphology changes and antioxidant enzymes activity during somatic embryogenesis of long-term-maintained callus of Zoysia matrella (L.) Merr.

A callus line of manila grass [Zoysia matrella (L.) Merr.] has been maintained for 8 years in our laboratory. The present study investigated changes in ultrastructure and antioxidant enzyme activity during regeneration of the callus and examined the correlation between these changes and regeneration ability. The changes in fresh weight and diameter of the callus over time could be described by a sigmoidal growth curve with different stages. Electron microscopy revealed small embryonic callus cells, isodiametric in shape, with large, obvious nuclei, and dense cytoplasm. The cellular structures and morphology changed dramatically as regeneration proceeded. Of particular note was the formation of folded scutellum-like embryos at 14 d, which might be the turning point for morphological differentiation. Catalase (CAT) and peroxidase (POD) activities were the lowest at 14 d, the same time when superoxide dismutase (SOD) activity was highest. Thus, we speculate that the formation of the scutellum-like structures is associated with higher activity of SOD and lower activities of CAT and POD.

Leaf stage as a defoliation criterion for the production of high-vigour annual ryegrass seeds

Previous research demonstrated that the interval between defoliation treatments based on the leaf stage is a promising tool for the management of annual ryegrass (Lolium multiflorum L.) pasture. The use of this tool, which is based on the physiological status of the plant, could also benefit the seed production. We assessed the effects of the time of defoliation based on leaf stage on seed yield and quality of annual ryegrass cut to three residual stubble heights (RSH) (50%, 25% and 0% of plant height pre-defoliation) and a second defoliation applied to certain treatments based on the leaf stage of the plant regrowth (two or three leaves per tiller). Higher defoliation intensities (lower RSH) increased the amount of harvested forage to 4.0 t DM ha–1. Moderate defoliation (50%) undertaken at the 3-leaf stage combined with intense defoliation (25% and 0%) at the 2-leaf stage resulted in the highest seed yields (1.8 t ha–1). However, lower RSH reduced mean seed weight and physiological seed quality, which was also associated with lower seed starch and protein content. Accelerated ageing (AA) tests were used to compare seed vigour between treatments. A second defoliation at the 3-leaf stage plus intense defoliation (RSH 0%) resulted in seed lots with a high rate of lipid peroxidation after the AA test, followed by lower catalase activity, germination, and seedling growth. The combination of a second defoliation at the 3-leaf stage and the retention of higher RSH (50%) promoted a greater proportion of leaf blades in the stubble, with a strong positive correlation with seed production and vigour. Antioxidant enzyme activity after the AA test is an important marker of annual ryegrass seed quality.