scholarly journals Toxin-Pathogen Synergy Reshaping Detoxification and Antioxidant Defense Mechanism of Oligonychus afrasiaticus (McGregor)

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1978 ◽  
Author(s):  
Ahmed AlJabr ◽  
Abid Hussain ◽  
Muhammad Rizwan-ul-haq
Keyword(s):  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Growth Parameters ◽  
Detoxification Enzymes ◽  
Antioxidant Enzyme Activities ◽  
Glutathione S Transferase ◽  
Biological Index ◽  
Joint Application ◽  
New Strategy

Current study reveals the likelihood to use pathogen and toxin mutually as an effective and eco-friendly strategy for Oligonychus afrasiaticus (McGregor) management, which could reduce toxicant dose and host killing time. Therefore, phytol and Beauveria bassiana in different proportions were evaluated to determine their effectiveness. Prior to ascertaining host mortality and defense mechanisms, we have recorded in vitro action of phytol using different concentrations (0.70, 1.40, 2.10, 2.80, and 3.50 mg/mL) against B. bassiana suspension. In vitro compatibility assays revealed that growth parameters (vegetative growth, sporulation, and viability) of B. bassiana were least affected by the action of phytol at all tested concentrations. Biological Index of B. bassiana exhibited compatibility with phytol allowed us to conduct Joint toxicity bioassays in which phytol and spores mixed in different proportions in order to attain maximum treatment effect in terms of high mortality at low concentration under short time. Results revealed that joint-application exhibited both synergistic (treatments with higher proportions of phytol), and antagonistic interaction (treatments with higher proportions of spores) interactions. Biochemical mechanisms involved in host antioxidant and detoxification response were explored by quantifying their respective enzymatic activities. Lethality of different treatments induced different patterns of detoxification enzymes including glutathione S-transferase (GST) and acetylcholinesterase (AchE). Overall, the least potent treatments (20% phytol:80% spores, and 40% phytol:60% spores) established in the current study induced relatively higher GST and AchE activities. On the other hand, the most potent treatment (80% phytol:20% spores) at its maximum concentration exhibited negligible relative GST and AchE activities. Antioxidant enzyme activities of CAT and SOD measured in the current study showed moderate to complex interaction might because of toxin-pathogen remarkable synergy. This study suggested that joint application of phytol with B. bassiana spores have shown tremendous acaricidal potential and found to be promising new strategy for controlling old world date mites.

scholarly journals Acceleration Breaks the Cells Defense Mechanisms against Vibration in Anthemis gilanica Calli

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Halimeh Hassanpour ◽  
Vahid Niknam ◽  
Sadaf Salami
Keyword(s):  
Protein Content ◽  
Defense Mechanisms ◽  
Growth Parameters ◽  
Resonance Effect ◽  
Total Carbohydrate ◽  
High Acceleration ◽  
Acceleration Amplitude ◽  
Relative Water ◽  
Stress Damage

Vibration is a mechanical stress which happens in nature and affects many biological aspects of plants. In this research, the effect of acceleration and vibration was investigated on some physiological and biochemical responses of Anthemis gilanica in vitro. Calli were induced from leaf (LS) and root segments (RS) and were applied to different frequencies of vibrations (0, 50, and 100 Hz) and accelerations (1, 2, and 4 g) on the A. gilanica calli for 30 min. Results showed that vibration significantly increased relative water content (RWC), growth parameters, protein and proline contents, ascorbate peroxidase (APX), peroxidase (POX), and superoxide dismutase (SOD) activities and decreased total carbohydrate, malondialdehyde (MDA), H2O2 contents, and polyphenol oxidase (PPO) activity in both LS and RS calli. Inversely, increase of acceleration in vibrated calli decreased growth parameters, RWC, protein content, and POX activity and induced proline and carbohydrate accumulations, SOD, APX, and PPO activities as compared to vibration alone. Different responses of two callus types were observed, and the highest growth, protein content, and membrane stability were observed in LS calli as compared to RS calli. It found that high acceleration amplitude intensified the resonance effect of vibration by induction of lipid peroxidation and oxidative stress damage in A. gilanica.

scholarly journals Glutamate ameliorates copper-induced oxidative injury by regulating antioxidant defences in fish intestine

2016 ◽  
Vol 116 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Jun Jiang ◽  
Xiao-Yun Wu ◽  
Xiao-Qiu Zhou ◽  
Lin Feng ◽  
Yang Liu ◽  
...  
Keyword(s):  
Antioxidant Enzyme ◽  
Oxidative Injury ◽  
Antioxidant Enzyme Activities ◽  
Glutathione S Transferase ◽  
Antioxidant Defences ◽  
Lactate Dehydrogenase Release ◽  
Fish Intestine ◽  
Pre Treatment

AbstractThe objective of this study was to determine the protective effect of glutamate (Glu) in Cu-induced oxidative injury in fish intestine in vivo and enterocytes in vitro. The results indicated that exposure to 6 mg/l Cu for 72 h induced the production of reactive oxygen species, thereby increasing protein oxidation and lipid peroxidation in enterocytes of grass carp in vitro. Cells exposed to Cu alone resulted in a significant increase in lactate dehydrogenase release, which is accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), glutathione S-transferase (GST), glutathione reductase (GR), anti-superoxide anion (ASA), anti-hydroxy radical (AHR) activities and GSH content. Pre-treatment with Glu remarkably prevented the toxic effects of Cu on the T-SOD, GST, GR, AHR, and ASA activities and GSH content in enterocytes. However, Cu induced an adaptive increase in the activities of catalase and glutathione peroxidase (GPx). Glu supplementation further increased GPx activity in enterocytes. Interestingly, the experiment in vivo showed that Glu pre-supplementation significantly elevated SOD, GPx, GST, GR, ASA and AHR activities, as well as GSH content. Further results showed that pre-treatment with Glu could alleviate Cu-induced oxidative injury by elevating antioxidant enzyme activities through regulating the expression of NF-E2-related nuclear factor 2 (Nrf2) mRNA. Together, these results indicated that Glu could attenuate Cu-induced cellular oxidative damage in fish intestine, likely mediated through Nrf2 signalling pathways regulating mRNA expressions of antioxidant enzyme genes and synthesis of GSH.

scholarly journals Health parameters and antioxidant response in Black Sea whiting Merlangius merlangus euxinus (Nordmann, 1840) parasitized by nematode Hysterothylacium aduncum (Rud., 1802)

2019 ◽  
Vol 9 (4) ◽  
pp. 700-709
Author(s):  
Ekaterina Skuratovskaya ◽  
Ekaterina Skuratovskaya ◽  
Andrey Zav'yalov ◽  
Irina Rudneva
Keyword(s):  
Black Sea ◽  
Defense Mechanisms ◽  
Parasitic Infection ◽  
Antioxidant Response ◽  
Infected Fish ◽  
Hepatosomatic Index ◽  
Antioxidant Enzyme Activities ◽  
Glutathione S Transferase ◽  
Merlangius Merlangus ◽  
Hysterothylacium Aduncum

Biometrical and biochemical parameters in healthy and parasitized by nematode Hysterothylacium aduncum Black Sea whiting Merlangius merlangus euxinus were studied. The increase of hepatosomatic index and decrease of spleen index in infected fish were found, while condition factor was similar in both groups. Antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), peroxidase (PER), glutathione reductase (GR) and glutathione-S-transferase (GST)) were higher in red blood cells in the parasitized fish as compared with the healthy animals. In the liver, the antioxidant response was not uniform: activities of SOD and GST decreased and activities of PER, GR and CAT increased in the infected individuals. The obtained results reflect host defense against oxidative stress caused parasitic infection. The tissue specific fluctuations of antioxidant response in parasitized and healthy fish are discussed. Data in this study can be used for understanding the defense mechanisms of fish against parasites.

scholarly journals FXa cleaves the SARS-CoV-2 spike protein and blocks cell entry to protect against infection with inferior effects in B.1.1.7 variant

2021 ◽  
Author(s):  
Jianhua Yu ◽  
Wenjuan Dong ◽  
Jing Wang ◽  
Lei Tian ◽  
Jianying Zhang ◽  
...  
Keyword(s):  
Viral Entry ◽  
Serine Proteases ◽  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Spike Protein ◽  
Natural Defense ◽  
Host Defense Mechanism ◽  
Direct Inhibitors

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human natural defense mechanisms against SARS-CoV-2 are largely unknown. Serine proteases (SPs) including furin and TMPRSS2 cleave SARS-CoV-2 spike protein, facilitating viral entry. Here, we show that FXa, a SP for blood coagulation, is upregulated in COVID 19 patients compared to non-COVID-19 donors and exerts anti-viral activity. Mechanistically, FXa cleaves the SARS-CoV-2 spike protein, which prevents its binding to ACE2, and thus blocks viral entry. Furthermore, the variant B.1.1.7 with several mutations is dramatically resistant to the anti-viral effect of FXa compared to wild-type SARA-CoV-2 in vivo and in vitro. The anti-coagulant rivaroxaban directly inhibits FXa and facilitates viral entry, whereas the indirect inhibitor fondaparinux does not. In a lethal humanized hACE2 mouse model of SARS-CoV-2, FXa prolonged survival while combination with rivaroxaban but not fondaparinux abrogated this protection. These preclinical results identify a previously unknown SP function and associated anti-viral host defense mechanism and suggest caution in considering direct inhibitors for prevention or treatment of thrombotic complications in COVID-19 patients.

The Use of the Defense Mechanism Test to Aid in Understanding the Personality of Senior Executives and the Implications for Their Careers

2009 ◽  
Vol 30 (1) ◽  
pp. 73-96 ◽  
Author(s):  
Olya Khaleelee
Keyword(s):  
Crisis Intervention ◽  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Senior Executives ◽  
Ideal Types ◽  
The Individual ◽  
Test Profiles ◽  
Real Test

This paper describes the use of the Defense Mechanism Test as an aid in helping to assess senior executives in four areas: for selection, development, career strategy, and crisis intervention. The origins of this test, developed to measure the defense mechanisms used to protect the individual from stress, are described. The paper shows how it was used to predict the capacity of trainee fighter pilots to withstand stress and its later application to other stressful occupations. Finally, some ideal types of the test are shown followed by four real test profiles, two of them with their associated histories.

A Study of Memory and Psychological Defense Mechanism in Julian Barnes’s The Sense of an Ending

2019 ◽  
Author(s):  
Hossein Aliakbari Harehdasht ◽  
Zahra Ekbatäni
Keyword(s):  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Human Mind ◽  
The Novel ◽  
Psychological Defense ◽  
Julian Barnes ◽  
Self Image

In The Sense of an Ending, Julian Barnes portrays the mysterious workings of the human mind as it distorts facts towards the end of a self-image that one can live with. The protagonist in the novel deploys certain psychological defense mechanisms in order to protect himself from feelings of anxiety, only to experience even more profound anxiety due to his excessive use of them. The significance of the present paper lies in its novel view of the book. So far, the critique on the novel has mainly been focused on the workings of time on memory; however, the present paper investigates how psychological defense mechanisms blur the protagonist’s perception of reality and distort his memories. This paper also attempts to attract scholarly interest in the study of psychological defense mechanisms in the study of The Sense of an Ending which has so far been to the best of our knowledge overlooked

Antifungal Proteins from Plant Latex

2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Hydrolytic Enzymes ◽  
Fungal Species ◽  
Biologically Active ◽  
Protein Classification ◽  
Fungal Cell ◽  
Antifungal Proteins ◽  
Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

scholarly journals In vitro Osmotic Stress Memory in Chrisanthemum hybridum: Structural and Physiological Responses

2017 ◽  
Vol 27 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Lidiia Samarina ◽  
Valentina Malyarovskaya ◽  
Yulija Abilfazova ◽  
Natalia Platonova ◽  
Kristina Klemeshova ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Relative Water Content ◽  
Soluble Protein ◽  
Growth Parameters ◽  
Physiological Responses ◽  
Proline Content ◽  
Stress Exposure ◽  
Stress Memory ◽  
Relative Water

Structural and physiological responses of chrysanthemum to repeated osmotic stress were studied. Plants were cultured for 2 weeks (for each stress1 and stress 2) on half MS supplemented with mannitol 100 mM (Treatment I) and 200 mM (Treatment II). First stress inhibited growth parameters stronger than second stress in treatment I. In treatment II both stress events strongly inhibited growth parameters of micro‐shoots. Proline content exceeded control 6 ‐ 8 times after 1st stress, and 2 ‐ 5 times after the 2nd stress in treatments I and II, respectively. Soluble protein was accumulated in leaves during both stress exposures, and 2 ‐ 2.5 times exceeded control after the 2nd stress. Relative water content in both treatments increased after the 2nd stress exposure. In treatment II chlorophyll а and carotenoids contents were 8.78 and 4.62 mg/g comparing to control (4.21 and 2.25 mg/g, respectively) after the 1st stress. But after the 2nd stress there was no difference with control.Plant Tissue Cult. & Biotech. 27(2): 161-169, 2017 (December)

scholarly journals Growth and Antioxidant Responses in Iron-Biofortified Lentil under Cadmium Stress

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 182
Author(s):  
Ruchi Bansal ◽  
Swati Priya ◽  
Harsh Kumar Dikshit ◽  
Sherry Rachel Jacob ◽  
Mahesh Rao ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Dry Weight ◽  
Cadmium Stress ◽  
Antioxidant Enzyme Activities ◽  
Limited Information ◽  
Cd Stress ◽  
Fresh Weight ◽  
Cd Uptake ◽  
Cd Tolerance ◽  
Controlled Conditions

Cadmium (Cd) is a hazardous heavy metal, toxic to our ecosystem even at low concentrations. Cd stress negatively affects plant growth and development by triggering oxidative stress. Limited information is available on the role of iron (Fe) in ameliorating Cd stress tolerance in legumes. This study assessed the effect of Cd stress in two lentil (Lens culinaris Medik.) varieties differing in seed Fe concentration (L4717 (Fe-biofortified) and JL3) under controlled conditions. Six biochemical traits, five growth parameters, and Cd uptake were recorded at the seedling stage (21 days after sowing) in the studied genotypes grown under controlled conditions at two levels (100 μM and 200 μM) of cadmium chloride (CdCl2). The studied traits revealed significant genotype, treatment, and genotype × treatment interactions. Cd-induced oxidative damage led to the accumulation of hydrogen peroxide (H2O2) and malondialdehyde in both genotypes. JL3 accumulated 77.1% more H2O2 and 75% more lipid peroxidation products than L4717 at the high Cd level. Antioxidant enzyme activities increased in response to Cd stress, with significant genotype, treatment, and genotype × treatment interactions (p < 0.01). L4717 had remarkably higher catalase (40.5%), peroxidase (43.9%), superoxide dismutase (31.7%), and glutathione reductase (47.3%) activities than JL3 under high Cd conditions. In addition, L4717 sustained better growth in terms of fresh weight and dry weight than JL3 under stress. JL3 exhibited high Cd uptake (14.87 mg g−1 fresh weight) compared to L4717 (7.32 mg g−1 fresh weight). The study concluded that the Fe-biofortified lentil genotype L4717 exhibited Cd tolerance by inciting an efficient antioxidative response to Cd toxicity. Further studies are required to elucidate the possibility of seed Fe content as a surrogacy trait for Cd tolerance.

scholarly journals Ameliorative Effects of Exogenous Proline on Photosynthetic Attributes, Nutrients Uptake, and Oxidative Stresses under Cadmium in Pigeon Pea (Cajanus cajan L.)

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 796
Author(s):  
Khizar Hayat ◽  
Jafar Khan ◽  
Asif Khan ◽  
Shakir Ullah ◽  
Shahid Ali ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Growth Traits ◽  
Growth Parameters ◽  
Thiobarbituric Acid ◽  
Pigeon Pea ◽  
Antioxidant Enzyme Activities ◽  
Chlorophyll Contents ◽  
Oxidative Stresses ◽  
Exogenous Proline ◽  
Photosynthetic Attributes

Proline plays a significant role in the plant response to stress conditions. However, its role in alleviating metal-induced stresses remains elusive. We conducted an experiment to evaluate the ameliorative role of exogenous proline on cadmium-induced inhibitory effects in pigeon pea subjected to different Cd treatments (4 and 8 mg/mL). Cadmium treatments reduced photosynthetic attributes, decreased chlorophyll contents, disturbed nutrient uptake, and affected growth traits. The elevated activity of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase), in association with relatively high contents of hydrogen peroxide, thiobarbituric acid reactive substances, electrolyte leakage, and endogenous proline, was measured. Exogenous proline application (3 and 6 mM) alleviated cadmium-induced oxidative damage. Exogenous proline increased antioxidant enzyme activities and improved photosynthetic attributes, nutrient uptake (Mg2+, Ca2+, K+), and growth parameters in cadmium-stressed pigeon pea plants. Our results reveal that proline supplementation can comprehensively alleviate the harmful effects of cadmium on pigeon pea plants.

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