scholarly journals Antioxidant enzymes and non-enzymatic antioxidants as defense mechanism of salinity stress in cowpea (Vigna unguiculata L. Walp)—Ife brown and Ife bpc

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Foluso Ologundudu
Keyword(s):  
Salinity Stress ◽  
Vigna Unguiculata ◽  
Saline Solution ◽  
Defense Mechanism ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Increase With Increase ◽  
Biochemical Mechanisms ◽  
Mechanisms Of Salt Tolerance ◽  
Screen House

Abstract Background Several mechanisms had been exhibited by plants to mitigate deleterious effects of salinity stress. A screen house experiment was conducted to investigate the effects of salinity stress on the activities of osmolytes (antioxidative and non-antioxidative enzymes) in the leaves of two cowpea (Vigna unguiculata L. Walp)—Ife brown and Ife bpc, with the aim of better understanding the biochemical mechanisms of salt tolerance. Salts of sodium chloride (NaCl) and sodium sulfate (Na2SO4) at 5, 10 and 15 dS/m concentrations were used for this study. The saline solution was prepared following standard methods. Proline, lipid peroxidase (LP), superoxide dismutase (SOD) and glutathione (GSH) were determined following standard protocols. Results Results showed that minimum proline content (12.07 mg/g) and maximum proline determination (16.05 mg/g) were observed in Ife bpc at 5 and at 15 dS/m under NaCl and Na2SO4 treatments. The LP content significantly increased in Ife brown at 15 dS/m under NaCl treatment and at 10 dS/m (9.49 mg/g) under Na2SO4 salinity. Minimum GSH content (120 µm/g) and maximum glutathione accumulation (138.97 µm/g) were observed in Ife bpc in the stressed cowpea seedlings (5 and 10 dS/m) under NaCl treatment with respect to the control. Also, SOD activities in the leaves of Ife brown increase with increase in salinity stress in both NaCl and Na2SO4 treatments. Conclusions This study concludes that the accumulation of enzymatic and non-enzymatic antioxidants is capable of detoxifying and scavenging reactive oxygen species, thereby mitigating salinity-induced oxidative damage.

scholarly journals Reactive Oxygen Species, Oxidative Damage, and Antioxidative Defense Mechanism in Plants under Stressful Conditions

2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Pallavi Sharma ◽  
Ambuj Bhushan Jha ◽  
Rama Shanker Dubey ◽  
Mohammad Pessarakli
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Defense Mechanism ◽  
Second Messengers ◽  
Reactive Oxygen ◽  
Environmental Stresses ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Antioxidative Defense ◽  
Normal Product

Reactive oxygen species (ROS) are produced as a normal product of plant cellular metabolism. Various environmental stresses lead to excessive production of ROS causing progressive oxidative damage and ultimately cell death. Despite their destructive activity, they are well-described second messengers in a variety of cellular processes, including conferment of tolerance to various environmental stresses. Whether ROS would serve as signaling molecules or could cause oxidative damage to the tissues depends on the delicate equilibrium between ROS production, and their scavenging. Efficient scavenging of ROS produced during various environmental stresses requires the action of several nonenzymatic as well as enzymatic antioxidants present in the tissues. In this paper, we describe the generation, sites of production and role of ROS as messenger molecules as well as inducers of oxidative damage. Further, the antioxidative defense mechanisms operating in the cells for scavenging of ROS overproduced under various stressful conditions of the environment have been discussed in detail.

scholarly journals Assessment of Morpho-Physiological, Biochemical and Antioxidant Responses of Tomato Landraces to Salinity Stress

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 696
Author(s):  
Reem H. Alzahib ◽  
Hussein M. Migdadi ◽  
Abdullah A. Al Ghamdi ◽  
Mona S. Alwahibi ◽  
Abdullah A. Ibrahim ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salinity Stress ◽  
Dry Weight ◽  
Proline Content ◽  
Enzymatic Antioxidants ◽  
Sod Activity ◽  
Carotene Content ◽  
Antioxidants Activity ◽  
Solanum Lycopersicum L ◽  
Salinity Levels

Understanding salt tolerance in tomato (Solanum lycopersicum L.) landraces will facilitate their use in genetic improvement. The study assessed the morpho-physiological variability of Hail tomato landraces in response to different salinity levels at seedling stages and recommended a tomato salt-tolerant landrace for future breeding programs. Three tomato landraces, Hail 548, Hail 747, and Hail 1072 were tested under three salinity levels: 75, 150, and 300 mM NaCl. Salinity stress reduced shoots’ fresh and dry weight by 71% and 72%, and roots were 86.5% and 78.6%, respectively. There was 22% reduced chlorophyll content, carotene content by 18.6%, and anthocyanin by 41.1%. Proline content increased for stressed treatments. The 300 mM NaCl treatment recorded the most proline content increases (67.37 mg/g fresh weight), with a percent increase in proline reaching 61.67% in Hail 747. Superoxide dismutase (SOD) activity decreased by 65% in Hail 548, while it relatively increased in Hail 747 and Hail 1072 treated with 300 mM NaCl. Catalase (CAT) activity was enhanced by salt stress in Hail 548 and recorded 7.6%, increasing at 75 and 5.1% at 300 mM NaCl. It revealed a reduction in malondialdehyde (MDA) at the 300 mM NaCl concentration in both Hail 548 and Hail 1072 landraces. Increasing salt concentrations showed a reduction in transpiration rate of 70.55%, 7.13% in stomatal conductance, and 72.34% in photosynthetic rate. K+/Na+ ratios decreased from 56% for 75 mM NaCl to 85% for 300 mM NaCl treatments in all genotypes. The response to salt stress in landraces involved some modifications in morphology, physiology, and metabolism. The landrace Hail 548 may have better protection against salt stress and observed protection against reactive oxygen species (ROS) by increasing enzymatic “antioxidants” activity under salt stress.

scholarly journals Responses of Peppermint and Spearmint Crops to Excessive Biostimulant Application and Increased Salinity in a Closed Soilless Production System

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1168
Author(s):  
Dimitrios S. Kasampalis ◽  
Danai-Christina Aktsoglou ◽  
Pavlos Tsouvaltzis ◽  
Anastasios S. Siomos
Keyword(s):  
Amino Acid ◽  
Osmotic Stress ◽  
Antioxidant Defense ◽  
Defense Mechanism ◽  
Substantial Improvement ◽  
Oxygen Species ◽  
Floating System ◽  
High Salt Tolerance ◽  
Heated Glass ◽  
Nutrient Solutions

A floating system was established in a heated glass greenhouse in order to investigate whether the effect of amino acids (0.25 or 0.50% of a commercial amino acid (AA) solution Amino16®) during peppermint and spearmint production on plant developmental and nutritional status may be in part attributed to salinity induced osmotic stress. For this reason, in some nutrient solutions, three levels of salinity were induced by adding 0, 10, or 20 mM NaCl. According to the results, it can be concluded that spearmint is mostly favored by the highest amino acid supplement of the nutrient solution (0.50%) in terms of a substantial improvement of the antioxidant nutritional quality (by up to 130%) at the expense of a reduced biomass production (by <30%). Enzymic antioxidant defense mechanism (APX and POD) was efficiently activated, preventing severe lipid peroxidation and the accumulation of reactive oxygen species such as H2O2 and maintaining the proline content at the normal levels. The osmotic stress that was induced by the excessive AA concentration and confirmed by the chlorophyl fluorescence variations was probably related to NH4+ excess supply in the growing media and was not associated with the elevated electrical conductivity in the solution. The absence of any adverse stressful consequences upon the addition of 20 mM NaCl may be attributed to the high salt tolerance of peppermint and spearmint species.

scholarly journals Exogenous Tebuconazole and Trifloxystrobin Regulates Reactive Oxygen Species Metabolism Toward Mitigating Salt-Induced Damages in Cucumber Seedling

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 428 ◽  
Author(s):  
Sayed Mohsin ◽  
Mirza Hasanuzzaman ◽  
M. Bhuyan ◽  
Khursheda Parvin ◽  
Masayuki Fujita
Keyword(s):  
Reactive Oxygen Species ◽  
Salt Stress ◽  
Antioxidant Defense ◽  
Ion Homeostasis ◽  
Reactive Oxygen ◽  
Cucumber Plant ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Exogenous Application ◽  
Antioxidant Defense Systems

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses of fungicides (1.375 µM TEB + 0.5 µM TRI and 2.75 µM TEB + 1.0 µM TRI) solely and in combination with NaCl (60 mM) for six days. The application of salt phenotypically deteriorated the cucumber plant growth that caused yellowing of the whole plant and significantly destructed the contents of chlorophyll and carotenoids. The oxidative damage was created under salinity by increasing the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolytic leakage (EL) resulting in the disruption of the antioxidant defense system. Furthermore, in the leaves, stems, and roots of cucumber plants increased Na+ content was observed under salt stress, whereas the K+/Na+ ratio and contents of K+, Ca2+, and Mg2+ decreased. In contrast, the exogenous application of TEB and TRI reduced the contents of MDA, H2O2, and EL by improving the activities of enzymatic and non-enzymatic antioxidants. In addition, ion homeostasis was regulated by reducing Na+ uptake and enhanced K+ accumulation and the K+/Na+ ratio after application of TEB and TRI. Therefore, this study indicates that the exogenous application of TEB and TRI enhanced salt tolerance in cucumber plants by regulating reactive oxygen species production and antioxidant defense systems.

STUDIES ON THE EFFECTS OF PHAGOCYTIC STIMULATION ON MICROBIAL DISEASE: V. STIMULATION OF PHAGOCYTIC ACTIVITY OF MONOCYTES AGAINST TUBERCLE BACILLI, STRAIN BCG

1956 ◽  
Vol 34 (1) ◽  
pp. 571-579
Author(s):  
Béla Gözsy ◽  
László Kátó
Keyword(s):  
Phagocytic Activity ◽  
Guinea Pigs ◽  
Saline Solution ◽  
Defense Mechanism ◽  
Direct Action ◽  
Intraperitoneal Administration ◽  
Cellular Defense ◽  
Appropriate Treatment ◽  
Stimulation Of

Monocytes were obtained by the washing of the peritoneal cavity of guinea pigs with Hanks' solution six days after intraperitoneal administration of a saline solution containing glycogen. Phagocytosis of tubercle bacilli (BCG strain) was studied after a one hour incubation at 37 °C. under the influence of histamine and 1,4-dimethyl-7-isopropyl-bicyclo-decapentane, which latter substance had shown a beneficial influence on the outcome of experimental tuberculosis. Histamine increased the phagocytic activity of monocytes, within the limits of 1 μgm. to 10 μgm per ml. This stimulation was inhibited in vitro by a synthetic antihistamine substance. Fifty and 100 μgm. per ml. histamine decreased the phagocytosis of tubercle bacilli (BCG) by the monocytes. Monocytes withdrawn from histamine treated guinea pigs showed no stimulated activity. From 0.5 to 100 μgm. per ml. of 1,4-dimethyl-7-isopropylbicyclo-decapentane stimulated the phagocytic activity of monocytes against tubercle bacilli (BCG) in vitro and monocytes withdrawn from animals treated with the same substance showed equally a stimulated activity. This increased phagocytosis was equally inhibited in vitro by the antihistamine, but to a lesser degree than the inhibition of the histamine stimulated phagocytosis. The above observations suggest that the stimulating action of the 1,4-dimethyl-7-isopropyl-bicyclo-decapentane is a direct action on the monocytes rather than an indirect one caused by activation of latent histamine. Experiments also show the possibility of stimulation of the cellular defense mechanism, by appropriate treatment.

scholarly journals Ecotype-Specific Pathways of Reactive Oxygen Species Deactivation in Facultative Metallophyte Silene vulgaris (Moench) Garcke Treated with Heavy Metals

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 102 ◽  
Author(s):  
Ewa Muszyńska ◽  
Mateusz Labudda ◽  
Adam Kral
Keyword(s):  
Heavy Metals ◽  
Reactive Oxygen Species ◽  
Metal Tolerance ◽  
Reactive Oxygen ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Silene Vulgaris ◽  
Ros Scavenging ◽  
Natural Habitats

This research aimed to indicate mechanisms involved in protection against the imbalanced generation of reactive oxygen species (ROS) during heavy metals (HMs) exposition of Silene vulgaris ecotypes with different levels of metal tolerance. Specimens of non-metallicolous (NM), calamine (CAL), and serpentine (SER) ecotypes were treated in vitro with Zn, Pb, and Cd ions applied simultaneously in concentrations that reflected their contents in natural habitats of the CAL ecotype (1× HMs) and 2.5- or 5.0-times higher than the first one. Our findings confirmed the sensitivity of the NM ecotype and revealed that the SER ecotype was not fully adapted to the HM mixture, since intensified lipid peroxidation, ultrastructural alternations, and decline in photosynthetic pigments’ content were ascertained under HM treatment. These changes resulted from insufficient antioxidant defense mechanisms based only on ascorbate peroxidase (APX) activity assisted (depending on HMs concentration) by glutathione-S-transferase (GST) and peroxidase activity at pH 6.8 in the NM ecotype or by GST and guaiacol-type peroxidase in the SER one. In turn, CAL specimens showed a hormetic reaction to 1× HMs, which manifested by both increased accumulation of pigments and most non-enzymatic antioxidants and enhanced activity of catalase and enzymes from the peroxidase family (with the exception of APX). Interestingly, no changes in superoxide dismutase activity were noticed in metallicolous ecotypes. To sum up, the ROS scavenging pathways in S. vulgaris relied on antioxidants specific to the respective ecotypes, however the synthesis of polyphenols was proved to be a universal reaction to HMs.

scholarly journals Silicon Alleviates Copper Toxicity in Flax Plants by Up-Regulating Antioxidant Defense and Secondary Metabolites and Decreasing Oxidative Damage

2020 ◽  
Vol 12 (11) ◽  
pp. 4732 ◽  
Author(s):  
Hossam S. El-Beltagi ◽  
Mahmoud R. Sofy ◽  
Mohammed I. Aldaej ◽  
Heba I. Mohamed
Keyword(s):  
Lipid Peroxidation ◽  
Plant Growth ◽  
Oxidative Damage ◽  
Antioxidant Defense ◽  
Growth Yield ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Total Chlorophyll ◽  
Yield Attributes ◽  
Cu Toxicity

In recent years, nutrient management has gained much attention as a way to mitigate heavy metal stress. Silicon (Si) promotes plant defense responses against toxic metal stresses. In this study, we evaluated the effects of silicon (Si) on copper (Cu) toxicity in two flax genotypes (Sakha 1 and Sakha 2) as it relates to plant growth, yield attributes, total chlorophyll, nucleic acid content, enzymatic and non-enzymatic antioxidants, oxidative damage, lipid peroxidation, copper and silicon content, and fatty acid composition. The results showed that Cu (100 and 200 µM) inhibited plant growth and increased Cu accumulation in soil, roots, and shoots. Cu significantly decreased the yield attributes, total chlorophyll by 9.5% and 22% in Sakha 1 and by 22.5% and 29% in Sakha 2, and enhanced the accumulation of non-enzymatic (tocopherol), enzymatic antioxidants such as superoxide dismnutase, peroxidase, ascorbate peroxidase and catalase) and secondary metabolites (phenol and flavonoids). The DNA content significantly decreased in stressed plants with 100 and 200 µM Cu about 22% and 44%, respectively, in Sakha 1 and about 21.6% and 34.7% in Sakha 2, and RNA content also decreased by about 20% and 29%, respectively, in Sakha 1 and by about 2% and 13% in Sakha 2 compared to the control plant. Furthermore, Cu stress accelerated the generation of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2) and induced cellular oxidative injury caused by lipid peroxidation. In parallel, Cu induced a change in the composition of fatty acids, resulting in lower unsaturated fatty acid levels and increased saturated fatty acids (increased saturation/unsaturation ratio for both genotypes). Treating the flax plants with irrigation three times with Si protected the plants from Cu toxicity. Si treatment decreased the uptake and the transport of Cu to the shoots and harvested seeds and promoted plant growth, yield attributes, and antioxidant defense systems by reducing Cu accumulation, lipid peroxidation, and the generation of H2O2. In addition, the alleviation of Cu toxicity correlated with increased Si accumulation in the roots and shoots. In conclusion, Si can be used to improve the resistance of flax plants to Cu toxicity by up-regulating the antioxidant defense system such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT) and decreasing the oxidative damage caused by reactive oxygen species (ROS).

scholarly journals The Influence of Reactive Oxygen Species in the Immune System and Pathogenesis of Multiple Sclerosis

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Mohammad javad Tavassolifar ◽  
Mohammad Vodjgani ◽  
Zahra Salehi ◽  
Maryam Izad
Keyword(s):  
Multiple Sclerosis ◽  
Reactive Oxygen Species ◽  
Immune System ◽  
T Cell ◽  
Reactive Oxygen ◽  
Autoimmune Response ◽  
Antioxidant Systems ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Nonenzymatic Antioxidants

Multiple roles have been indicated for reactive oxygen species (ROS) in the immune system in recent years. ROS have been extensively studied due to their ability to damage DNA and other subcellular structures. Noticeably, they have been identified as a pivotal second messenger for T-cell receptor signaling and T-cell activation and participate in antigen cross-presentation and chemotaxis. As an agent with direct toxic effects on cells, ROS lead to the initiation of the autoimmune response. Moreover, ROS levels are regulated by antioxidant systems, which include enzymatic and nonenzymatic antioxidants. Enzymatic antioxidants include superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Nonenzymatic antioxidants contain vitamins C, A, and E, glutathione, and thioredoxin. Particularly, cellular antioxidant systems have important functions in maintaining the redox system homeostasis. This review will discuss the significant roles of ROS generation and antioxidant systems under normal conditions, in the immune system, and pathogenesis of multiple sclerosis.

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