Modulation of the Antioxidant Defense System by Exogenous l-Glutamic Acid Application Enhances Salt Tolerance in Lentil (Lens culinaris Medik.)

Salt stress greatly disturbs the growth, morpho-physiological, and biochemical performance of plants. However, different physiological processes and acclimation mechanisms can be induced under stress, while some of them can be modulated by the appropriate chemical stimulus. The objective of this study was to evaluate the impact of exogenous pretreatment with 10 mM l-glutamic acid (l-Glu) on the physiological and biochemical parameters of lentil (Lensculinaris Medik.) under 110 mM NaCl stress. Salt stress inhibited the growth and reduced the photosynthetic pigment (chlorophylls and carotenoids) level, water content, and survival of lentil seedlings during recovery from the stress. Salt stress also induced oxidative damage, as indicated by higher hydrogen peroxide and malonaldehyde contents and electrolyte leakage, by interrupting the antioxidant defense system and promoting the accumulation of toxic levels of Na+. However, l-Glu pretreatment mitigated the salt-induced damage in lentil seedlings by reducing the accumulation of Na+, maintaining ion homeostasis, and increasing the activities of antioxidant enzymes (catalase and ascorbate peroxidase). As a result, salt-induced oxidative damage was reduced, seedling growth and photosynthetic pigment contents were enhanced, and the survival rate of the lentil seedlings was improved in response to salt stress, indicating an ameliorative role for l-Glu in lentil seedling growth under salt stress.

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Regulation of Reactive Oxygen Species and Antioxidant Defense in Plants under Salinity

International Journal of Molecular Sciences ◽

10.3390/ijms22179326 ◽

2021 ◽

Vol 22 (17) ◽

pp. 9326

Author(s):

Mirza Hasanuzzaman ◽

Md. Rakib Hossain Raihan ◽

Abdul Awal Chowdhury Masud ◽

Khussboo Rahman ◽

Farzana Nowroz ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Salt Stress ◽

Oxidative Damage ◽

Antioxidant Defense ◽

Reactive Oxygen ◽

Antioxidant Defense System ◽

Ros Generation ◽

Oxygen Species ◽

Defense System

The generation of oxygen radicals and their derivatives, known as reactive oxygen species, (ROS) is a part of the signaling process in higher plants at lower concentrations, but at higher concentrations, those ROS cause oxidative stress. Salinity-induced osmotic stress and ionic stress trigger the overproduction of ROS and, ultimately, result in oxidative damage to cell organelles and membrane components, and at severe levels, they cause cell and plant death. The antioxidant defense system protects the plant from salt-induced oxidative damage by detoxifying the ROS and also by maintaining the balance of ROS generation under salt stress. Different plant hormones and genes are also associated with the signaling and antioxidant defense system to protect plants when they are exposed to salt stress. Salt-induced ROS overgeneration is one of the major reasons for hampering the morpho-physiological and biochemical activities of plants which can be largely restored through enhancing the antioxidant defense system that detoxifies ROS. In this review, we discuss the salt-induced generation of ROS, oxidative stress and antioxidant defense of plants under salinity.

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Alteration of photosynthetic pigments and antioxidant systems in tomato under drought with Tebuconazole and Hexaconazole applications

Journal of Scientific Agriculture ◽

10.25081/jsa.2017.v1.52 ◽

2017 ◽

Vol 1 ◽

pp. 146

Author(s):

Maruthaiya Arivalagan ◽

Ramamurthy Somasundaram

Keyword(s):

Drought Stress ◽

Photosynthetic Pigments ◽

Antioxidant Defense ◽

Photosynthetic Pigment ◽

Antioxidant Defense System ◽

Antioxidant Systems ◽

Defense System ◽

Antioxidant Enzymes Activities ◽

Effects Of Drought ◽

Pigment Variation

Present investigation was focused on the response and regulation of the antioxidant defense system and photosynthetic pigment variation effect of two important fungicides or plant growth regulators Hexaconazole (HEX) and Tebuconazole (TBZ) on drought stressed tomato (Lycopersicon esculentum Mill.) plants. Drought stress was imposed for 30 Days after sowing (DAS) of tomato plant. The water was irrigated by 4 Days Interval Drought (DID) and the control plants were regularly irrigated. Triazole treatment like HEX at 15 mg L-1 and TBZ at 10 mg L-1 imposed on 30, 40 and 50 DAS. The plant samples were collected on 40, 50 and 60 DAS. The photosynthetic pigments like chlorophyll – a, chlorophyll – b and total chlorophyll were estimated. The drought stress reduced the photosynthetic pigments and increased the antioxidant contents and antioxidant enzymes activities. The combined drought stress with triazole treatments increased the photosynthetic pigments then reduced the ascorbic acid (AA), α-tocopherol, catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) activities, when compared to drought stressed plants. It can be concluded that the triazole treatment partially mitigated the adverse effects of drought stress in L. esculentum.

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A rice mutant defective in antioxidant-defense system and sodium homeostasis possesses increased sensitivity to salt stress

Biologia Plantarum ◽

10.1007/s10535-015-0561-7 ◽

2016 ◽

Vol 60 (1) ◽

pp. 86-94 ◽

Cited By ~ 8

Author(s):

K. -C. Lin ◽

W. -S. Jwo ◽

N. N. P. Chandrika ◽

T. -M. Wu ◽

M. -H. Lai ◽

...

Keyword(s):

Salt Stress ◽

Antioxidant Defense ◽

Antioxidant Defense System ◽

Defense System ◽

Sodium Homeostasis ◽

Rice Mutant ◽

Increased Sensitivity

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Magnetopriming regulates antioxidant defense system in soybean against salt stress

Biocatalysis and Agricultural Biotechnology ◽

10.1016/j.bcab.2019.101090 ◽

2019 ◽

Vol 18 ◽

pp. 101090 ◽

Cited By ~ 11

Author(s):

Sunita Kataria ◽

Lokesh Baghel ◽

Meeta Jain ◽

K.N. Guruprasad

Keyword(s):

Salt Stress ◽

Antioxidant Defense ◽

Antioxidant Defense System ◽

Defense System

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Effect of Cadmium Toxicity on Growth, Oxidative Damage, Antioxidant Defense System and Cadmium Accumulation in Two Sorghum Cultivars

Plants ◽

10.3390/plants9111575 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1575

Author(s):

Muhammad Jawad Hassan ◽

Muhammad Ali Raza ◽

Sana Ur Rehman ◽

Muhammad Ansar ◽

Harun Gitari ◽

...

Keyword(s):

Heavy Metal ◽

Oxidative Damage ◽

Antioxidant Defense ◽

Cadmium Toxicity ◽

Antioxidant Defense System ◽

Agricultural Crop ◽

Cd Stress ◽

Defense System ◽

Cd Uptake ◽

Semi Arid

Heavy metal stress is a leading environmental issue reducing crop growth and productivity, particularly in arid and semi-arid agro-ecological zones. Cadmium (Cd), a non-redox heavy metal, can indirectly increase the production of reactive oxygen species (ROS), inducing cell death. A pot experiment was conducted to investigate the effects of different concentrations of Cd (0, 5, 25, 50, 100 µM) on physiological and biochemical parameters in two sorghum (Sorghum bicolor L.) cultivars: JS-2002 and Chakwal Sorghum. The results showed that various concentrations of Cd significantly increased the Cd uptake in both cultivars; however, the uptake was higher in JS-2002 compared to Chakwal Sorghum in leaf, stem and root. Regardless of the cultivars, there was a higher accumulation of the Cd in roots than in shoots. The Cd stress significantly reduced the growth and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) concentration and malondialdehyde (MDA) content in both cultivars, but the Chakwal Sorghum showed more pronounced oxidative damage than the JS-2002, as reflected by higher H2O2, MDA and EL. Moreover, Cd stress, particularly 50 µM and 100 µM, decreased the activity of different antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the JS-2002 exhibited higher SOD, POD and CAT activities than the Chakwal Sorghum under different Cd-levels. These findings revealed that JS-2002 had a stronger Cd enrichment capacity and also exhibited a better tolerance to Cd stress due to its efficient antioxidant defense system than Chakwal Sorghum. The present study provides the available information about Cd enrichment and tolerance in S. bicolor, which is used as an important agricultural crop for livestock feed in arid and semi-arid regions.

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Rapid Determination of Glutathione Peroxidase and Thioredoxin Reductase Activities Using a 96-well Microplate Format: Comparison to Standard Cuvette-based Assays

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.71.1.87 ◽

2001 ◽

Vol 71 (1) ◽

pp. 87-92 ◽

Cited By ~ 26

Author(s):

Allen D. Smith ◽

Virginia C. Morris ◽

Orville A. Levander

Keyword(s):

Glutathione Peroxidase ◽

High Throughput ◽

Antioxidant Defense ◽

Rapid Determination ◽

Thioredoxin Reductase ◽

Antioxidant Defense System ◽

Defense System ◽

Expensive Equipment ◽

Multiple Samples ◽

The Impact

Gluthatione peroxidase and thioredoxin reductase are selenocysteine-containing enzymes that are constituents of the cellular antioxidant defense system. Conventional cuvette-based assays for glutathione peroxidase and thioredoxin reductase enzymes are laborious and time consuming. The ability to assay their activities rapidly in multiple samples would aid efforts focused on understanding the impact of these enzymes on the cellular antioxidant defense system. High throughput can be achieved with assays adapted to work in a clinical analyzer but require expensive equipment. Assays designed to work in a 96-well microplate reader provide an alternative methodology for high throughput with reduced instrumentation cost. However, due to differences in the light pathlength when using a 96-well format, the values obtained cannot be compared directly with those obtained using a 1-cm cuvette. Described here are assays for glutathione peroxidase and thioredoxin reductase modified to work in a 96-well format that incorporates light pathlength determinations into the assays. The values obtained using a high throughput 96-well format in conjunction with pathlength determinations are in agreement with those obtained using a standard 1-cm cuvette. While spectrophotometrically derived pathlengths are the most accurate, calculated pathlengths based on assay volume and well size can be used with only a small amount of error introduced. This method can also be applied to many other enzyme assays, thus allowing the rapid analysis of large numbers of samples without the need for expensive equipment.

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