scholarly journals Exogenous melatonin confers drought stress by promoting plant growth, photosynthetic capacity and antioxidant defense system of maize seedlings

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7793 ◽  
Author(s):  
Shakeel Ahmad ◽  
Muhammad Kamran ◽  
Ruixia Ding ◽  
Xiangping Meng ◽  
Haiqi Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Growth And Development ◽  
Antioxidant Defense ◽  
Antioxidant Defense System ◽  
Maize Seedling ◽  
Oxygen Species ◽  
Maize Seedlings ◽  
Defense System ◽  
Plant Growth And Development

Melatonin is an important biologically active hormone that plays a vital role in plant growth and development. In particular, it has been investigated for its roles in abiotic stress management. The current experiment was carried out to investigate the protective role of melatonin in photosynthetic traits and the antioxidant defense system of maize seedling under drought stress. Maize seedlings were subjected to drought stress (40–45% FC) after two weeks of seedling emergence, followed by a foliar spray (0, 25, 50, 75 and 100 µM) and soil drench of melatonin (0, 25, 50, 75 and 100 µM). Our results indicated that drought stress negatively affected maize seedling and decreased plant growth and development, biomass accumulation, reduced chlorophyll, and carotenoid content, and significantly declined photosynthetic rate and stomatal conductance. On the other hand, reactive oxygen species, soluble protein, and proline content increased under drought stress. However, the application of exogenous melatonin reduced the reactive oxygen species burst and enhanced the photosynthetic activity by protecting from damages through activation of various antioxidant enzymes under drought stress. Foliar application of 100 µM and soil drench of 50 µM melatonin was the most effective treatment concentrations under drought stress. Our current findings hereby confirmed the mitigating potential of melatonin application for drought stress by maintaining plant growth, improving the photosynthetic characteristics and activities of antioxidants enzymes.

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

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.

Antioxidant Defense System and Reactive Oxygen Species (ROS) Interplay in Plants Under Drought Condition

2021 ◽  
pp. 93-117
Author(s):  
Mohsin Nawaz ◽  
Shakeel Ahmad Anjum ◽  
Umair Ashraf ◽  
Farrukh Azeem ◽  
Zhiyong Wang
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Defense ◽  
Reactive Oxygen ◽  
Antioxidant Defense System ◽  
Oxygen Species ◽  
Drought Condition ◽  
Defense System

scholarly journals Molecular Mechanism of Heavy Metal Toxicity and Tolerance in Plants: Central Role of Glutathione in Detoxification of Reactive Oxygen Species and Methylglyoxal and in Heavy Metal Chelation

2012 ◽  
Vol 2012 ◽  
pp. 1-37 ◽  
Author(s):  
Mohammad Anwar Hossain ◽  
Pukclai Piyatida ◽  
Jaime A. Teixeira da Silva ◽  
Masayuki Fujita
Keyword(s):  
Reactive Oxygen Species ◽  
Heavy Metal ◽  
Antioxidant Defense ◽  
Plant Cells ◽  
Reactive Oxygen ◽  
Antioxidant Defense System ◽  
Peroxidation Of Lipids ◽  
Oxygen Species ◽  
Defense System ◽  
Glyoxalase System

Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in plants. A common consequence of HM toxicity is the excessive accumulation of reactive oxygen species (ROS) and methylglyoxal (MG), both of which can cause peroxidation of lipids, oxidation of protein, inactivation of enzymes, DNA damage and/or interact with other vital constituents of plant cells. Higher plants have evolved a sophisticated antioxidant defense system and a glyoxalase system to scavenge ROS and MG. In addition, HMs that enter the cell may be sequestered by amino acids, organic acids, glutathione (GSH), or by specific metal-binding ligands. Being a central molecule of both the antioxidant defense system and the glyoxalase system, GSH is involved in both direct and indirect control of ROS and MG and their reaction products in plant cells, thus protecting the plant from HM-induced oxidative damage. Recent plant molecular studies have shown that GSH by itself and its metabolizing enzymes—notably glutathione S-transferase, glutathione peroxidase, dehydroascorbate reductase, glutathione reductase, glyoxalase I and glyoxalase II—act additively and coordinately for efficient protection against ROS- and MG-induced damage in addition to detoxification, complexation, chelation and compartmentation of HMs. The aim of this review is to integrate a recent understanding of physiological and biochemical mechanisms of HM-induced plant stress response and tolerance based on the findings of current plant molecular biology research.

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