scholarly journals The Presence of Biomarker Enzymes of Selected Scleractinian Corals of Palk Bay, Southeast Coast of India

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
R. Anithajothi ◽  
K. Duraikannu ◽  
G. Umagowsalya ◽  
C. M. Ramakritinan
Keyword(s):  
Coral Reef ◽  
Anthropogenic Impacts ◽  
Radical Scavenging ◽  
Scleractinian Corals ◽  
Habitat Destruction ◽  
Shoreline Development ◽  
Defensive Enzymes ◽  
Acropora Formosa ◽  
Reef Decline ◽  
Scavenging Enzymes

The health and existence of coral reefs are in danger by an increasing range of environmental and anthropogenic impacts. The causes of coral reef decline include worldwide climate change, shoreline development, habitat destruction, pollution, sedimentation and overexploitation. These disasters have contributed to an estimated loss of 27% of the reefs. If the current pressure continues unabated, the estimated loss of coral reef will be about 60% by the year 2030. Therefore, the present study was aimed to analyze the enzymes involved in stress induced by coral pathogen and its resistance. We focused on the enzymes involved in melanin synthesis pathway (phenoloxidase (PO) and peroxidases (POD)) and free radical scavenging enzymes (super oxide dismutase (SOD), catalase (CAT)) and glutathione peroxidase (Gpx) in selected scleractinian corals such asAcropora formosa, Echinopora lamellosa, Favia favus, Favites halicora, Poritessp., andAnacropora forbesi.Overall, PO activity of coral was significantly lower than that of zooxanthellae except forFavia favus.Coral colonies with lower PO and POD activities are prone to disease. Maximum antioxidant defensive enzymes were observed inFavia favusfollowed byEchinopora lamellose.It is concluded that assay of these enzymes can be used as biomarkers for identifying the susceptibility of corals towards coral bleaching induced by pathogen.

Effects of a Flavonoid Extract from Cynomorium songaricum on the Swimming Endurance of Rats

2010 ◽  
Vol 38 (01) ◽  
pp. 65-73 ◽  
Author(s):  
Fa-Rong Yu ◽  
Ying Liu ◽  
Yong-Zhi Cui ◽  
Er-Qing Chan ◽  
Ming-Ren Xie ◽  
...  
Keyword(s):  
Body Weight ◽  
Free Radical ◽  
Radical Scavenging ◽  
Copper Zinc Superoxide Dismutase ◽  
Zinc Superoxide Dismutase ◽  
Body Weights ◽  
Copper Zinc ◽  
Scavenging Enzymes ◽  
Swimming Endurance ◽  
Dose Dependent

The present study investigated the effects of a flavonoid extract from Cynomorium songaricum on the swimming endurance of rats by measuring changes of free radical scavenging enzymes, such as CuZn-SOD (copper, zinc-superoxide dismutase) and GSH-px (glutathione peroxidase), and body weights. Significant and dose-dependent antioxidant and anti-fatigue effects of flavonoids (rutin, catechin and isoquercitrin) on swimming rats were observed during 10 days of swimming exercise. After treatment with the flavonoid extract at doses of 0.5, 1.0, and 2.0 g/kg body weight, the CuZn-SOD and GSH-px activities in swimming rats were increased by 1.4%, 3.3%, 4.1% and 112.2%, 208.7%, 261.7%, respectively, while the levels of MDA (malondialdehyde) were decreased by 64.7%, 79.4%, and 86.4% respectively. Furthermore, the average body weight and the total swimming time were increased by 3.1%, 8.8%, 10.6%, and 7.7%, 34.5%, 61.5%, respectively. Our experimental results suggest that flavonoid supplementation could not only reduce free radical formation and scavenge free radicals, but also enhance endurance exercise performance by reducing muscle fatigue.

scholarly journals Characterization and Analyses of Hydrophobic Clusters, Acetylation and Myristoylation Sites in Plant Glutathione Peroxidase Sequences

2014 ◽  
Vol 28 ◽  
pp. 27-33
Author(s):  
Sayak Ganguli ◽  
Anisha Polley ◽  
Abhijit Datta
Keyword(s):  
Glutathione Peroxidase ◽  
Alternative Pathway ◽  
Vascular Plant ◽  
Radical Scavenging ◽  
Primary Source ◽  
Land Plant ◽  
Defense Strategies ◽  
Glutathione Peroxidases ◽  
Plant Groups ◽  
Scavenging Enzymes

Incomplete reduction of oxygen molecules is the primary source for the formation of reactive oxygen species (ROS) during cytosolic metabolism or mitochondrial respiration. These phenomenons may be as a result of biotic or abiotic stress. Exposure to exogenous stimuli such as radiation might be an alternative pathway of ROS production. Thus plants require counter defense strategies to combat the increase of this toxic molecular build up in its cell cytoplasm. As a result they have devised an army of free radical scavenging enzymes which enable them to dissipate the oxidative stress imposed by the accumulation of these toxic moieties. Glutathione Peroxidase forms an important part of this arms race along with several catalases and organelle specific enzymes such as superoxide dismutase. Plant glutathione peroxidases (GPXs) have been studied exclusively for their evolutionary lineages since they represent a hybrid class of molecules in context of the presence and absence of selenocysteine at their catalytic centres, the former situation predominant in non vascular plant groups while the later a predominant feature of vascular plants. This analysis focuses on three important aspects of protein structure analyses – hydrophobic cluster analyses for identification of homologues, and acetylation and myristoylation sites which provide us with information regarding the post translational modifications of a particular protein group. Specific patterns of clusters along with acetylation and myristoylation site frequencies were obtained which indicate that GPXs of non vascular plant members possess less chances of getting myristoylated while acetylation was predominant in most land plant lineages but absent in aquatic members.

scholarly journals Thermal plasticity in coral reef symbionts is mediated by oxidation of membrane lipids

2020 ◽  
Author(s):  
Marina Botana ◽  
Adriano Chaves-Filho ◽  
Alex Inague ◽  
Arthur Guth ◽  
Flavia Saldanha-Corrêa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Coral Reef ◽  
Coral Bleaching ◽  
Membrane Lipids ◽  
Physiological Mechanism ◽  
Heat Sensitivity ◽  
Stress Theory ◽  
Thermal Plasticity ◽  
Coral Health ◽  
Reef Decline

Abstract The oxidation of polyunsaturated fatty acids (PUFA) is a common stress response across biomes with potential to trigger impairment of cell growth and reproduction. The oxidative stress theory of coral bleaching induced by global warming has been widely accepted to explain coral reef decline, but its underlying physiological mechanism remains under debate. Here we used lipidomic and population density data to examine cell cultures of three coral reef symbionts after a heat shock (sudden rise of 12 °C for 4 hours). Heat tolerance in S. microadriaticum and C. goreaui was characterized by preservation of thylakoid-derived glycolipids. Conversely, heat sensitivity in B. minutum was linked to elevated concentrations of oxidized PUFA esterified to glycolipids, suggesting that culture growth had ceased due to severe oxidative damage. Our findings provide a basis to further understand the role played by oxidative stress in coral bleaching and reveal novel biomarkers for the monitoring of symbiont-coral health.

Desiccation sensitivity and activities of free radical-scavenging enzymes in recalcitrant Theobroma cacao seeds

1999 ◽  
Vol 9 (3) ◽  
pp. 209-217 ◽  
Author(s):  
Changrun Li ◽  
Wendell Q. Sun
Keyword(s):  
Lipid Peroxidation ◽  
Superoxide Dismutase ◽  
Water Content ◽  
Theobroma Cacao ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Desiccation Sensitivity ◽  
Critical Water Content ◽  
Scavenging Enzymes ◽  
Water Contents

AbstractMature and immature axes of Theobroma cacao (cocoa) seeds tolerated desiccation under a rapid-drying regime to critical water contents of 1.0 and 1.7 g g-1 dw, respectively. These critical water contents corresponded to water contents below which activities of free radical-scavenging enzymes (ascorbate peroxidase, peroxidase and superoxide dismutase) decreased rapidly during desiccation. The decline in axis viability below the critical water content was correlated with sharp increases in lipid peroxidation and cellular leakage. Cotyledon tissues were more desiccation-tolerant than axes, with a low critical water content of 0.24 g g–1dw. Desiccation sensitivity in cotyledon tissues was also correlated with the decrease in superoxide dismutase activity and increased lipid peroxidation products. However, in the cotyledons, no ascorbate peroxidase activity was detected at any water content, and peroxidase activity was gradually reduced as desiccation proceeded. Cocoa embryonic axes contained large amounts of sucrose, raffinose and stachyose but only traces of reducing monosaccharides. Desiccation sensitivity of recalcitrant cocoa axes did not appear to be due to the lack of sugar-related protective mechanisms during desiccation, and it was more likely related to the decrease of enzymic protection against desiccation-induced oxidative stresses.

scholarly journals Divergence of seafloor elevation and sea level rise in coral reef ecosystems

2017 ◽  
Vol 14 (6) ◽  
pp. 1739-1772 ◽  
Author(s):  
Kimberly K. Yates ◽  
David G. Zawada ◽  
Nathan A. Smiley ◽  
Ginger Tiling-Range
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level Rise ◽  
Sea Level ◽  
Anthropogenic Impacts ◽  
Regional Scale ◽  
Coastal Hazards ◽  
Carbonate Production ◽  
Coral Reef Ecosystems ◽  
Study Sites

Abstract. Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves, and erosion. Projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. Here, we provide a comprehensive assessment of the combined effect of all of the processes affecting seafloor accretion and erosion by measuring changes in seafloor elevation and volume for five coral reef ecosystems in the Atlantic, Pacific, and Caribbean over the last several decades. Regional-scale mean elevation and volume losses were observed at all five study sites and in 77 % of the 60 individual habitats that we examined across all study sites. Mean seafloor elevation losses for whole coral reef ecosystems in our study ranged from −0.09 to −0.8 m, corresponding to net volume losses ranging from 3.4  ×  106 to 80.5  ×  106 m3 for all study sites. Erosion of both coral-dominated substrate and non-coral substrate suggests that the current rate of carbonate production is no longer sufficient to support net accretion of coral reefs or adjacent habitats. We show that regional-scale loss of seafloor elevation and volume has accelerated the rate of relative sea level rise in these regions. Current water depths have increased to levels not predicted until near the year 2100, placing these ecosystems and nearby communities at elevated and accelerating risk to coastal hazards. Our results set a new baseline for projecting future impacts to coastal communities resulting from degradation of coral reef systems and associated losses of natural and socioeconomic resources.

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