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- Hu, M., et al.
(författare)
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Effect of pH and temperature on antioxidant responses of the thick shell mussel Mytilus coruscus
- 2015
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Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 46:2, s. 573-583
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the combined effects of seawater pH decrease and temperature increase on the activity of antioxidant enzymes in the thick shell mussel Mytilus coruscus, an ecological and economic bivalve species widely distributed along the East China Sea. Mussels were exposed to three pH levels (8.1, 7.7 and 7.3) and two temperatures (25 °C and 30 °C) for 14 days. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), acid phosphatase (ACP), alkaline phosphatase (AKP) and glutamic-pyruvic transaminase (GPT) were measured in gills and digestive glands after 1, 3, 7 and 14 days of exposure. All enzymatic activities were significantly impacted by pH, temperature. Enzymatic activities at the high temperature were significantly higher than those at the low temperature, and the mussels exposed to pH 7.3 showed significantly higher activities than those under higher pH condition for all enzymes except ACP. There was no interaction between temperature and pH in two third of the measured activities suggesting similar mode of action for both drivers. Interaction was only consistently significant for GPX. PCA revealed positive relationships between the measured biochemical indicators in both gills and digestive glands. Overall, our results suggest that decreased pH and increased temperature induce a similar anti-oxidative response in the thick shell mussel. © 2015 Elsevier Ltd.
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| 2. |
- Sui, Y, et al.
(författare)
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Defense responses to short-term hypoxia and seawater acidification in the thick shell mussel Mytilus coruscus
- 2017
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The rising anthropogenic atmospheric CO2 results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell mussel Mytilus coruscus were exposed to three pH/pCO(2) levels (7.3/2800 [(mu atm, 7.7/1020 mu atm, 8.1/376 mu atm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L-1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments.
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| 3. |
- Sui, Y. M., et al.
(författare)
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Antioxidant response of the hard shelled mussel Mytilus coruscus exposed to reduced pH and oxygen concentration
- 2017
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513. ; 137, s. 94-102
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Tidskriftsartikel (refereegranskat)abstract
- Ocean acidification (OA) and hypoxic events are increasing worldwide problems, their interactive effects have not been well clarified, although their co-occurrence is prevalent. The East China Sea (the Yangtze River estuary area) suffers from not only coastal hypoxia but also pH fluctuation, representing an ideal study site to explore the combined effect of OA and hypoxia on marine bivalves. We experimentally evaluated the antioxidant response of the mussel Mytilus coruscus exposed to three pH levels (8.1, 7.7 and 7.3) at two dissolved oxygen (DO) levels (2.0 mg L-1 and 6.0 mg L-1) for 72 h. Activities of superoxide dismutase, catalase, glutathione peroxidase, acid phosphatase, and alkaline phosphatase and levels of malondialdehyde were measured in gills and hemolymph. All enzymatic activities in hemolymph and gills followed a similar pattern throughout the experiment duration. Generally, low DO showed greater effects on enzyme activities than elevated CO2. Significant interactions between DO, pH and time were only observed at superoxide dismutase and catalase in both tissues. PCA revealed positive relationships between most enzyme activities in both gills and hemolymph with the exception of alkaline phosphatase activity and the level of malondialdehyde in the hemolymph. Overall, our results suggested that decreased pH and low DO induced similar antioxidant responses in the hard shelled mussel, and showed an additive effect on most enzyme activities. The evaluation of multiple environmental stessors, a more realistic scenario than single ones, is crucial to predict the effect of future global changes on coastal species and our results supply some insights on the potential combined effects of reduced pH and DO on marine bivalves.
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