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Rodriguez IB, Lin S, Ho J, Ho TY. Effects of Trace Metal Concentrations on the Growth of the Coral Endosymbiont Symbiodinium kawagutii. Front Microbiol 2016; 7:82. [PMID: 26903964 PMCID: PMC4744903 DOI: 10.3389/fmicb.2016.00082] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 01/18/2016] [Indexed: 11/13/2022] Open
Abstract
Symbiodinium is an indispensable endosymbiont in corals and the most important primary producer in coral reef ecosystems. During the past decades, coral bleaching attributed to the disruption of the symbiosis has frequently occurred resulting in reduction of coral reef coverage globally. Growth and proliferation of corals require some specific trace metals that are essential components of pertinent biochemical processes, such as in photosynthetic systems and electron transport chains. In addition, trace metals are vital in the survival of corals against oxidative stress because these metals serve as enzymatic cofactors in antioxidative defense mechanisms. The basic knowledge about trace metal requirements of Symbiodinium is lacking. Here we show that the requirement of Symbiodinium kawagutii for antioxidant-associated trace metals exhibits the following order: Fe >> Cu/Zn/Mn >> Ni. In growth media with Cu, Zn, Mn, and varying Fe concentrations, we observed that Cu, Zn, and Mn cellular quotas were inversely related to Fe concentrations. In the absence of Cu, Zn, and Mn, growth rates increased with increasing inorganic Fe concentrations up to 1250 pM, indicating the relatively high Fe requirement for Symbiodinium growth and potential functional complementarity of these metals. These results demonstrate the relative importance of trace metals to sustain Symbiodinium growth and a potential metal inter replacement strategy in Symbiodinium to ensure survival of coral reefs in an oligotrophic and stressful environment.
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Affiliation(s)
- Irene B Rodriguez
- Research Center for Environmental Changes, Academia Sinica Taipei, Taiwan
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, Xiamen UniversityXiamen, China; Department of Marine Sciences, University of Connecticut, GrotonCT, USA
| | - Jiaxuan Ho
- Research Center for Environmental Changes, Academia SinicaTaipei, Taiwan; School of Marine Sciences and Engineering, Plymouth UniversityDevon, UK
| | - Tung-Yuan Ho
- Research Center for Environmental Changes, Academia Sinica Taipei, Taiwan
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52
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Downs CA, Kramarsky-Winter E, Segal R, Fauth J, Knutson S, Bronstein O, Ciner FR, Jeger R, Lichtenfeld Y, Woodley CM, Pennington P, Cadenas K, Kushmaro A, Loya Y. Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 70:265-88. [PMID: 26487337 DOI: 10.1007/s00244-015-0227-7] [Citation(s) in RCA: 292] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/13/2015] [Indexed: 05/26/2023]
Abstract
Benzophenone-3 (BP-3; oxybenzone) is an ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet light. Oxybenzone is an emerging contaminant of concern in marine environments—produced by swimmers and municipal, residential, and boat/ship wastewater discharges. We examined the effects of oxybenzone on the larval form (planula) of the coral Stylophora pistillata, as well as its toxicity in vitro to coral cells from this and six other coral species. Oxybenzone is a photo-toxicant; adverse effects are exacerbated in the light. Whether in darkness or light, oxybenzone transformed planulae from a motile state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of oxybenzone. Oxybenzone is a genotoxicant to corals, exhibiting a positive relationship between DNA-AP lesions and increasing oxybenzone concentrations. Oxybenzone is a skeletal endocrine disruptor; it induced ossification of the planula, encasing the entire planula in its own skeleton. The LC50 of planulae exposed to oxybenzone in the light for an 8- and 24-h exposure was 3.1 mg/L and 139 µg/L, respectively. The LC50s for oxybenzone in darkness for the same time points were 16.8 mg/L and 779 µg/L. Deformity EC20 levels (24 h) of planulae exposed to oxybenzone were 6.5 µg/L in the light and 10 µg/L in darkness. Coral cell LC50s (4 h, in the light) for 7 different coral species ranges from 8 to 340 µg/L, whereas LC20s (4 h, in the light) for the same species ranges from 0.062 to 8 µg/L. Coral reef contamination of oxybenzone in the U.S. Virgin Islands ranged from 75 µg/L to 1.4 mg/L, whereas Hawaiian sites were contaminated between 0.8 and 19.2 µg/L. Oxybenzone poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change.
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Affiliation(s)
- C A Downs
- Haereticus Environmental Laboratory, P.O. Box 92, Clifford, VA 24533, USA.
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Camaya AP, Sekida S, Okuda K. Changes in the Ultrastructures of the Coral Pocillopora damicornis after Exposure to High Temperature, Ultraviolet and Far-Red Radiation. CYTOLOGIA 2016. [DOI: 10.1508/cytologia.81.465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Alex Pulvinar Camaya
- Graduate School of Kuroshio Science, Kochi University
- Coastal Resource Management Unit, Bicol University Tabaco Campus
| | - Satoko Sekida
- Graduate School of Kuroshio Science, Kochi University
| | - Kazuo Okuda
- Graduate School of Kuroshio Science, Kochi University
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54
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Krueger T, Hawkins TD, Becker S, Pontasch S, Dove S, Hoegh-Guldberg O, Leggat W, Fisher PL, Davy SK. Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress. Comp Biochem Physiol A Mol Integr Physiol 2015; 190:15-25. [DOI: 10.1016/j.cbpa.2015.08.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 12/29/2022]
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Hardefeldt JM, Reichelt-Brushett AJ. Unravelling the role of zooxanthellae in the uptake and depuration of an essential metal in Exaiptasia pallida; an experiment using a model cnidarian. MARINE POLLUTION BULLETIN 2015; 96:294-303. [PMID: 25998725 DOI: 10.1016/j.marpolbul.2015.04.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 04/22/2015] [Accepted: 04/25/2015] [Indexed: 06/04/2023]
Abstract
Coral skeletons record historical trace metal levels in the environment, however, the use of coral skeletal records for biomonitoring studies mostly fail to consider the influence of metal regulation by the living components of coral and subsequent incorporation into the skeleton. This study presents Exaiptasia pallida as a representative of the living components of coral and shows metal partitioning between the tissue and zooxanthellae after chronic exposure to Zn. A strong tendency for preferential accumulation in the zooxanthellae occurred after 32 days exposure and Zn concentrations in tissue and zooxanthellae were 123.3±0.7 mg kg(-1) and 294.9±8.5 respectively. This study shows zooxanthellae density plays an important role in controlling Zn loading in whole anemones and must be considered when investigating metal uptake and loading in zooxanthellate organisms. Further studies that investigate links between aragonite deposition rates and zooxanthellae density and incorporation pathways of metals into skeleton are warranted.
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Affiliation(s)
- Jannah M Hardefeldt
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia
| | - Amanda J Reichelt-Brushett
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
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Suzuki T, Casareto BE, Shioi Y, Ishikawa Y, Suzuki Y. Finding of 13(2) , 17(3) -cyclopheophorbide a enol as a degradation product of chlorophyll in shrunk zooxanthellae of the coral Montipora digitata. JOURNAL OF PHYCOLOGY 2015; 51:37-45. [PMID: 26986257 DOI: 10.1111/jpy.12253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 09/23/2014] [Indexed: 06/05/2023]
Abstract
We examined the morphology and pigment composition of zooxanthellae in corals subjected to normal temperature (27°C) and thermal stress (32°C). We observed several normal and abnormal morphological types of zooxanthellar cells. Normal cells were intact and their chloroplasts were unbroken (healthy); abnormal cells were shrunken and had partially degraded or broken chloroplasts, or they were bleached and without chloroplasts. At 27°C, most healthy zooxanthellar cells were retained in the coral tissue, whereas shrunken zooxanthellae were expelled. Under thermal stress, the abundance of healthy zooxanthellae declined and the proportion of shrunken/abnormal cells increased in coral tissues. The rate of algal cell expulsion was reduced under thermal stress. Within the shrunken cells, we detected the presence of a chl-like pigment that is not ordinarily found in healthy zooxanthellae. Analysis of the absorption spectrum, absorption maxima, and retention time (by HPLC) indicated that this pigment was 13(2) , 17(3) -cyclopheophorbide a enol (cPPB-aE), which is frequently found in marine and lacustrine sediments, and in protozoans that graze on phytoplankton. The production of cPPB-aE in shrunken zooxanthellae suggests that the chls have been degraded to cPPB-aE, a compound that is not fluorescent. The lack of a fluorescence function precludes the formation of reactive oxygen species. We therefore consider the formation of cPPB-aE in shrunken zooxanthellae to be a mechanism for avoiding oxidative stress.
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Affiliation(s)
- Toshiyuki Suzuki
- Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Beatriz Estela Casareto
- Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Yuzo Shioi
- Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Yoshio Ishikawa
- Institute of Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori, 039-3212, Japan
| | - Yoshimi Suzuki
- Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
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Roth MS. The engine of the reef: photobiology of the coral-algal symbiosis. Front Microbiol 2014; 5:422. [PMID: 25202301 PMCID: PMC4141621 DOI: 10.3389/fmicb.2014.00422] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/25/2014] [Indexed: 01/09/2023] Open
Abstract
Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis, and recent advances in the field. Studies integrating physiology with the developing "omics" fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.
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Affiliation(s)
- Melissa S. Roth
- Department of Plant and Microbial Biology, University of California BerkeleyBerkeley, CA, USA
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58
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Downs CA, Kramarsky-Winter E, Fauth JE, Segal R, Bronstein O, Jeger R, Lichtenfeld Y, Woodley CM, Pennington P, Kushmaro A, Loya Y. Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:175-91. [PMID: 24352829 DOI: 10.1007/s10646-013-1161-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/07/2013] [Indexed: 05/26/2023]
Abstract
Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an "emerging contaminant of concern" that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic fields and unmanaged cesspits. Although BP-2 may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light, BP-2 induced coral planulae to transform from a motile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastro dermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death.The LC50 of BP-2 in the light for an 8 and 24 hour exposure was 120 parts per million (ppm) and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 parts per million and 548 parts per billion [corrected].
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Affiliation(s)
- C A Downs
- Haereticus Environmental Laboratory, P.O. Box 92, Clifford, VA, 24533, USA,
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