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McQuagge A, Pahl KB, Wong S, Melman T, Linn L, Lowry S, Hoadley KD. Cellular traits regulate fluorescence-based light-response phenotypes of coral photosymbionts living in-hospite. Front Physiol 2023; 14:1244060. [PMID: 37885802 PMCID: PMC10598705 DOI: 10.3389/fphys.2023.1244060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023] Open
Abstract
Diversity across algal family Symbiodiniaceae contributes to the environmental resilience of certain coral species. Chlorophyll-a fluorescence measurements are frequently used to determine symbiont health and resilience, but more work is needed to refine these tools and establish how they relate to underlying cellular traits. We examined trait diversity in symbionts from the generas Cladocopium and Durusdinium, collected from 12 aquacultured coral species. Photophysiological metrics (ΦPSII, σPSII, ρ, τ1, τ2, antenna bed quenching, non-photochemical quenching, and qP) were assessed using a prototype multi-spectral fluorometer over a variable light protocol which yielded a total of 1,360 individual metrics. Photophysiological metrics were then used to establish four unique light-response phenotypic variants. Corals harboring C15 were predominantly found within a single light-response phenotype which clustered separately from all other coral fragments. The majority of Durusdinium dominated colonies also formed a separate light-response phenotype which it shared with a few C1 dominated corals. C15 and D1 symbionts appear to differ in which mechanisms they use to dissipate excess light energy. Spectrally dependent variability is also observed across light-response phenotypes that may relate to differences in photopigment utilization. Symbiont cell biochemical and structural traits (atomic C:N:P, cell size, chlorophyll-a, neutral lipid content) was also assessed within each sample and differ across light-response phenotypes, linking photophysiological metrics with underlying primary cellular traits. Strong correlations between first- and second-order traits, such as Quantum Yield and cellular N:P content, or light dissipation pathways (qP and NPQ) and C:P underline differences across symbiont types and may also provide a means for using fluorescence-based metrics as biomarkers for certain primary-cellular traits.
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Affiliation(s)
- Audrey McQuagge
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - K. Blue Pahl
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Sophie Wong
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
- Department of Environmental Science, University of Virginia, Charlottesville, VA, United States
| | - Todd Melman
- Reef Systems Coral Farm, New Albany, OH, United States
| | - Laura Linn
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Sean Lowry
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Kenneth D. Hoadley
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
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Yang Y, Chen H, Lu J. Inactivation of algae by visible-light-driven modified photocatalysts: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159640. [PMID: 36302431 DOI: 10.1016/j.scitotenv.2022.159640] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/18/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Harmful algal blooms have raised great concerns due to their adverse effects on aquatic ecosystems and human health. Recently, visible light-driven (VLD) photocatalysis has attracted attention for algae inactivation owing to its unique characteristics of low cost, mechanical stability, and excellent removal efficiency. However, the low utilization of visible light and the high complexation rate of electron-hole (e--h+) pairs are essential drawbacks of conventional photocatalysts. Scientific efforts have been devoted to modifying VLD photocatalysts to enhance their antialgal activity. This review concisely summarizes the anti-algae performance of the latest modified VLD photocatalysts. The summary of the mechanisms in VLD photocatalytic inactivation demonstrates that reactive oxygen species (ROS) can induce oxidative damage to algal cells and photocatalytic degradation of released organic matter. In addition, the factors, such as photocatalyst dosage, algal concentration and species, and the physicochemical properties of different water matrices, such as pH, natural organic matter, and inorganic ions, affecting the efficacy of VLD catalytic oxidation for algae removal are briefly outlined. Thereafter, this review compiles perspectives on the emerging field of VLD photocatalytic inactivation.
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Affiliation(s)
- Yue Yang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin 300071, China
| | - Hao Chen
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin 300071, China; College of Environmental Science and Engineering, Nankai University, Tianjin 300050, China
| | - Jinfeng Lu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin 300071, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, Nankai University, Tianjin 300350, China; College of Environmental Science and Engineering, Nankai University, Tianjin 300050, China.
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3
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Lysenko V, D. Rajput V, Kumar Singh R, Guo Y, Kosolapov A, Usova E, Varduny T, Chalenko E, Yadronova O, Dmitriev P, Zaruba T. Chlorophyll fluorometry in evaluating photosynthetic performance: key limitations, possibilities, perspectives and alternatives. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:2041-2056. [PMID: 36573148 PMCID: PMC9789293 DOI: 10.1007/s12298-022-01263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/25/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Non-destructive methods for the assessment of photosynthetic parameters of plants are widely applied to evaluate rapidly the photosynthetic performance, plant health, and shifts in plant productivity induced by environmental and cultivation conditions. Most of these methods are based on measurements of chlorophyll fluorescence kinetics, particularly on pulse modulation (PAM) fluorometry. In this paper, fluorescence methods are critically discussed in regard to some their possibilities and limitations inherent to vascular plants and microalgae. Attention is paid to the potential errors related to the underestimation of thylakoidal cyclic electron transport and anoxygenic photosynthesis. PAM-methods are also observed considering the color-addressed measurements. Photoacoustic methods are discussed as an alternative and supplement to fluorometry. Novel Fourier modifications of PAM-fluorometry and photoacoustics are noted as tools allowing simultaneous application of a dual or multi frequency measuring light for one sample.
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Affiliation(s)
- Vladimir Lysenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Vishnu D. Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Rupesh Kumar Singh
- Centre of Molecular and Environmental Biology, Department of Biology, Campus of Gualtar, University of Minho, Braga, Portugal
| | - Ya Guo
- School of IoT Engineering, Jiangnan University, Wuxi, China
| | - Alexey Kosolapov
- Russian Research Institute for the Integrated Use and Protection of Water Resources, Rostov-on-Don, Russia
| | - Elena Usova
- Russian Research Institute for the Integrated Use and Protection of Water Resources, Rostov-on-Don, Russia
| | - Tatyana Varduny
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Elizaveta Chalenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Olga Yadronova
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Pavel Dmitriev
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Tatyana Zaruba
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
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4
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Nitschke MR, Rosset SL, Oakley CA, Gardner SG, Camp EF, Suggett DJ, Davy SK. The diversity and ecology of Symbiodiniaceae: A traits-based review. ADVANCES IN MARINE BIOLOGY 2022; 92:55-127. [PMID: 36208879 DOI: 10.1016/bs.amb.2022.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.
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Affiliation(s)
- Matthew R Nitschke
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand; Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia.
| | - Sabrina L Rosset
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Clinton A Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Stephanie G Gardner
- Center for Marine Science and Innovation, University of New South Wales Sydney, Kensington, NSW, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW, Australia
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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Bollati E, Lyndby NH, D'Angelo C, Kühl M, Wiedenmann J, Wangpraseurt D. Green fluorescent protein-like pigments optimize the internal light environment in symbiotic reef building corals. eLife 2022; 11:73521. [PMID: 35801683 PMCID: PMC9342951 DOI: 10.7554/elife.73521] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Pigments homologous to the green fluorescent protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and environmental conditions. However, direct measurements of the in vivo light conditions inside the coral tissue supporting this conclusion are lacking. Here, we quantified the intra-tissue spectral light environment of corals expressing GFP-like proteins from widely different light regimes. We focus on: (1) photoconvertible red fluorescent proteins (pcRFPs), thought to enhance photosynthesis in mesophotic habitats via wavelength conversion, and (2) chromoproteins (CPs), which provide photoprotection to the symbionts in shallow water via light absorption. Optical microsensor measurements indicated that both pigment groups strongly alter the coral intra-tissue light environment. Estimates derived from light spectra measured in pcRFP-containing corals showed that fluorescence emission can contribute to >50% of orange-red light available to the photosynthetic symbionts at mesophotic depths. We further show that upregulation of pink CPs in shallow-water corals during bleaching leads to a reduction of orange light by 10–20% compared to low-CP tissue. Thus, screening by CPs has an important role in mitigating the light-enhancing effect of coral tissue scattering and skeletal reflection during bleaching. Our results provide the first experimental quantification of the importance of GFP-like proteins in fine-tuning the light microclimate of corals during photoacclimation.
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Affiliation(s)
- Elena Bollati
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Niclas H Lyndby
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Cecilia D'Angelo
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Michael Kühl
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Jörg Wiedenmann
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Daniel Wangpraseurt
- Department of NanoEngineering, University of California, San Diego, San Diego, United States
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6
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González-Guerrero LA, Vásquez-Elizondo RM, López-Londoño T, Hernán G, Iglesias-Prieto R, Enríquez S. Validation of parameters and protocols derived from chlorophyll a fluorescence commonly utilised in marine ecophysiological studies. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:517-532. [PMID: 34372966 DOI: 10.1071/fp21101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
This study documents the first validation of the suitability of the most common parameters and protocols used in marine ecophysiology to characterise photosynthesis by means of chlorophyll a fluorescence tools. We demonstrate that the effective yield of PSII (ΔF /F m ') is significantly underestimated when using short inductions times (≤1 min) following the rapid light curve protocol (RLC). The consequent electron transport rates (ETR) underestimations are species-specific and highly variable with irradiance and the photoacclimatory condition of the sample. Our analysis also questions the use of relative descriptors (relETR), as they not only overestimate photosynthesis, but overlook one of the fundamental components of the photosynthetic response: light absorption regulation. Absorptance determinations were fundamental to characterise the ETR response of low-pigmented seagrass leaves, and also uncovered relevant differences between two coral species and the accclimatory response of a cultured dinoflagellate to temperature. ETR and oxygen evolution determinations showed close correlations for all organisms tested with the expected slope of 4 e- per O2 molecule evolved, when correct photosynthesis inductions and light absorption determinations were applied. However, ETR curves cannot be equated to conventional photosynthetic response to irradiance (P vs E ) curves, and caution is needed when using ETR to characterise photosynthesis rates above photosynthesis saturation (E k ). This validation strongly supports the utility of fluorescence tools, underlining the need to correct two decades of propagation of erroneous concepts, protocols and parameters in marine eco-physiology. We aim also to emphasise the importance of optical descriptions for understanding photosynthesis, and for interpreting fluorescence measurements. In combination with conventional gross photosynthesis (GPS) approaches, optical characterisations open an extraordinary opportunity to determine two central parameters of photosynthesis performance: the quantum yield (φmax ) of the process and its minimum quantum requirements (1/φmax ). The combination of both approaches potentiates the possibilities of chlorophyll a fluorescence tools to characterise marine photosynthesis biodiversity.
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Affiliation(s)
| | - Román M Vásquez-Elizondo
- Laboratory of Photobiology of coral reef primary producers, Unidad Académica de Sistemas Arrecifales Puerto Morelos, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 13, 77500 Cancún, Mexico; and Present address: Laboratorio de Ficología Aplicada, Departamento de Recursos del Mar, CINVESTAV, Mérida
| | | | - Gema Hernán
- Laboratory of Photobiology of coral reef primary producers, Unidad Académica de Sistemas Arrecifales Puerto Morelos, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 13, 77500 Cancún, Mexico
| | | | - Susana Enríquez
- Laboratory of Photobiology of coral reef primary producers, Unidad Académica de Sistemas Arrecifales Puerto Morelos, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 13, 77500 Cancún, Mexico; and Corresponding author
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7
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Luo Y, Huang L, Lei X, Yu X, Liu C, Jiang L, Sun Y, Cheng M, Gan J, Zhang Y, Zhou G, Liu S, Lian J, Huang H. Light availability regulated by particulate organic matter affects coral assemblages on a turbid fringing reef. MARINE ENVIRONMENTAL RESEARCH 2022; 177:105613. [PMID: 35429821 DOI: 10.1016/j.marenvres.2022.105613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/08/2021] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Recently, increasing evidence suggests that reef-building corals exposed to elevated suspended solids (SS) are largely structured by changes in underwater light availability (ULA). However, there are few direct and quantitative observations in situ support for this hypothesis; in particular, the contribution of SS to the diffuse attenuation coefficient of the photosynthetically active radiation (Kd-PAR) variations is not yet fully understood. Here, we investigated the variations in ULA, the structure of coral assemblages, and the concentration and composition of SS on the Luhuitou fringing reef, Sanya, China. Light attenuation was rapid (Kd-PAR: 0.60 ± 0.39 m-1) resulting in a shallow euphotic depth (Zeu-PAR) (<11 m). Benthic PAR showed significant positive correlations with branching and corymbose corals (e.g. Acropora spp.), while massive and encrusting species (e.g. Porites spp.) dominated the coral communities and showed no significant correlations with PAR. These results indicate that the depth range available for coral growth is shallow and the tolerance to low-light stress differs among coral species. Notably, Kd-PAR showed no significant correlations with the grain size fractions of SS, whereas significant positive correlations were found with its organic fraction content, demonstrating that the light attenuation of SS is mainly regulated by particulate organic matter (POM). Intriguingly, our isotopic evidence revealed that POM concentration contributed the most to changes in Kd-PAR, with its source being slightly less important. Combined, our results highlight ULA regulated by POM is an important factor in contributing to changes in coral assemblages on inshore turbid reefs, and reducing the input of terrestrial materials, especially POM, is an effective measure to alleviate the low-light stress on sensitive coral species.
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Affiliation(s)
- Yong Luo
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lintao Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinming Lei
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Xiaolei Yu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengyue Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Lei Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Youfang Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Meng Cheng
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianfeng Gan
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuyang Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Guowei Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Sheng Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Jiansheng Lian
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Hui Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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Michel-Rodriguez M, Lefebvre S, Crouvoisier M, Mériaux X, Lizon F. Underwater light climate and wavelength dependence of microalgae photosynthetic parameters in a temperate sea. PeerJ 2021; 9:e12101. [PMID: 34707925 PMCID: PMC8496463 DOI: 10.7717/peerj.12101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 08/11/2021] [Indexed: 11/20/2022] Open
Abstract
Studying how natural phytoplankton adjust their photosynthetic properties to the quantity and quality of underwater light (i.e. light climate) is essential to understand primary production. A wavelength-dependent photoacclimation strategy was assessed using a multi-color pulse-amplitude-modulation chlorophyll fluorometer for phytoplankton samples collected in the spring at 19 locations across the English Channel. The functional absorption cross section of photosystem II, photosynthetic electron transport (PETλ) parameters and non-photochemical quenching were analyzed using an original approach with a sequence of three statistical analyses. Linear mixed-effects models using wavelength as a longitudinal variable were first applied to distinguish the fixed effect of the population from the random effect of individuals. Population and individual trends of wavelength-dependent PETλ parameters were consistent with photosynthesis and photoacclimation theories. The natural phytoplankton communities studied were in a photoprotective state for blue wavelengths (440 and 480 nm), but not for other wavelengths (green (540 nm), amber (590 nm) and light red (625 nm)). Population-detrended PETλ values were then used in multivariate analyses (partial triadic analysis and redundancy analysis) to study ecological implications of PETλ dynamics among water masses. Two wavelength ratios based on the microalgae saturation parameter Ek (in relative and absolute units), related to the hydrodynamic regime and underwater light climate, clearly confirmed the physiological state of microalgae. They also illustrate more accurately that natural phytoplankton communities can implement photoacclimation processes that are influenced by in situ light quality during the daylight cycle in temporarily and weakly stratified water. Ecological implications and consequences of PETλ are discussed in the context of turbulent coastal ecosystems.
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Affiliation(s)
- Monica Michel-Rodriguez
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Lille, France
| | - Sebastien Lefebvre
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Lille, France
| | - Muriel Crouvoisier
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Lille, France
| | - Xavier Mériaux
- Univ. Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187-LOG-Laboratoire d'Océanologie et de Géosciences, Wimereux, France
| | - Fabrice Lizon
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Lille, France
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9
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In vivo assessment of mitochondrial respiratory alternative oxidase activity and cyclic electron flow around photosystem I on small coral fragments. Sci Rep 2020; 10:17514. [PMID: 33060749 PMCID: PMC7562913 DOI: 10.1038/s41598-020-74557-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 10/05/2020] [Indexed: 12/31/2022] Open
Abstract
The mutualistic relationship existing between scleractinian corals and their photosynthetic endosymbionts involves a complex integration of the metabolic pathways within the holobiont. Respiration and photosynthesis are the most important of these processes and although they have been extensively studied, our understanding of their interactions and regulatory mechanisms is still limited. In this work we performed chlorophyll-a fluorescence, oxygen exchange and time-resolved absorption spectroscopy measurements on small and thin fragments (0.3 cm2) of the coral Stylophora pistillata. We showed that the capacity of mitochondrial alternative oxidase accounted for ca. 25% of total coral respiration, and that the high-light dependent oxygen uptake, commonly present in isolated Symbiodiniaceae, was negligible. The ratio between photosystem I (PSI) and photosystem II (PSII) active centers as well as their respective electron transport rates, indicated that PSI cyclic electron flow occurred in high light in S. pistillata and in some branching and lamellar coral species freshly collected in the field. Altogether, these results show the potential of applying advanced biophysical and spectroscopic methods on small coral fragments to understand the complex mechanisms of coral photosynthesis and respiration and their responses to environmental changes.
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10
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Li Y, Han T, Bi K, Liang K, Chen J, Lu J, He C, Lu Z. The 3D Reconstruction of Pocillopora Colony Sheds Light on the Growth Pattern of This Reef-Building Coral. iScience 2020; 23:101069. [PMID: 32504876 PMCID: PMC7276440 DOI: 10.1016/j.isci.2020.101069] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/09/2019] [Accepted: 04/13/2020] [Indexed: 11/27/2022] Open
Abstract
Coral reefs are formed by living polyps, and understanding the dynamic processes behind the reefs is crucial for marine ecosystem restoration. However, these processes are still unclear because the growth and budding patterns of living polyps are poorly known. Here, we investigate the growth pattern of a widely distributed reef-building coral Pocillopora damicornis from Xisha Islands using high-resolution computed tomography. We examine the corallites in a single corallum of the species in detail, to interpret the budding, growth, and distribution pattern of the polyps, to reconstruct the growth pattern of this important reef-building species. Our results reveal a three-stage growth pattern of P. damicornis, based on different growth bundles that are secreted by polyps along the dichotomous growth axes of the corallites. Our work on the three-dimensional reconstruction of calice and inter-septal space structure of P. damicornis sheds lights on its reef-building processes by reconstructing the budding patterns. We use high-resolution computed tomography to investigate coral forming and polyp budding processes The calice reconstruction shows coral growth patterns and budding information Our work visualizes the growth pattern of Pocillopora damicornis High-resolution computed tomography is a method for future reef-building coral studies
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Affiliation(s)
- Yixin Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Tingyu Han
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Kun Bi
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Kun Liang
- Nanjing Institute of Paleontology and Geology, 39 East Beijing Road, Nanjing 210008, China
| | - Junyuan Chen
- Nanjing Institute of Paleontology and Geology, 39 East Beijing Road, Nanjing 210008, China
| | - Jing Lu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China.
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
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11
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Bellantuono AJ, Dougan KE, Granados‐Cifuentes C, Rodriguez‐Lanetty M. Free‐living and symbiotic lifestyles of a thermotolerant coral endosymbiont display profoundly distinct transcriptomes under both stable and heat stress conditions. Mol Ecol 2019; 28:5265-5281. [DOI: 10.1111/mec.15300] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 10/22/2019] [Accepted: 10/25/2019] [Indexed: 02/06/2023]
Affiliation(s)
| | - Katherine E. Dougan
- Department of Biological Sciences Florida International University Miami FL USA
| | - Camila Granados‐Cifuentes
- Department of Biological Sciences Florida International University Miami FL USA
- Baruch College The City University of New York New York NY USA
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12
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Host-symbiont combinations dictate the photo-physiological response of reef-building corals to thermal stress. Sci Rep 2019; 9:9985. [PMID: 31292499 PMCID: PMC6620294 DOI: 10.1038/s41598-019-46412-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/24/2019] [Indexed: 01/10/2023] Open
Abstract
High sea surface temperatures often lead to coral bleaching wherein reef-building corals lose significant numbers of their endosymbiotic dinoflagellates (Symbiodiniaceae). These increasingly frequent bleaching events often result in large scale coral mortality, thereby devasting reef systems throughout the world. The reef habitats surrounding Palau are ideal for investigating coral responses to climate perturbation, where many inshore bays are subject to higher water temperature as compared with offshore barrier reefs. We examined fourteen physiological traits in response to high temperature across various symbiotic dinoflagellates in four common Pacific coral species, Acropora muricata, Coelastrea aspera, Cyphastrea chalcidicum and Pachyseris rugosa found in both offshore and inshore habitats. Inshore corals were dominated by a single homogenous population of the stress tolerant symbiont Durusdinium trenchii, yet symbiont thermal response and physiology differed significantly across coral species. In contrast, offshore corals harbored specific species of Cladocopium spp. (ITS2 rDNA type-C) yet all experienced similar patterns of photoinactivation and symbiont loss when heated. Additionally, cell volume and light absorption properties increased in heated Cladocopium spp., leading to a greater loss in photo-regulation. While inshore coral temperature response was consistently muted relative to their offshore counterparts, high physiological variability in D. trenchii across inshore corals suggests that bleaching resilience among even the most stress tolerant symbionts is still heavily influenced by their host environment.
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13
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Chartrand KM, Szabó M, Sinutok S, Rasheed MA, Ralph PJ. Living at the margins - The response of deep-water seagrasses to light and temperature renders them susceptible to acute impacts. MARINE ENVIRONMENTAL RESEARCH 2018; 136:126-138. [PMID: 29503105 DOI: 10.1016/j.marenvres.2018.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Seagrasses inhabit environments where light varies at different timescales, nonetheless are acutely sensitive to reductions in light beyond some conditional bounds. Two tropical deep-water seagrasses, Halophila decipiens and Halophila spinulosa, from the Great Barrier Reef were tested for their response to defined light and temperature regimes to identify their growth requirements and potential thresholds of mortality. Species were exposed to two light intensities, saturating (75 μmol photons m-2 s-1) and limiting (25 μmol photons m-2 s-1) light and two temperature treatments (26 °C and 30 °C) over a four-week period. Wavelength-specific parameters of PSII photochemistry were evaluated for seagrass leaves, as well as shoot density, gas exchange, and pigment content. Both species were sustained under saturating light levels (3.2 mol photons m-2 d-1) while limiting light led to decreased shoot density for H. decipiens and H. spinulosa after two and four weeks, respectively. Wavelength-specific photochemistry was also affected under light-limiting treatments for both species while the functional absorption cross section was highly conserved. Photoacclimation and physiological adjustments by either species was not adequate to compensate for reduced irradiance suggesting these plants reside at the margins of their functional limits. As such, relatively short periods of light attenuating events, like dredging or flood plumes, may be detrimental to deep-water seagrass populations.
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Affiliation(s)
- Kathryn M Chartrand
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia; Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia.
| | - Milán Szabó
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia; Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Sutinee Sinutok
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia; Faculty of Environmental Management, Prince of Songkla University, Hat Yai, Thailand; Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Thailand
| | - Michael A Rasheed
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Queensland, Australia
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales, Australia
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14
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Smith EG, D'Angelo C, Sharon Y, Tchernov D, Wiedenmann J. Acclimatization of symbiotic corals to mesophotic light environments through wavelength transformation by fluorescent protein pigments. Proc Biol Sci 2017; 284:20170320. [PMID: 28679724 PMCID: PMC5524488 DOI: 10.1098/rspb.2017.0320] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 06/22/2017] [Indexed: 11/17/2022] Open
Abstract
The depth distribution of reef-building corals exposes their photosynthetic symbionts of the genus Symbiodinium to extreme gradients in the intensity and spectral quality of the ambient light environment. Characterizing the mechanisms used by the coral holobiont to respond to the low intensity and reduced spectral composition of the light environment in deeper reefs (greater than 20 m) is fundamental to our understanding of the functioning and structure of reefs across depth gradients. Here, we demonstrate that host pigments, specifically photoconvertible red fluorescent proteins (pcRFPs), can promote coral adaptation/acclimatization to deeper-water light environments by transforming the prevalent blue light into orange-red light, which can penetrate deeper within zooxanthellae-containing tissues; this facilitates a more homogeneous distribution of photons across symbiont communities. The ecological importance of pcRFPs in deeper reefs is supported by the increasing proportion of red fluorescent corals with depth (measured down to 45 m) and increased survival of colour morphs with strong expression of pcRFPs in long-term light manipulation experiments. In addition to screening by host pigments from high light intensities in shallow water, the spectral transformation observed in deeper-water corals highlights the importance of GFP-like protein expression as an ecological mechanism to support the functioning of the coral-Symbiodinium association across steep environmental gradients.
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Affiliation(s)
- Edward G Smith
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- Marine Biology Laboratory/Centre for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Cecilia D'Angelo
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- IfLS, Institute for Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Yoni Sharon
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
| | - Dan Tchernov
- The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel
- Department of Marine Biology, University of Haifa, 31905 Mt Carmel, Israel
| | - Joerg Wiedenmann
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
- IfLS, Institute for Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
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15
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Wangpraseurt D, Holm JB, Larkum AWD, Pernice M, Ralph PJ, Suggett DJ, Kühl M. In vivo Microscale Measurements of Light and Photosynthesis during Coral Bleaching: Evidence for the Optical Feedback Loop? Front Microbiol 2017; 8:59. [PMID: 28174567 PMCID: PMC5258690 DOI: 10.3389/fmicb.2017.00059] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/09/2017] [Indexed: 12/21/2022] Open
Abstract
Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment. We created tissue areas with different densities of Symbiodinium cells in order to understand the optical properties and light microenvironment of corals during bleaching. Our results showed that in bleached Pocillopora damicornis corals, Symbiodinium light exposure was up to fivefold enhanced relative to healthy corals, and the relationship between symbiont loss and light enhancement was well-described by a power-law function. Cell-specific rates of Symbiodinium gross photosynthesis and light respiration were enhanced in bleached P. damicornis compared to healthy corals, while areal rates of net photosynthesis decreased. Symbiodinium light exposure in Favites sp. revealed the presence of low light microniches in bleached coral tissues, suggesting that light scattering in thick coral tissues can enable photoprotection of cryptic symbionts. Our study provides evidence for the acceleration of in vivo light exposure during coral bleaching but this optical feedback mechanism differs between coral hosts. Enhanced photosynthesis in relation to accelerating light exposure shows that coral microscale optics exerts a key role on coral photophysiology and the subsequent degree of radiative stress during coral bleaching.
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Affiliation(s)
- Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark; Climate Change Cluster, Department of Environmental Sciences, University of Sydney, SydneyNSW, Australia
| | - Jacob B Holm
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
| | - Anthony W D Larkum
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Mathieu Pernice
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Peter J Ralph
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - David J Suggett
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark; Climate Change Cluster, Department of Environmental Sciences, University of Sydney, SydneyNSW, Australia
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16
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Lichtenberg M, Larkum AWD, Kühl M. Photosynthetic Acclimation of Symbiodinium in hospite Depends on Vertical Position in the Tissue of the Scleractinian Coral Montastrea curta. Front Microbiol 2016; 7:230. [PMID: 26955372 PMCID: PMC4768073 DOI: 10.3389/fmicb.2016.00230] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/12/2016] [Indexed: 01/26/2023] Open
Abstract
Coral photophysiology has been studied intensively from the colony scale down to the scale of single fluorescent pigment granules as light is one of the key determinants for coral health. We studied the photophysiology of the oral and aboral symbiont band of scleractinian coral Montastrea curta to investigate if different acclimation to light exist in hospite on a polyp scale. By combined use of electrochemical and fiber-optic microsensors for O2, scalar irradiance and variable chlorophyll fluorescence, we could characterize the physical and chemical microenvironment experienced by the symbionts and, for the first time, estimate effective quantum yields of PSII photochemistry and rates of electron transport at the position of the zooxanthellae corrected for the in-tissue gradient of scalar irradiance. The oral- and aboral Symbiodinium layers received ∼71% and ∼33% of surface scalar irradiance, respectively, and the two symbiont layers experience considerable differences in light exposure. Rates of gross photosynthesis did not differ markedly between the oral- and aboral layer and curves of PSII electron transport rates corrected for scalar irradiance in hospite, showed that the light use efficiency under sub-saturating light conditions were similar between the two layers. However, the aboral Symbiodinium band did not experience photosynthetic saturation, even at the highest investigated irradiance where the oral layer was clearly saturated. We thus found a different light acclimation response for the oral and aboral symbiont bands in hospite, and discuss whether such response could be shaped by spectral shifts caused by tissue gradients of scalar irradiance. Based on our experimental finding, combined with previous knowledge, we present a conceptual model on the photophysiology of Symbiodinium residing inside living coral tissue under natural gradients of light and chemical parameters.
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Affiliation(s)
- Mads Lichtenberg
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
| | - Anthony W D Larkum
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology Sydney Sydney, NSW, Australia
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark; Plant Functional Biology and Climate Change Cluster (C3), University of Technology SydneySydney, NSW, Australia
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17
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Jones R, Bessell-Browne P, Fisher R, Klonowski W, Slivkoff M. Assessing the impacts of sediments from dredging on corals. MARINE POLLUTION BULLETIN 2016; 102:9-29. [PMID: 26654296 DOI: 10.1016/j.marpolbul.2015.10.049] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 10/19/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
There is a need to develop water quality thresholds for dredging near coral reefs that can relate physical pressures to biological responses and define exposure conditions above which effects could occur. Water quality characteristics during dredging have, however, not been well described. Using information from several major dredging projects, we describe sediment particle sizes in the water column/seabed, suspended sediment concentrations at different temporal scales during natural and dredging-related turbidity events, and changes in light quantity/quality underneath plumes. These conditions differ considerably from those used in past laboratory studies of the effects of sediments on corals. The review also discusses other problems associated with using information from past studies for developing thresholds such as the existence of multiple different and inter-connected cause-effect pathways (which can confuse/confound interpretations), the use of sediment proxies, and the reliance on information from sediment traps to justify exposure regimes in sedimentation experiments.
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Affiliation(s)
- Ross Jones
- Australian Institute of Marine Science (AIMS), Perth, Australia; Western Australian Marine Science Institution, Perth, Australia.
| | - Pia Bessell-Browne
- Australian Institute of Marine Science (AIMS), Perth, Australia; Centre of Microscopy, Charaterisation and Analysis, The University of Western Australia, Perth, Australia; Western Australian Marine Science Institution, Perth, Australia
| | - Rebecca Fisher
- Australian Institute of Marine Science (AIMS), Perth, Australia; Curtin University, Bentley, Perth, Australia
| | - Wojciech Klonowski
- Curtin University, Bentley, Perth, Australia; In situ Marine Optics, Bibra Lake, Perth, Australia
| | - Matthew Slivkoff
- Curtin University, Bentley, Perth, Australia; In situ Marine Optics, Bibra Lake, Perth, Australia
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18
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Suggett DJ, Goyen S, Evenhuis C, Szabó M, Pettay DT, Warner ME, Ralph PJ. Functional diversity of photobiological traits within the genus Symbiodinium appears to be governed by the interaction of cell size with cladal designation. THE NEW PHYTOLOGIST 2015; 208:370-81. [PMID: 26017701 DOI: 10.1111/nph.13483] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/23/2015] [Indexed: 05/13/2023]
Abstract
Dinoflagellates of the genus Symbiodinium express broad diversity in both genetic identity (phylogeny) and photosynthetic function to presumably optimize ecological success across extreme light environments; however, whether differences in the primary photobiological characteristics that govern photosynthetic optimization are ultimately a function of phylogeny is entirely unresolved. We applied a novel fast repetition rate fluorometry approach to screen genetically distinct Symbiodinium types (n = 18) spanning five clades (A-D, F) for potential phylogenetic trends in factors modulating light absorption (effective cross-section, reaction center content) and utilization (photochemical vs dynamic nonphotochemical quenching; [1 - C] vs [1 - Q]) by photosystem II (PSII). The variability of PSII light absorption was independent of phylogenetic designation, but closely correlated with cell size across types, whereas PSII light utilization intriguingly followed one of three characteristic patterns: (1) similar reliance on [1 - C] and [1 - Q] or (2) preferential reliance on [1 - C] (mostly A, B types) vs (3) preferential reliance on [1 - Q] (mostly C, D, F types), and thus generally consistent with cladal designation. Our functional trait-based approach shows, for the first time, how Symbiodinium photosynthetic function is governed by the interplay between phylogenetically dependent and independent traits, and is potentially a means to reconcile complex biogeographic patterns of Symbiodinium phylogenetic diversity in nature.
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Affiliation(s)
- David J Suggett
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, 2007, NSW, Australia
| | - Samantha Goyen
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, 2007, NSW, Australia
| | - Chris Evenhuis
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, 2007, NSW, Australia
| | - Milán Szabó
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, 2007, NSW, Australia
| | - D Tye Pettay
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - Mark E Warner
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, 2007, NSW, Australia
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19
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Light microenvironment and single-cell gradients of carbon fixation in tissues of symbiont-bearing corals. ISME JOURNAL 2015; 10:788-92. [PMID: 26241503 DOI: 10.1038/ismej.2015.133] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/23/2015] [Accepted: 07/01/2015] [Indexed: 11/08/2022]
Abstract
Recent coral optics studies have revealed the presence of steep light gradients and optical microniches in tissues of symbiont-bearing corals. Yet, it is unknown whether such resource stratification allows for physiological differences of Symbiodinium within coral tissues. Using a combination of stable isotope labelling and nanoscale secondary ion mass spectrometry, we investigated in hospite carbon fixation of individual Symbiodinium as a function of the local O2 and light microenvironment within the coral host determined with microsensors. We found that net carbon fixation rates of individual Symbiodinium cells differed on average about sixfold between upper and lower tissue layers of single coral polyps, whereas the light and O2 microenvironments differed ~15- and 2.5-fold, respectively, indicating differences in light utilisation efficiency along the light microgradient within the coral tissue. Our study suggests that the structure of coral tissues might be conceptually similar to photosynthetic biofilms, where steep physico-chemical gradients define form and function of the local microbial community.
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20
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Lichtenberg M, Kühl M. Pronounced gradients of light, photosynthesis and O2 consumption in the tissue of the brown alga Fucus serratus. THE NEW PHYTOLOGIST 2015; 207:559-69. [PMID: 25827160 DOI: 10.1111/nph.13396] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/04/2015] [Indexed: 06/04/2023]
Abstract
Macroalgae live in an ever-changing light environment affected by wave motion, self-shading and light-scattering effects, and on the thallus scale, gradients of light and chemical parameters influence algal photosynthesis. However, the thallus microenvironment and internal gradients remain underexplored. In this study, microsensors were used to quantify gradients of light, O2 concentration, variable chlorophyll fluorescence, photosynthesis and O2 consumption as a function of irradiance in the cortex and medulla layers of Fucus serratus. The two cortex layers showed more efficient light utilization compared to the medulla, calculated both from electron transport rates through photosystem II and from photosynthesis-irradiance curves. At moderate irradiance, the upper cortex exhibited onset of photosynthetic saturation, whereas lower thallus layers exhibited net O2 consumption. O2 consumption rates in light varied with depth and irradiance and were more than two-fold higher than dark respiration. We show that the thallus microenvironment of F. serratus exhibits a highly stratified balance of production and consumption of O2 , and when the frond was held in a fixed position, high incident irradiance levels on the upper cortex did not saturate photosynthesis in the lower thallus layers. We discuss possible photoadaptive responses and consequences for optimizing photosynthetic activity on the basis of vertical differences in light attenuation coefficients.
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Affiliation(s)
- Mads Lichtenberg
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000, Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000, Helsingør, Denmark
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
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21
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Klughammer C, Schreiber U. Apparent PS II absorption cross-section and estimation of mean PAR in optically thin and dense suspensions of Chlorella. PHOTOSYNTHESIS RESEARCH 2015; 123:77-92. [PMID: 25218266 DOI: 10.1007/s11120-014-0040-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 09/03/2014] [Indexed: 05/12/2023]
Abstract
Theoretical prediction of effective mean PAR in optically dense samples is complicated by various optical effects, including light scattering and reflections. Direct information on the mean rate of photon absorption by PS II is provided by the kinetics of the fluorescence rise induced upon onset of strong actinic illumination (O-I1 rise). A recently introduced kinetic multi-color PAM fluorometer was applied to study the relationship between initial slope and cell density in the relatively simple model system of suspensions of Chlorella. Use of a curve fitting routine was made which was originally developed for assessment of the wavelength-dependent absorption cross-section of PS II, σ II(λ), in dilute suspensions. The model underlying analysis of the O-I1 rise kinetics is outlined and data on the relationship between fitted values of σ II(λ) and PAR in dilute samples are presented. With increasing cell density, lowering of apparent cross-section, <σ>(λ), with respect to σ II(λ), relates to a decrease of effective mean PAR, <PAR>(λ), relative to incident PAR(λ). When ML and AL are applied in the same direction, the decline of <σ>(λ)/σ II(λ) with increasing optical density is less steep than that of the theoretically predicted <PAR>(λ)/PAR(λ). It approaches a value of 0.5 when the same colors of ML and AL are used, in agreement with theory. These observations open the way for estimating mean PAR in optically dense samples via measurements of <σ>(λ)/σ II(λ)).
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Affiliation(s)
- Christof Klughammer
- Julius-von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany
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22
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Wangpraseurt D, Tamburic B, Szabó M, Suggett D, Ralph PJ, Kühl M. Spectral effects on Symbiodinium photobiology studied with a programmable light engine. PLoS One 2014; 9:e112809. [PMID: 25389753 PMCID: PMC4229233 DOI: 10.1371/journal.pone.0112809] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
The spectral light field of Symbiodinium within the tissue of the coral animal host can deviate strongly from the ambient light field on a coral reef and that of artificial light sources used in lab studies on coral photobiology. Here, we used a novel approach involving light microsensor measurements and a programmable light engine to reconstruct the spectral light field that Symbiodinium is exposed to inside the coral host and the light field of a conventional halogen lamp in a comparative study of Symbiodinium photobiology. We found that extracellular gross photosynthetic O2 evolution was unchanged under different spectral illumination, while the more red-weighted halogen lamp spectrum decreased PSII electron transport rates and there was a trend towards increased light-enhanced dark respiration rates under excess irradiance. The approach provided here allows for reconstructing and comparing intra-tissue coral light fields and other complex spectral compositions of incident irradiance. This novel combination of sensor technologies provides a framework to studying the influence of macro- and microscale optics on Symbiodinium photobiology with unprecedented spectral resolution.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Bojan Tamburic
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Milán Szabó
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - David Suggett
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Peter J. Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
- Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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