1
|
Scharfenstein HJ, Peplow LM, Alvarez-Roa C, Nitschke MR, Chan WY, Buerger P, van Oppen MJH. Pushing the limits: expanding the temperature tolerance of a coral photosymbiont through differing selection regimes. THE NEW PHYTOLOGIST 2024; 243:2130-2145. [PMID: 39049585 DOI: 10.1111/nph.19996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 07/03/2024] [Indexed: 07/27/2024]
Abstract
Coral thermal bleaching resilience can be improved by enhancing photosymbiont thermal tolerance via experimental evolution. While successful for some strains, selection under stable temperatures was ineffective at increasing the thermal threshold of an already thermo-tolerant photosymbiont (Durusdinium trenchii). Corals from environments with fluctuating temperatures tend to have comparatively high heat tolerance. Therefore, we investigated whether exposure to temperature oscillations can raise the upper thermal limit of D. trenchii. We exposed a D. trenchii strain to stable and fluctuating temperature profiles, which varied in oscillation frequency. After 2.1 yr (54-73 generations), we characterised the adaptive responses under the various experimental evolution treatments by constructing thermal performance curves of growth from 21 to 31°C for the heat-evolved and wild-type lineages. Additionally, the accumulation of extracellular reactive oxygen species, photophysiology, photosynthesis and respiration rates were assessed under increasing temperatures. Of the fluctuating temperature profiles investigated, selection under the most frequent oscillations (diurnal) induced the greatest widening of D. trenchii's thermal niche. Continuous selection under elevated temperatures induced the only increase in thermal optimum and a degree of generalism. Our findings demonstrate how differing levels of thermal homogeneity during selection drive unique adaptive responses to heat in a coral photosymbiont.
Collapse
Affiliation(s)
- Hugo J Scharfenstein
- School of BioSciences, The University of Melbourne, Parkville, Vic., 3010, Australia
- Australian Institute of Marine Science, Townsville, Qld, 4810, Australia
| | - Lesa M Peplow
- Australian Institute of Marine Science, Townsville, Qld, 4810, Australia
| | - Carlos Alvarez-Roa
- Australian Institute of Marine Science, Townsville, Qld, 4810, Australia
| | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville, Qld, 4810, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand
| | - Wing Yan Chan
- School of BioSciences, The University of Melbourne, Parkville, Vic., 3010, Australia
| | - Patrick Buerger
- School of BioSciences, The University of Melbourne, Parkville, Vic., 3010, Australia
- Applied BioSciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, Vic., 3010, Australia
- Australian Institute of Marine Science, Townsville, Qld, 4810, Australia
| |
Collapse
|
2
|
Deore P, Tsang Min Ching SJ, Nitschke MR, Rudd D, Brumley DR, Hinde E, Blackall LL, van Oppen MJH. Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4005-4023. [PMID: 38636949 PMCID: PMC11233414 DOI: 10.1093/jxb/erae170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/17/2024] [Indexed: 04/20/2024]
Abstract
The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-B1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40 °C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms that include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimizing oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.
Collapse
Affiliation(s)
- Pranali Deore
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | | | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington 6102, New Zealand
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Elizabeth Hinde
- School of Physics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
| |
Collapse
|
3
|
Nitschke MR, Abrego D, Allen CE, Alvarez-Roa C, Boulotte NM, Buerger P, Chan WY, Fae Neto WA, Ivory E, Johnston B, Meyers L, Parra V C, Peplow L, Perez T, Scharfenstein HJ, van Oppen MJH. The use of experimentally evolved coral photosymbionts for reef restoration. Trends Microbiol 2024:S0966-842X(24)00139-2. [PMID: 38942718 DOI: 10.1016/j.tim.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/07/2024] [Accepted: 05/23/2024] [Indexed: 06/30/2024]
Abstract
The heat tolerance of corals is largely determined by their microbial photosymbionts (Symbiodiniaceae, colloquially known as zooxanthellae). Therefore, manipulating symbiont communities may enhance the ability of corals to survive summer heatwaves. Although heat-tolerant and -sensitive symbiont species occur in nature, even corals that harbour naturally tolerant symbionts have been observed to bleach during summer heatwaves. Experimental evolution (i.e., laboratory selection) of Symbiodiniaceae cultures under elevated temperatures has been successfully used to enhance their upper thermal tolerance, both in vitro and, in some instances, following their reintroduction into corals. In this review, we present the state of this intervention and its potential role within coral reef restoration, and discuss the next critical steps required to bridge the gap to implementation.
Collapse
Affiliation(s)
- Matthew R Nitschke
- Australian Institute of Marine Science, Townsville, QLD, Australia; School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - David Abrego
- Australian Institute of Marine Science, Townsville, QLD, Australia; Faculty of Science and Engineering, Southern Cross University, East Lismore, NSW, Australia
| | - Corinne E Allen
- Australian Institute of Marine Science, Townsville, QLD, Australia; School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | | | | | - Patrick Buerger
- Australian Institute of Marine Science, Townsville, QLD, Australia; Applied BioSciences, Macquarie University, Sydney, NSW, Australia
| | - Wing Yan Chan
- Australian Institute of Marine Science, Townsville, QLD, Australia; Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC, Australia
| | | | - Elizabeth Ivory
- Australian Institute of Marine Science, Townsville, QLD, Australia; Faculty of Science and Engineering, Southern Cross University, East Lismore, NSW, Australia
| | - Bede Johnston
- Australian Institute of Marine Science, Townsville, QLD, Australia; School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Luka Meyers
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Catalina Parra V
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Lesa Peplow
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Tahirih Perez
- Australian Institute of Marine Science, Townsville, QLD, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Hugo J Scharfenstein
- Australian Institute of Marine Science, Townsville, QLD, Australia; School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville, QLD, Australia; School of BioSciences, The University of Melbourne, Parkville, VIC, Australia.
| |
Collapse
|
4
|
Barton S, Padfield D, Masterson A, Buckling A, Smirnoff N, Yvon-Durocher G. Comparative experimental evolution reveals species-specific idiosyncrasies in marine phytoplankton adaptation to warming. GLOBAL CHANGE BIOLOGY 2023; 29:5261-5275. [PMID: 37395481 DOI: 10.1111/gcb.16827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/30/2023] [Indexed: 07/04/2023]
Abstract
A number of experimental studies have demonstrated that phytoplankton can display rapid thermal adaptation in response to warmed environments. While these studies provide insight into the evolutionary responses of single species, they tend to employ different experimental techniques. Consequently, our ability to compare the potential for thermal adaptation across different, ecologically relevant, species remains limited. Here, we address this limitation by conducting simultaneous long-term warming experiments with the same experimental design on clonal isolates of three phylogenetically diverse species of marine phytoplankton; the cyanobacterium Synechococcus sp., the prasinophyte Ostreococcus tauri and the diatom Phaeodoactylum tricornutum. Over the same experimental time period, we observed differing levels of thermal adaptation in response to stressful supra-optimal temperatures. Synechococcus sp. displayed the greatest improvement in fitness (i.e., growth rate) and thermal tolerance (i.e., temperature limits of growth). Ostreococcus tauri was able to improve fitness and thermal tolerance, but to a lesser extent. Finally, Phaeodoactylum tricornutum showed no signs of adaptation. These findings could help us understand how the structure of phytoplankton communities may change in response to warming, and possible biogeochemical implications, as some species show relatively more rapid adaptive shifts in their thermal tolerance.
Collapse
Affiliation(s)
- Samuel Barton
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Daniel Padfield
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Abigail Masterson
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| |
Collapse
|
5
|
Yang F, Wei Z, Long L. Response mechanisms to ocean warming exposure in Effrenium voratum (Symbiodiniaceae). MARINE POLLUTION BULLETIN 2022; 182:114032. [PMID: 35969902 DOI: 10.1016/j.marpolbul.2022.114032] [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: 02/21/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Ocean warming is an extreme environment event that has profound and lasting impacts on Symbiodiniaceae. However, their response mechanisms to elevated temperature exposure are poorly understood. In this study, the physiological and transcriptional responses of Effrenium voratum (Symbiodiniaceae) to ocean warming were examined. After exposure to 30 °C, no significant variations in growth, chlorophyll a, or photosynthetic and respiration rates were observed, while a higher temperature (34 °C) significantly reduced these physiological measurements. Meanwhile, lipid content and fatty acid composition were altered at high temperature (i.e., elevated degree of fatty acid saturation). Such biochemical constituents likely contributed to the mitigation of the negative effects of elevated temperatures. Furthermore, higher expression levels of genes related to the synthesis and elongation of fatty acids were detected at high temperature. The adjustment of lipids and fatty acid composition may be a potential mechanism by which E. voratum may survive under future global warming. ONE SENTENCE SUMMARY: The adjustment of lipids and fatty acid composition may be a potential mechanism by which E. voratum acclimate to future global warming.
Collapse
Affiliation(s)
- Fangfang Yang
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Zhangliang Wei
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Lijuan Long
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China.
| |
Collapse
|
6
|
terHorst CP, Coffroth MA. Individual variation in growth and physiology of symbionts in response to temperature. Ecol Evol 2022; 12:e9000. [PMID: 35784077 PMCID: PMC9173866 DOI: 10.1002/ece3.9000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 05/09/2022] [Accepted: 05/16/2022] [Indexed: 11/14/2022] Open
Abstract
In many cases, understanding species' responses to climate change requires understanding variation among individuals in response to such change. For species with strong symbiotic relationships, such as many coral reef species, genetic variation in symbiont responses to temperature may affect the response to increased ocean temperatures. To assess variation among symbiont genotypes, we examined the population dynamics and physiological responses of genotypes of Breviolum antillogorgium in response to increased temperature. We found broad temperature tolerance across genotypes, with all genotypes showing positive growth at 26, 30, and 32°C. Genotypes differed in the magnitude of the response of growth rate and carrying capacity to increasing temperature, suggesting that natural selection could favor different genotypes at different temperatures. However, the historical temperature at which genotypes were reared (26 or 30°C) was not a good predictor of contemporary temperature response. We found increased photosynthetic rates and decreased respiration rates with increasing contemporary temperature, and differences in physiology among genotypes, but found no significant differences in the response of these traits to temperature among genotypes. In species with such broad thermal tolerance, selection experiments on symbionts outside of the host may not yield results sufficient for evolutionary rescue from climate change.
Collapse
Affiliation(s)
- Casey P. terHorst
- Department of BiologyCalifornia State University, NorthridgeNorthridgeCaliforniaUSA
| | | |
Collapse
|
7
|
Jandang S, Viyakarn V, Yoshioka Y, Shinzato C, Chavanich S. The seasonal investigation of Symbiodiniaceae in broadcast spawning, Acropora humilis and brooding, Pocillopora cf. damicornis corals. PeerJ 2022; 10:e13114. [PMID: 35722256 PMCID: PMC9205303 DOI: 10.7717/peerj.13114] [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: 09/15/2021] [Accepted: 02/23/2022] [Indexed: 01/12/2023] Open
Abstract
The density and diversity of Symbiodiniaceae associated with corals can be influenced by seasonal changes . This study provided the first annual investigation of Symbiodiniaceae density and diversity associated with Acropora humilis and Pocillopora cf. damicornis corals in the Gulf of Thailand using both zooxanthellae cell count and next-generation sequencing (ITS-1, ITS-2 regions) techniques, respectively. The results from this study indicated that zooxanthellae cell densities in both coral species differ significantly. The number of zooxanthellae was negatively correlated with the physical environment variable (light intensity). The diversity within A. humilis consisted of two genera, Cladocopium (Cspc_C3: 56.39%, C3w: 33.62%, C93type1: 4.42% and Cspf: 3.59%) and a small amount of Durusdinium (D1: 1.03%) whereas P. cf. damicornis was found to be 100% associated with Durusdinium (D1: 95.58%, D6: 1.01% and D10: 2.7%) suggesting that each coral species may select their appropriate genus/species of Symbiodiniaceae in response to local environmental stressors. The results of this study provided some information on the coral-Symbiodiniaceae relationship between seasons, which may be applied to predict the potential adaptation of corals in localized reef environments.
Collapse
Affiliation(s)
- Suppakarn Jandang
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Voranop Viyakarn
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand,Aquatic Resources Research Institute, Chulalongkorn University, Bangkok, Thailand
| | - Yuki Yoshioka
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Chuya Shinzato
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Suchana Chavanich
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand,Aquatic Resources Research Institute, Chulalongkorn University, Bangkok, Thailand,Center of Excellence for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| |
Collapse
|
8
|
Gain G, Vega de Luna F, Cordoba J, Perez E, Degand H, Morsomme P, Thiry M, Baurain D, Pierangelini M, Cardol P. Trophic state alters the mechanism whereby energetic coupling between photosynthesis and respiration occurs in Euglena gracilis. THE NEW PHYTOLOGIST 2021; 232:1603-1617. [PMID: 34392544 PMCID: PMC9292222 DOI: 10.1111/nph.17677] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
The coupling between mitochondrial respiration and photosynthesis plays an important role in the energetic physiology of green plants and some secondary-red photosynthetic eukaryotes (diatoms), allowing an efficient CO2 assimilation and optimal growth. Using the flagellate Euglena gracilis, we first tested if photosynthesis-respiration coupling occurs in this species harbouring secondary green plastids (i.e. originated from an endosymbiosis between a green alga and a phagotrophic euglenozoan). Second, we tested how the trophic state (mixotrophy and photoautotrophy) of the cell alters the mechanisms involved in the photosynthesis-respiration coupling. Energetic coupling between photosynthesis and respiration was determined by testing the effect of respiratory inhibitors on photosynthesis, and measuring the simultaneous variation of photosynthesis and respiration rates as a function of temperature (i.e. thermal response curves). The mechanism involved in the photosynthesis-respiration coupling was assessed by combining proteomics, biophysical and cytological analyses. Our work shows that there is photosynthesis-respiration coupling and membrane contacts between mitochondria and chloroplasts in E. gracilis. However, whereas in mixotrophy adjustment of the chloroplast ATP/NADPH ratio drives the interaction, in photoautotrophy the coupling is conditioned by CO2 limitation and photorespiration. This indicates that maintenance of photosynthesis-respiration coupling, through plastic metabolic responses, is key to E. gracilis functioning under changing environmental conditions.
Collapse
Affiliation(s)
- Gwenaëlle Gain
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Félix Vega de Luna
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Javier Cordoba
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Emilie Perez
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Hervé Degand
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Pierre Morsomme
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Marc Thiry
- Laboratoire de Biologie Cellulaire et TissulaireGiga‐NeurosciencesULiègeLiègeB‐4000Belgium
| | - Denis Baurain
- InBioS – PhytoSYSTEMSEukaryotic PhylogenomicsULiègeLiègeB‐4000Belgium
| | - Mattia Pierangelini
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Pierre Cardol
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| |
Collapse
|
9
|
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.
Collapse
|