1
|
Rosic N, Delamare-Deboutteville J, Dove S. Heat stress in symbiotic dinoflagellates: Implications on oxidative stress and cellular changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173916. [PMID: 38866148 DOI: 10.1016/j.scitotenv.2024.173916] [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: 12/30/2023] [Revised: 05/18/2024] [Accepted: 06/08/2024] [Indexed: 06/14/2024]
Abstract
Global warming has been shown to harmfully affect symbiosis between Symbiodiniaceae and other marine invertebrates. When symbiotic dinoflagellates (the genus Breviolum) were in vitro exposed to acute heat stress of +7 °C for a period of 5 days, the results revealed the negative impact on all physiological and other cellular parameters measured. Elevated temperatures resulted in a severe reduction in algal density of up to 9.5-fold, as well as pigment concentrations, indicating the status of the physiological stress and early signs of photo-bleaching. Reactive oxygen species (ROS) were increased in all heated dinoflagellate cells, while the antioxidant-reduced glutathione levels initially dropped on day one but increased under prolonged temperature stress. The cell viability parameters were reduced by 97 % over the heating period, with an increased proportion of apoptotic and necrotic cells. Autofluorescence (AF) for Cy5-PE 660-20 was reduced from 1.7-fold at day 1 to up to 50-fold drop at the end of heating time, indicating that the AF changes were highly sensitive to heat stress and that it could be an extremely sensitive tool for assessing the functionality of algal photosynthetic machinery. The addition of the drug 5-AZA-2'-deoxycytidine (5-AZA), which inhibits DNA methylation processes, was assessed in parallel and contributed to some alterations in algal cellular stress response. The presence of drug 5-AZA combined with the temperature stress had an additional impact on Symbiodiniaceae density and cell complexity, including the AF levels. These variations in cellular stress response under heat stress and compromised DNA methylation conditions may indicate the importance of this epigenetic mechanism for symbiotic dinoflagellate thermal tolerance adaptability over a longer period, which needs further exploration. Consequently, the increased ROS levels and changes in AF signals reported during ongoing heat stress in dinoflagellate cells could be used as early stress biomarkers in these microalgae and potentially other photosynthetic species.
Collapse
Affiliation(s)
- Nedeljka Rosic
- Faculty of Health, Southern Cross University, Gold Coast, QLD, Australia; Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia.
| | | | - Sophie Dove
- School of Biological Sciences, The University of Queensland, St. Lucia, Qld, Australia
| |
Collapse
|
2
|
Faulstich NG, Deloach AR, Ksor YB, Mesa GH, Sharma DS, Sisk SL, Mitchell GC. Evidence for phosphate-dependent control of symbiont cell division in the model anemone Exaiptasia diaphana. mBio 2024:e0105924. [PMID: 39105583 DOI: 10.1128/mbio.01059-24] [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: 04/09/2024] [Accepted: 07/09/2024] [Indexed: 08/07/2024] Open
Abstract
Reef-building corals depend on symbiosis with photosynthetic algae that reside within their cells. As important as this relationship is for maintaining healthy reefs, it is strikingly delicate. When ocean temperatures briefly exceed the average summer maximum, corals can bleach, losing their endosymbionts. Although the mechanisms governing bleaching are unknown, studies implicate uncoupling of coral and algal cell divisions at high temperatures. Still, little is known regarding the coordination of host and algal cell divisions. Control of nutrient exchange is one likely mechanism. Both nitrogen and phosphate are necessary for dividing cells, and although nitrogen enrichment is known to increase symbiont density in the host, the consequences of phosphate enrichment are poorly understood. Here, we examined the effects of phosphate depletion on symbiont growth in culture and compared the physiology of phosphate-starved symbionts in culture to symbionts that were freshly isolated from a host. We found that available phosphate is as low in freshly isolated symbionts as it is in phosphate-starved cultures. Furthermore, RNAseq revealed that phosphate-limited and freshly isolated symbionts have similar patterns of gene expression for phosphate-dependent genes, most notably upregulation of phosphatases, which is consistent with phosphate recycling. Similarly, lipid profiling revealed a substantial decrease in phospholipid abundance in both phosphate-starved cultures and freshly isolated symbionts. These findings are important because they suggest that limited access to phosphate controls algal cell divisions within a host. IMPORTANCE The corals responsible for building tropical reefs are disappearing at an alarming rate as elevated sea temperatures cause them to bleach and lose the algal symbionts they rely on. Without these symbionts, corals are unable to harvest energy from sunlight and, therefore, struggle to thrive or even survive in the nutrient-poor waters of the tropics. To devise solutions to address the threat to coral reefs, it is necessary to understand the cellular events underpinning the bleaching process. One model for bleaching proposes that heat stress impairs algal photosynthesis and transfer of sugar to the host. Consequently, the host's demands for nitrogen decrease, increasing nitrogen availability to the symbionts, which leads to an increase in algal proliferation that overwhelms the host. Our work suggests that phosphate may play a similar role to nitrogen in this feedback loop.
Collapse
Affiliation(s)
| | | | - Ykok B Ksor
- Wofford College, Spartanburg, South Carolina, USA
| | | | | | | | | |
Collapse
|
3
|
Hu G, Huang J, Fussenegger M. Toward Photosynthetic Mammalian Cells through Artificial Endosymbiosis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2310310. [PMID: 38506612 DOI: 10.1002/smll.202310310] [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: 11/10/2023] [Revised: 02/20/2024] [Indexed: 03/21/2024]
Abstract
Photosynthesis in plants occurs within specialized organelles known as chloroplasts, which are postulated to have originated through endosymbiosis with cyanobacteria. In nature, instances are also observed wherein specific invertebrates engage in symbiotic relationships with photosynthetic bacteria, allowing them to subsist as photoautotrophic organisms over extended durations. Consequently, the concept of engineering artificial endosymbiosis between mammalian cells and cyanobacteria represents a promising avenue for enabling photosynthesis in mammals. The study embarked with the identification of Synechocystis PCC 6803 as a suitable candidate for establishing a long-term endosymbiotic relationship with macrophages. The cyanobacteria internalized by macrophages exhibited the capacity to rescue ATP deficiencies within their host cells under conditions of illumination. Following this discovery, a membrane-coating strategy is developed for the intracellular delivery of cyanobacteria into non-macrophage mammalian cells. This pioneering technique led to the identification of human embryonic kidney cells HEK293 as optimal hosts for achieving sustained endosymbiosis with Synechocystis PCC 6803. The study offers valuable insights that may serve as a reference for the eventual achievement of artificial photosynthesis in mammals.
Collapse
Affiliation(s)
- Guipeng Hu
- Department of Biosystems Science and Engineering, ETH Zurich, Klingelbergstrasse 48, Basel, CH-4056, Switzerland
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, China
| | - Jinbo Huang
- Department of Biosystems Science and Engineering, ETH Zurich, Klingelbergstrasse 48, Basel, CH-4056, Switzerland
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zurich, Klingelbergstrasse 48, Basel, CH-4056, Switzerland
- Faculty of Science, University of Basel, Klingelbergstrasse 48, Basel, CH-4056, Switzerland
| |
Collapse
|
4
|
Dougan KE, Bellantuono AJ, Kahlke T, Abbriano RM, Chen Y, Shah S, Granados-Cifuentes C, van Oppen MJH, Bhattacharya D, Suggett DJ, Rodriguez-Lanetty M, Chan CX. Whole-genome duplication in an algal symbiont bolsters coral heat tolerance. SCIENCE ADVANCES 2024; 10:eadn2218. [PMID: 39028812 PMCID: PMC11259175 DOI: 10.1126/sciadv.adn2218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 06/14/2024] [Indexed: 07/21/2024]
Abstract
The algal endosymbiont Durusdinium trenchii enhances the resilience of coral reefs under thermal stress. D. trenchii can live freely or in endosymbiosis, and the analysis of genetic markers suggests that this species has undergone whole-genome duplication (WGD). However, the evolutionary mechanisms that underpin the thermotolerance of this species are largely unknown. Here, we present genome assemblies for two D. trenchii isolates, confirm WGD in these taxa, and examine how selection has shaped the duplicated genome regions using gene expression data. We assess how the free-living versus endosymbiotic lifestyles have contributed to the retention and divergence of duplicated genes, and how these processes have enhanced the thermotolerance of D. trenchii. Our combined results suggest that lifestyle is the driver of post-WGD evolution in D. trenchii, with the free-living phase being the most important, followed by endosymbiosis. Adaptations to both lifestyles likely enabled D. trenchii to provide enhanced thermal stress protection to the host coral.
Collapse
Affiliation(s)
- Katherine E. Dougan
- School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD 4072, Australia
- Department of Biological Sciences, Biomolecular Science Institute, Florida International University, Miami, FL 33099, USA
| | - Anthony J. Bellantuono
- Department of Biological Sciences, Biomolecular Science Institute, Florida International University, Miami, FL 33099, USA
| | - Tim Kahlke
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Raffaela M. Abbriano
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Yibi Chen
- School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sarah Shah
- School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Camila Granados-Cifuentes
- Department of Biological Sciences, Biomolecular Science Institute, Florida International University, Miami, FL 33099, USA
| | - 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
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - David J. Suggett
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW 2007, Australia
- KAUST Reefscape Restoration Initiative (KRRI) and Red Sea Research Center (RSRC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Biomolecular Science Institute, Florida International University, Miami, FL 33099, USA
| | - Cheong Xin Chan
- School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD 4072, Australia
| |
Collapse
|
5
|
Huang S, Luo L, Wen B, Liu X, Yu K, Zhang M. Metabolic signatures of two scleractinian corals from the northern South China sea in response to extreme high temperature events. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106490. [PMID: 38636276 DOI: 10.1016/j.marenvres.2024.106490] [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: 11/28/2023] [Revised: 03/27/2024] [Accepted: 04/04/2024] [Indexed: 04/20/2024]
Abstract
Coral bleaching events are becoming increasingly common worldwide, causing widespread coral mortality. However, not all colonies within the same coral taxa show sensitivity to bleaching events, and the current understanding of the metabolic mechanisms underlying thermal bleaching in corals remains limited. We used untargeted metabolomics to analyze the biochemical processes involved in the survival of two bleaching phenotypes of the common corals Pavona decussata and Acropora pruinosa, during a severe bleaching event in the northern South China Sea in 2020. During thermal bleaching, P. decussata and A. pruinosa significantly accumulated energy products such as succinate and EPA, antioxidants and inflammatory markers, and reduced energy storage substances like glutamate and thymidine. KEGG analysis revealed enrichment of energy production pathways such as ABC transporters, nucleotide metabolism and lipid metabolism, suggesting the occurrence of oxidative stress and energy metabolism disorders in bleached corals. Notably, heat stress exerted distinct effects on metabolic pathways in the two coral species, e.g., P. decussata activating carbohydrate metabolism pathways like glycolysis and the TCA cycle, along with amino acid metabolism pathways, whereas A. pruinosa significantly altered the content of multiple small peptides affected amino acid metabolism. Furthermore, the osmoregulatory potential of corals correlates with their ability to survive in heat-stress environments in the wild. This study provides valuable insights into the metabolic mechanisms linked to thermal tolerance in reef-building corals, contributes to the understanding of corals' adaptive potential to heat stress induced by global warming and lays the foundation for developing targeted conservation strategies in the future.
Collapse
Affiliation(s)
- Shan Huang
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Li Luo
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Beihua Wen
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Xurui Liu
- School of Animal Science and Technology, Guangxi University, Nanning 530004, China
| | - Kefu Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
| | - Man Zhang
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China.
| |
Collapse
|
6
|
Helgoe J, Davy SK, Weis VM, Rodriguez-Lanetty M. Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms. Biol Rev Camb Philos Soc 2024; 99:715-752. [PMID: 38217089 DOI: 10.1111/brv.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/15/2024]
Abstract
The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
Collapse
Affiliation(s)
- Joshua Helgoe
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
| | - Simon K Davy
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA
| | - Mauricio Rodriguez-Lanetty
- Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA
- Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA
| |
Collapse
|
7
|
Nanes Sarfati D, Xue Y, Song ES, Byrne A, Le D, Darmanis S, Quake SR, Burlacot A, Sikes J, Wang B. Coordinated wound responses in a regenerative animal-algal holobiont. Nat Commun 2024; 15:4032. [PMID: 38740753 DOI: 10.1038/s41467-024-48366-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
Animal regeneration involves coordinated responses across cell types throughout the animal body. In endosymbiotic animals, whether and how symbionts react to host injury and how cellular responses are integrated across species remain unexplored. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis sp. green algae and can regenerate entire bodies from tissue fragments. We show that animal injury causes a decline in the photosynthetic efficiency of the symbiotic algae, alongside two distinct, sequential waves of transcriptional responses in acoel and algal cells. The initial algal response is characterized by the upregulation of a cohort of photosynthesis-related genes, though photosynthesis is not necessary for regeneration. A conserved animal transcription factor, runt, is induced after injury and required for acoel regeneration. Knockdown of Cl-runt dampens transcriptional responses in both species and further reduces algal photosynthetic efficiency post-injury. Our results suggest that the holobiont functions as an integrated unit of biological organization by coordinating molecular networks across species through the runt-dependent animal regeneration program.
Collapse
Affiliation(s)
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Eun Sun Song
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | | | - Daniel Le
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | | | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Adrien Burlacot
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - James Sikes
- Department of Biology, University of San Francisco, San Francisco, CA, USA.
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
8
|
Pasaribu B, Purba NP, Dewanti LP, Pasaribu D, Khan AMA, Harahap SA, Syamsuddin ML, Ihsan YN, Siregar SH, Faizal I, Herawati T, Irfan M, Simorangkir TPH, Kurniawan TA. Lipid Droplets in Endosymbiotic Symbiodiniaceae spp. Associated with Corals. PLANTS (BASEL, SWITZERLAND) 2024; 13:949. [PMID: 38611478 PMCID: PMC11013053 DOI: 10.3390/plants13070949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/16/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
Symbiodiniaceae species is a dinoflagellate that plays a crucial role in maintaining the symbiotic mutualism of reef-building corals in the ocean. Reef-building corals, as hosts, provide the nutrition and habitat to endosymbiotic Symbiodiniaceae species and Symbiodiniaceae species transfer the fixed carbon to the corals for growth. Environmental stress is one of the factors impacting the physiology and metabolism of the corals-dinoflagellate association. The environmental stress triggers the metabolic changes in Symbiodiniaceae species resulting in an increase in the production of survival organelles related to storage components such as lipid droplets (LD). LDs are found as unique organelles, mainly composed of triacylglycerols surrounded by phospholipids embedded with some proteins. To date, it has been reported that investigation of lipid droplets significantly present in animals and plants led to the understanding that lipid droplets play a key role in lipid storage and transport. The major challenge of investigating endosymbiotic Symbiodiniaceae species lies in overcoming the strategies in isolating lesser lipid droplets present in its intercellular cells. Here, we review the most recent highlights of LD research in endosymbiotic Symbiodiniaceae species particularly focusing on LD biogenesis, mechanism, and major lipid droplet proteins. Moreover, to comprehend potential novel ways of energy storage in the symbiotic interaction between endosymbiotic Symbiodiniaceae species and its host, we also emphasize recent emerging environmental factors such as temperature, ocean acidification, and nutrient impacting the accumulation of lipid droplets in endosymbiotic Symbiodiniaceae species.
Collapse
Affiliation(s)
- Buntora Pasaribu
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
- Shallow Coastal and Aquatic Research Forensic (SCARF) Laboratory, Faculty of Fishery and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia
- Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA;
| | - Noir Primadona Purba
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
| | - Lantun Paradhita Dewanti
- Department of Fisheries, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia;
| | - Daniel Pasaribu
- Faculty of Law, Social, and Political Sciences, Universitas Terbuka, Tangerang 15437, Indonesia;
| | - Alexander Muhammad Akbar Khan
- Tropical Marine Fisheries Undergraduate Programme for Pangandaran Campus, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia;
| | - Syawaludin Alisyahbana Harahap
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
| | - Mega Laksmini Syamsuddin
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
| | - Yudi Nurul Ihsan
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
| | - Sofyan Husein Siregar
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Riau, Pekanbaru 28291, Indonesia;
| | - Ibnu Faizal
- Department of Marine Science, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia; (N.P.P.); (S.A.H.); (M.L.S.); (Y.N.I.); (I.F.)
| | - Titin Herawati
- Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA;
- Master Program of Marine Conservation, Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Bandung 40600, Indonesia
| | - Mohammad Irfan
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850, USA;
| | | | | |
Collapse
|
9
|
Zhou Y, Li Q, Zhang Q, Yuan M, Zhu X, Li Y, Li Q, Downs CA, Huang D, Chou LM, Zhao H. Environmental Concentrations of Herbicide Prometryn Render Stress-Tolerant Corals Susceptible to Ocean Warming. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4545-4557. [PMID: 38386019 DOI: 10.1021/acs.est.3c10417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Global warming has caused the degradation of coral reefs around the world. While stress-tolerant corals have demonstrated the ability to acclimatize to ocean warming, it remains unclear whether they can sustain their thermal resilience when superimposed with other coastal environmental stressors. We report the combined impacts of a photosystem II (PSII) herbicide, prometryn, and ocean warming on the stress-tolerant coral Galaxea fascicularis through physiological and omics analyses. The results demonstrate that the heat-stress-induced inhibition of photosynthetic efficiency in G. fascicularis is exacerbated in the presence of prometryn. Transcriptomics and metabolomics analyses indicate that the prometryn exposure may overwhelm the photosystem repair mechanism in stress-tolerant corals, thereby compromising their capacity for thermal acclimation. Moreover, prometryn might amplify the adverse effects of heat stress on key energy and nutrient metabolism pathways and induce a stronger response to oxidative stress in stress-tolerant corals. The findings indicate that the presence of prometryn at environmentally relevant concentrations would render corals more susceptible to heat stress and exacerbate the breakdown of coral Symbiodiniaceae symbiosis. The present study provides valuable insights into the necessity of prioritizing PSII herbicide pollution reduction in coral reef protection efforts while mitigating the effects of climate change.
Collapse
Affiliation(s)
- Yanyu Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Qiuli Li
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Quan Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Meile Yuan
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Xiaoshan Zhu
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Yuanchao Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou 571126, China
| | - Qipei Li
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| | - Craig A Downs
- Haereticus Environmental Laboratory, P.O. Box 92, Clifford, Virginia 24533, United States
| | - Danwei Huang
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore 117377, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Loke-Ming Chou
- Tropical Marine Science Institute, National University of Singapore, Singapore 119227, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Hongwei Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
- Center for Eco-Environment Restoration of Hainan Province & Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environment and Ecology, Hainan University, Haikou 570228, China
| |
Collapse
|
10
|
Allen-Waller LR, Jones KG, Martynek MP, Brown KT, Barott KL. Comparative physiology reveals heat stress disrupts acid-base homeostasis independent of symbiotic state in the model cnidarian Exaiptasia diaphana. J Exp Biol 2024; 227:jeb246222. [PMID: 38269486 PMCID: PMC10911193 DOI: 10.1242/jeb.246222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Climate change threatens the survival of symbiotic cnidarians by causing photosymbiosis breakdown in a process known as bleaching. Direct effects of temperature on cnidarian host physiology remain difficult to describe because heatwaves depress symbiont performance, leading to host stress and starvation. The symbiotic sea anemone Exaiptasia diaphana provides an opportune system to disentangle direct versus indirect heat effects on the host, as it can survive indefinitely without symbionts. We tested the hypothesis that heat directly impairs cnidarian physiology by comparing symbiotic and aposymbiotic individuals of two laboratory subpopulations of a commonly used clonal strain of E. diaphana, CC7. We exposed anemones to a range of temperatures (ambient, +2°C, +4°C and +6°C) for 15-18 days, then measured their symbiont population densities, autotrophic carbon assimilation and translocation, photosynthesis, respiration and host intracellular pH (pHi). Symbiotic anemones from the two subpopulations differed in size and symbiont density and exhibited distinct heat stress responses, highlighting the importance of acclimation to different laboratory conditions. Specifically, the cohort with higher initial symbiont densities experienced dose-dependent symbiont loss with increasing temperature and a corresponding decline in host photosynthate accumulation. In contrast, the cohort with lower initial symbiont densities did not lose symbionts or assimilate less photosynthate when heated, similar to the response of aposymbiotic anemones. However, anemone pHi decreased at higher temperatures regardless of cohort, symbiont presence or photosynthate translocation, indicating that heat consistently disrupts cnidarian acid-base homeostasis independent of symbiotic status or mutualism breakdown. Thus, pH regulation may be a critical vulnerability for cnidarians in a changing climate.
Collapse
Affiliation(s)
| | - Katelyn G. Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Kristen T. Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Katie L. Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
11
|
Jinkerson RE, Poveda-Huertes D, Cooney EC, Cho A, Ochoa-Fernandez R, Keeling PJ, Xiang T, Andersen-Ranberg J. Biosynthesis of chlorophyll c in a dinoflagellate and heterologous production in planta. Curr Biol 2024; 34:594-605.e4. [PMID: 38157859 DOI: 10.1016/j.cub.2023.12.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
Chlorophyll c is a key photosynthetic pigment that has been used historically to classify eukaryotic algae. Despite its importance in global photosynthetic productivity, the pathway for its biosynthesis has remained elusive. Here we define the CHLOROPHYLL C SYNTHASE (CHLCS) discovered through investigation of a dinoflagellate mutant deficient in chlorophyll c. CHLCSs are proteins with chlorophyll a/b binding and 2-oxoglutarate-Fe(II) dioxygenase (2OGD) domains found in peridinin-containing dinoflagellates; other chlorophyll c-containing algae utilize enzymes with only the 2OGD domain or an unknown synthase to produce chlorophyll c. 2OGD-containing synthases across dinoflagellate, diatom, cryptophyte, and haptophyte lineages form a monophyletic group, 8 members of which were also shown to produce chlorophyll c. Chlorophyll c1 to c2 ratios in marine algae are dictated in part by chlorophyll c synthases. CHLCS heterologously expressed in planta results in the accumulation of chlorophyll c1 and c2, demonstrating a path to augment plant pigment composition with algal counterparts.
Collapse
Affiliation(s)
- Robert E Jinkerson
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA; Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA 92521, USA.
| | - Daniel Poveda-Huertes
- Department of Plant and Environmental Science, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Elizabeth C Cooney
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anna Cho
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Rocio Ochoa-Fernandez
- Department of Plant and Environmental Science, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Tingting Xiang
- Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA.
| | - Johan Andersen-Ranberg
- Department of Plant and Environmental Science, University of Copenhagen, 1871 Frederiksberg C, Denmark
| |
Collapse
|
12
|
Zwolak R, Clement D, Sih A, Schreiber SJ. Granivore abundance shapes mutualism quality in plant-scatterhoarder interactions. THE NEW PHYTOLOGIST 2024; 241:1840-1850. [PMID: 38044708 DOI: 10.1111/nph.19443] [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: 07/25/2023] [Accepted: 11/08/2023] [Indexed: 12/05/2023]
Abstract
Conditional mutualisms involve costs and benefits that vary with environmental factors, but mechanisms driving these dynamics remain poorly understood. Scatterhoarder-plant interactions are a prime example of this phenomenon, as scatterhoarders can either increase or reduce plant recruitment depending on the balance between seed dispersal and predation. We explored factors that drive the magnitude of net benefits for plants in this interaction using a mathematical model, with parameter values based on European beech (Fagus sylvatica) and yellow-necked mice (Apodemus flavicollis). We measured benefits as the percentage of germinating seeds, and examined how varying rodent survival (reflecting, e.g. changes in predation pressure), the rate of seed loss to other granivores, the abundance of alternative food resources, and changes in masting patterns affect the quality of mutualism. We found that increasing granivore abundance can degrade the quality of plant-scatterhoarder mutualism due to increased cache pilferage. Scatterhoarders are predicted to respond by increasing immediate consumption of gathered seeds, leading to higher costs and reduced benefits for plants. Thus, biotic changes that are detrimental to rodent populations can be beneficial for tree recruitment due to adaptive behavior of rodents. When scatterhoarder populations decline too drastically (< 5 individuals ha-1 ); however, tree recruitment may also suffer.
Collapse
Affiliation(s)
- Rafał Zwolak
- Department of Systematic Zoology, Institute of Environmental Biology, Adam Mickiewicz University, Umultowska 89, Poznań, 61-614, Poland
| | - Dale Clement
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
| | - Andrew Sih
- Center of Population Biology, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Sebastian J Schreiber
- Center of Population Biology, University of California, One Shields Avenue, Davis, CA, 95616, USA
| |
Collapse
|
13
|
Garai S, Bhowal B, Gupta M, Sopory SK, Singla-Pareek SL, Pareek A, Kaur C. Role of methylglyoxal and redox homeostasis in microbe-mediated stress mitigation in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 338:111922. [PMID: 37952767 DOI: 10.1016/j.plantsci.2023.111922] [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: 07/17/2023] [Revised: 10/04/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
One of the general consequences of stress in plants is the accumulation of reactive oxygen (ROS) and carbonyl species (like methylglyoxal) to levels that are detrimental for plant growth. These reactive species are inherently produced in all organisms and serve different physiological functions but their excessive accumulation results in cellular toxicity. It is, therefore, essential to restore equilibrium between their synthesis and breakdown to ensure normal cellular functioning. Detoxification mechanisms that scavenge these reactive species are considered important for stress mitigation as they maintain redox balance by restricting the levels of ROS, methylglyoxal and other reactive species in the cellular milieu. Stress tolerance imparted to plants by root-associated microbes involves a multitude of mechanisms, including maintenance of redox homeostasis. By improving the overall antioxidant response in plants, microbes can strengthen defense pathways and hence, the adaptive abilities of plants to sustain growth under stress. Hence, through this review we wish to highlight the contribution of root microbiota in modulating the levels of reactive species and thereby, maintaining redox homeostasis in plants as one of the important mechanisms of stress alleviation. Further, we also examine the microbial mechanisms of resistance to oxidative stress and their role in combating plant stress.
Collapse
Affiliation(s)
- Sampurna Garai
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Bidisha Bhowal
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Mayank Gupta
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sudhir K Sopory
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sneh L Singla-Pareek
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ashwani Pareek
- National Agri-Food Biotechnology Institute, SAS Nagar, Mohali, Punjab 140306, India
| | - Charanpreet Kaur
- National Agri-Food Biotechnology Institute, SAS Nagar, Mohali, Punjab 140306, India.
| |
Collapse
|
14
|
Jacobovitz MR, Hambleton EA, Guse A. Unlocking the Complex Cell Biology of Coral-Dinoflagellate Symbiosis: A Model Systems Approach. Annu Rev Genet 2023; 57:411-434. [PMID: 37722685 DOI: 10.1146/annurev-genet-072320-125436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Symbiotic interactions occur in all domains of life, providing organisms with resources to adapt to new habitats. A prime example is the endosymbiosis between corals and photosynthetic dinoflagellates. Eukaryotic dinoflagellate symbionts reside inside coral cells and transfer essential nutrients to their hosts, driving the productivity of the most biodiverse marine ecosystem. Recent advances in molecular and genomic characterization have revealed symbiosis-specific genes and mechanisms shared among symbiotic cnidarians. In this review, we focus on the cellular and molecular processes that underpin the interaction between symbiont and host. We discuss symbiont acquisition via phagocytosis, modulation of host innate immunity, symbiont integration into host cell metabolism, and nutrient exchange as a fundamental aspect of stable symbiotic associations. We emphasize the importance of using model systems to dissect the cellular complexity of endosymbiosis, which ultimately serves as the basis for understanding its ecology and capacity to adapt in the face of climate change.
Collapse
Affiliation(s)
- Marie R Jacobovitz
- Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Elizabeth A Hambleton
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria;
| | - Annika Guse
- Faculty of Biology, Ludwig-Maximilians-Universität Munich, Munich, Germany;
| |
Collapse
|
15
|
Rädecker N, Escrig S, Spangenberg JE, Voolstra CR, Meibom A. Coupled carbon and nitrogen cycling regulates the cnidarian-algal symbiosis. Nat Commun 2023; 14:6948. [PMID: 37914705 PMCID: PMC10620199 DOI: 10.1038/s41467-023-42579-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Efficient nutrient recycling underpins the ecological success of cnidarian-algal symbioses in oligotrophic waters. In these symbioses, nitrogen limitation restricts the growth of algal endosymbionts in hospite and stimulates their release of photosynthates to the cnidarian host. However, the mechanisms controlling nitrogen availability and their role in symbiosis regulation remain poorly understood. Here, we studied the metabolic regulation of symbiotic nitrogen cycling in the sea anemone Aiptasia by experimentally altering labile carbon availability in a series of experiments. Combining 13C and 15N stable isotope labeling experiments with physiological analyses and NanoSIMS imaging, we show that the competition for environmental ammonium between the host and its algal symbionts is regulated by labile carbon availability. Light regimes optimal for algal photosynthesis increase carbon availability in the holobiont and stimulate nitrogen assimilation in the host metabolism. Consequently, algal symbiont densities are lowest under optimal environmental conditions and increase toward the lower and upper light tolerance limits of the symbiosis. This metabolic regulation promotes efficient carbon recycling in a stable symbiosis across a wide range of environmental conditions. Yet, the dependence on resource competition may favor parasitic interactions, explaining the instability of the cnidarian-algal symbiosis as environmental conditions in the Anthropocene shift towards its tolerance limits.
Collapse
Affiliation(s)
- Nils Rädecker
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Stéphane Escrig
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Jorge E Spangenberg
- Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | | | - Anders Meibom
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Center for Advanced Surface Analysis, Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
16
|
Cui G, Mi J, Moret A, Menzies J, Zhong H, Li A, Hung SH, Al-Babili S, Aranda M. A carbon-nitrogen negative feedback loop underlies the repeated evolution of cnidarian-Symbiodiniaceae symbioses. Nat Commun 2023; 14:6949. [PMID: 37914686 PMCID: PMC10620218 DOI: 10.1038/s41467-023-42582-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Symbiotic associations with Symbiodiniaceae have evolved independently across a diverse range of cnidarian taxa including reef-building corals, sea anemones, and jellyfish, yet the molecular mechanisms underlying their regulation and repeated evolution are still elusive. Here, we show that despite their independent evolution, cnidarian hosts use the same carbon-nitrogen negative feedback loop to control symbiont proliferation. Symbiont-derived photosynthates are used to assimilate nitrogenous waste via glutamine synthetase-glutamate synthase-mediated amino acid biosynthesis in a carbon-dependent manner, which regulates the availability of nitrogen to the symbionts. Using nutrient supplementation experiments, we show that the provision of additional carbohydrates significantly reduces symbiont density while ammonium promotes symbiont proliferation. High-resolution metabolic analysis confirmed that all hosts co-incorporated glucose-derived 13C and ammonium-derived 15N via glutamine synthetase-glutamate synthase-mediated amino acid biosynthesis. Our results reveal a general carbon-nitrogen negative feedback loop underlying these symbioses and provide a parsimonious explanation for their repeated evolution.
Collapse
Affiliation(s)
- Guoxin Cui
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia.
| | - Jianing Mi
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, the BioActives Lab, Center for Desert Agriculture, Thuwal, 23955- 6900, Saudi Arabia
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Alessandro Moret
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Jessica Menzies
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Huawen Zhong
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Angus Li
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Shiou-Han Hung
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Salim Al-Babili
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, the BioActives Lab, Center for Desert Agriculture, Thuwal, 23955- 6900, Saudi Arabia
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, the Plant Science Program, Thuwal, 23955- 6900, Saudi Arabia
| | - Manuel Aranda
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division, Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Gong S, Liang J, Jin X, Xu L, Zhao M, Yu K. Unfolding the secrets of microbiome (Symbiodiniaceae and bacteria) in cold-water coral. Microbiol Spectr 2023; 11:e0131523. [PMID: 37729536 PMCID: PMC10580923 DOI: 10.1128/spectrum.01315-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 07/09/2023] [Indexed: 09/22/2023] Open
Abstract
Recent deep-ocean exploration has uncovered a variety of cold-water coral (CWC) ecosystems around the world ocean, but it remains unclear how microbiome is associated with these corals at a molecular levels. This study utilized metabarcoding, tissue section observation, and metatranscriptomes to investigate the microbiome (Symbiodiniaceae and bacteria) of CWC species (Narella versluysi, Heterogorgia uatumani, and Muriceides sp.) from depths ranging from 260 m to 370 m. Warm-water coral (WWC) species (Acropora pruinosa, Pocillopora damicornis, and Galaxea fascicularis) were used as control groups. Results revealed that CWC host diverse bacteria and Symbiodiniaceae cells were observed in endoderm of CWC tissues. Several new candidate bacterial phyla were found in both CWC and WWC, including Coralsanbacteria, Coralqiangbacteria, Coralgsqaceae, Coralgongineae, etc. Both the 16S rRNA gene sequencing and metatranscriptomes revealed that Actinobacteria and Proteobacteria were abundant bacterial phyla in CWC. At the gene transcription level, the CWC-associated Symbiodiniaceae community showed a low-level transcription of genes involved in photosynthesis, CO2 fixation, glycolysis, citric acid cycle, while bacteria associated with CWC exhibited a high-level transcription of genes for carbon fixation via the Wood-Lijungdahl pathway, short chain fatty acids production, nitrogen, and sulfur cycles. IMPORTANCE This study shed new light on the functions of both Symbiodiniaceae and bacteria in cold-water coral (CWC). The results demonstrated that Symbiodiniaceae can survive and actively transcribe genes in CWC, suggesting a possible symbiotic or parasitic relationship with the host. This study also revealed complete non-photosynthetic CO2 fixation pathway of bacteria in CWC, as well as their roles in short chain fatty acids production and assimilation of host-derived organic nitrogen and sulfur. These findings highlight the important role of bacteria in the carbon, nitrogen sulfur cycles in CWC, which were possibly crucial for CWC survival in in deep-water environments.
Collapse
Affiliation(s)
- Sanqiang Gong
- 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, China
- Coral Reef Research Center of China, Guangxi University, Nanning, China
| | - Jiayuan Liang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
| | - Xujie Jin
- 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, China
| | - Lijia Xu
- South China Institute of Environmental Sciences, The Ministry of Ecology and Environment of PRC, Guangzhou, China
| | - Meixia Zhao
- 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, China
| | - Kefu Yu
- Coral Reef Research Center of China, Guangxi University, Nanning, China
| |
Collapse
|
19
|
Hambleton EA. How corals get their nutrients. eLife 2023; 12:e90916. [PMID: 37594170 PMCID: PMC10438905 DOI: 10.7554/elife.90916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023] Open
Abstract
Algae living inside corals provide sugars for their host by digesting their own cell walls.
Collapse
Affiliation(s)
- Elizabeth A Hambleton
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of ViennaViennaAustria
| |
Collapse
|
20
|
Ishii Y, Ishii H, Kuroha T, Yokoyama R, Deguchi R, Nishitani K, Minagawa J, Kawata M, Takahashi S, Maruyama S. Environmental pH signals the release of monosaccharides from cell wall in coral symbiotic alga. eLife 2023; 12:e80628. [PMID: 37594171 PMCID: PMC10438907 DOI: 10.7554/elife.80628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/20/2023] [Indexed: 08/19/2023] Open
Abstract
Reef-building corals thrive in oligotrophic environments due to their possession of endosymbiotic algae. Confined to the low pH interior of the symbiosome within the cell, the algal symbiont provides the coral host with photosynthetically fixed carbon. However, it remains unknown how carbon is released from the algal symbiont for uptake by the host. Here we show, using cultured symbiotic dinoflagellate, Breviolum sp., that decreases in pH directly accelerates the release of monosaccharides, that is, glucose and galactose, into the ambient environment. Under low pH conditions, the cell surface structures were deformed and genes related to cellulase were significantly upregulated in Breviolum. Importantly, the release of monosaccharides was suppressed by the cellulase inhibitor, glucopyranoside, linking the release of carbon to degradation of the agal cell wall. Our results suggest that the low pH signals the cellulase-mediated release of monosaccharides from the algal cell wall as an environmental response in coral reef ecosystems.
Collapse
Affiliation(s)
- Yuu Ishii
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
- Department of Biology, Miyagi University of EducationSendaiJapan
| | - Hironori Ishii
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Takeshi Kuroha
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Ryusuke Yokoyama
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Ryusaku Deguchi
- Department of Biology, Miyagi University of EducationSendaiJapan
| | - Kazuhiko Nishitani
- Department of Biological Sciences, Faculty of Science, Kanagawa UniversityYokohamaJapan
| | - Jun Minagawa
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies)OkazakiJapan
- Division of Environmental Photobiology, National Institute for Basic BiologyOkazakiJapan
| | - Masakado Kawata
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Shunichi Takahashi
- Tropical Biosphere Research Center, University of the RyukyusOkinawaJapan
| | - Shinichiro Maruyama
- Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
- Graduate School of Humanities and Sciences, Ochanomizu UniversityTokyoJapan
| |
Collapse
|
21
|
Amario M, Villela LB, Jardim-Messeder D, Silva-Lima AW, Rosado PM, de Moura RL, Sachetto-Martins G, Chaloub RM, Salomon PS. Physiological response of Symbiodiniaceae to thermal stress: Reactive oxygen species, photosynthesis, and relative cell size. PLoS One 2023; 18:e0284717. [PMID: 37535627 PMCID: PMC10399794 DOI: 10.1371/journal.pone.0284717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 04/06/2023] [Indexed: 08/05/2023] Open
Abstract
This study investigates the physiological response to heat stress of three genetically different Symbiodiniaceae strains isolated from the scleractinian coral Mussismilia braziliensis, endemic of the Abrolhos Bank, Brazil. Cultures of two Symbiodinium sp. and one Cladocopium sp. were exposed to a stepwise increase in temperature (2°C every second day) ranging from 26°C (modal temperature in Abrolhos) to 32°C (just above the maximum temperature registered in Abrolhos during the third global bleaching event-TGBE). After the cultures reached their final testing temperature, reactive oxygen species (ROS) production, single cell attributes (relative cell size and chlorophyll fluorescence), and photosynthetic efficiency (effective (Y(II)) and maximum (Fv/Fm) quantum yields) were measured within 4 h and 72 h. Non-photochemical coefficient (NPQ) was estimated based on fluorescence values. Population average ROS production was variable across strains and exposure times, reaching up a 2-fold increase at 32°C in one of the Symbiodinium sp. strains. A marked intrapopulation difference was observed in ROS production, with 5 to 25% of the cells producing up to 10 times more than the population average, highlighting the importance of single cell approaches to assess population physiology. Average cell size increases at higher temperatures, likely resulting from cell cycle arrest, whereas chlorophyll fluorescence decreased, especially in 4 h, indicating a photoacclimation response. The conditions tested do not seem to have elicited loss of photosynthetic efficiency nor the activation of non-photochemical mechanisms in the cells. Our results unveiled a generalized thermotolerance in three Symbiodiniaceae strains originated from Abrolhos' corals. Inter and intra-specific variability could be detected, likely reflecting the genetic differences among the strains.
Collapse
Affiliation(s)
- Michelle Amario
- Laboratório de Fitoplâncton Marinho, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Genética, Rio de Janeiro, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lívia Bonetti Villela
- Laboratório de Fitoplâncton Marinho, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Genética, Rio de Janeiro, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Douglas Jardim-Messeder
- Laboratório de Genômica Funcional e Transdução de Sinal, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratório de Biologia Molecular de Plantas, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Arthur Weiss Silva-Lima
- Laboratório de Fitoplâncton Marinho, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Rodrigo Leão de Moura
- Laboratório de Monitoramento da Biodiversidade, Instituto de Biologia SAGE-COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gilberto Sachetto-Martins
- Laboratório de Genômica Funcional e Transdução de Sinal, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ricardo Moreira Chaloub
- Laboratório de Estudos Aplicados em Fotossíntese, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paulo Sergio Salomon
- Laboratório de Fitoplâncton Marinho, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
22
|
Kaare-Rasmussen JO, Moeller HV, Pfab F. Modeling food dependent symbiosis in Exaiptasia pallida. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2023.110325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
|
23
|
Tong H, Zhang F, Sun J, McIlroy SE, Zhang W, Wang Y, Huang H, Zhou G, Qian PY. Meta-organism gene expression reveals that the impact of nitrate enrichment on coral larvae is mediated by their associated Symbiodiniaceae and prokaryotic assemblages. MICROBIOME 2023; 11:89. [PMID: 37101227 PMCID: PMC10131396 DOI: 10.1186/s40168-023-01495-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 02/16/2023] [Indexed: 05/12/2023]
Abstract
BACKGROUND Coral meta-organisms consist of the coral, and its associated Symbiodiniaceae (dinoflagellate algae), bacteria, and other microbes. Corals can acquire photosynthates from Symbiodiniaceae, whilst Symbiodiniaceae uses metabolites from corals. Prokaryotic microbes provide Symbiodiniaceae with nutrients and support the resilience of corals as meta-organisms. Eutrophication is a major cause of coral reef degradation; however, its effects on the transcriptomic response of coral meta-organisms remain unclear, particularly for prokaryotic microbes associated with corals in the larval stage. To understand acclimation of the coral meta-organism to elevated nitrate conditions, we analyzed the physiological and transcriptomic responses of Pocillopora damicornis larvae, an ecologically important scleractinian coral, after 5 days of exposure to elevated nitrate levels (5, 10, 20, and 40 µM). RESULTS The major differentially expressed transcripts in coral, Symbiodiniaceae, and prokaryotic microbes included those related to development, stress response, and transport. The development of Symbiodiniaceae was not affected in the 5 and 20 µM groups but was downregulated in the 10 and 40 µM groups. In contrast, prokaryotic microbe development was upregulated in the 10 and 40 µM groups and downregulated in the 5 and 20 µM groups. Meanwhile, coral larval development was less downregulated in the 10 and 40 µM groups than in the 5 and 20 µM groups. In addition, multiple larval, Symbiodiniaceae, and prokaryotic transcripts were significantly correlated with each other. The core transcripts in correlation networks were related to development, nutrient metabolism, and transport. A generalized linear mixed model, using least absolute shrinkage and selection operator, demonstrated that the Symbiodiniaceae could both benefit and cost coral larval development. Furthermore, the most significantly correlated prokaryotic transcripts maintained negative correlations with the physiological functions of Symbiodiniaceae. CONCLUSIONS Results suggested that Symbiodiniaceae tended to retain more nutrients under elevated nitrate concentrations, thereby shifting the coral-algal association from mutualism towards parasitism. Prokaryotic microbes provided Symbiodiniaceae with essential nutrients and may control Symbiodiniaceae growth through competition, whereby prokaryotes can also restore coral larval development inhibited by Symbiodiniaceae overgrowth. Video Abstract.
Collapse
Affiliation(s)
- Haoya Tong
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Fang Zhang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Hainan Key Laboratory of Tropical Marine Biotechnology, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, China
| | - Jin Sun
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Shelby E. McIlroy
- The Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Weipeng Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yan Wang
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Hui Huang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Hainan Key Laboratory of Tropical Marine Biotechnology, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, China
| | - Guowei Zhou
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Institute of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Hainan Key Laboratory of Tropical Marine Biotechnology, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, China
| | - Pei-Yuan Qian
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
- CAS-HKUST Sanya Joint Laboratory of Marine Science Research and Hainan Key Laboratory of Tropical Marine Biotechnology, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, China
| |
Collapse
|
24
|
Reich HG, Camp EF, Roger LM, Putnam HM. The trace metal economy of the coral holobiont: supplies, demands and exchanges. Biol Rev Camb Philos Soc 2023; 98:623-642. [PMID: 36897260 DOI: 10.1111/brv.12922] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/23/2022]
Abstract
The juxtaposition of highly productive coral reef ecosystems in oligotrophic waters has spurred substantial interest and progress in our understanding of macronutrient uptake, exchange, and recycling among coral holobiont partners (host coral, dinoflagellate endosymbiont, endolithic algae, fungi, viruses, bacterial communities). By contrast, the contribution of trace metals to the physiological performance of the coral holobiont and, in turn, the functional ecology of reef-building corals remains unclear. The coral holobiont's trace metal economy is a network of supply, demand, and exchanges upheld by cross-kingdom symbiotic partnerships. Each partner has unique trace metal requirements that are central to their biochemical functions and the metabolic stability of the holobiont. Organismal homeostasis and the exchanges among partners determine the ability of the coral holobiont to adjust to fluctuating trace metal supplies in heterogeneous reef environments. This review details the requirements for trace metals in core biological processes and describes how metal exchanges among holobiont partners are key to sustaining complex nutritional symbioses in oligotrophic environments. Specifically, we discuss how trace metals contribute to partner compatibility, ability to cope with stress, and thereby to organismal fitness and distribution. Beyond holobiont trace metal cycling, we outline how the dynamic nature of the availability of environmental trace metal supplies can be influenced by a variability of abiotic factors (e.g. temperature, light, pH, etc.). Climate change will have profound consequences on the availability of trace metals and further intensify the myriad stressors that influence coral survival. Lastly, we suggest future research directions necessary for understanding the impacts of trace metals on the coral holobiont symbioses spanning subcellular to organismal levels, which will inform nutrient cycling in coral ecosystems more broadly. Collectively, this cross-scale elucidation of the role of trace metals for the coral holobiont will allow us to improve forecasts of future coral reef function.
Collapse
Affiliation(s)
- Hannah G Reich
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI, 02881, USA
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Liza M Roger
- Chemical & Life Science Engineering, Virginia Commonwealth University, 601 W. Main Street, Richmond, VA, 23284, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, RI, 02881, USA
| |
Collapse
|
25
|
Cui G, Konciute MK, Ling L, Esau L, Raina JB, Han B, Salazar OR, Presnell JS, Rädecker N, Zhong H, Menzies J, Cleves PA, Liew YJ, Krediet CJ, Sawiccy V, Cziesielski MJ, Guagliardo P, Bougoure J, Pernice M, Hirt H, Voolstra CR, Weis VM, Pringle JR, Aranda M. Molecular insights into the Darwin paradox of coral reefs from the sea anemone Aiptasia. SCIENCE ADVANCES 2023; 9:eadf7108. [PMID: 36921053 PMCID: PMC10017044 DOI: 10.1126/sciadv.adf7108] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Symbiotic cnidarians such as corals and anemones form highly productive and biodiverse coral reef ecosystems in nutrient-poor ocean environments, a phenomenon known as Darwin's paradox. Resolving this paradox requires elucidating the molecular bases of efficient nutrient distribution and recycling in the cnidarian-dinoflagellate symbiosis. Using the sea anemone Aiptasia, we show that during symbiosis, the increased availability of glucose and the presence of the algae jointly induce the coordinated up-regulation and relocalization of glucose and ammonium transporters. These molecular responses are critical to support symbiont functioning and organism-wide nitrogen assimilation through glutamine synthetase/glutamate synthase-mediated amino acid biosynthesis. Our results reveal crucial aspects of the molecular mechanisms underlying nitrogen conservation and recycling in these organisms that allow them to thrive in the nitrogen-poor ocean environments.
Collapse
Affiliation(s)
- Guoxin Cui
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Migle K. Konciute
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Lorraine Ling
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Luke Esau
- Core Labs, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Baoda Han
- DARWIN21, Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Octavio R. Salazar
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jason S. Presnell
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Nils Rädecker
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Huawen Zhong
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jessica Menzies
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Phillip A. Cleves
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Yi Jin Liew
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Cory J. Krediet
- Department of Marine Science, Eckerd College, St. Petersburg, FL 33711, USA
| | - Val Sawiccy
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Maha J. Cziesielski
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Paul Guagliardo
- Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| | - Jeremy Bougoure
- Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia
| | - Mathieu Pernice
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Heribert Hirt
- DARWIN21, Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Christian R. Voolstra
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - John R. Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Manuel Aranda
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
26
|
Mashini AG, Oakley CA, Beepat SS, Peng L, Grossman AR, Weis VM, Davy SK. The Influence of Symbiosis on the Proteome of the Exaiptasia Endosymbiont Breviolum minutum. Microorganisms 2023; 11:292. [PMID: 36838257 PMCID: PMC9967746 DOI: 10.3390/microorganisms11020292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/13/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
The cellular mechanisms responsible for the regulation of nutrient exchange, immune response, and symbiont population growth in the cnidarian-dinoflagellate symbiosis are poorly resolved. Here, we employed liquid chromatography-mass spectrometry to elucidate proteomic changes associated with symbiosis in Breviolum minutum, a native symbiont of the sea anemone Exaiptasia diaphana ('Aiptasia'). We manipulated nutrients available to the algae in culture and to the holobiont in hospite (i.e., in symbiosis) and then monitored the impacts of our treatments on host-endosymbiont interactions. Both the symbiotic and nutritional states had significant impacts on the B. minutum proteome. B. minutum in hospite showed an increased abundance of proteins involved in phosphoinositol metabolism (e.g., glycerophosphoinositol permease 1 and phosphatidylinositol phosphatase) relative to the free-living alga, potentially reflecting inter-partner signalling that promotes the stability of the symbiosis. Proteins potentially involved in concentrating and fixing inorganic carbon (e.g., carbonic anhydrase, V-type ATPase) and in the assimilation of nitrogen (e.g., glutamine synthase) were more abundant in free-living B. minutum than in hospite, possibly due to host-facilitated access to inorganic carbon and nitrogen limitation by the host when in hospite. Photosystem proteins increased in abundance at high nutrient levels irrespective of the symbiotic state, as did proteins involved in antioxidant defences (e.g., superoxide dismutase, glutathione s-transferase). Proteins involved in iron metabolism were also affected by the nutritional state, with an increased iron demand and uptake under low nutrient treatments. These results detail the changes in symbiont physiology in response to the host microenvironment and nutrient availability and indicate potential symbiont-driven mechanisms that regulate the cnidarian-dinoflagellate symbiosis.
Collapse
Affiliation(s)
| | - Clinton A. Oakley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Sandeep S. Beepat
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Lifeng Peng
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Simon K. Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| |
Collapse
|
27
|
Xiang N, Rädecker N, Pogoreutz C, Cárdenas A, Meibom A, Wild C, Gärdes A, Voolstra CR. Presence of algal symbionts affects denitrifying bacterial communities in the sea anemone Aiptasia coral model. ISME COMMUNICATIONS 2022; 2:105. [PMID: 37938763 PMCID: PMC9723753 DOI: 10.1038/s43705-022-00190-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 09/28/2022] [Accepted: 10/10/2022] [Indexed: 11/09/2023]
Abstract
The coral-algal symbiosis is maintained by a constant and limited nitrogen availability in the holobiont. Denitrifiers, i.e., prokaryotes reducing nitrate/nitrite to dinitrogen, could contribute to maintaining the nitrogen limitation in the coral holobiont, however the effect of host and algal identity on their community is still unknown. Using the coral model Aiptasia, we quantified and characterized the denitrifier community in a full-factorial design combining two hosts (CC7 and H2) and two strains of algal symbionts of the family Symbiodiniaceae (SSA01 and SSB01). Strikingly, relative abundance of denitrifiers increased by up to 22-fold in photosymbiotic Aiptasia compared to their aposymbiotic (i.e., algal-depleted) counterparts. In line with this, while the denitrifier community in aposymbiotic Aiptasia was largely dominated by diet-associated Halomonas, we observed an increasing relative abundance of an unclassified bacterium in photosymbiotic CC7, and Ketobacter in photosymbiotic H2, respectively. Pronounced changes in denitrifier communities of Aiptasia with Symbiodinium linucheae strain SSA01 aligned with the higher photosynthetic carbon availability of these holobionts compared to Aiptasia with Breviolum minutum strain SSB01. Our results reveal that the presence of algal symbionts increases abundance and alters community structure of denitrifiers in Aiptasia. Thereby, patterns in denitrifier community likely reflect the nutritional status of aposymbiotic vs. symbiotic holobionts. Such a passive regulation of denitrifiers may contribute to maintaining the nitrogen limitation required for the functioning of the cnidarian-algal symbiosis.
Collapse
Affiliation(s)
- Nan Xiang
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, 28359, Bremen, Germany.
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570, Bremerhaven, Germany.
| | - Nils Rädecker
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Claudia Pogoreutz
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Anders Meibom
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- Center for Advanced Surface Analysis (CASA), Institute of Earth Science, University of Lausanne, 1015, Lausanne, Switzerland
| | - Christian Wild
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, 28359, Bremen, Germany
| | - Astrid Gärdes
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570, Bremerhaven, Germany
- Hochschule Bremerhaven, Fachbereich 1, An der Karlstadt 8, 27568, Bremerhaven, Germany
| | | |
Collapse
|
28
|
Luo H, Wang J, Goes JI, Gomes HDR, Al-Hashmi K, Tobias C, Koerting C, Lin S. A grazing-driven positive nutrient feedback loop and active sexual reproduction underpin widespread Noctiluca green tides. ISME COMMUNICATIONS 2022; 2:103. [PMID: 37938758 PMCID: PMC9723592 DOI: 10.1038/s43705-022-00187-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/29/2022] [Accepted: 10/06/2022] [Indexed: 11/09/2023]
Abstract
The mixoplankton green Noctiluca scintillans (gNoctiluca) is known to form extensive green tides in tropical coastal ecosystems prone to eutrophication. In the Arabian Sea, their recent appearance and annual recurrence have upended an ecosystem that was once exclusively dominated by diatoms. Despite evidence of strong links to eutrophication, hypoxia and warming, the mechanisms underlying outbreaks of this mixoplanktonic dinoflagellate remain uncertain. Here we have used eco-physiological measurements and transcriptomic profiling to ascribe gNoctiluca's explosive growth during bloom formation to the form of sexual reproduction that produces numerous gametes. Rapid growth of gNoctiluca coincided with active ammonium and phosphate release from gNoctiluca cells, which exhibited high transcriptional activity of phagocytosis and metabolism generating ammonium. This grazing-driven nutrient flow ostensibly promotes the growth of phytoplankton as prey and offers positive support successively for bloom formation and maintenance. We also provide the first evidence that the host gNoctiluca cell could be manipulating growth of its endosymbiont population in order to exploit their photosynthetic products and meet critical energy needs. These findings illuminate gNoctiluca's little known nutritional and reproductive strategies that facilitate its ability to form intense and expansive gNoctiluca blooms to the detriment of regional water, food and the socio-economic security in several tropical countries.
Collapse
Affiliation(s)
- Hao Luo
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China
| | - Jingtian Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China
| | - Joaquim I Goes
- Lamont-Doherty Earth Observatory at Columbia University, Palisades, NY, 10964, USA.
| | - Helga do R Gomes
- Lamont-Doherty Earth Observatory at Columbia University, Palisades, NY, 10964, USA
| | - Khalid Al-Hashmi
- Department of Marine Sciences and Fisheries, Sultan Qaboos University, Muscat, Oman
| | - Craig Tobias
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Claudia Koerting
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China.
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA.
| |
Collapse
|
29
|
Brown AL, Pfab F, Baxter EC, Detmer AR, Moeller HV, Nisbet RM, Cunning R. Analysis of a mechanistic model of corals in association with multiple symbionts: within-host competition and recovery from bleaching. CONSERVATION PHYSIOLOGY 2022; 10:coac066. [PMID: 36247693 PMCID: PMC9558299 DOI: 10.1093/conphys/coac066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 07/25/2022] [Accepted: 09/09/2022] [Indexed: 06/14/2023]
Abstract
Coral reefs are increasingly experiencing stressful conditions, such as high temperatures, that cause corals to undergo bleaching, a process where they lose their photosynthetic algal symbionts. Bleaching threatens both corals' survival and the health of the reef ecosystems they create. One possible mechanism for corals to resist bleaching is through association with stress-tolerant symbionts, which are resistant to bleaching but may be worse partners in mild conditions. Some corals have been found to associate with multiple symbiont species simultaneously, which potentially gives them access to the benefits of both stress-sensitive and -tolerant symbionts. However, within-host competition between symbionts may lead to competitive exclusion of one partner, and the consequences of associating with multiple partners simultaneously are not well understood. We modify a mechanistic model of coral-algal symbiosis to investigate the effect of environmental conditions on within-host competitive dynamics between stress-sensitive and -tolerant symbionts and the effect of access to a tolerant symbiont on the dynamics of recovery from bleaching. We found that the addition of a tolerant symbiont can increase host survival and recovery from bleaching in high-light conditions. Competitive exclusion of the tolerant symbiont occurred slowly at intermediate light levels. Interestingly, there were some cases of post-bleaching competitive exclusion after the tolerant symbiont had helped the host recover.
Collapse
Affiliation(s)
- Alexandra Lynne Brown
- Corresponding author: Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. E-mail:
| | - Ferdinand Pfab
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ethan C Baxter
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - A Raine Detmer
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA
| |
Collapse
|
30
|
Abstract
Coral reefs depend on the highly optimized mutualistic relationship between corals and Symbiodiniaceae dinoflagellates. Both partners exchange nutrients obtained through heterotrophy of the host and autotrophy of the symbionts. While heterotrophy helps corals withstand the harmful effects of seawater warming, the exchange of heterotrophic nutrients between the two partners is poorly understood. Here, we used compound-specific δ15N and δ13C of amino acids (δ15NAA and δ13CAA) and a 15N pulse-chase experiment with Artemia salina nauplii in two coral-dinoflagellate associations to trace the assimilation and allocation of heterotrophic nutrients within the partners. We observed that changes in the trophic position (TPGlx-Phe), δ15NAA, and δ13CAA with heterotrophy were holobiont-dependent. Furthermore, while TPGlx-Phe and δ15N of all AAs significantly increased with heterotrophy in the symbionts and host of Stylophora pistillata, only the δ15NAA of the symbionts changed in Turbinaria reniformis. Together with the pulse-chase experiment, the results suggested a direct transfer of heterotrophically acquired AAs to the symbionts of S. pistillata and a transfer of ammonium to the symbionts of T. reniformis. Overall, we demonstrated that heterotrophy underpinned the nutrition of Symbiodinaceae and possibly influenced their stress tolerance under changing environmental conditions.
Collapse
|
31
|
Maruyama S, Unsworth JR, Sawiccy V, Weis VM. Algae from Aiptasia egesta are robust representations of Symbiodiniaceae in the free-living state. PeerJ 2022; 10:e13796. [PMID: 35923894 PMCID: PMC9341449 DOI: 10.7717/peerj.13796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/06/2022] [Indexed: 01/18/2023] Open
Abstract
Many cnidarians rely on their dinoflagellate partners from the family Symbiodiniaceae for their ecological success. Symbiotic species of Symbiodiniaceae have two distinct life stages: inside the host, in hospite, and outside the host, ex hospite. Several aspects of cnidarian-algal symbiosis can be understood by comparing these two life stages. Most commonly, algae in culture are used in comparative studies to represent the ex hospite life stage, however, nutrition becomes a confounding variable for this comparison because algal culture media is nutrient rich, while algae in hospite are sampled from hosts maintained in oligotrophic seawater. In contrast to cultured algae, expelled algae may be a more robust representation of the ex hospite state, as the host and expelled algae are in the same seawater environment, removing differences in culture media as a confounding variable. Here, we studied the physiology of algae released from the sea anemone Exaiptasia diaphana (commonly called Aiptasia), a model system for the study of coral-algal symbiosis. In Aiptasia, algae are released in distinct pellets, referred to as egesta, and we explored its potential as an experimental system to represent Symbiodiniaceae in the ex hospite state. Observation under confocal and differential interference contrast microscopy revealed that egesta contained discharged nematocysts, host tissue, and were populated by a diversity of microbes, including protists and cyanobacteria. Further experiments revealed that egesta were released at night. In addition, algae in egesta had a higher mitotic index than algae in hospite, were photosynthetically viable for at least 48 hrs after expulsion, and could competently establish symbiosis with aposymbiotic Aiptasia. We then studied the gene expression of nutrient-related genes and studied their expression using qPCR. From the genes tested, we found that algae from egesta closely mirrored gene expression profiles of algae in hospite and were dissimilar to those of cultured algae, suggesting that algae from egesta are in a nutritional environment that is similar to their in hospite counterparts. Altogether, evidence is provided that algae from Aiptasia egesta are a robust representation of Symbiodiniaceae in the ex hospite state and their use in experiments can improve our understanding of cnidarian-algal symbiosis.
Collapse
Affiliation(s)
- Shumpei Maruyama
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
| | - Julia R. Unsworth
- Department of Biology, Lewis and Clark College, Portland, OR, United States of America
| | - Valeri Sawiccy
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
| | | | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
| |
Collapse
|
32
|
Immunolocalization of Metabolite Transporter Proteins in a Model Cnidarian-Dinoflagellate Symbiosis. Appl Environ Microbiol 2022; 88:e0041222. [PMID: 35678605 DOI: 10.1128/aem.00412-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bidirectional nutrient flow between partners is integral to the cnidarian-dinoflagellate endosymbiosis. However, our current knowledge of the transporter proteins that regulate nutrient and metabolite trafficking is nascent. Four transmembrane transporters that likely play an important role in interpartner nitrogen and carbon exchange were investigated with immunocytochemistry in the model sea anemone Exaiptasia diaphana ("Aiptasia"; strain NZ1): ammonium transporter 1 (AMT1), V-type proton ATPase (VHA), facilitated glucose transporter member 8 (GLUT8), and aquaporin-3 (AQP3). Anemones lacking symbionts were compared with those in symbiosis with either their typical, homologous dinoflagellate symbiont, Breviolum minutum, or the heterologous species, Durusdinium trenchii and Symbiodinium microadriaticum. AMT1 and VHA were only detected in symbiotic Aiptasia, irrespective of symbiont type. However, GLUT8 and AQP3 were detected in both symbiotic and aposymbiotic states. All transporters were localized to both the epidermis and gastrodermis, though localization patterns in host tissues were heavily influenced by symbiont identity, with S. microadriaticum-colonized anemones showing the most distinct patterns. These patterns suggested disruption of fixed carbon and inorganic nitrogen fluxes when in symbiosis with heterologous versus homologous symbionts. This study enhances our understanding of nutrient transport and host-symbiont integration, while providing a platform for further investigation of nutrient transporters and the host-symbiont interface in the cnidarian-dinoflagellate symbiosis. IMPORTANCE Coral reefs are in serious decline, in particular due to the thermally induced dysfunction of the cnidarian-dinoflagellate symbiosis that underlies their success. Yet our ability to react to this crisis is hindered by limited knowledge of how this symbiosis functions. Indeed, we still have much to learn about the cellular integration that determines whether a particular host-symbiont combination can persist, and hence whether corals might be able to adapt by acquiring new, more thermally resistant symbionts. Here, we employed immunocytochemistry to localize and quantify key nutrient transporters in tissues of the sea anemone Aiptasia, a globally adopted model system for this symbiosis, and compared the expression of these transporters when the host is colonized by native versus nonnative symbionts. We showed a clear link between transporter expression and symbiont identity, elucidating the cellular events that dictate symbiosis success, and we provide a methodological platform for further examination of cellular integration in this ecologically important symbiosis.
Collapse
|
33
|
Nair VV, Arunprasath D, Solai P, Sekar G. Synergistic Dual Amine/Transition Metal Catalysis ‐ Recent Advances. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Pandidurai Solai
- IIT Madras: Indian Institute of Technology Madras Department of Chemistry INDIA
| | - Govindasamy Sekar
- Indian Institute of Technology Madras Department of Chemistry IIT Campus 600 036 Chennai INDIA
| |
Collapse
|
34
|
Cui G, Liew YJ, Konciute MK, Zhan Y, Hung SH, Thistle J, Gastoldi L, Schmidt-Roach S, Dekker J, Aranda M. Nutritional control regulates symbiont proliferation and life history in coral-dinoflagellate symbiosis. BMC Biol 2022; 20:103. [PMID: 35549698 PMCID: PMC9102920 DOI: 10.1186/s12915-022-01306-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 04/22/2022] [Indexed: 12/18/2022] Open
Abstract
Background The coral-Symbiodiniaceae symbiosis is fundamental for the coral reef ecosystem. Corals provide various inorganic nutrients to their algal symbionts in exchange for the photosynthates to meet their metabolic demands. When becoming symbionts, Symbiodiniaceae cells show a reduced proliferation rate and a different life history. While it is generally believed that the animal hosts play critical roles in regulating these processes, far less is known about the molecular underpinnings that allow the corals to induce the changes in their symbionts. Results We tested symbiont cell proliferation and life stage changes in vitro in response to different nutrient-limiting conditions to determine the key nutrients and to compare the respective symbiont transcriptomic profiles to cells in hospite. We then examined the effects of nutrient repletion on symbiont proliferation in coral hosts and quantified life stage transitions in vitro using time-lapse confocal imaging. Here, we show that symbionts in hospite share gene expression and pathway activation profiles with free-living cells under nitrogen-limited conditions, strongly suggesting that symbiont proliferation in symbiosis is limited by nitrogen availability. Conclusions We demonstrate that nitrogen limitation not only suppresses cell proliferation but also life stage transition to maintain symbionts in the immobile coccoid stage. Nutrient repletion experiments in corals further confirmed that nitrogen availability is the major factor limiting symbiont density in hospite. Our study emphasizes the importance of nitrogen in coral-algae interactions and, more importantly, sheds light on the crucial role of nitrogen in symbiont life history regulation. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01306-2.
Collapse
Affiliation(s)
- Guoxin Cui
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
| | - Yi Jin Liew
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Migle K Konciute
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Ye Zhan
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Shiou-Han Hung
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Jana Thistle
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Lucia Gastoldi
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Sebastian Schmidt-Roach
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Manuel Aranda
- Biological and Environmental Sciences and Engineering Division (BESE), Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
| |
Collapse
|
35
|
Iyagbaye L, Reichelt-Brushett A, Benkendorff K. Manganese uptake and partitioning between the tissue of the anemone host Exaiptasia pallida and Symbiodinium spp., including assessment of stress and recovery. CHEMOSPHERE 2022; 295:133895. [PMID: 35143868 DOI: 10.1016/j.chemosphere.2022.133895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Manganese (Mn) is essential for global steel and Mn-iron (Fe) alloy production. The human health effects of elevated Mn concentrations have been well established, but studies on its impact on marine invertebrates are limited. This study is the first to investigate Mn uptake in the sea anemone Exaiptasia pallida after chronic exposure (0.5, 1, 10, and 100 mg/L) for 24-d. Following exposure, E. pallida were transferred to ambient seawater for 6-d to assess Mn depuration. Mn accumulation and partitioning in host tissue and symbionts (Symbiodinium spp.), tentacle retraction, and symbiont cell density were measured during exposure and depuration. Mn concentrations were substantially higher in symbionts than tissue in all treatments after 24-d. No significant difference was observed for symbiont cell density after Mn exposure. Tentacle retractions were significantly higher in all Mn exposed treatments than controls at all time points. Mn depuration was observed for both tissue and symbionts but was more rapid in symbionts. This study reveals that Symbiodinium spp. can play a role in Mn uptake and depuration in anemones, but Mn loading does not affect cell density. These results help understand metal uptake and depuration in complex relationships between Symbiodinium spp. and other host taxa like corals.
Collapse
Affiliation(s)
- Louis Iyagbaye
- Faculty of Science and Engineering, Southern Cross University, NSW, Australia
| | | | - Kirsten Benkendorff
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, NSW, Australia
| |
Collapse
|
36
|
Jinkerson RE, Russo JA, Newkirk CR, Kirk AL, Chi RJ, Martindale MQ, Grossman AR, Hatta M, Xiang T. Cnidarian-Symbiodiniaceae symbiosis establishment is independent of photosynthesis. Curr Biol 2022; 32:2402-2415.e4. [DOI: 10.1016/j.cub.2022.04.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/18/2022] [Accepted: 04/08/2022] [Indexed: 11/29/2022]
|
37
|
Suescún-Bolívar LP, Thomé PE. The specific inhibition of glycerol synthesis and the phosphorylation of a putative MAPK give insight into the mechanism of osmotic sensing in a dinoflagellate symbiont. J Eukaryot Microbiol 2021; 69:e12883. [PMID: 34936156 DOI: 10.1111/jeu.12883] [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: 09/22/2021] [Revised: 12/03/2021] [Accepted: 12/14/2021] [Indexed: 11/30/2022]
Abstract
Signaling pathways are fundamental for the establishment and maintenance of diverse symbioses. The symbiosis of cnidarians and dinoflagellate algae is the foundation for the ecological success of coral reefs, involving the transfer of photosynthetic products from symbiont to host. However, signal transduction pathways for this symbiosis remain uncharacterized. Cultured and natural cnidarian symbionts can produce glycerol, one of the main translocated photosynthates. Here, we investigate whether a signal transduction pathway may be involved in inducing glycerol synthesis in cultured symbionts under an osmotic stress model. We evaluated the effect of specific inhibitors of the main transduction pathways, p38, JNK, and ERK 1/2 in Brevolium minutum, the symbiont of the Aiptasia model system. We found that glycerol production and the specific activity of the enzyme Gpdh were selectively inhibited by a p38 MAPK inhibitor. Additionally, the phosphorylation of a putative p38-like protein was rapidly detected. Finally, we studied the presence of each of the components of the p38 MAPK pathway in silico, in genomes and transcriptomes reported up to date for different symbiont types. We propose a model for the arrangement of this pathway in the family of dinoflagellate symbionts known as Symbiodiniaceae.
Collapse
Affiliation(s)
- L P Suescún-Bolívar
- Universidad Nacional Autónoma de México Instituto de Ciencias del Mar y Limnología Unidad Académica de Sistemas Arrecifales Puerto Morelos, Puerto Morelos, Mexico
| | - P E Thomé
- Universidad Nacional Autónoma de México Instituto de Ciencias del Mar y Limnología Unidad Académica de Sistemas Arrecifales Puerto Morelos, Puerto Morelos, Mexico
| |
Collapse
|
38
|
Drew GC, King KC. More or Less? The Effect of Symbiont Density in Protective Mutualisms. Am Nat 2021; 199:443-454. [DOI: 10.1086/718593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
39
|
de Oliveira AL, Mitchell J, Girguis P, Bright M. Novel insights on obligate symbiont lifestyle and adaptation to chemosynthetic environment as revealed by the giant tubeworm genome. Mol Biol Evol 2021; 39:6454105. [PMID: 34893862 PMCID: PMC8789280 DOI: 10.1093/molbev/msab347] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The mutualism between the giant tubeworm Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone has been extensively researched over the past 40 years. However, the lack of the host whole genome information has impeded the full comprehension of the genotype/phenotype interface in Riftia. Here we described the high-quality draft genome of Riftia, its complete mitogenome, and tissue-specific transcriptomic data. The Riftia genome presents signs of reductive evolution, with gene family contractions exceeding expansions. Expanded gene families are related to sulphur metabolism, detoxification, anti-oxidative stress, oxygen transport, immune system, and lysosomal digestion, reflecting evolutionary adaptations to the vent environment and endosymbiosis. Despite the derived body plan, the developmental gene repertoire in the gutless tubeworm is extremely conserved with the presence of a near intact and complete Hox cluster. Gene expression analyses establishes that the trophosome is a multi-functional organ marked by intracellular digestion of endosymbionts, storage of excretory products and haematopoietic functions. Overall, the plume and gonad tissues both in contact to the environment harbour highly expressed genes involved with cell cycle, programmed cell death, and immunity indicating a high cell turnover and defence mechanisms against pathogens. We posit that the innate immune system plays a more prominent role into the establishment of the symbiosis during the infection in the larval stage, rather than maintaining the symbiostasis in the trophosome. This genome bridges four decades of physiological research in Riftia, whilst simultaneously provides new insights into the development, whole organism functions and evolution in the giant tubeworm.
Collapse
Affiliation(s)
| | - Jessica Mitchell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Peter Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Monika Bright
- Department of Functional and Evolutionary Ecology, University of Vienna, Austria
| |
Collapse
|
40
|
Liu Y, Liao X, Han T, Su A, Guo Z, Lu N, He C, Lu Z. Full-Length Transcriptome Sequencing of the Scleractinian Coral Montipora foliosa Reveals the Gene Expression Profile of Coral-Zooxanthellae Holobiont. BIOLOGY 2021; 10:biology10121274. [PMID: 34943189 PMCID: PMC8698432 DOI: 10.3390/biology10121274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Coral-zooxanthellae holobionts are one of the most productive ecosystems in the ocean. With global warming and ocean acidification, coral ecosystems are facing unprecedented challenges. To save the coral ecosystems, we need to understand the symbiosis of coral-zooxanthellae. Although some Scleractinia (stony corals) transcriptomes have been sequenced, the reliable full-length transcriptome is still lacking due to the short-read length of second-generation sequencing and the uncertainty of the assembly results. Herein, PacBio Sequel II sequencing technology polished with the Illumina RNA-seq platform was used to obtain relatively complete scleractinian coral M. foliosa transcriptome data and to quantify M. foliosa gene expression. A total of 38,365 consensus sequences and 20,751 unique genes were identified. Seven databases were used for the gene function annotation, and 19,972 genes were annotated in at least one database. We found 131 zooxanthellae transcripts and 18,829 M. foliosa transcripts. A total of 6328 lncRNAs, 847 M. foliosa transcription factors (TFs), and 2 zooxanthellae TF were identified. In zooxanthellae we found pathways related to symbiosis, such as photosynthesis and nitrogen metabolism. Pathways related to symbiosis in M. foliosa include oxidative phosphorylation and nitrogen metabolism, etc. We summarized the isoforms and expression level of the symbiont recognition genes. Among the membrane proteins, we found three pathways of glycan biosynthesis, which may be involved in the organic matter storage and monosaccharide stabilization in M. foliosa. Our results provide better material for studying coral symbiosis.
Collapse
Affiliation(s)
- Yunqing Liu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Xin Liao
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Beihai 536000, China;
| | - Tingyu Han
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Ao Su
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Zhuojun Guo
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Na Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Chunpeng He
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, China; (Y.L.); (T.H.); (A.S.); (Z.G.); (N.L.)
| |
Collapse
|
41
|
Rivera HE, Davies SW. Symbiosis maintenance in the facultative coral, Oculina arbuscula, relies on nitrogen cycling, cell cycle modulation, and immunity. Sci Rep 2021; 11:21226. [PMID: 34707162 PMCID: PMC8551165 DOI: 10.1038/s41598-021-00697-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/11/2021] [Indexed: 12/24/2022] Open
Abstract
Symbiosis with unicellular algae in the family Symbiodiniaceae is common across tropical marine invertebrates. Reef-building corals offer a clear example of cellular dysfunction leading to a dysbiosis that disrupts entire ecosystems in a process termed coral bleaching. Due to their obligate symbiotic relationship, understanding the molecular underpinnings that sustain this symbiosis in tropical reef-building corals is challenging, as any aposymbiotic state is inherently coupled with severe physiological stress. Here, we leverage the subtropical, facultatively symbiotic and calcifying coral Oculina arbuscula to investigate gene expression differences between aposymbiotic and symbiotic branches within the same colonies under baseline conditions. We further compare gene ontology (GO) and KOG enrichment in gene expression patterns from O. arbuscula with prior work in the sea anemone Exaiptasia pallida (Aiptasia) and the salamander Ambystoma maculatum-both of which exhibit endophotosymbiosis with unicellular algae. We identify nitrogen cycling, cell cycle control, and immune responses as key pathways involved in the maintenance of symbiosis under baseline conditions. Understanding the mechanisms that sustain a healthy symbiosis between corals and Symbiodiniaceae algae is of urgent importance given the vulnerability of these partnerships to changing environmental conditions and their role in the continued functioning of critical and highly diverse marine ecosystems.
Collapse
Affiliation(s)
- H E Rivera
- Department of Biology, Boston University, Boston, MA, USA.
| | - S W Davies
- Department of Biology, Boston University, Boston, MA, USA.
| |
Collapse
|
42
|
Jiang L, Sullivan H, Seligman C, Gilchrist S, Wang B. An NMR-based metabolomics study on sea anemones Exaiptasia diaphana ( Rapp, 1829) with atrazine exposure. Mol Omics 2021; 17:1012-1020. [PMID: 34633404 DOI: 10.1039/d1mo00223f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sea anemones have been recommended as critical bioindicators for marine environmental stressors; however, the understanding of the biological effects in response to sublethal pollutant exposure is still limited. In this study, NMR-based metabolomics was performed to investigate the effects of atrazine on Exaiptasia diaphana with concentrations ranging from 3 to 90 ppb. As a result, the metabolic profiling of E. diaphana was significantly affected after 70 ppb treatment while a partial perturbation was observed as early as 3 ppb treatment. Glutamate was significantly changed at low atrazine concentrations with increased upregulation in concentrated atrazine experiments which is a potential biomarker for E. diaphana exposed to atrazine stressors. The TCA intermediates succinate and malate as well as the TCA cycle-related metabolites such as alanine, glycine, and taurine downregulated after atrazine treatment which also indicated the lower energy supply of E. diaphana. In summary, our study demonstrated that significant metabolic level perturbation could be detected at low atrazine concentrations before a physical change could be observed, and glutamate or the nitrogen metabolism may be the initial target for sea anemones by atrazine. The study may provide pioneering results for using E. diaphana to predict the impacts of exposure to atrazine toxin in marine systems.
Collapse
Affiliation(s)
- Lin Jiang
- Division of Natural Sciences, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, USA.
| | - Hunter Sullivan
- Division of Natural Sciences, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, USA.
| | - Cole Seligman
- Division of Natural Sciences, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, USA.
| | - Sandra Gilchrist
- Division of Natural Sciences, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, USA.
| | - Bo Wang
- Department of Chemistry, North Carolina A&T State University, Greensboro, NC, USA.
| |
Collapse
|
43
|
Cytoklepty in the plankton: A host strategy to optimize the bioenergetic machinery of endosymbiotic algae. Proc Natl Acad Sci U S A 2021; 118:2025252118. [PMID: 34215695 DOI: 10.1073/pnas.2025252118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Endosymbioses have shaped the evolutionary trajectory of life and remain ecologically important. Investigating oceanic photosymbioses can illuminate how algal endosymbionts are energetically exploited by their heterotrophic hosts and inform on putative initial steps of plastid acquisition in eukaryotes. By combining three-dimensional subcellular imaging with photophysiology, carbon flux imaging, and transcriptomics, we show that cell division of endosymbionts (Phaeocystis) is blocked within hosts (Acantharia) and that their cellular architecture and bioenergetic machinery are radically altered. Transcriptional evidence indicates that a nutrient-independent mechanism prevents symbiont cell division and decouples nuclear and plastid division. As endosymbiont plastids proliferate, the volume of the photosynthetic machinery volume increases 100-fold in correlation with the expansion of a reticular mitochondrial network in close proximity to plastids. Photosynthetic efficiency tends to increase with cell size, and photon propagation modeling indicates that the networked mitochondrial architecture enhances light capture. This is accompanied by 150-fold higher carbon uptake and up-regulation of genes involved in photosynthesis and carbon fixation, which, in conjunction with a ca.15-fold size increase of pyrenoids demonstrates enhanced primary production in symbiosis. Mass spectrometry imaging revealed major carbon allocation to plastids and transfer to the host cell. As in most photosymbioses, microalgae are contained within a host phagosome (symbiosome), but here, the phagosome invaginates into enlarged microalgal cells, perhaps to optimize metabolic exchange. This observation adds evidence that the algal metamorphosis is irreversible. Hosts, therefore, trigger and benefit from major bioenergetic remodeling of symbiotic microalgae with potential consequences for the oceanic carbon cycle. Unlike other photosymbioses, this interaction represents a so-called cytoklepty, which is a putative initial step toward plastid acquisition.
Collapse
|
44
|
Abstract
Ocean warming is causing repeated mass coral bleaching, leading to catastrophic losses of coral reefs worldwide. Our ability to slow or revert this decline is hampered by an incomplete understanding of the processes underlying the breakdown of the coral–algal symbiosis. Here, we show that heat stress destabilizes the nutrient cycling between corals and their endosymbiotic algae long before bleaching becomes apparent. Notably, increased metabolic energy demands shift the coral–algal symbiosis from a nitrogen- to a carbon-limited state, reducing translocation and recycling of photosynthetic carbon. This effectively undermines the ecological advantage of harboring algal symbionts and directly contributes to the breakdown of the coral–algal symbiosis during heat stress. Recurrent mass bleaching events are pushing coral reefs worldwide to the brink of ecological collapse. While the symptoms and consequences of this breakdown of the coral–algal symbiosis have been extensively characterized, our understanding of the underlying causes remains incomplete. Here, we investigated the nutrient fluxes and the physiological as well as molecular responses of the widespread coral Stylophora pistillata to heat stress prior to the onset of bleaching to identify processes involved in the breakdown of the coral–algal symbiosis. We show that altered nutrient cycling during heat stress is a primary driver of the functional breakdown of the symbiosis. Heat stress increased the metabolic energy demand of the coral host, which was compensated by the catabolic degradation of amino acids. The resulting shift from net uptake to release of ammonium by the coral holobiont subsequently promoted the growth of algal symbionts and retention of photosynthates. Together, these processes form a feedback loop that will gradually lead to the decoupling of carbon translocation from the symbiont to the host. Energy limitation and altered symbiotic nutrient cycling are thus key factors in the early heat stress response, directly contributing to the breakdown of the coral–algal symbiosis. Interpreting the stability of the coral holobiont in light of its metabolic interactions provides a missing link in our understanding of the environmental drivers of bleaching and may ultimately help uncover fundamental processes underpinning the functioning of endosymbioses in general.
Collapse
|
45
|
Tilstra A, Roth F, El-Khaled YC, Pogoreutz C, Rädecker N, Voolstra CR, Wild C. Relative abundance of nitrogen cycling microbes in coral holobionts reflects environmental nitrate availability. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201835. [PMID: 34109033 PMCID: PMC8170195 DOI: 10.1098/rsos.201835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
Recent research suggests that nitrogen (N) cycling microbes are important for coral holobiont functioning. In particular, coral holobionts may acquire bioavailable N via prokaryotic dinitrogen (N2) fixation or remove excess N via denitrification activity. However, our understanding of environmental drivers on these processes in hospite remains limited. Employing the strong seasonality of the central Red Sea, this study assessed the effects of environmental parameters on the proportional abundances of N cycling microbes associated with the hard corals Acropora hemprichii and Stylophora pistillata. Specifically, we quantified changes in the relative ratio between nirS and nifH gene copy numbers, as a proxy for seasonal shifts in denitrification and N2 fixation potential in corals, respectively. In addition, we assessed coral tissue-associated Symbiodiniaceae cell densities and monitored environmental parameters to provide a holobiont and environmental context, respectively. While ratios of nirS to nifH gene copy numbers varied between seasons, they revealed similar seasonal patterns in both coral species, with ratios closely following patterns in environmental nitrate availability. Symbiodiniaceae cell densities aligned with environmental nitrate availability, suggesting that the seasonal shifts in nirS to nifH gene abundance ratios were probably driven by nitrate availability in the coral holobiont. Thereby, our results suggest that N cycling in coral holobionts probably adjusts to environmental conditions by increasing and/or decreasing denitrification and N2 fixation potential according to environmental nitrate availability. Microbial N cycling may, thus, extenuate the effects of changes in environmental nitrate availability on coral holobionts to support the maintenance of the coral-Symbiodiniaceae symbiosis.
Collapse
Affiliation(s)
- Arjen Tilstra
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Florian Roth
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Baltic Sea Centre, Stockholm University, Stockholm, Sweden
- Tvärminne Zoological Station, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Yusuf C. El-Khaled
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Claudia Pogoreutz
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Nils Rädecker
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz, Germany
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christian R. Voolstra
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Christian Wild
- Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany
| |
Collapse
|
46
|
Teh LSX, Poo JST, Boo MV, Chew SF, Ip YK. Using glutamine synthetase 1 to evaluate the symbionts' potential of ammonia assimilation and their responses to illumination in five organs of the giant clam, Tridacna squamosa. Comp Biochem Physiol A Mol Integr Physiol 2021; 255:110914. [PMID: 33540079 DOI: 10.1016/j.cbpa.2021.110914] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 11/16/2022]
Abstract
Nitrogen-deficient symbiotic dinoflagellates (zooxanthellae) living inside the fluted giant clam, Tridacna squamosa, need to obtain nitrogen from the host. Glutamine synthetase 1 (GS1) is a cytosolic enzyme that assimilates ammonia into glutamine. We determined the transcript levels of zooxanthellal GS1 (Zoox-GS1), which represented comprehensively GS1 transcripts of Symbiodinium, Cladocopium and Durusdinium, in five organs of T. squamosa. The outer mantle had significantly higher transcript level of Zoox-GS1 than the inner mantle, foot muscle, hepatopancreas and ctenidium, but the transcript ratios of Zoox-GS1 to zooxanthellal form II ribulose-1,5-bisphosphate carboxylase/oxygenase (Zoox-rbcII), which represented the potential of ammonia assimilation relative to the phototrophic potential, were comparable among these five organs. Based on transcript ratios of Zoox-GS1 to zooxanthellal Urease (Zoox-URE), the outer mantle had the highest potential of urea degradation relative to ammonia assimilation among the five organs, probably because urea degradation could furnish CO2 and NH3 for photosynthesis and amino acid synthesis, respectively, in the symbionts therein. The protein abundance of Zoox-GS1 was upregulated in the outer mantle and the inner mantle during illumination. Zoox-GS1 could catalyze light-enhanced glutamine formation using ammonia absorbed from the host or ammonia released through urea degradation in the cytoplasm. The glutamine produced could be used to synthesize other nitrogenous compounds, including amino acids in the cytoplasm or in the plastid of the dinoflagellates. Some of the amino acids synthesized by the symbionts in the inner mantle and foot muscle could be donated to the host to support shell organic matrix formation and muscle production, respectively.
Collapse
Affiliation(s)
- Leanne S X Teh
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore
| | - Jeslyn S T Poo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore
| | - Mel V Boo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore
| | - Shit F Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Republic of Singapore
| | - Yuen K Ip
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore.
| |
Collapse
|
47
|
Maruyama S, Weis VM. Limitations of Using Cultured Algae to Study Cnidarian-Algal Symbioses and Suggestions for Future Studies. JOURNAL OF PHYCOLOGY 2021; 57:30-38. [PMID: 33191496 DOI: 10.1111/jpy.13102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Much of our understanding of the cellular mechanisms underlying cnidarian-algal symbiosis comes from studying the biological differences between the partners when they are engaged in symbiosis and when they are isolated from one another. When comparing the in hospite and ex hospite states in Symbiodiniaceae, the in hospite state is represented by algae sampled from hosts, and the ex hospite state is commonly represented by cultured algae. The use of cultured algae in this comparison may introduce nutrition as a confounding variable because, while hosts are kept in nutrient-depleted conditions, culture media is nutrient rich and designed to facilitate algal growth. In this perspective, we reexamine how nutrition may be a confounding variable in studies that compare the biology of Symbiodiniaceae in hospite and in culture. We also suggest several innovations in experimental design to strengthen the comparison of the two lifestyles, including the adoption of nutritional controls, alternatives to culture for the representation of Symbiodiniaceae ex hospite, and the adoption of several proteomic approaches to find novel Symbiodiniaceae genes important for symbiosis.
Collapse
Affiliation(s)
- Shumpei Maruyama
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, Oregon, 97331, USA
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, Oregon, 97331, USA
| |
Collapse
|
48
|
Clowez S, Renicke C, Pringle JR, Grossman AR. Impact of Menthol on Growth and Photosynthetic Function of Breviolum Minutum (Dinoflagellata, Dinophyceae, Symbiodiniaceae) and Interactions with its Aiptasia Host. JOURNAL OF PHYCOLOGY 2021; 57:245-257. [PMID: 33025575 DOI: 10.1111/jpy.13081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 09/01/2020] [Accepted: 09/19/2020] [Indexed: 06/11/2023]
Abstract
Environmental change, including global warming and chemical pollution, can compromise cnidarian-(e.g., coral-) dinoflagellate symbioses and cause coral bleaching. Understanding the mechanisms that regulate these symbioses will inform strategies for sustaining healthy coral-reef communities. A model system for corals is the symbiosis between the sea anemone Exaiptasia pallida (common name Aiptasia) and its dinoflagellate partners (family Symbiodiniaceae). To complement existing studies of the interactions between these organisms, we examined the impact of menthol, a reagent often used to render cnidarians aposymbiotic, on the dinoflagellate Breviolum minutum, both in culture and in hospite. In both environments, the growth and photosynthesis of this alga were compromised at either 100 or 300 µM menthol. We observed reduction in PSII and PSI functions, the abundances of reaction-center proteins, and, at 300 µM menthol, of total cellular proteins. Interestingly, for free-living algae exposed to 100 µM menthol, an initial decline in growth, photosynthetic activities, pigmentation, and protein abundances reversed after 5-15 d, eventually approaching control levels. This behavior was observed in cells maintained in continuous light, but not in cells experiencing a light-dark regimen, suggesting that B. minutum can detoxify menthol or acclimate and repair damaged photosynthetic complexes in a light- and/or energy-dependent manner. Extended exposures of cultured algae to 300 µM menthol ultimately resulted in algal death. Most symbiotic anemones were also unable to survive this menthol concentration for 30 d. Additionally, cells impaired for photosynthesis by pre-treatment with 300 µM menthol exhibited reduced efficiency in re-populating the anemone host.
Collapse
Affiliation(s)
- Sophie Clowez
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California, 94305, USA
| | - Christian Renicke
- Department of Genetics, Stanford University, Stanford, California, 94305, USA
| | - John R Pringle
- Department of Genetics, Stanford University, Stanford, California, 94305, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California, 94305, USA
| |
Collapse
|
49
|
Li T, Chen X, Lin S. Physiological and transcriptomic responses to N-deficiency and ammonium: Nitrate shift in Fugacium kawagutii (Symbiodiniaceae). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:141906. [PMID: 32890873 DOI: 10.1016/j.scitotenv.2020.141906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Symbiodiniaceae are the source of essential coral symbionts of reef building corals. The growth and density of endosymbiotic Symbiodiniaceae within the coral host is dependent on nutrient availability, yet little is known about how Symbiodiniaceae respond to the dynamics of the nutrients, including switch between different chemical forms and changes in abundance. In this study, we investigated physiological, cytometric, and transcriptomic responses in Fugacium kawagutii to nitrogen (N)-nutrient deficiency and different chemical N forms (nitrate and ammonium) in batch culture conditions. We mainly found that ammonium was consumed faster than nitrate when provided separately, and was preferentially utilized over nitrate when both N compounds were supplied at 1:2, 1:1 and 2:1 molarity ratios. Besides, N-deficiency caused decreases in growth, energy production, antioxidative capacity and investment in photosynthate transport but increased energy consumption. Growing on ammonium produced a similar cell yield as nitrate, but with a reduced investment in nutrient transport and assimilation; yet at high concentrations ammonium exhibited inhibitory effects. These findings together have important implications in N-nutrient regulation of coral symbiosis. In addition, we identified ten highly and stably expressed genes as candidate reference genes, which will be potentially useful for gene expression studies in the future.
Collapse
Affiliation(s)
- Tangcheng Li
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA
| | - Xibei Chen
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao 266237, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| |
Collapse
|
50
|
Alderdice R, Suggett DJ, Cárdenas A, Hughes DJ, Kühl M, Pernice M, Voolstra CR. Divergent expression of hypoxia response systems under deoxygenation in reef-forming corals aligns with bleaching susceptibility. GLOBAL CHANGE BIOLOGY 2021; 27:312-326. [PMID: 33197302 DOI: 10.1111/gcb.15436] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/27/2020] [Indexed: 06/11/2023]
Abstract
Exposure of marine life to low oxygen is accelerating worldwide via climate change and localized pollution. Mass coral bleaching and mortality have recently occurred where reefs have experienced chronic low oxygen events. However, the mechanistic basis of tolerance to oxygen levels inadequate to sustain normal functioning (i.e. hypoxia) and whether it contributes to bleaching susceptibility, remain unknown. We therefore experimentally exposed colonies of the environmentally resilient Acropora tenuis, a common reef-building coral from the Great Barrier Reef, to deoxygenation-reoxygenation stress that was aligned to their natural night-day light cycle. Specifically, the treatment involved removing the 'night-time O2 buffer' to challenge the inherent hypoxia thresholds. RNA-Seq analysis revealed that coral possess a complete and active hypoxia-inducible factor (HIF)-mediated hypoxia response system (HRS) homologous to other metazoans. As expected, A. tenuis exhibited bleaching resistance and showed a strong inducibility of HIF target genes in response to deoxygenation stress. We applied this same approach in parallel to a colony of Acropora selago, known to be environmnetally susceptible, which conversely exhibited a bleaching phenotype response. This phenotypic divergence of A. selago was accompanied by contrasting gene expression profiles indicative of varied effectiveness of their HIF-HRS. Based on our RNA-Seq analysis, we propose (a) that the HIF-HRS is central for corals to manage deoxygenation stress and (b) that key genes of this system (and the wider gene network) may contribute to variation in coral bleaching susceptibility. Our analysis suggests that heat shock protein (hsp) 70 and 90 are important for low oxygen stress tolerance and further highlights how hsp90 expression might also affect the inducibility of coral HIF-HRS in overcoming a metabolic crisis under deoxygenation stress. We propose that differences in coral HIF-HRS could be central in regulating sensitivity to other climate change stressors-notably thermal stress-that commonly drive bleaching.
Collapse
Affiliation(s)
- Rachel Alderdice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David J Hughes
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Michael Kühl
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
- Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | | |
Collapse
|