1
|
Ye J, Wang Y, Li Q, Hussain S, Chen S, Zhou X, Hou S, Feng Y. Phagocytosis in Marine Coccolithophore Gephyrocapsa huxleyi: Comparison between Calcified and Non-Calcified Strains. BIOLOGY 2024; 13:310. [PMID: 38785792 PMCID: PMC11117637 DOI: 10.3390/biology13050310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/19/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024]
Abstract
Coccolithophores play a significant role in marine calcium carbonate production and carbon cycles, attributing to their unique feature of producing calcareous plates, coccoliths. Coccolithophores also possess a haplo-diplontic life cycle, presenting distinct morphology types and calcification states. However, differences in nutrient acquisition strategies and mixotrophic behaviors of the two life phases remain unclear. In this study, we conducted a series of phagocytosis experiments of calcified diploid and non-calcified haploid strains of coccolithophore Gephyrocapsa huxleyi under light and dark conditions. The phagocytosis capability of each strain was examined based on characteristic fluorescent signals from ingested beads using flow cytometry and fluorescence microscopy. The results show a significantly higher phagocytosis percentage on fluorescent beads in the bacterial prey surrogates of the non-calcified haploid Gephyrocapsa huxleyi strain, than the calcified diploid strain with or without light. In addition, the non-calcified diploid cells seemingly to presented a much higher phagocytosis percentage in darkness than under light. The differential phagocytosis capacities between the calcified diploid and non-calcified haploid Gephyrocapsa huxleyi strains indicate potential distinct nutritional strategies at different coccolithophore life and calcifying stages, which may further shed light on the potential strategies that coccolithophore possesses in unfavorable environments such as twilight zones and the expanding coccolithophore niches in the natural marine environment under the climate change scenario.
Collapse
Affiliation(s)
- Jiayang Ye
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.Y.); (Q.L.)
- Shanghai Key Laboratory of Polar Life and Environment Sciences, Shanghai Jiao Tong University, Shanghai 200030, China;
- Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Ministry of Education, Shanghai 200030, China
| | - Ying Wang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.Y.); (Q.L.)
| | - Qian Li
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.Y.); (Q.L.)
| | - Sarfraz Hussain
- Department of Ocean Science & Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Songze Chen
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen 518049, China
| | - Xunying Zhou
- Department of Ocean Science & Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shengwei Hou
- Shanghai Key Laboratory of Polar Life and Environment Sciences, Shanghai Jiao Tong University, Shanghai 200030, China;
- Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Ministry of Education, Shanghai 200030, China
- Department of Ocean Science & Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuanyuan Feng
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.Y.); (Q.L.)
- Shanghai Key Laboratory of Polar Life and Environment Sciences, Shanghai Jiao Tong University, Shanghai 200030, China;
- Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Ministry of Education, Shanghai 200030, China
| |
Collapse
|
2
|
Helbling EW, Villafañe VE, Narvarte MA, Burgueño GM, Saad JF, González RA, Cabrerizo MJ. The impact of extreme weather events exceeds those due to global-change drivers on coastal phytoplankton assemblages. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170644. [PMID: 38320708 DOI: 10.1016/j.scitotenv.2024.170644] [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: 11/15/2023] [Revised: 01/28/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
Extreme wind and rainfall events have become more frequent phenomena, impacting coastal ecosystems by inducing increased mixing regimes in the upper mixed layers (UML) and reduced transparency (i.e. browning), hence affecting phytoplankton photosynthesis. In this study, five plankton assemblages from the South Atlantic Ocean, from a gradient of environmental variability and anthropogenic exposure, were subjected to simulated extreme weather events under a global change scenario (GCS) of increased temperature and nutrients and decreased pH, and compared to ambient conditions (Control). Using multiple linear regression (MLR) analysis we determined that evenness and the ratio of diatoms/ (flagellates + dinoflagellates) significantly explained the variations (81-91 %) of the photosynthesis efficiency (i.e. Pchla/ETRchla ratio) for each site under static conditions. Mixing speed and the optical depth (i.e. attenuation coefficient * depth, kdz), as single drivers, explained 40-76 % of the variability in the Pchla/ETRchla ratio, while GCS drivers <9 %. Overall, assemblages with high diversity and evenness were less vulnerable to extreme weather events under a GCS. Extreme weather events should be considered in global change studies and conservation/management plans as even at local/regional scales, they can exceed the predicted impacts of mean global climate change on coastal primary productivity.
Collapse
Affiliation(s)
- E Walter Helbling
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina.
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Maite A Narvarte
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Giuliana M Burgueño
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Juan F Saad
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Raúl A González
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Marco J Cabrerizo
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Departamento de Ecología, Facultad de Ciencias, Campus de Fuentenueva s/n & Instituto Universitario de Investigación del Agua, Universidad de Granada, 18071 Granada, Spain
| |
Collapse
|
3
|
Armstrong E, Law CS. Resilience of Emiliania huxleyi to future changes in subantarctic waters. PLoS One 2023; 18:e0284415. [PMID: 37917737 PMCID: PMC10621989 DOI: 10.1371/journal.pone.0284415] [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: 11/28/2022] [Accepted: 03/30/2023] [Indexed: 11/04/2023] Open
Abstract
Lower pH and elevated temperature alter phytoplankton growth and biomass in short-term incubations, but longer-term responses and adaptation potential are less well-studied. To determine the future of the coccolithophore Emiliania huxleyi, a mixed genotype culture from subantarctic water was incubated for 720 days under present-day temperature and pH, and also projected future conditions by the year 2100. The future population exhibited a higher growth rate relative to present-day cells transferred to future conditions after 309 days, indicating adaptation or genotype selection; this was reflected by an increase in optimum growth temperature of ~2.5°C by the end of the experiment. Following transfer to opposing conditions in short-term cross-over incubations, cell volume responded rapidly, within eight generations, confirming trait plasticity. The changes in growth rate and cell volume were larger than reported in previous single stressor relationships and incubations, suggesting synergistic or additive effects of combined elevated temperature and lower pH and highlighting the importance of long-term multiple stressor experiments. At the end of the incubation there were no significant differences in cellular composition (particulate organic content and chlorophyll a), or primary production between present-day and future populations. Conversely, two independent methods showed a 50% decrease in both particulate inorganic carbon and calcification rate, consistent with the decrease in cell volume, in the future population. The observed plasticity and adaptive capacity of E. huxleyi indicate resilience to future conditions in subantarctic waters, although changes in cell volume and carbonate may alter grazing loss and cell ballast, so influencing carbon export to the deep ocean.
Collapse
Affiliation(s)
- Evelyn Armstrong
- NIWA/University of Otago Research Centre for Oceanography, University of Otago, Dunedin, New Zealand
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Cliff S. Law
- Department of Marine Science, University of Otago, Dunedin, New Zealand
- NIWA, Greta Point, Wellington, New Zealand
| |
Collapse
|
4
|
Xu H, Liu H, Chen F, Zhang X, Zhang Z, Ma J, Pan K, Liu H. Ocean acidification affects physiology of coccolithophore Emiliania huxleyi and weakens its mechanical resistance to copepods. MARINE ENVIRONMENTAL RESEARCH 2023; 192:106232. [PMID: 37866975 DOI: 10.1016/j.marenvres.2023.106232] [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: 07/31/2023] [Revised: 10/12/2023] [Accepted: 10/15/2023] [Indexed: 10/24/2023]
Abstract
The effects of ocean acidification (OA) on coccolithophore's photosynthesis, calcification rates, and growth have been extensively studied. However, how the intracellular Ca2+, mechanical properties and chemical composition of the coccoliths are affected by OA have not yet been investigated. This study tries to fill these gaps using Emiliania huxleyi as a model coccolithophore. When the seawater pCO2 increased from 400 μatm to 1200 μatm, the intracellular Ca2+ and coccolith area were reduced by 66% and 36%, respectively. Single-cell mapping by atomic force microscopy revealed that the modulus and hardness of coccolith decreased from 23.6 ± 0.2 GPa to 12.0 ± 5.5 GPa and from 0.53 ± 0.15 GPa to 0.20 ± 0.06 GPa, respectively. Additionally, the proportional organic matter and silicon in the coccolith surfaces increased with pCO2. The copepods Acartia pacifica fed on more E. huxleyi grown at higher pCO2. Our study implies that OA could change coccolithophore's competitive interactions with other phytoplankton and ultimately influence carbon export to the deep ocean.
Collapse
Affiliation(s)
- Huo Xu
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Haijiao Liu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Fengyuan Chen
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiaodong Zhang
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhen Zhang
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China; Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jie Ma
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Ke Pan
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China.
| | - Hongbin Liu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Branch of Southern Marine Science & Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China.
| |
Collapse
|
5
|
Wu F, Guo J, Duan H, Li T, Wang Y, Wang Y, Wang S, Feng Y. Ocean Acidification Affects the Response of the Coastal Coccolithophore Pleurochrysis carterae to Irradiance. BIOLOGY 2023; 12:1249. [PMID: 37759648 PMCID: PMC10525560 DOI: 10.3390/biology12091249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023]
Abstract
The ecologically important marine phytoplankton group coccolithophores have a global distribution. The impacts of ocean acidification on the cosmopolitan species Emiliania huxleyi have received much attention and have been intensively studied. However, the species-specific responses of coccolithophores and how these responses will be regulated by other environmental drivers are still largely unknown. To examine the interactive effects of irradiance and ocean acidification on the physiology of the coastal coccolithophore species Pleurochrysis carterae, we carried out a semi-continuous incubation experiment under a range of irradiances (50, 200, 500, 800 μmol photons m-2 s-1) at two CO2 concentration conditions of 400 and 800 ppm. The results suggest that the saturation irradiance for the growth rate was higher at an elevated CO2 concentration. Ocean acidification weakened the particulate organic carbon (POC) production of Pleurochrysis carterae and the inhibition rate was decreased with increasing irradiance, indicating that ocean acidification may affect the tolerating capacity of photosynthesis to higher irradiance. Our results further provide new insight into the species-specific responses of coccolithophores to the projected ocean acidification under different irradiance scenarios in the changing marine environment.
Collapse
Affiliation(s)
- Fengxia Wu
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200040, China
| | - Jia Guo
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
| | - Haozhen Duan
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
| | - Tongtong Li
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
| | - Yanan Wang
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
| | - Yuntao Wang
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Shiqiang Wang
- College of Marine and Environment, Tianjin University of Science and Technology, Tianjin 300453, China
| | - Yuanyuan Feng
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200040, China
- Shanghai Frontiers Science Center of Polar Science (SCOPS), Shanghai 200030, China
| |
Collapse
|
6
|
Sheward RM, Liefer JD, Irwin AJ, Finkel ZV. Elemental stoichiometry of the key calcifying marine phytoplankton Emiliania huxleyi under ocean climate change: A meta-analysis. GLOBAL CHANGE BIOLOGY 2023; 29:4259-4278. [PMID: 37279257 DOI: 10.1111/gcb.16807] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/08/2023]
Abstract
The elemental composition of marine microorganisms (their C:N:P ratio, or stoichiometry) is central to understanding the biotic and biogeochemical processes underlying key marine ecosystem functions. Phytoplankton C:N:P is species specific and flexible to changing environmental conditions. However, bulk or fixed phytoplankton stoichiometry is usually assumed in biogeochemical and ecological models because more realistic, environmentally responsive C:N:P ratios have yet to be defined for key functional groups. Here, a comprehensive meta-analysis of experimental laboratory data reveals the variable C:N:P stoichiometry of Emiliania huxleyi, a globally significant calcifying phytoplankton species. Mean C:N:P of E. huxleyi is 124C:16N:1P under control conditions (i.e. growth not limited by one or more environmental stressors) and shows a range of responses to changes in nutrient and light availability, temperature and pCO2 . Macronutrient limitation caused strong shifts in stoichiometry, increasing N:P and C:P under P deficiency (by 305% and 493% respectively) and doubling C:N under N deficiency. Responses to light, temperature and pCO2 were mixed but typically shifted cellular elemental content and C:N:P stoichiometry by ca. 30% or less. Besides these independent effects, the interactive effects of multiple environmental changes on E. huxleyi stoichiometry under future ocean conditions could be additive, synergistic or antagonistic. To synthesise our meta-analysis results, we explored how the cellular elemental content and C:N:P stoichiometry of E. huxleyi may respond to two hypothetical future ocean scenarios (increased temperature, irradiance and pCO2 combined with either N deficiency or P deficiency) if an additive effect is assumed. Both future scenarios indicate decreased calcification (which is predominantly sensitive to elevated pCO2 ), increased C:N, and up to fourfold shifts in C:P and N:P. Our results strongly suggest that climate change will significantly alter the role of E. huxleyi (and potentially other calcifying phytoplankton species) in marine biogeochemical processes.
Collapse
Affiliation(s)
- Rosie M Sheward
- Institute of Geosciences, Goethe-University Frankfurt, Frankfurt am Main, Germany
- Department of Geography and Environment, Mount Allison University, Sackville, New Brunswick, Canada
| | - Justin D Liefer
- Department of Biology/Geography and Environment, Mount Allison University, Sackville, New Brunswick, Canada
| | - Andrew J Irwin
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Zoe V Finkel
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
7
|
Wang C, Sun X, Wang J, Tang JM, Gu Y, Lin S. Physiological and metabolic effects of glyphosate as the sole P source on a cosmopolitan phytoplankter and biogeochemical implications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:155094. [PMID: 35398121 DOI: 10.1016/j.scitotenv.2022.155094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/29/2022] [Accepted: 04/03/2022] [Indexed: 06/14/2023]
Abstract
Nutrient conditions influence the physiology and stoichiometry of marine phytoplankton. While extensive studies have documented the effects of abundances and types of nutrients such as nitrogen (N) and phosphorus (P), the effect of phosphonates as a P source is less understood and underexplored. Here, with the cosmopolitan coccolithophorid Emiliania huxleyi as a model phytoplankter, we investigated the effect of the phosphonate type of herbicide glyphosate as the sole P source in comparison with the P-depleted and P-replete (with 36 μM dissolved inorganic phosphate [DIP]) cultures. We measured changes in cellular C (carbon):P and N:P ratios and physiological performance and documented the corresponding transcriptomic and miRNAomic responses in E. huxleyi to glyphosate treatment. We found that glyphosate supported population growth but not to the full scale relative to DIP, and this was under the concerted regulation of DNA replication and cell cycle arrest genes as well as the growth-regulating miRNA. Furthermore, our data suggest that E. huxleyi took up glyphosate directly, bypassing extracellular hydrolysis, and this involved ABC transporters. Meanwhile, glyphosate-grown cultures displayed marked increases in cellular particulate organic C (POC) and PON contents, cell size, and transcription of genes for CO2 fixation and citrate cycle, nitrate transport, and protein biosynthesis. However, compared to DIP, the maximum absorption rate of glyphosate was only 33%, and glyphosate-grown E. huxleyi cells exhibited a mild P-stress symptom and elevated cellular C:P and N:P ratios. Interestingly, glyphosate-grown cells showed an increased sinking rate, suggesting that glyphosate as the sole P source might enhance the efficiency of C export by E. huxleyi, which would compensate for the expected decline in primary productivity (and hence carbon efflux) in the future more nutrient-depleted ocean. This biogeochemical implication needs to be further studied and verified, however.
Collapse
Affiliation(s)
- Cong Wang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xueqiong Sun
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jingtian Wang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jin-Ming Tang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yifan Gu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; Department of Marine Sciences, University of Connecticut, Groton, CT, United States of America.
| |
Collapse
|
8
|
Collins S, Whittaker H, Thomas MK. The need for unrealistic experiments in global change biology. Curr Opin Microbiol 2022; 68:102151. [PMID: 35525129 DOI: 10.1016/j.mib.2022.102151] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/21/2022] [Accepted: 04/01/2022] [Indexed: 11/27/2022]
Abstract
Climate change is an existential threat, and our ability to conduct experiments on how organisms will respond to it is limited by logistics and resources, making it vital that experiments be maximally useful. The majority of experiments on phytoplankton responses to warming and CO2 use only two levels of each driver. However, to project the characters of future populations, we need a mechanistic and generalisable explanation for how phytoplankton respond to concurrent changes in temperature and CO2. This requires experiments with more driver levels, to produce response surfaces that can aid in the development of predictive models. We recommend prioritising experiments or programmes that produce such response surfaces on multiple scales for phytoplankton.
Collapse
Affiliation(s)
- Sinéad Collins
- University of Edinburgh, Institute of Evolutionary Biology, The King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Harriet Whittaker
- University of Edinburgh, Institute of Evolutionary Biology, The King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Mridul K Thomas
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences and Institute for Environmental Sciences, CH-1211 Geneva, Switzerland
| |
Collapse
|
9
|
Cabrerizo MJ, Medina-Sánchez JM, González-Olalla JM, Sánchez-Gómez D, Carrillo P. Microbial plankton responses to multiple environmental drivers in marine ecosystems with different phosphorus limitation degrees. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151491. [PMID: 34752863 DOI: 10.1016/j.scitotenv.2021.151491] [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: 07/02/2021] [Revised: 10/21/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Multiple drivers are threatening the functioning of the microbial food webs and trophic interactions. Our understanding about how temperature, CO2, nutrient inputs, and solar ultraviolet radiation (UVR) availability interact to alter ecosystem functioning is scarce because research has focused on single and double interactions. Moreover, the role that the degree of in situ nutrient limitation could play in the outcome of these interactions has been largely neglected, despite it is predominant in marine ecosystems. We address these uncertainties by combining remote-sensing analyses, and a collapsed experimental design with natural microbial communities from Mediterranean Sea and Atlantic Ocean exposed to temperature, nutrients, CO2, and UVR interactions. At the decade scale, we found that more intense and frequent (and longer lasting) Saharan dust inputs (and marine heatwaves) were only coupled with reduced phytoplankton biomass production. When microbial communities were concurrently exposed to future temperature, CO2, nutrient, and UVR conditions (i.e. the drivers studied over long-term scales), we found shifts from net autotrophy [primary production:respiration (PP:R) ratio > 1] towards a metabolic equilibrium (PP:R ratio ~ 1) or even a net heterotrophy (PP:R ratio < 1), as P-limitation degree was higher (i.e. Atlantic Ocean). These changes in the metabolic balance were coupled with a weakened phytoplankton-bacteria interaction (i.e. bacterial carbon demand exceeded phytoplankton carbon supply. Our work reveals that an accentuated in situ P limitation may promote reductions both in carbon uptake and fluxes between trophic levels in microbial plankton communities under global-change conditions. We show that considering long-term series can aid in identifying major local environmental drivers (i.e. temperature and nutrients in our case), easing the design of future global-change studies, but also that the abiotic environment to which microbial plankton communities are acclimated should be taken into account to avoid biased predictions concerning the effects of multiple interacting global-change drivers on marine ecosystems.
Collapse
Affiliation(s)
- Marco J Cabrerizo
- Departamento de Ecología y Biología Animal, Facultad de Ciencias del Mar, Universidad de Vigo, Campus Lagoas Marcosende s/n, 36310 Vigo, Spain; Centro de Investigación Mariña, Universidad de Vigo (CIM-UVigo), Illa de Toralla s/n, 36331 Vigo, Spain; Departamento de Ecología, Universidad de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
| | - Juan Manuel Medina-Sánchez
- Departamento de Ecología, Universidad de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain; Instituto Universitario de Investigación del Agua, C/Ramón y Cajal, n 4, 18071 Granada, Spain
| | | | - Daniel Sánchez-Gómez
- Instituto Universitario de Investigación del Agua, C/Ramón y Cajal, n 4, 18071 Granada, Spain
| | - Presentación Carrillo
- Instituto Universitario de Investigación del Agua, C/Ramón y Cajal, n 4, 18071 Granada, Spain
| |
Collapse
|
10
|
Nitrogen-limitation exacerbates the impact of ultraviolet radiation on the coccolithophore Gephyrocapsa oceanica. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 226:112368. [PMID: 34864530 DOI: 10.1016/j.jphotobiol.2021.112368] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 12/13/2022]
Abstract
To investigate effects of UV radiation (UVR, 280-400 nm) on coccolithophorids under nutrient-limited conditions, we grew Gephyrocapsa oceanica to determine its resilience to consecutive daily short-term exposures to +UVR (irradiances >295 nm) under a range of nitrate availabilities (100, 24, 12, 6 and 3 μM). +UVR alone significantly hampered the growth of G. oceanica, with the synergistic negative effects of +UVR and N-limitation being about 58% and 22% greater than under UVR or N-limitation alone, respectively. Most 3 μM nitrate cultures died, but those exposed to UVR succumbed sooner. This was due to a failure of photoprotection and repair mechanisms under low N-availability with exposures to UVR. Additionally, the UVR-induced inhibition of the effective quantum yield of photosystem II (PSII) was significantly higher and was further aggravated by N limitation. The algal cells increased photoprotective pigments and UV-absorbing compounds as a priority rather than using calcification for defense against UVR, indicating a trade-off in energy and resource allocation. Our results indicate the negative effects of UVR on coccolithophorid growth and photosynthesis, and highlight the important role of N availability in defense against UVR as well as high PAR. We predict that enhanced N-limitation in future surface oceans due to warming-induced stratification will exacerbate the sensitivity of G. oceanica to UVR, while coccolithophores can be potentially more susceptible to other environmental stresses due to increased levels of nutrient limitation.
Collapse
|
11
|
Xie E, Xu K, Li Z, Li W, Yi X, Li H, Han Y, Zhang H, Zhang Y. Disentangling the Effects of Ocean Carbonation and Acidification on Elemental Contents and Macromolecules of the Coccolithophore Emiliania huxleyi. Front Microbiol 2021; 12:737454. [PMID: 34745039 PMCID: PMC8564145 DOI: 10.3389/fmicb.2021.737454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/29/2021] [Indexed: 11/21/2022] Open
Abstract
Elemental contents change with shifts in macromolecular composition of marine phytoplankton. Recent studies focus on the responses of elemental contents of coccolithophores, a major calcifying phytoplankton group, to changing carbonate chemistry, caused by the dissolution of anthropogenically derived CO2 into the surface ocean. However, the effects of changing carbonate chemistry on biomacromolecules, such as protein and carbohydrate of coccolithophores, are less documented. Here, we disentangled the effects of elevated dissolved inorganic carbon (DIC) concentration (900 to 4,930μmolkg−1) and reduced pH value (8.04 to 7.70) on physiological rates, elemental contents, and macromolecules of the coccolithophore Emiliania huxleyi. Compared to present DIC concentration and pH value, combinations of high DIC concentration and low pH value (ocean acidification) significantly increased pigments content, particulate organic carbon (POC), and carbohydrate content and had less impact on growth rate, maximal relative electron transport rate (rETRmax), particulate organic nitrogen (PON), and protein content. In high pH treatments, elevated DIC concentration significantly increased growth rate, pigments content, rETRmax, POC, particulate inorganic carbon (PIC), protein, and carbohydrate contents. In low pH treatments, the extents of the increase in growth rate, pigments and carbohydrate content were reduced. Compared to high pH value, under low DIC concentration, low pH value significantly increased POC and PON contents and showed less impact on protein and carbohydrate contents; however, under high DIC concentration, low pH value significantly reduced POC, PON, protein, and carbohydrate contents. These results showed that reduced pH counteracted the positive effects of elevated DIC concentration on growth rate, rETRmax, POC, PON, carbohydrate, and protein contents. Elevated DIC concentration and reduced pH acted synergistically to increase the contribution of carbohydrate–carbon to POC, and antagonistically to affect the contribution of protein–nitrogen to PON, which further shifted the carbon/nitrogen ratio of E. huxleyi.
Collapse
Affiliation(s)
- Emei Xie
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| | - Kui Xu
- Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization, Hubei Engineering Research Center of Special Wild Vegetables Breeding and Comprehensive Utilization Technology, College of Life Sciences, Hubei Normal University, Huangshi, China
| | - Zhengke Li
- School of Food and Biological Engineering, Shanxi University of Science and Technology, Xi'an, China
| | - Wei Li
- College of Life and Environmental Sciences, Huangshan University, Huangshan, China
| | - Xiangqi Yi
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Hongzhou Li
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| | - Yonghe Han
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| | - Hong Zhang
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| | - Yong Zhang
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control and Resource Recycling, Fujian Normal University, Fuzhou, China
| |
Collapse
|