1
|
Wang G, Huang L, Zhuang S, Han F, Huang Q, Hao M, Lin G, Chen L, Shen B, Li F, Li X, Chen C, Gao Y, Mock T, Liang J. Resting cell formation in the marine diatom Thalassiosira pseudonana. THE NEW PHYTOLOGIST 2024; 243:1347-1360. [PMID: 38402560 DOI: 10.1111/nph.19646] [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: 12/12/2023] [Accepted: 02/08/2024] [Indexed: 02/26/2024]
Abstract
Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many diatoms sink at the end of their blooming season and therefore need to endure cold and dark conditions in the deeper layers of the water column. How they survive these conditions is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, and genetics to reveal the biological mechanism of resting-cell formation in the model diatom Thalassiosira pseudonana. Resting-cell formation was triggered by a decrease in light and temperature with subsequent catabolism of storage compounds. Resting cells were characterised by an acidic and viscous cytoplasm and altered morphology of the chloroplast ultrastructure. The formation of resting cells in T. pseudonana is an energy demanding process required for a biophysical alteration of the cytosol and chloroplasts to endure the unfavourable conditions of the deeper ocean as photosynthetic organisms. However, most resting cells (> 90%) germinate upon return to favorable growth conditions.
Collapse
Affiliation(s)
- Guangning Wang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Lu Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Shanshan Zhuang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Fang Han
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Qianqian Huang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Mengyuan Hao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Guifang Lin
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Longnan Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Biying Shen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Feng Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Xuesong Li
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Changping Chen
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yahui Gao
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
- State Key Laboratory of Marine Environment Science, Xiamen University, Xiamen, 361102, Fujian, China
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia (UEA), Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Junrong Liang
- School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen Key Laboratory of Plant Genetics, Xiamen University, Xiamen, 361102, Fujian, China
| |
Collapse
|
2
|
García-Moreiras I, Amorim A, Zonneveld K. Transport and preservation of calcareous and organic-walled dinoflagellate cysts off Cape Blanc (NW africa) in relation to nepheloid layers. MARINE ENVIRONMENTAL RESEARCH 2024; 199:106577. [PMID: 38878348 DOI: 10.1016/j.marenvres.2024.106577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 05/01/2024] [Accepted: 06/02/2024] [Indexed: 07/14/2024]
Abstract
Our understanding of dinoflagellates' present-day and past ecology is limited due to the scarcity of data on the transport of dinoflagellate cysts in oceanic environments. Previous studies have shown that lateral transport affects the source-to-sink trajectory of cysts in the very productive region off Cape Blanc (NW Africa). Unsolved questions remain, such as: how far these cysts can be advected, whether the cyst sources vary over time and whether lateral transport is a permanent feature or restricted to individual events. To fill these gaps and assess the role of nepheloid layers on the lateral transport and preservation of dinoflagellate cysts, new data on dinoflagellate cyst distributions in the water column and sediments along a land-sea transect were obtained. Samples were collected in November 2018 along a shelf break-offshore transect during intense upwelling, notably, within and between the nepheloid layers. The composition and abundance of cysts with organic walls in the water column and surface sediments were studied. Moreover, the distribution of calcareous cysts was also analysed in the water samples, using non-destructive acid-free preparation methods. The records were dominated by empty cysts, but no clear indications that these originated from local resuspension of older sediments were observed. Clustering, principal component analysis and redundant discriminant analysis were used to compare cyst assemblages in the water column and surface sediments, and environmental conditions in the upper water column. The strong similarity in species composition of water samples collected in the active upwelling region to those collected from the more onshore parts of the Benthic Nepheloid Layer (BNL), upper Intermediate Nepheloid Layer (INL) (∼1000 m depth) and lower INL (∼2200 m depth) indicated that lateral transport of cysts within these NLs occurred until about ∼110 km from the shelf break. Cyst assemblages from above and below these NLs showed significantly different taxa composition reinforcing the role of NLs in the lateral advection of cysts. In the more offshore stations, vertically similar cyst assemblages were observed in the same station, independent of the sample depth, within or between the NLs, which supported that at these stations vertical transport was the dominant process influencing cyst assemblages. Consequently, the cyst signal in sediments off Cape Blanc may be affected both by horizontal transport of allochthonous cysts and vertical deposition of locally-produced cysts, particularly in the more offshore stations (>2000 m depth). Despite lateral transport and possible species-specific preservation effects, horizontal distributions of most cyst taxa in the water column and the surface sediments could be explained to a great extent by the main environmental gradients in the upper water column. This agrees with observations made in other regions, and reinforces that dinoflagellate cysts as good proxies to reconstruct past environmental conditions in offshore environments. New data on dinoflagellate cyst distribution, transport and accumulation patterns in deep environments off Cape Blanc may be useful for interpreting past environmental signals in the region. This is particularly relevant regarding calcareous cysts, as information on their distribution and ecology is very scarce. The present work contributes to a better understanding of the dispersal patterns of dinoflagellate cysts in the deep ocean, highlighting the significant role played by nepheloid layers in this process and thus on the dinoflagellate cyst signature in deep-sea sediments.
Collapse
Affiliation(s)
- Iria García-Moreiras
- Centro de Investigación Mariña (CIM), Universidade de Vigo, Facultade de Ciencias, Campus As Lagoas-Marcosende, University of Vigo, 36310 Vigo, Spain; Universidade de Vigo, Departamento de Bioloxía Vexetal e Ciencias do Solo, University of Vigo, 36310 Vigo, Spain.
| | - Ana Amorim
- Centro de Ciências do Mar e do Ambiente (MARE) / Aquatic Research Network (ARNET), Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisbon, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisbon, Portugal
| | - Karin Zonneveld
- Zentrum für Marine Umweltwissenschaften der Universität Bremen (MARUM), Leobener Str. 8, 28359, Bremen, Germany; Geosciences Department, University of Bremen, Klagenfurter Str., 28359, Bremen, Germany
| |
Collapse
|
3
|
da Silva TT, Bortolini JC, Iatskiu P, Pilatti MC, Medeiros G, Amaral MWW, Guicho R, Bueno NC. Local environmental factors are the main drivers of phytoplankton biovolume in subtropical streams of Brazil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171663. [PMID: 38485007 DOI: 10.1016/j.scitotenv.2024.171663] [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: 10/03/2023] [Revised: 03/08/2024] [Accepted: 03/10/2024] [Indexed: 03/25/2024]
Abstract
The ecological attributes of phytoplankton in freshwater environments are strongly influenced by limnological factors and temporal variability. In this study, we investigated the importance of local environmental and regional (spatial and landscape) predictors in structuring stream phytoplankton from the perspective of metacommunity theory. We seasonally sampled phytoplankton and abiotic variables from nine streams in three subtropical basins. Variation partitioning was used to investigate the influence of environmental, landscape, and spatial predictors on phytoplankton biovolume. Independent of the hydrological period (dry and rainy), the phytoplankton communities were predominantly structured by local environmental factors. In addition, the different land uses considered (landscape) showed weak significance during the dry season, with emphasis on the rural category. Biovolume values remained low, and diatoms and green algae were the most representative groups. Our findings are consistent with recognized ecological patterns for potamoplankton and emphasize local environmental filters as a fundamental regulator of phytoplankton biodiversity in lotic environments.
Collapse
Affiliation(s)
- Thaís Tagliati da Silva
- Programa de Pós-graduação em Conservação e Manejo de Recursos Naturais, Universidade Estadual do Oeste do Paraná, Universitária Street, 2019, Cascavel, Paraná 85819-110, Brazil
| | - Jascieli Carla Bortolini
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Esperança Ave, s/n, Goiânia, Goiás 74690-900, Brazil.
| | - Patricia Iatskiu
- Programa de Pós-graduação em Conservação e Manejo de Recursos Naturais, Universidade Estadual do Oeste do Paraná, Universitária Street, 2019, Cascavel, Paraná 85819-110, Brazil.
| | - Maria Clara Pilatti
- Programa de Pós-graduação em Conservação e Manejo de Recursos Naturais, Universidade Estadual do Oeste do Paraná, Universitária Street, 2019, Cascavel, Paraná 85819-110, Brazil
| | - Gabriela Medeiros
- Centro Universitário de Cascavel, 2317, Tito Muffato Ave, Cascavel, Paraná 85806-080, Brazil
| | | | - Ricardo Guicho
- Centro Universitário de Cascavel, 2317, Tito Muffato Ave, Cascavel, Paraná 85806-080, Brazil
| | - Norma Catarina Bueno
- Programa de Pós-graduação em Conservação e Manejo de Recursos Naturais, Universidade Estadual do Oeste do Paraná, Universitária Street, 2019, Cascavel, Paraná 85819-110, Brazil
| |
Collapse
|
4
|
Stenow R, Robertson EK, Kourtchenko O, Whitehouse MJ, Pinder MIM, Benvenuto G, Töpel M, Godhe A, Ploug H. Resting cells of Skeletonema marinoi assimilate organic compounds and respire by dissimilatory nitrate reduction to ammonium in dark, anoxic conditions. Environ Microbiol 2024; 26:e16625. [PMID: 38653479 DOI: 10.1111/1462-2920.16625] [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: 09/01/2023] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
Diatoms can survive long periods in dark, anoxic sediments by forming resting spores or resting cells. These have been considered dormant until recently when resting cells of Skeletonema marinoi were shown to assimilate nitrate and ammonium from the ambient environment in dark, anoxic conditions. Here, we show that resting cells of S. marinoi can also perform dissimilatory nitrate reduction to ammonium (DNRA), in dark, anoxic conditions. Transmission electron microscope analyses showed that chloroplasts were compacted, and few large mitochondria had visible cristae within resting cells. Using secondary ion mass spectrometry and isotope ratio mass spectrometry combined with stable isotopic tracers, we measured assimilatory and dissimilatory processes carried out by resting cells of S. marinoi under dark, anoxic conditions. Nitrate was both respired by DNRA and assimilated into biomass by resting cells. Cells assimilated nitrogen from urea and carbon from acetate, both of which are sources of dissolved organic matter produced in sediments. Carbon and nitrogen assimilation rates corresponded to turnover rates of cellular carbon and nitrogen content ranging between 469 and 10,000 years. Hence, diatom resting cells can sustain their cells in dark, anoxic sediments by slowly assimilating and respiring substrates from the ambient environment.
Collapse
Affiliation(s)
- Rickard Stenow
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Olga Kourtchenko
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Matthew I M Pinder
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | | | - Mats Töpel
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
- IVL-Swedish Environmental Research Institute, Gothenburg, SE, Sweden
| | - Anna Godhe
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| | - Helle Ploug
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SE, Sweden
| |
Collapse
|
5
|
Li S, Nilsson E, Seidel L, Ketzer M, Forsman A, Dopson M, Hylander S. Baltic Sea coastal sediment-bound eukaryotes have increased year-round activities under predicted climate change related warming. Front Microbiol 2024; 15:1369102. [PMID: 38596378 PMCID: PMC11002985 DOI: 10.3389/fmicb.2024.1369102] [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: 01/11/2024] [Accepted: 03/05/2024] [Indexed: 04/11/2024] Open
Abstract
Climate change related warming is a serious environmental problem attributed to anthropogenic activities, causing ocean water temperatures to rise in the coastal marine ecosystem since the last century. This particularly affects benthic microbial communities, which are crucial for biogeochemical cycles. While bacterial communities have received considerable scientific attention, the benthic eukaryotic community response to climate change remains relatively overlooked. In this study, sediments were sampled from a heated (average 5°C increase over the whole year for over 50 years) and a control (contemporary conditions) Baltic Sea bay during four different seasons across a year. RNA transcript counts were then used to investigate eukaryotic community changes under long-term warming. The composition of active species in the heated and control bay sediment eukaryotic communities differed, which was mainly attributed to salinity and temperature. The family level RNA transcript alpha diversity in the heated bay was higher during May but lower in November, compared with the control bay, suggesting altered seasonal activity patterns and dynamics. In addition, structures of the active eukaryotic communities varied between the two bays during the same season. Hence, this study revealed that long-term warming can change seasonality in eukaryotic diversity patterns. Relative abundances and transcript expression comparisons between bays suggested that some taxa that now have lower mRNA transcripts numbers could be favored by future warming. Furthermore, long-term warming can lead to a more active metabolism in these communities throughout the year, such as higher transcript numbers associated with diatom energy production and protein synthesis in the heated bay during winter. In all, these data can help predict how future global warming will affect the ecology and metabolism of eukaryotic community in coastal sediments.
Collapse
Affiliation(s)
- Songjun Li
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Emelie Nilsson
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Laura Seidel
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Marcelo Ketzer
- Department of Biology and Environmental Sciences, Linnaeus University, Kalmar, Sweden
| | - Anders Forsman
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Samuel Hylander
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| |
Collapse
|
6
|
Deng H, He C, Worden AZ, Gong J. Employing a triple metabarcoding approach to differentiate active, dormant and dead microeukaryotes in sediments. Environ Microbiol 2024; 26:e16615. [PMID: 38501240 DOI: 10.1111/1462-2920.16615] [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: 01/12/2024] [Accepted: 03/08/2024] [Indexed: 03/20/2024]
Abstract
Microbial communities are commonly characterised through the metabarcoding of environmental DNA. This DNA originates from both viable (including dormant and active) and dead organisms, leading to recent efforts to distinguish between these states. In this study, we further these approaches by distinguishing not only between viable and dead cells but also between dormant and actively growing cells. This is achieved by sequencing both rRNA and rDNA, in conjunction with propidium monoazide cross-linked rDNA, to partition the active, dormant and relic fractions in environmental samples. We apply this method to characterise the diversity and assemblage structure of these fractions of microeukaryotes in intertidal sediments during a wet-dry-rewet incubation cycle. Our findings indicate that a significant proportion of microeukaryotic phylotypes detected in the total rDNA pools originate from dormant and relic microeukaryotes in the sediments, both in terms of richness (dormant, 13 ± 2%; relic, 47 ± 5%) and read abundance (dormant, 20 ± 7%; relic, 14 ± 5%). The richness and sequence proportion of dormant microeukaryotes notably increase during the transition from wet to dry conditions. Statistical analyses suggest that the dynamics of diversity and assemblage structure across different activity fractions are influenced by various environmental drivers. Our strategy offers a versatile approach that can be adapted to characterise other microbes in a wide range of environments.
Collapse
Affiliation(s)
- Huiwen Deng
- School of Marine Sciences, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou, China
| | - Cui He
- School of Marine Sciences, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
| | - Alexandra Z Worden
- Marine Biological Laboratory, Woods Hole, Massachusetts, USA
- Department of Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Jun Gong
- School of Marine Sciences, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou, China
| |
Collapse
|
7
|
Hedberg P, Olsson M, Höglander H, Brüchert V, Winder M. Climate change effects on plankton recruitment from coastal sediments. JOURNAL OF PLANKTON RESEARCH 2024; 46:117-125. [PMID: 38572122 PMCID: PMC10987100 DOI: 10.1093/plankt/fbad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 12/18/2023] [Indexed: 04/05/2024]
Abstract
In highly seasonal systems, the emergence of planktonic resting stages from the sediment is a key driver for bloom timing and plankton community composition. The termination of the resting phase is often linked to environmental cues, but the extent to which recruitment of resting stages is affected by climate change remains largely unknown for coastal environments. Here we investigate phyto- and zooplankton recruitment from oxic sediments in the Baltic Sea in a controlled experiment under proposed temperature and light increase during the spring and summer. We find that emergence of resting stage differs between seasons and the abiotic environment. Phytoplankton recruitment from resting stages were high in spring with significantly higher emergence rates at increased temperature and light levels for dinoflagellate and cyanobacteria than for diatoms, which had highest emergence under cold and dark conditions. In comparison, hatching of copepod nauplii was not affected by increased temperature and light levels. These results show that activation of plankton resting stages are affected to different degrees by increasing temperature and light levels, indicating that climate change affects plankton dynamics through processes related to resting stage termination with potential consequences for bloom timing, community composition and trophic mismatch.
Collapse
Affiliation(s)
- Per Hedberg
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- University of Helsinki, Tvärminne Zoological Station, 10900 Hanko, Finland
| | - Markus Olsson
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Helena Höglander
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Volker Brüchert
- Department of Geological Sciences, Stockholm University, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | - Monika Winder
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| |
Collapse
|
8
|
van der Reis AL, Sewell MA, Nelson WA. Investigating seed bank potential of crustose coralline algae using DNA metabarcoding. JOURNAL OF PHYCOLOGY 2024; 60:195-202. [PMID: 37864777 DOI: 10.1111/jpy.13403] [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: 06/12/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/23/2023]
Abstract
To examine the potential for the autogenic ecosystem engineers, crustose coralline algae (CCA), to serve as seed banks or refugia for life stages of other species, it is critical to develop sampling protocols that reflect the diversity of life present. In this pilot study on two shallow water species of CCA collected from Raoul Island (Kermadec Islands; Rangitāhua) New Zealand, we investigated two preservation methods (ethanol vs. silica gel), sampled inner and outer regions of the crusts, and used DNA metabarcoding and seven genes/gene regions (16S rRNA, 18S rRNA, 23S rRNA, cox1, rbcL, and tufA genes and the ITS rRNA region) to develop a protocol for taxa identification. The results revealed immense diversity, with typically more taxa identified within the inner layers than the outer layers. As highlighted in other metabarcoding studies and in earlier work on rhodoliths (nodose coralline algae), reference databases are incomplete, and to some extent, the use of multiple markers mitigates this issue. Specifically, the 23S rRNA and rbcL genes are currently more suitable for identifying algae, while the cox1 gene fares better at capturing the diversity present inclusive of algae. Further investigation of these autogenic ecosystem engineers that likely act as marine seed banks is needed.
Collapse
Affiliation(s)
| | - Mary A Sewell
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Wendy A Nelson
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Auckland War Memorial Museum Tāmaki Paenga Hira, Auckland, New Zealand
| |
Collapse
|
9
|
Mena C, Deulofeu-Capo O, Forn I, Dordal-Soriano J, Mantilla-Arias YA, Samos IP, Sebastián M, Cardelús C, Massana R, Romera-Castillo C, Mallenco-Fornies R, Gasol JM, Ruiz-González C. High amino acid osmotrophic incorporation by marine eukaryotic phytoplankton revealed by click chemistry. ISME COMMUNICATIONS 2024; 4:ycae004. [PMID: 38425478 PMCID: PMC10902890 DOI: 10.1093/ismeco/ycae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/12/2024] [Accepted: 01/12/2024] [Indexed: 03/02/2024]
Abstract
The osmotrophic uptake of dissolved organic compounds in the ocean is considered to be dominated by heterotrophic prokaryotes, whereas the role of planktonic eukaryotes is still unclear. We explored the capacity of natural eukaryotic plankton communities to incorporate the synthetic amino acid L-homopropargylglycine (HPG, analogue of methionine) using biorthogonal noncanonical amino acid tagging (BONCAT), and we compared it with prokaryotic HPG use throughout a 9-day survey in the NW Mediterranean. BONCAT allows to fluorescently identify translationally active cells, but it has never been applied to natural eukaryotic communities. We found a large diversity of photosynthetic and heterotrophic eukaryotes incorporating HPG into proteins, with dinoflagellates and diatoms showing the highest percentages of BONCAT-labelled cells (49 ± 25% and 52 ± 15%, respectively). Among them, pennate diatoms exhibited higher HPG incorporation in the afternoon than in the morning, whereas small (≤5 μm) photosynthetic eukaryotes and heterotrophic nanoeukaryotes showed the opposite pattern. Centric diatoms (e.g. Chaetoceros, Thalassiosira, and Lauderia spp.) dominated the eukaryotic HPG incorporation due to their high abundances and large sizes, accounting for up to 86% of the eukaryotic BONCAT signal and strongly correlating with bulk 3H-leucine uptake rates. When including prokaryotes, eukaryotes were estimated to account for 19-31% of the bulk BONCAT signal. Our results evidence a large complexity in the osmotrophic uptake of HPG, which varies over time within and across eukaryotic groups and highlights the potential of BONCAT to quantify osmotrophy and protein synthesis in complex eukaryotic communities.
Collapse
Affiliation(s)
- Catalina Mena
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Ona Deulofeu-Capo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Irene Forn
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Júlia Dordal-Soriano
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Yulieth A Mantilla-Arias
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Iván P Samos
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Marta Sebastián
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Clara Cardelús
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Ramon Massana
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Cristina Romera-Castillo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Rebeca Mallenco-Fornies
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Josep M Gasol
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| | - Clara Ruiz-González
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona 08003, Spain
| |
Collapse
|
10
|
Xiao X, Peng Y, Zhang W, Yang X, Zhang Z, Ren B, Zhu G, Zhou S. Current status and prospects of algal bloom early warning technologies: A Review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 349:119510. [PMID: 37951110 DOI: 10.1016/j.jenvman.2023.119510] [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: 07/26/2023] [Revised: 10/21/2023] [Accepted: 10/31/2023] [Indexed: 11/13/2023]
Abstract
In recent years, frequent occurrences of algal blooms due to environmental changes have posed significant threats to the environment and human health. This paper analyzes the reasons of algal bloom from the perspective of environmental factors such as nutrients, temperature, light, hydrodynamics factors and others. Various commonly used algal bloom monitoring methods are discussed, including traditional field monitoring methods, remote sensing techniques, molecular biology-based monitoring techniques, and sensor-based real-time monitoring techniques. The advantages and limitations of each method are summarized. Existing algal bloom prediction models, including traditional models and machine learning (ML) models, are introduced. Support Vector Machine (SVM), deep learning (DL), and other ML models are discussed in detail, along with their strengths and weaknesses. Finally, this paper provides an outlook on the future development of algal bloom warning techniques, proposing to combine various monitoring methods and prediction models to establish a multi-level and multi-perspective algal bloom monitoring system, further improving the accuracy and timeliness of early warning, and providing more effective safeguards for environmental protection and human health.
Collapse
Affiliation(s)
- Xiang Xiao
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Yazhou Peng
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
| | - Wei Zhang
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
| | - Xiuzhen Yang
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Zhi Zhang
- Laboratory of Three Gorges Reservoir Region, Chongqing University, Chongqing, 400045, China
| | - Bozhi Ren
- School of Earth Sciences and Spatial Information Engineering, Hunan University of Science and Technology, Xiangtan, 411201, Hunan, China
| | - Guocheng Zhu
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Saijun Zhou
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| |
Collapse
|
11
|
Zhang X, Zhang Y, Chen Z, Gu P, Li X, Wang G. Exploring cell aggregation as a defense strategy against perchlorate stress in Chlamydomonas reinhardtii through multi-omics analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167045. [PMID: 37709088 DOI: 10.1016/j.scitotenv.2023.167045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
Perchlorate (ClO4-) is a type of novel, widely distributed, and persistent inorganic pollutant. However, the impacts of perchlorate on freshwater algae remain unclear. In this study, the response and defense mechanisms of microalgae (Chlamydomonas reinhardtii) under perchlorate stress were investigated by integrating physiological and biochemical monitoring, transcriptomics, and metabolomics. Weighted gene co-expression network analysis (WGCNA) of transcriptome data was used to analyze the relationship between genes and phenotype and screen the key pathways. C. reinhardtii exhibited aggregate behavior when exposed to 100- and 200-mM perchlorate but was restored to its unicellular lifestyle when transferred to fresh medium. WGCNA results found that the "carbohydrate metabolism" and "lipid metabolism" pathways were closely related to cell aggregation phenotype. The differential expression genes (DEGs) and differentially accumulated metabolites (DAMs) of these pathways were upregulated, indicating that the lipid and carbohydrate metabolisms were enhanced in aggregated cells. Additionally, most genes and metabolites related to phytohormone abscisic acid (ABA) biosynthesis and the mitogen-activated protein kinase (MAPK) signaling pathway were significantly upregulated, indicating their crucial roles in the signal transmission of aggregated cells. Meanwhile, in aggregated cells, extracellular polymeric substances (EPS) and lipid contents increased, photosynthesis activity decreased, and the antioxidant system was activated. These characteristics contributed to C. reinhardtii's improved resistance to perchlorate stress. Above results demonstrated that cell aggregation behavior was the principal defense strategy of C. reinhardtii against perchlorate. Overall, this study sheds new light on the impact mechanisms of perchlorate to aquatic microalgae and provides multi-omics insights into the research of multicellular-like aggregation as an adaptation strategy to abiotic stress. These results are beneficial for assessing the risk of perchlorate in aquatic environments.
Collapse
Affiliation(s)
- Xianyuan Zhang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yixiao Zhang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; School of Science, Tibet University, Lasha 850000, China
| | - Zixu Chen
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peifan Gu
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Li
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Gaohong Wang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
12
|
Woltz CR, Anderson RP, Tosca NJ, Porter SM. The role of clay minerals in the preservation of Precambrian organic-walled microfossils. GEOBIOLOGY 2023; 21:708-724. [PMID: 37724627 DOI: 10.1111/gbi.12573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 06/20/2023] [Accepted: 08/12/2023] [Indexed: 09/21/2023]
Abstract
Precambrian organic-walled microfossils (OWMs) are primarily preserved in mudstones and shales that are low in total organic carbon (TOC). Recent work suggests that high TOC may hinder OWM preservation, perhaps because it interferes with chemical interactions involving certain clay minerals that inhibit the decay of microorganisms. To test if clay mineralogy controls OWM preservation, and if TOC moderates the effect of clay minerals, we compared OWM preservational quality (measured by pitting on fossil surfaces and the deterioration of wall margins) to TOC, total clay, and specific clay mineral concentrations in 78 shale samples from 11 lithologic units ranging in age from ca. 1650 to 650 million years ago. We found that the probability of finding well-preserved microfossils positively correlates with total clay concentrations and confirmed that it negatively correlates with TOC concentrations. However, we found no evidence that TOC influences the effect of clay mineral concentrations on OWM preservation, supporting an independent role of both factors on preservation. Within the total clay fraction, well-preserved microfossils are more likely to occur in shales with high illite concentrations and low berthierine/chamosite concentrations; however, the magnitude of their effect on preservation is small. Therefore, there is little evidence that bulk clay chemistry is important in OWM preservation. Instead, we propose that OWM preservation is largely regulated by physical properties that isolate organic remains from microbial degradation such as food scarcity (low TOC) and low sediment permeability (high total clay content): low TOC increases the diffusive distances between potential carbon sources and heterotrophic microbes (or their degradative enzymes), while high clay concentrations reduce sediment pore space, thereby limiting the diffusion of oxidants and degradative enzymes to the sites of decay.
Collapse
Affiliation(s)
- C R Woltz
- Department of Earth Science, University of California, Santa Barbara, California, USA
- Department of Earth and Planetary Sciences, Stanford University, Stanford, California, USA
| | - R P Anderson
- All Souls College, University of Oxford, Oxford, UK
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - N J Tosca
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - S M Porter
- Department of Earth Science, University of California, Santa Barbara, California, USA
| |
Collapse
|
13
|
Meyvisch P, Mertens KN, Gurdebeke PR, Sandt C, Pospelova V, Vrielinck H, Borondics F, Louwye S. Does dinocyst wall composition really reflect trophic affinity? New evidence from ATR micro-FTIR spectroscopy measurements. JOURNAL OF PHYCOLOGY 2023; 59:1064-1084. [PMID: 37623312 DOI: 10.1111/jpy.13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/02/2023] [Accepted: 07/21/2023] [Indexed: 08/26/2023]
Abstract
Attenuated total reflection (ATR) microscope Fourier transform infrared (micro-FTIR) spectroscopy was used to investigate the dinosporin composition in the walls of modern, organic-walled dinoflagellate resting cysts (dinocysts). Variable cyst wall compositions were observed, which led to the erection of four spectrochemical groups, some with striking similarities to other resistant biomacromolecules such as sporopollenin and algaenan. Furthermore, possible proxies derivable from the spectrochemical composition of modern and fossil dinocysts were discussed. The color of the dinocyst walls was reflected in the spectral data. When comparing that color with a standard and the results of a series of bleaching experiments with oxidative agents, eumelanin was assigned as a likely pigment contributing to the observed color. Following this assignment, the role of eumelanin as an ultraviolet sunscreen in colored dinocysts was hypothesized, and its implications on the autofluorescence and morphological preservation of dinocysts were further discussed. Unlike what had previously been assumed, it was shown that micro-FTIR data from dinocysts cannot be used to unambiguously infer trophic affinities of their associated cells. Finally, using methods with high spatial resolutions (synchrotron transmission micro-FTIR and optical photothermal infrared spectroscopy), it was shown that dinocyst wall layers are chemically homogenous at the probed scales. This study fills a large knowledge gap in our understanding of the chemical nature of dinocyst walls and has nuanced certain assumptions and interpretations made in the past.
Collapse
Affiliation(s)
| | | | | | | | - Vera Pospelova
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Henk Vrielinck
- Department of Solid-State Sciences, Ghent University, Ghent, Belgium
| | | | | |
Collapse
|
14
|
Ramond P, Siano R, Sourisseau M, Logares R. Assembly processes and functional diversity of marine protists and their rare biosphere. ENVIRONMENTAL MICROBIOME 2023; 18:59. [PMID: 37443126 PMCID: PMC10347826 DOI: 10.1186/s40793-023-00513-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023]
Abstract
BACKGROUND The mechanisms shaping the rare microbial biosphere and its role in ecosystems remain unclear. We developed an approach to study ecological patterns in the rare biosphere and use it on a vast collection of marine microbiomes, sampled in coastal ecosystems at a regional scale. We study the assembly processes, and the ecological strategies constituting the rare protistan biosphere. Using the phylogeny and morpho-trophic traits of these protists, we also explore their functional potential. RESULTS Taxonomic community composition remained stable along rank abundance curves. Conditionally rare taxa, driven by selection processes, and transiently rare taxa, with stochastic distributions, were evidenced along the rank abundance curves of all size-fractions. Specific taxa within the divisions Sagenista, Picozoa, Telonemia, and Choanoflagellida were rare across time and space. The distribution of traits along rank abundance curves outlined a high functional redundancy between rare and abundant protists. Nevertheless, trophic traits illustrated an interplay between the trophic groups of different size-fractions. CONCLUSIONS Our results suggest that rare and abundant protists are evolutionary closely related, most notably due to the high microdiversity found in the rare biosphere. We evidenced a succession of assembly processes and strategies of rarity along rank abundance curves that we hypothesize to be common to most microbiomes at the regional scale. Despite high functional redundancy in the rare protistan biosphere, permanently rare protists were evidenced, and they could play critical functions as bacterivores and decomposers from within the rare biosphere. Finally, changes in the composition of the rare protistan biosphere could be influenced by the trophic regime of aquatic ecosystems. Our work contributes to understanding the role of rare protists in microbiomes.
Collapse
Affiliation(s)
- Pierre Ramond
- Institute of Marine Sciences (ICM), Department of Marine Biology and Oceanography, CSIC, Barcelona, Catalunya, 08003, Spain.
| | - Raffaele Siano
- DYNECO/Pelagos, Ifremer-Centre de Brest, Technopôle Brest Iroise, Plouzané, 29280, France
| | - Marc Sourisseau
- DYNECO/Pelagos, Ifremer-Centre de Brest, Technopôle Brest Iroise, Plouzané, 29280, France
| | - Ramiro Logares
- Institute of Marine Sciences (ICM), Department of Marine Biology and Oceanography, CSIC, Barcelona, Catalunya, 08003, Spain
| |
Collapse
|
15
|
Schwartz DA, Shoemaker WR, Măgălie A, Weitz JS, Lennon JT. Bacteria-phage coevolution with a seed bank. THE ISME JOURNAL 2023:10.1038/s41396-023-01449-2. [PMID: 37286738 DOI: 10.1038/s41396-023-01449-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/25/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
Dormancy is an adaptation to living in fluctuating environments. It allows individuals to enter a reversible state of reduced metabolic activity when challenged by unfavorable conditions. Dormancy can also influence species interactions by providing organisms with a refuge from predators and parasites. Here we test the hypothesis that, by generating a seed bank of protected individuals, dormancy can modify the patterns and processes of antagonistic coevolution. We conducted a factorially designed experiment where we passaged a bacterial host (Bacillus subtilis) and its phage (SPO1) in the presence versus absence of a seed bank consisting of dormant endospores. Owing in part to the inability of phages to attach to spores, seed banks stabilized population dynamics and resulted in minimum host densities that were 30-fold higher compared to bacteria that were unable to engage in dormancy. By supplying a refuge to phage-sensitive strains, we show that seed banks retained phenotypic diversity that was otherwise lost to selection. Dormancy also stored genetic diversity. After characterizing allelic variation with pooled population sequencing, we found that seed banks retained twice as many host genes with mutations, whether phages were present or not. Based on mutational trajectories over the course of the experiment, we demonstrate that seed banks can dampen bacteria-phage coevolution. Not only does dormancy create structure and memory that buffers populations against environmental fluctuations, it also modifies species interactions in ways that can feed back onto the eco-evolutionary dynamics of microbial communities.
Collapse
Affiliation(s)
- Daniel A Schwartz
- Department of Biology, Indiana University, Bloomington, Indiana, IN, USA
| | - William R Shoemaker
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
| | - Andreea Măgălie
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
- Institut de Biologie, École Normale Supérieure, Paris, France
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, Indiana, IN, USA.
| |
Collapse
|
16
|
Patil JS, Sathish K. Responses of Phytoplankton Benthic Propagules to Macronutrient Enrichment and Varying Light Intensities: Elucidation from Monsoon-Influenced Mandovi and Zuari Riverine System : Responses of Phytoplankton Benthic Propagules to Macronutrient Enrichment and Varying Light Intensities: Elucidation from Monsoon-Influenced Mandovi and Zuari Riverine System. MICROBIAL ECOLOGY 2023; 85:1367-1381. [PMID: 35575806 DOI: 10.1007/s00248-022-02021-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 04/20/2022] [Indexed: 05/10/2023]
Abstract
The ecological importance of phytoplankton-benthic-propagules (PBP) from coastal sediments, except tropical monsoon-influenced rivers and estuaries, is well documented. PBP in such systems is often transported from upstream (near freshwater) to downstream (estuary) through freshwater discharges during monsoon and thereby experiences higher salinities (>30 PSU) and nutrients with varying light conditions due to reducing discharges during the monsoon-break/withdrawal-phase. However, the PBP responses (germination and subsequent growth) to such changes are unknown and are examined here at ~35 PSU salinity. For the study, macronutrients (nitrate, phosphate, silicate, and nitrate+phosphate+silicate) and light intensities were considered to assess the response of PBP representing estuarine, brackish, and near freshwater locations of monsoon-influenced Mandovi and Zuari rivers (Goa, India). Diatoms dominated the viable PBP community, but the maximum growth and sustained photosynthetic activity were observed when all macronutrients were supplied than individually. Here, variable fluorescence technique utility in PBP resurrection (detection of viability and responses) was also explored. The PBP growth was similar for macronutrients but increased with light intensity indicating a longer growth response during monsoon. For PBP (germination and photosynthetic activity), light intensities drive the rate of improvement/development, whereas the nutrients are essential for maintaining vegetative growth upon germination in the region. The PBP dominance of common planktonic species (Skeletonema and Thalassiosira) along the river also signifies the role of seawater intrusion (up to upstream locations) in distribution. Skeletonema and Thalassiosira, which contribute significantly to the total community, are light-sensitive with a similar response and cause single species blooms during monsoon and non-monsoon, respectively, depending on the species' tolerance to salinity.
Collapse
Affiliation(s)
- Jagadish S Patil
- CSIR - National Institute of Oceanography, Dona Paula,, 403 004, Goa, India.
| | - K Sathish
- CSIR - National Institute of Oceanography, Dona Paula,, 403 004, Goa, India
| |
Collapse
|
17
|
McCourt RM, Lewis LA, Strother PK, Delwiche CF, Wickett NJ, de Vries J, Bowman JL. Green land: Multiple perspectives on green algal evolution and the earliest land plants. AMERICAN JOURNAL OF BOTANY 2023; 110:e16175. [PMID: 37247371 DOI: 10.1002/ajb2.16175] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 05/31/2023]
Abstract
Green plants, broadly defined as green algae and the land plants (together, Viridiplantae), constitute the primary eukaryotic lineage that successfully colonized Earth's emergent landscape. Members of various clades of green plants have independently made the transition from fully aquatic to subaerial habitats many times throughout Earth's history. The transition, from unicells or simple filaments to complex multicellular plant bodies with functionally differentiated tissues and organs, was accompanied by innovations built upon a genetic and phenotypic toolkit that have served aquatic green phototrophs successfully for at least a billion years. These innovations opened an enormous array of new, drier places to live on the planet and resulted in a huge diversity of land plants that have dominated terrestrial ecosystems over the past 500 million years. This review examines the greening of the land from several perspectives, from paleontology to phylogenomics, to water stress responses and the genetic toolkit shared by green algae and plants, to the genomic evolution of the sporophyte generation. We summarize advances on disparate fronts in elucidating this important event in the evolution of the biosphere and the lacunae in our understanding of it. We present the process not as a step-by-step advancement from primitive green cells to an inevitable success of embryophytes, but rather as a process of adaptations and exaptations that allowed multiple clades of green plants, with various combinations of morphological and physiological terrestrialized traits, to become diverse and successful inhabitants of the land habitats of Earth.
Collapse
Affiliation(s)
- Richard M McCourt
- Department of Biodiversity, Earth, and Environmental Sciences, Drexel University, Philadelphia, PA, 19118, USA
| | - Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - Paul K Strother
- Department of Earth and Environmental Sciences, Boston College Weston Observatory, 381 Concord Road, Weston, MA, 02493, USA
| | - Charles F Delwiche
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA
| | - Norman J Wickett
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA
| | - Jan de Vries
- Göttingen Center for Molecular Biosciences, Department of Applied Bioinformatics, University of Göttingen Goldschmidtstr. 1, Göttingen, 37077, Germany
| | - John L Bowman
- School of Biological Sciences, Monash University, Clayton Campus, Melbourne, Victoria, 3800, Australia
| |
Collapse
|
18
|
Gene expression during the formation of resting spores induced by nitrogen starvation in the marine diatom Chaetoceros socialis. BMC Genomics 2023; 24:106. [PMID: 36899305 PMCID: PMC9999646 DOI: 10.1186/s12864-023-09175-x] [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: 07/21/2022] [Accepted: 02/09/2023] [Indexed: 03/12/2023] Open
Abstract
BACKGROUND Dormancy is widespread in both multicellular and unicellular organisms. Among diatoms, unicellular microalgae at the base of all aquatic food webs, several species produce dormant cells (spores or resting cells) that can withstand long periods of adverse environmental conditions. RESULTS We present the first gene expression study during the process of spore formation induced by nitrogen depletion in the marine planktonic diatom Chaetoceros socialis. In this condition, genes related to photosynthesis and nitrate assimilation, including high-affinity nitrate transporters (NTRs), were downregulated. While the former result is a common reaction among diatoms under nitrogen stress, the latter seems to be exclusive of the spore-former C. socialis. The upregulation of catabolic pathways, such as tricarboxylic acid cycle, glyoxylate cycle and fatty acid beta-oxidation, suggests that this diatom could use lipids as a source of energy during the process of spore formation. Furthermore, the upregulation of a lipoxygenase and several aldehyde dehydrogenases (ALDHs) advocates the presence of oxylipin-mediated signaling, while the upregulation of genes involved in dormancy-related pathways conserved in other organisms (e.g. serine/threonine-protein kinases TOR and its inhibitor GATOR) provides interesting avenues for future explorations. CONCLUSIONS Our results demonstrate that the transition from an active growth phase to a resting one is characterized by marked metabolic changes and provides evidence for the presence of signaling pathways related to intercellular communication.
Collapse
|
19
|
Klemm K, Cembella A, Clarke D, Cusack C, Arneborg L, Karlson B, Liu Y, Naustvoll L, Siano R, Gran-Stadniczeñko S, John U. Apparent biogeographical trends in Alexandrium blooms for northern Europe: identifying links to climate change and effective adaptive actions. HARMFUL ALGAE 2022; 119:102335. [PMID: 36344194 DOI: 10.1016/j.hal.2022.102335] [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: 12/31/2021] [Revised: 09/15/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
The marine dinoflagellate Alexandrium Halim represents perhaps the most significant and intensively studied genus with respect to species diversity, life history strategies, toxigenicity, biogeographical distribution, and global magnitude and consequences harmful algal blooms (HABs). The socioeconomic impacts, environmental and human health risks, and mitigation strategies for toxigenic Alexandrium blooms have also been explored in recent years. Human adaptive actions based on future scenarios of bloom dynamics and shifts in biogeographical distribution under climate-change parameters remain under development and not yet implemented on a regional scale. In the CoCliME (Co-development of climate services for adaptation to changing marine ecosystems) project these issues were addressed with respect to past, current and anticipated future status of key HAB genera and expected benefits of enhanced monitoring. Data on the distribution and frequency of Alexandrium blooms related to paralytic shellfish toxin (PST) events from key CoCliME Case Study areas, comprising the North Sea and adjacent Kattegat-Skagerrak, Norwegian Sea, and Baltic Sea, and eastern North Atlantic marginal seas, were evaluated in a contemporary and historical context over the past several decades. The first evidence of possible biogeographical expansion of Alexandrium taxa into eastern Arctic gateways was provided from DNA barcoding signatures. Various key climate change indicators, such as salinity, temperature, and water-column stratification, relevant to Alexandrium bloom initiation and development were identified. The possible influence of changing variables on bloom dynamics, magnitude, frequency and spatial and temporal distribution were interpreted in the context of regional ocean climate models. These climate change impact indicators may play key roles in selecting for the occurrence and diversity of Alexandrium species within the broader microeukaryote communities. For example, shifts to higher temperature and lower salinity regimes predicted for the southern North Sea indicate the potential for increased Alexandrium blooms, currently absent from this area. Ecological and socioeconomic impacts of Alexandrium blooms and effects on fisheries and aquaculture resources and coastal ecosystem function are evaluated, and, where feasible, effective adaptation strategies are proposed herein as emerging climate services.
Collapse
Affiliation(s)
- Kerstin Klemm
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany
| | - Allan Cembella
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany
| | - Dave Clarke
- Marine Institute, Rinville, Oranmore, Co. Galway, Ireland
| | | | - Lars Arneborg
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Bengt Karlson
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Ye Liu
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Lars Naustvoll
- Institute of Marine Research, PO Box 1870 Nordnes, Bergen NO-5817, Norway
| | | | - Sandra Gran-Stadniczeñko
- Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, Oslo 0316, Norway
| | - Uwe John
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany.
| |
Collapse
|
20
|
Rodríguez-Villegas C, Díaz PA, Salgado P, Tomasetti SJ, Díaz M, Marín SL, Baldrich ÁM, Niklitschek E, Pino L, Matamala T, Espinoza K, Figueroa RI. The role of physico-chemical interactions in the seasonality of toxic dinoflagellate cyst assemblages: The case of the NW Patagonian fjords system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:119901. [PMID: 35963388 DOI: 10.1016/j.envpol.2022.119901] [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: 04/22/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Harmful algal blooms (HABs) are recurrent in the NW Patagonia fjords system and their frequency has increased over the last few decades. Outbreaks of HAB species such as Alexandrium catenella, a causal agent of paralytic shellfish poisoning, and Protoceratium reticulatum, a yessotoxins producer, have raised considerable concern due to their adverse socioeconomic consequences. Monitoring programs have mainly focused on their planktonic stages, but since these species produce benthic resting cysts, the factors influencing cyst distributions are increasingly gaining recognition as potentially important to HAB recurrence in some regions. Still, a holistic understanding of the physico-chemical conditions influencing cyst distribution in this region is lacking, especially as it relates to seasonal changes in drivers of cyst distributions, as the characteristics that favor cyst preservation in the sediment may change through the seasons. In this study, we analyzed the physico-chemical properties of the sediment (temperature, pH, redox potential) and measured the bottom dissolved oxygen levels in a "hotspot" area of southern Chile, sampling during the spring and summer as well as the fall and winter, to determine the role these factors may play as modulators of dinoflagellate cyst distribution, and specifically for the cysts of A. catenella and P. reticulatum. A permutational analysis of variance (PERMANOVA) showed the significant effect of sediment redox conditions in explaining the differences in the cyst assemblages between spring-summer and fall-winter periods (seasonality). In a generalized linear model (GLM), sediment redox potential and pH were associated with the highest abundances of A. catenella resting cysts in the spring-summer, however it was sediment temperature that most explained the distribution of A. catenella in the fall-winter. For P. reticulatum, only spring-summer sediment redox potential and temperature explained the variation in cyst abundances. The implications of environmental (physico-chemical) seasonality for the resting cysts dynamics of both species are discussed.
Collapse
Affiliation(s)
- Camilo Rodríguez-Villegas
- Programa de Doctorado en Ciencias, Mención Conservación y Manejo de Recursos Naturales, Universidad de Los Lagos, Camino Chinquihue Km 6, Puerto Montt, Chile; Centro i∼mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile; CeBiB, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile.
| | - Patricio A Díaz
- Centro i∼mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile; CeBiB, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile
| | - Pablo Salgado
- Centro de Estudios de Algas Nocivas (CREAN), Instituto de Fomento Pesquero (IFOP), Enrique Abello 0552, Punta Arenas, Chile
| | | | - Manuel Díaz
- Programa de Investigación Pesquera, Universidad Austral de Chile, Puerto Montt, Chile; Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Sandra L Marín
- Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Ángela M Baldrich
- Programa de Doctorado en Ciencias, Mención Conservación y Manejo de Recursos Naturales, Universidad de Los Lagos, Camino Chinquihue Km 6, Puerto Montt, Chile; Centro i∼mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile; CeBiB, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile
| | - Edwin Niklitschek
- Centro i∼mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, Chile
| | - Loreto Pino
- Programa de Investigación Pesquera, Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Thamara Matamala
- Programa de Investigación Pesquera, Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Katherine Espinoza
- Programa de Investigación Pesquera, Instituto de Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - Rosa I Figueroa
- Centro Oceanográfico de Vigo, Instituto Español de Oceanografía (IEO-CSIC), Subida a Radio Faro 50, 36390, Vigo, Spain
| |
Collapse
|
21
|
A case for an active eukaryotic marine biosphere during the Proterozoic era. Proc Natl Acad Sci U S A 2022; 119:e2122042119. [PMID: 36191216 PMCID: PMC9564328 DOI: 10.1073/pnas.2122042119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The microfossil record demonstrates the presence of eukaryotic organisms in the marine ecosystem by about 1,700 million years ago (Ma). Despite this, steranes, a biomarker indicator of eukaryotic organisms, do not appear in the rock record until about 780 Ma in what is known as the "rise of algae." Before this, it is argued that eukaryotes were minor ecosystem members, with prokaryotes dominating both primary production and ecosystem dynamics. In this view, the rise of algae was possibly sparked by increased nutrient availability supplying the higher nutrient requirements of eukaryotic algae. Here, we challenge this view. We use a size-based ecosystem model to show that the size distribution of preserved eukaryotic microfossils from 1,700 Ma and onward required an active eukaryote ecosystem complete with phototrophy, osmotrophy, phagotrophy, and mixotrophy. Model results suggest that eukaryotes accounted for one-half or more of the living biomass, with eukaryotic algae contributing to about one-half of total marine primary production. These ecosystems lived with deep-water phosphate levels of at least 10% of modern levels. The general lack of steranes in the pre-780-Ma rock record could be a result of poor preservation.
Collapse
|
22
|
Lin S, Yu L, Wu X, Li M, Zhang Y, Luo H, Li H, Li T, Li L. Active meiosis during dinoflagellate blooms: A 'sex for proliferation' hypothesis. HARMFUL ALGAE 2022; 118:102307. [PMID: 36195414 DOI: 10.1016/j.hal.2022.102307] [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: 07/21/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 06/16/2023]
Abstract
In dinoflagellates, sexual reproduction is best known to be induced by adverse environmental conditions and culminate in encystment for survival ('sex for encystment'). Although increasing laboratory observations indicate that sex can lead to production of vegetative cells bypassing encystment, the occurrence of this alternative pathway in natural populations and its ecological roles remain poorly understood. Here we report evidence that sex in dinoflagellates can potentially be an instrument for bloom proliferation or extension. By bloom metatranscriptome profiling, we documented elevated expression of meiosis genes in two evolutionarily distinct species (Prorocentrum shikokuense and Karenia mikimotoi) during bloom, a timing unexpected of the 'sex for encystment' scenario. To link these genes to meiosis, we induced encystment and cyst germination in the cyst-forming species Scrippsiella acuminata, and found that five of these genes were upregulated during cyst germination, when meiosis occurs. Integrating data from all three species revealed that SPO11, MND1, and DMC1 were likely common between cyst-forming and non-encysting sex in dinoflagellates. Furthermore, flow cytometric analyses revealed consecutive rounds of DNA halving during blooms of P. shikokuense and K. mikimotoi, evidencing meiosis. These data provided novel evidence that sexual reproduction in dinoflagellates might serve to promote cell proliferation, and along with the consequent enhancement of genetic diversity facilitating resistance against pathogens and environmental stress, to boost or extend a bloom ('sex for proliferation'). The putative meiosis-specific genes and insights reported here will prove to be helpful for rigorously testing the hypothesis and addressing whether the two modes of sex are genetically predisposed (i.e. species-specific) or environmentally induced (switchable within species), and if the latter what triggers the switch.
Collapse
Affiliation(s)
- Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaomei Wu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Meizhen Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yaqun Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hao Luo
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hongfei Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Tangcheng Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| |
Collapse
|
23
|
Arroyo-Esquivel J, Hastings A, Baskett ML. Characterizing Long Transients in Consumer–Resource Systems With Group Defense and Discrete Reproductive Pulses. Bull Math Biol 2022; 84:102. [PMID: 35964274 PMCID: PMC9376152 DOI: 10.1007/s11538-022-01059-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022]
Abstract
AbstractDuring recent years, the study of long transients has been expanded in ecological theory to account for shifts in long-term behavior of ecological systems. These long transients may lead to regime shifts between alternative states that resemble the dynamics of alternative stable states for a prolonged period of time. One dynamic that potentially leads to long transients is the group defense of a resource in a consumer–resource interaction. Furthermore, time lags in the population caused by discrete reproductive pulses have the potential to produce long transients, either independently or in conjunction to the transients caused by the group defense. In this work, we analyze the potential for long transients in a model for a consumer–resource system in which the resource exhibits group defense and reproduces in discrete reproductive pulses. This system exhibits crawl-by transients near the extinction and carrying capacity states of resource, and a transcritical bifurcation, under which a ghost limit cycle appears. We estimate the transient time of our system from these transients using perturbation theory. This work advances an understanding of how systems shift between alternate states and their duration of staying in a given regime and what ecological dynamics may lead to long transients.
Collapse
Affiliation(s)
| | - Alan Hastings
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, USA
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, USA
| |
Collapse
|
24
|
Zhong Y, Su Y, Zhang D, She C, Chen N, Chen J, Yang H, Balaji-Prasath B. The spatiotemporal variations in microalgae communities in vertical waters of a subtropical reservoir. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 317:115379. [PMID: 35751236 DOI: 10.1016/j.jenvman.2022.115379] [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: 12/05/2021] [Revised: 05/02/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
The construction of cascade reservoirs increases eutrophication and exacerbates algal blooms and thus threatens water quality. Previous studies on the microalgae in reservoir have mainly focused on the spatio-temporal patterns of surface microalgae communities at the horizontal scale, while few studies have simultaneously considered the successions of microalgae in vertical profiles including the sediments and the effects of the nutrients release and microalgae in sediments on microalgae in upper waters. In this study, we investigated the effects of microalgae and physico-chemical parameters in waters and sediments on the successions of vertical microalgae communities in Xipi Reservoir, Southeast China. The seasonal variations in microalgae compositions decreased gradually from the surface water (the dominance of Cryptophyta and Chlorophyta in spring, Chlorophyta and Cyanophyta in summer, and relatively uniform in autumn and winter) to the sediment (the dominance of Bacillariophyta throughout the year), which was influenced by the variations of physico-chemical factors in different layers. The spatio-temporal variations in microalgae communities in waters was attributing to not only the heterogeneities of the stratification, and the physico-chemical factors such as water temperature, pH, and nutrient concentrations, especially for phosphorus in the water column, but also the combinations of phosphorus release and microalgae composition in sediments. Environmental changes would be especially problematic for microalgae groups such as Cryptophyta, Dinophyta and Chlorophyta that were sensitive to the changes of temperature and nutrients. Our results are helpful for an extensive understanding of the dynamics of microalgae communities in reservoir, and contribute to reservoir management for ensuring the safety of drinking water.
Collapse
Affiliation(s)
- Yanping Zhong
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, 350007, China; College of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Yuping Su
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, 350007, China.
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Chenxing She
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, 350007, China
| | - Nengwang Chen
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen, 361005, China
| | - Jixin Chen
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen, 361005, China
| | - Hong Yang
- Department of Geography and Environmental Science, University of Reading, Reading, RG6 6AB, UK
| | - Barathan Balaji-Prasath
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, 350007, China
| |
Collapse
|
25
|
Wang Z, Peng L, Xie C, Wang W, Zhang Y, Xiao L, Tang Y, Yang Y. Metabarcoding of harmful algal bloom species in sediments from four coastal areas of the southeast China. Front Microbiol 2022; 13:999886. [PMID: 36118226 PMCID: PMC9471092 DOI: 10.3389/fmicb.2022.999886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/16/2022] [Indexed: 11/17/2022] Open
Abstract
In the past three decades, harmful algal blooms (HAB) have become more frequent and widespread in southeast Chinese sea areas. Resting stages are regarded as the “seed bank” of algal blooms, and play an important role in initiating HABs. The distribution of resting stages in sediments especially those of HAB species can make good predictions about the potential risk of future blooms, however with limited reports. In this study, surface sediment samples were collected in the four sea areas along the southeast Chinese coasts, including Dafeng Port (DF) in the southern Yellow Sea, Xiangshan Bay (XS), Funing Bay (FN), and Dongshan Bay (DS) in the East China Sea. Diversity and community structure of eukaryotic microalgae in surface sediments were assessed by metabarcoding V4 region of the 18S rDNA, focusing on the distribution of HAB species. Biogenic elements including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), biogenic silicon (BSi), and moisture content (MC) were analyzed. A total of 454 eukaryotic algal OTUs were detected, which belonged to 31 classes of 9 phyla. Altogether 149 algal species were detected in this study, and 59 taxa have been reported to form resting stages. Eukaryotic algal community was similar in XS, FN and DS of the East China Sea, which were predominated by dinoflagellates. However, algal community was different in DF of the Yellow Sea, and characterized by the dominance of chrysophytes and low OTU richness. The distribution of most abundant HAB species showed positive correlations with TN, BSi, and TOC, suggesting that eutrophication and consequent increase in diatom productivity may have a significant influence on the distribution of HAB species and facilitate the occurrence of HABs. Furthermore, HAB species occurred more abundantly and widely in FN. Our results suggest high potential risks of HABs in the southeast Chinese coast especially in Funing Bay.
Collapse
Affiliation(s)
- Zhaohui Wang
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Liang Peng
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Changliang Xie
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Wenting Wang
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Yuning Zhang
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Lijuan Xiao
- College of Life Science and Technology, Jinan University, Guangzhou, China
- *Correspondence: Lijuan Xiao,
| | - Yali Tang
- College of Life Science and Technology, Jinan University, Guangzhou, China
- Yali Tang,
| | - Yufeng Yang
- College of Life Science and Technology, Jinan University, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| |
Collapse
|
26
|
Wu X, Li L, Lin S. Energy metabolism and genetic information processing mark major transitions in the life history of Scrippsiella acuminata (Dinophyceae). HARMFUL ALGAE 2022; 116:102248. [PMID: 35710202 DOI: 10.1016/j.hal.2022.102248] [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: 12/28/2021] [Revised: 05/01/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Many dinoflagellates perform sexual reproduction and form cysts as a life history strategy to survive adverse environmental conditions and seed annual harmful algal blooms (HABs). The molecular mechanisms underpinning the life stage transitions can provide clues about how key environmental factors induce encystment and initiation of a HAB but are still poorly understood. Here, we conducted an integrated physiological and transcriptomic study to unravel the mechanisms in Scrippsiella acuminata. We established a culture from a bloom, induced cyst formation, and divided the process into four life stages. Transcriptomic analysis of these stages revealed 19,900 differentially expressed genes (DEGs). The expression of genes related to photosynthesis was significantly up-regulated from vegetative stage to immature cyst stage, consistent with the marked increase in cell contents of energy-storing macromolecules (carbohydrates and lipids). When proceeding to resting cysts, most photosynthesis genes were down-regulated while "genetic information processing" related genes were up-regulated. Comparing germinating cysts with resting cysts revealed 100 DEGs involved in energy metabolism, indicating a high energy requirement of germination. In addition, the transition from germinating cysts to vegetative cells featured up-regulation of photosynthesis. Our results demonstrate that energy storage and consumption play a pivotal role in cyst formation and germination respectively and genetic information processing is crucial in cyst dormancy.
Collapse
Affiliation(s)
- Xiaomei Wu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| |
Collapse
|
27
|
Flynn KJ, Mitra A, Wilson WH, Kimmance SA, Clark DR, Pelusi A, Polimene L. 'Boom-and-busted' dynamics of phytoplankton-virus interactions explain the paradox of the plankton. THE NEW PHYTOLOGIST 2022; 234:990-1002. [PMID: 35179778 PMCID: PMC9313554 DOI: 10.1111/nph.18042] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/04/2022] [Indexed: 05/13/2023]
Abstract
Rapid virus proliferation can exert a powerful control on phytoplankton host populations, playing a significant role in marine biogeochemistry and ecology. We explore how marine lytic viruses impact phytoplankton succession, affecting host and nonhost populations. Using an in silico food web we conducted simulation experiments under a range of different abiotic and biotic conditions, exploring virus-host-grazer interactions and manipulating competition, allometry, motility and cyst cycles. Virus-host and predator-prey interactions, and interactions with competitors, generate bloom dynamics with a pronounced 'boom-and-busted' dynamic (BBeD) which leads to the suppression of otherwise potentially successful phytoplankton species. The BBeD is less pronounced at low nutrient loading through distancing of phytoplankton hosts, while high sediment loading and high nonhost biomass decrease the abundance of viruses through adsorption. Larger hosts are inherently more distanced, but motility increases virus attack, while cyst cycles promote spatial and temporal distancing. Virus control of phytoplankton bloom development appears more important than virus-induced termination of those blooms. This affects plankton succession - not only the growth of species infected by the virus, but also those that compete for the same resources and are collectively subjected to common grazer control. The role of viruses in structuring plankton communities via BBeDs can thus provide an explanation for the paradox of the plankton.
Collapse
Affiliation(s)
- Kevin J. Flynn
- Plymouth Marine LaboratoryProspect Place, West HoePlymouthPL1 3DHUK
| | - Aditee Mitra
- School of Earth and Environmental SciencesCardiff UniversityCardiffCF10 3ATUK
| | - William H. Wilson
- Marine Biological Association of the UK, The LaboratoryCitadel HillPlymouthPL1 2PBUK
- School of Biological and Marine SciencesUniversity of PlymouthPL4 8AAUK
| | | | - Darren R. Clark
- Plymouth Marine LaboratoryProspect Place, West HoePlymouthPL1 3DHUK
| | - Angela Pelusi
- School of Earth and Environmental SciencesCardiff UniversityCardiffCF10 3ATUK
| | - Luca Polimene
- Plymouth Marine LaboratoryProspect Place, West HoePlymouthPL1 3DHUK
| |
Collapse
|
28
|
Gill RL, Collins S, Argyle PA, Larsson ME, Fleck R, Doblin MA. Predictability of thermal fluctuations influences functional traits of a cosmopolitan marine diatom. Proc Biol Sci 2022; 289:20212581. [PMID: 35473374 PMCID: PMC9043731 DOI: 10.1098/rspb.2021.2581] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Evolutionary theory predicts that organismal plasticity should evolve in environments that fluctuate regularly. However, in environments that fluctuate less predictably, plasticity may be constrained because environmental cues become less reliable for expressing the optimum phenotype. Here, we examine how the predictability of +5°C temperature fluctuations impacts the phenotype of the marine diatom Thalassiosira pseudonana. Thermal regimes were informed by temperatures experienced by microbes in an ocean simulation and featured regular or irregular temporal sequences of fluctuations that induced mild physiological stress. Physiological traits (growth, cell size, complexity and pigmentation) were quantified at the individual cell level using flow cytometry. Changes in cellular complexity emerged as the first impact of predictability after only 8–11 days, followed by deleterious impacts on growth on days 13–16. Specifically, cells with a history of irregular fluctuation exposure exhibited a 50% reduction in growth compared with the stable reference environment, while growth was 3–18 times higher when fluctuations were regular. We observed no evidence of heat hardening (increasingly positive growth) with recurrent fluctuations. This study demonstrates that unpredictable temperature fluctuations impact this cosmopolitan diatom under ecologically relevant time frames, suggesting shifts in environmental stochasticity under a changing climate could have widespread consequences among ocean primary producers.
Collapse
Affiliation(s)
- Raissa L Gill
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Sinead Collins
- Institute for Evolutionary Biology, University of Edinburgh, EH8 9YL, UK
| | - Phoebe A Argyle
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Michaela E Larsson
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Robert Fleck
- School of Life Sciences, Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Martina A Doblin
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, NSW, Australia.,Sydney Institute of Marine Science, Mosman, NSW, Australia
| |
Collapse
|
29
|
Tashyreva D, Simpson A, Prokopchuk G, Škodová-Sveráková I, Butenko A, Hammond M, George EE, Flegontova O, Záhonová K, Faktorová D, Yabuki A, Horák A, Keeling PJ, Lukeš J. Diplonemids – A Review on “New“ Flagellates on the Oceanic Block. Protist 2022; 173:125868. [DOI: 10.1016/j.protis.2022.125868] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/26/2022] [Accepted: 02/28/2022] [Indexed: 11/15/2022]
|
30
|
Evolution of Phytoplankton in Relation to Their Physiological Traits. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Defining the physiological traits that characterise phytoplankton involves comparison with related organisms in benthic habitats. Comparison of survival time in darkness under natural conditions requires more information. Gas vesicles and flagella as mechanisms of upward movement relative to surrounding water, allowing periodic vertical migration, are not confined to plankton, although buoyancy changes related to compositional changes of a large central vacuole may be restricted to plankton. Benthic microalgae have the same range of photosynthetic pigments as phytoplankton; it is not clear if there are differences in the rate of regulation and acclimation of photosynthetic machinery to variations in irradiance for phytoplankton and for microphytobenthos. There are inadequate data to determine if responses to variations in frequency or magnitude of changes in the supply of inorganic carbon, nitrogen or phosphorus differ between phytoplankton and benthic microalgae. Phagophotomixotrophy and osmophotomixotrophy occur in both phytoplankton and benthic microalgae. Further progress in identifying physiological traits specific to phytoplankton requires more experimentation on benthic microalgae that are closely related to planktonic microalgae, with attention to whether the benthic algae examined have, as far as can be determined, never been planktonic during their evolution or are derived from planktonic ancestors.
Collapse
|
31
|
Capo E, Monchamp ME, Coolen MJL, Domaizon I, Armbrecht L, Bertilsson S. Environmental paleomicrobiology: using DNA preserved in aquatic sediments to its full potential. Environ Microbiol 2022; 24:2201-2209. [PMID: 35049133 PMCID: PMC9304175 DOI: 10.1111/1462-2920.15913] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/14/2022] [Accepted: 01/16/2022] [Indexed: 11/30/2022]
Abstract
In‐depth knowledge about spatial and temporal variation in microbial diversity and function is needed for a better understanding of ecological and evolutionary responses to global change. In particular, the study of microbial ancient DNA preserved in sediment archives from lakes and oceans can help us to evaluate the responses of aquatic microbes in the past and make predictions about future biodiversity change in those ecosystems. Recent advances in molecular genetic methods applied to the analysis of historically deposited DNA in sediments have not only allowed the taxonomic identification of past aquatic microbial communities but also enabled tracing their evolution and adaptation to episodic disturbances and gradual environmental change. Nevertheless, some challenges remain for scientists to take full advantage of the rapidly developing field of paleo‐genetics, including the limited ability to detect rare taxa and reconstruct complete genomes for evolutionary studies. Here, we provide a brief review of some of the recent advances in the field of environmental paleomicrobiology and discuss remaining challenges related to the application of molecular genetic methods to study microbial diversity, ecology, and evolution in sediment archives. We anticipate that, in the near future, environmental paleomicrobiology will shed new light on the processes of microbial genome evolution and microbial ecosystem responses to quaternary environmental changes at an unprecedented level of detail. This information can, for example, aid geological reconstructions of biogeochemical cycles and predict ecosystem responses to environmental perturbations, including in the context of human‐induced global changes.
Collapse
Affiliation(s)
- Eric Capo
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, 75007, Uppsala, Sweden
| | - Marie-Eve Monchamp
- Department of Biology, McGill University, Montréal, QC, H3A 1B1, Canada.,Groupe de recherche interuniversitaire en limnologie (GRIL)
| | - Marco J L Coolen
- Western Australia Organic and Isotope Geochemistry Centre (WA-OIGC), Curtin University, Bentley, 6102, Australia
| | - Isabelle Domaizon
- INRAE, Université Savoie Mont Blanc, CARRTEL, 74200 Thonon les Bains, France.,UMR CARRTEL, Pôle R&D ECLA, 74200 Thonon les Bains, France
| | - Linda Armbrecht
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7004, Australia.,Australian Centre for Ancient DNA, School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, 75007, Uppsala, Sweden
| |
Collapse
|
32
|
Picoche C, Barraquand F. Seed banks can help to maintain the diversity of interacting phytoplankton species. J Theor Biol 2022; 538:111020. [PMID: 35032473 DOI: 10.1016/j.jtbi.2022.111020] [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: 04/29/2021] [Revised: 01/01/2022] [Accepted: 01/06/2022] [Indexed: 10/19/2022]
Abstract
Seed formation is part of the reproductive cycle, leading to the accumulation of resistance stages that can withstand harsh environmental conditions for long periods of time. At the community level, multiple species with such long-lasting life stages can be more likely to coexist. While the implications of this process for biodiversity have been studied in terrestrial plants, seed banks are usually neglected in phytoplankton multispecies dynamic models, in spite of widespread empirical evidence for such seed banks. In this study, we build a metacommunity model of interacting phytoplankton species, including a resting stage supplying the seed bank. The model is parameterized with empirically-driven growth rate functions and field-based interaction estimates, which include both facilitative and competitive interactions. Exchanges between compartments (coastal pelagic cells, coastal resting cells on the seabed, and open ocean pelagic cells) are controlled by hydrodynamical parameters to which the sensitivity of the model is assessed. We consider two models, i.e., with and without a saturating effect of the interactions on the growth rates. Our results are consistent between models, and show that a seed bank allows to maintain all species in the community over 30 years. Indeed, a fraction of the species are vulnerable to extinction at specific times within the year, but this process is buffered by their survival in their resting stage. We thus highlight the potential role of the seed bank in the recurrent re-invasion of the coastal community, and of coastal environments in re-seeding oceanic regions. Moreover, the seed bank enables populations to tolerate stronger interactions within the community as well as more severe changes in the environment, such as those predicted within a climate change context. Our study therefore shows how a resting stage may help phytoplanktonic diversity maintenance.
Collapse
Affiliation(s)
- Coralie Picoche
- Institute of Mathematics of Bordeaux, University of Bordeaux and CNRS, Talence, France; Integrative and Theoretical Ecology, LabEx COTE, University of Bordeaux, Pessac, France.
| | - Frédéric Barraquand
- Institute of Mathematics of Bordeaux, University of Bordeaux and CNRS, Talence, France; Integrative and Theoretical Ecology, LabEx COTE, University of Bordeaux, Pessac, France
| |
Collapse
|
33
|
Deng Y, Vallet M, Pohnert G. Temporal and Spatial Signaling Mediating the Balance of the Plankton Microbiome. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:239-260. [PMID: 34437810 DOI: 10.1146/annurev-marine-042021-012353] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The annual patterns of plankton succession in the ocean determine ecological and biogeochemical cycles. The temporally fluctuating interplay between photosynthetic eukaryotes and the associated microbiota balances the composition of aquatic planktonic ecosystems. In addition to nutrients and abiotic factors, chemical signaling determines the outcome of interactions between phytoplankton and their associated microbiomes. Chemical mediators control essential processes, such as the development of key morphological, physiological, behavioral, and life-history traits during algal growth. These molecules thus impact species succession and community composition across time and space in processes that are highlighted in this review. We focus on spatial, seasonal, and physiological dynamics that occur during the early association of algae with bacteria, the exponential growth of a bloom, and its decline and recycling. We also discuss how patterns from field data and global surveys might be linked to the actions of metabolic markers in natural phytoplankton assemblages.
Collapse
Affiliation(s)
- Yun Deng
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany;
| | - Marine Vallet
- Research Group Phytoplankton Community Interactions, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany;
- Research Group Phytoplankton Community Interactions, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| |
Collapse
|
34
|
Sanyal A, Larsson J, van Wirdum F, Andrén T, Moros M, Lönn M, Andrén E. Not dead yet: Diatom resting spores can survive in nature for several millennia. AMERICAN JOURNAL OF BOTANY 2022; 109:67-82. [PMID: 34648178 DOI: 10.1002/ajb2.1780] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Understanding the adaptive capacities of species over long timescales lies in examining the revived recent and millennia-old resting spores buried in sediments. We show for the first time the revival, viability, and germination rate of resting spores of the diatom Chaetoceros deposited in sub-seafloor sediments from three ages (recent: 0 to 80 years; ancient: ~1250 (Medieval Climate Anomaly) and ~6600 (Holocene Thermal Maximum) calendar year before present. METHODS Recent and ancient Chaetoceros spores were revived to examine their viability and germination rate. Light and scanning electron microscopy and Sanger sequencing was done to identify the species. RESULTS We show that ~6600 cal. year BP old Chaetoceros resting spores are still viable and that the vegetative reproduction in recent and ancient resting spores varies. The time taken to germinate is three hours to 2 to 3 days in both recent and ancient spores, but the germination rate of the spores decreased with increasing age. The germination rate of the recent spores was ~41% while that of the ancient spores were ~31% and ~12% for the ~1250 and ~6600 cal. year BP old resting spores, respectively. Based on the morphology of the germinated vegetative cells we identified the species as Chaetoceros muelleri var. subsalsum. Sanger sequences of nuclear and chloroplast markers identified the species as Chaetoceros muelleri. CONCLUSIONS We identify a unique model system, Chaetoceros muelleri var. subsalsum and show that recent and ancient resting spores of the species buried in sediments in the Baltic Sea can be revived and used for long-term evolutionary studies.
Collapse
Affiliation(s)
- Anushree Sanyal
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-75651 Uppsala, Sweden
| | - Josefine Larsson
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
| | - Falkje van Wirdum
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
| | - Thomas Andrén
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
| | - Matthias Moros
- Leibniz Institute for Baltic Sea Research Warnemünde, Seestraße 15, DE-18119 Rostock, Germany
| | - Mikael Lönn
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
| | - Elinor Andrén
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Alfred Nobels allé 7, SE-14189 Huddinge, Stockholm, Sweden
| |
Collapse
|
35
|
Latitudinal Variation in the Toxicity and Sexual Compatibility of Alexandrium catenella Strains from Southern Chile. Toxins (Basel) 2021; 13:toxins13120900. [PMID: 34941737 PMCID: PMC8706904 DOI: 10.3390/toxins13120900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 12/13/2022] Open
Abstract
The bloom-forming toxic dinoflagellate Alexandrium catenella was first detected in southern Chile (39.5–55° S) 50 years ago and is responsible for most of the area’s cases of paralytic shellfish poisoning (PSP). Given the complex life history of A. catenella, which includes benthic sexual cysts, in this study, we examined the potential link between latitude, toxicity, and sexual compatibility. Nine clones isolated from Chilean Patagonia were used in self- and out-crosses in all possible combinations (n = 45). The effect of latitude on toxicity, reproductive success indexes, and cyst production was also determined. Using the toxin profiles for all strains, consisting of C1, C2, GTX4, GTX1, GTX3, and NeoSTX, a latitudinal gradient was determined for their proportions (%) and content per cell (pg cell−1), with the more toxic strains occurring in the north (−40.6° S). Reproductive success also showed a latitudinal tendency and was lower in the north. None of the self-crosses yielded resting cysts. Rather, the production of resting cysts was highest in pairings of clones separated by distances of 1000–1650 km. Our results contribute to a better understanding of PSP outbreaks in the region and demonstrate the importance of resting cysts in fueling new toxic events. They also provide additional evidence that the introduction of strains from neighboring regions is a cause for concern.
Collapse
|
36
|
Daignan-Fornier B, Laporte D, Sagot I. Quiescence Through the Prism of Evolution. Front Cell Dev Biol 2021; 9:745069. [PMID: 34778256 PMCID: PMC8586652 DOI: 10.3389/fcell.2021.745069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/11/2021] [Indexed: 01/13/2023] Open
Abstract
Being able to reproduce and survive is fundamental to all forms of life. In primitive unicellular organisms, the emergence of quiescence as a reversible proliferation arrest has most likely improved cell survival under unfavorable environmental conditions. During evolution, with the repeated appearances of multicellularity, several aspects of unicellular quiescence were conserved while new quiescent cell intrinsic abilities arose. We propose that the formation of a microenvironment by neighboring cells has allowed disconnecting quiescence from nutritional cues. In this new context, non-proliferative cells can stay metabolically active, potentially authorizing the emergence of new quiescent cell properties, and thereby favoring cell specialization. Through its co-evolution with cell specialization, quiescence may have been a key motor of the fascinating diversity of multicellular complexity.
Collapse
|
37
|
Hejduková E, Nedbalová L. Experimental freezing of freshwater pennate diatoms from polar habitats. PROTOPLASMA 2021; 258:1213-1229. [PMID: 33909137 DOI: 10.1007/s00709-021-01648-8] [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: 01/20/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
Diatoms are microalgae that thrive in a range of habitats worldwide including polar areas. Remarkably, non-marine pennate diatoms do not create any morphologically distinct dormant stages that could help them to successfully face unfavourable conditions. Their survival is probably connected with the adaptation of vegetative cells to freezing and desiccation. Here we assessed the freezing tolerance of vegetative cells and vegetative-looking resting cells of 12 freshwater strains of benthic pennate diatoms isolated from polar habitats. To test the effect of various environmental factors, the strains were exposed to -20 °C freezing in four differently treated cultures: (1) vegetative cells growing in standard conditions in standard WC medium and (2) resting cells induced by cold and dark acclimation and resting cells, where (3) phosphorus or (4) nitrogen deficiency were used in addition to cold and dark acclimation. Tolerance was evaluated by measurement of basal cell fluorescence of chlorophyll and determination of physiological cell status using a multiparameter fluorescent staining. Four strains out of 12 were able to tolerate freezing in at least some of the treatments. The minority of cells appeared to be active immediately after thawing process, while most cells were inactive, injured or dead. Overall, the results showed a high sensitivity of vegetative and resting cells to freezing stress among strains originating from polar areas. However, the importance of resting cells for survival was emphasized by a slight but statistically significant increase of freezing tolerance of nutrient-depleted cells. Low numbers of surviving cells in our experimental setup could indicate their importance for the overwintering of diatom populations in harsh polar conditions.
Collapse
Affiliation(s)
- Eva Hejduková
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 44, Prague 2, Czech Republic.
- Institute of Botany of the Czech Academy of Sciences, Dukelská 135, 379 82, Třeboň, Czech Republic.
| | - Linda Nedbalová
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 128 44, Prague 2, Czech Republic
- Institute of Botany of the Czech Academy of Sciences, Dukelská 135, 379 82, Třeboň, Czech Republic
| |
Collapse
|
38
|
Damoo DY, Durnford DG. Long-term survival of Chlamydomonas reinhardtii during conditional senescence. Arch Microbiol 2021; 203:5333-5344. [PMID: 34383108 DOI: 10.1007/s00203-021-02508-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/22/2021] [Accepted: 08/02/2021] [Indexed: 12/29/2022]
Abstract
Chlamydomonas reinhardtii undergoes conditional senescence when grown in batch culture due to nutrient limitation. Here, we explored plastid and photo-physiological adaptations in Chlamydomonas reinhardtii during a long-term ageing experiment by methodically sampling them over 22 weeks. Following exponential growth, Chlamydomonas entered an extended declining growth phase where cells continued to divide, although at a lower rate. Ultimately, this ongoing division was fueled by the recycling of macromolecules that was obvious in the rapidly declining protein and chlorophyll content in the cell during this phase. This process was sufficient to maintain a high level of cell viability as the culture entered stationary phase. Beyond that the cell viability starts to plummet. During the turnover of macromolecules after exponential growth that saw RuBisCO levels drop, the LHCII antenna was relatively stable. This, along with the upregulation of the light stress-related proteins (LHCSR), contributes to an efficient energy dissipation mechanism to protect the ageing cells from photooxidative stress during the senescence process. Ultimately, viability dropped to about 7% at 22 weeks in a batch culture. We anticipate that this research will help further understand the various acclimation strategies carried out by Chlamydomonas to maximize survival under conditional senescence.
Collapse
Affiliation(s)
- Djihane Yushrina Damoo
- Department of Biology, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada.,Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Dion G Durnford
- Department of Biology, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada.
| |
Collapse
|
39
|
Liu Y, Deng Y, Shang L, Yi L, Hu Z, Tang YZ. Geographic distribution and historical presence of the resting cysts of Karenia mikimotoi in the seas of China. HARMFUL ALGAE 2021; 109:102121. [PMID: 34815021 DOI: 10.1016/j.hal.2021.102121] [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: 05/15/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
The toxic dinoflagellate Karenia mikimotoi frequently forms harmful algal blooms (HABs) and thus causes massive kills of fish and shellfish in worldwide coastal waters, which has led to intensive investigations on multiple facets of the species. Following our recent discovery of K. mikimotoi forming resting cyst, a very possible mechanism for the inoculation of blooms and geographic expansion for this and many other HABs-causing species, here we report our detection of K. mikimotoi resting cysts in 125 surface sediment samples collected from the coastal waters (covering a latitude range from 18.29°N to 39.85°N) and 3 sediment cores (accumulated in 70‒100 years) collected from the East China Sea where are adjacent to the frequent blooming areas of K. mikimotoi. Via applications of quantitative real-time PCR (LSU rDNA-targeted), species-specific fluorescence in situ hybridization (FISH), and nested-PCR-and-sequencing to both types of the sediment samples that were pretreated with sodium polytungstate solution (SPT), we demonstrated that 1) K. mikimotoi cysts are widely present in surface sediments of the China seas (Bohai Sea (BS), Yellow Sea (YS), East China Sea (ECS), and South China Sea (SCS)), 2) the abundance of cysts is generally low (0 to 33 cysts in 32 g wet sediment), with that in the ECS and the SCS being higher than that in the YS and the BS, and the highest abundance was observed in sites of the ECS (e.g., Ningde, Fujian province) where the blooms of the species occurred frequently, as quantified by both methods, and 3) the cysts of K. mikimotoi have been present in the sediments of the ECS since 1970s, a short time prior to the first recorded bloom of K. mikimotoi in the SCS at 1980s. Our results not only demonstrated the wide geographic distribution of resting cyst of K. mikimotoi along the coast of China, but also proved a 50 years preservation of the cysts in the sediments of coastal area prone to forming frequent blooms. We consider our results have provided critical insights into the mechanisms of frequent bloom outbreaks and global distribution of K. mikimotoi in general, and particularly into the historical origin of K. mikimotoi in China. Further investigations are suggested to focus on on-site surveys for the cyst production and germination rates.
Collapse
Affiliation(s)
- Yuyang Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yunyan Deng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lixia Shang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Liang Yi
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Zhangxi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Ying Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| |
Collapse
|
40
|
Expression Patterns of the Heat Shock Protein 90 (Hsp90) Gene Suggest Its Possible Involvement in Maintaining the Dormancy of Dinoflagellate Resting Cysts. Int J Mol Sci 2021; 22:ijms222011054. [PMID: 34681714 PMCID: PMC8538777 DOI: 10.3390/ijms222011054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 11/21/2022] Open
Abstract
Heat shock protein 90 (Hsp90) is a highly conserved molecular chaperone functioning in cellular structural folding and conformational integrity maintenance and thus plays vital roles in a variety of biological processes. However, many aspects of these functions and processes remain to be fully elucidated, particularly for non-model organisms. Dinoflagellates are a group of eukaryotes that are exceedingly important in primary production and are responsible for the most harmful algal blooms (HABs) in aquatic ecosystems. The success of dinoflagellates in dominating the plankton community is undoubtedly pertinent to their remarkable adaptive strategies, characteristic of resting cyst production and broad tolerance to stresses of temperature and others. Therefore, this study was conducted to examine the putative roles of Hsp90 in the acclimation to temperature stress and life stage alterations of dinoflagellates. Firstly, we isolated the full-length cDNA of an Hsp90 gene (StHsp90) via RACE from the cosmopolitan HAB species Scrippsiella trochoidea and tracked its transcriptions in response to varied scenarios via real-time qPCR. The results indicated that StHsp90 displayed significant mRNA augment patterns, escalating during 180-min treatments, when the cells were exposed to elevated and lowered temperatures. Secondly, we observed prominently elevated StHsp90 transcriptions in the cysts that were stored at the cold and dark conditions compared to those in newly formed resting cysts and vegetative cells. Finally, and perhaps most importantly, we identified 29 entries of Hsp90-encoding genes with complete coding regions from a dinoflagellate-specific environmental cDNA library generated from marine sediment assemblages. The observed active transcription of these genes in sediment-buried resting cysts was fully supported by the qPCR results for the cold-stored resting cysts of S. trochoidea. Hsp90s expressions in both laboratory-raised and field-collected cysts collectively highlighted the possible involvement and engagement of Hsp90 chaperones in the resting stage persistence of dinoflagellates.
Collapse
|
41
|
The Implication Inferred from the Expression of Small Heat-Shock Protein Genes in Dinoflagellate Resting Cysts Buried in Marine Sediment. DIVERSITY 2021. [DOI: 10.3390/d13100471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dinoflagellates are unicellular eukaryotic microalgae, occupying pivotal niches in aquatic ecosystems with great ecological, biological, and economic significance. Small heat shock proteins (sHsps) are the most omnipresent, but the least conserved, family of molecular chaperones found in all domains of life. Although their common name (small Hsp) implies to exclusively stress their heat shock-responsive function, many sHsps in fact engage in a variety of physiological processes, from cell growth and proliferation to embryogenesis, development, differentiation, apoptosis, and even to human disease prevention. Recent years have greatly expanded our understanding of sHsps in higher plants; however, comprehensive study aiming to delineate the composition and expression pattern of dinoflagellate sHsp gene family has not yet been performed. In this study, we constructed dinoflagellate-specific environmental cDNA library from marine sediment and sequenced using the third-generation sequencing technique. Screening of sHsp genes from the library returned 13 entries with complete coding regions, which were considered to be transcriptionally activated in the natural community of dinoflagellate resting cysts. All the 13 dinoflagellate sHsps consisted of a solely characteristic α-crystallin domain, covering 88–123 amino acid residues with the typical A-X-X-X-N-G-V-L motif, flanked by variable N- and C-terminal extensions. Multiple alignment revealed considerable amino acid divergence (~26.7% average similarity) among them. An unexpected close relationship was revealed between dinoflagellate and green algal sHsps in the phylogenetic tree, seemingly reflecting a close evolutionary relationship of these sHsps themselves. We confirmed that sHsp mRNAs are expressed during dormancy of the resting cyst assemblages of dinoflagellates that were buried in marine sediment, which raised the possibility that the sHsp expression is part of the machinery of maintaining the dormancy or/and the adaptation to ambient conditions of dinoflagellate resting cysts. Our results, although preliminary, gained an important glance on the universal presence of sHsps in dinoflagellates and their active expressions in the assemblage of resting cysts that were buried in the marine sediment. The essentiality of sHsps functioning in resting cysts necessitate more intensive and extensive investigations on all possible functions of Hsps in dinoflagellates, a group of protists with vital ecological and biological importance.
Collapse
|
42
|
Miller AK, Brown JS, Enderling H, Basanta D, Whelan CJ. The Evolutionary Ecology of Dormancy in Nature and in Cancer. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.676802] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Dormancy is an inactive period of an organism’s life cycle that permits it to survive through phases of unfavorable conditions in highly variable environments. Dormancy is not binary. There is a continuum of dormancy phenotypes that represent some degree of reduced metabolic activity (hypometabolism), reduced feeding, and reduced reproduction or proliferation. Similarly, normal cells and cancer cells exhibit a range of states from quiescence to long-term dormancy that permit survival in adverse environmental conditions. In contrast to organismal dormancy, which entails a reduction in metabolism, dormancy in cells (both normal and cancer) is primarily characterized by lack of cell division. “Cancer dormancy” also describes a state characterized by growth stagnation, which could arise from cells that are not necessarily hypometabolic or non-proliferative. This inconsistent terminology leads to confusion and imprecision that impedes progress in interdisciplinary research between ecologists and cancer biologists. In this paper, we draw parallels and contrasts between dormancy in cancer and other ecosystems in nature, and discuss the potential for studies in cancer to provide novel insights into the evolutionary ecology of dormancy.
Collapse
|
43
|
Tang YZ, Gu H, Wang Z, Liu D, Wang Y, Lu D, Hu Z, Deng Y, Shang L, Qi Y. Exploration of resting cysts (stages) and their relevance for possibly HABs-causing species in China. HARMFUL ALGAE 2021; 107:102050. [PMID: 34456016 DOI: 10.1016/j.hal.2021.102050] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 06/13/2023]
Abstract
The studies on the species diversity, distribution, environmental implications, and molecular basis of resting cysts (stages) of dinoflagellates and a few species of other groups conducted in China during the last three decades are reviewed. The major achievements are summarized as the following five aspects: 1) The continual efforts in detecting the species diversity of resting cysts (spores) in dinoflagellates and other classes using either morphological or molecular approaches, or both, in the four seas of China, which led to identifications of 106 species of dinoflagellate resting cysts and 4 species of resting stages from other groups of microalgae, with a total of 64 species of dinoflagellate cysts and the resting stage of the brown tide-causing Aureococcus anophagefferens being unequivocally identified via molecular approaches from the sediments of Chinese coastal waters; 2) The well-known toxic and HABs-causing dinoflagellates Karenia mikimotoi, Karlodinium veneficum, Akashiwo sanguinea and the pelagophyte A. anophagefferens were proven to be resting cyst (stage) producers via laboratory studies on their life cycles and field detections of resting cysts (resting stage cells). And, via germination experiment and subsequent characterization of vegetative cells, numerous dinoflagellate species that had never been described or found to form cysts were discovered and characterized; 3) The distributions of the resting cysts of Alexandrium catenella, A. pacificum, Gymnodinium catenatum, K. mikimotoi, K. veneficum and Azadinium poporum and the resting stage cells of A. anophagefferens were morphologically and molecularly mapped in all four seas of China, with A. anophagefferens proven to have been present in the Bohai Sea for at least 1,500 years; 4) Obtaining important insights into the 'indicator' values of the dinoflagellate cyst assemblages in sediment cores for tracking eutrophication, environmental pollution and other anthropological influences in coastal waters; 5) Studies on the cyst-pertinent processes and genetic basis (transcriptomics together with physiological and chemical measurements) of resting cyst dormancy not only revealed the regulating patterns of some environmental factors in cyst formation and germination, but also identified many characteristically active or inactive metabolic pathways, differentially expressed genes, and the possibly vital regulating function of the phytohormone abscisic acid and a group of molecular chaperones in resting cysts. We also identified seven issues and three themes that should be addressed and explored by Chinese scientists working in the area in the future.
Collapse
Affiliation(s)
- Ying Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Haifeng Gu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Zhaohui Wang
- Institute of Hydrology, College of Life Science and Technology, Ji'nan University, Guangzhou 510632, China
| | - Dongyan Liu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Yan Wang
- Research Center of Red Tide and Marine Biology, College of Life Science and Technology, Ji'nan University, Guangzhou 510632, China
| | - Douding Lu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Zhangxi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yunyan Deng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lixia Shang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yuzao Qi
- Research Center of Red Tide and Marine Biology, College of Life Science and Technology, Ji'nan University, Guangzhou 510632, China
| |
Collapse
|
44
|
Kim K, Park J, Jo N, Park S, Yoo H, Kim J, Lee SH. Monthly Variation in the Macromolecular Composition of Phytoplankton Communities at Jang Bogo Station, Terra Nova Bay, Ross Sea. Front Microbiol 2021; 12:618999. [PMID: 33643247 PMCID: PMC7905043 DOI: 10.3389/fmicb.2021.618999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/21/2021] [Indexed: 11/17/2022] Open
Abstract
Organic carbon fixed by photosynthesis of phytoplankton during the polar growing period could be important for their survival and consumers during the long polar night. Differences in biochemical traits of phytoplankton between ice-free and polar night periods were investigated in biweekly water samples obtained at the Korean “Jang Bogo Station” located in Terra Nova Bay, Antarctica. The average concentration of total Chl-a from phytoplankton dominated by micro-sized species from the entire sampling period was 0.32 μg L–1 (SD = ± 0.88 μg L–1), with the highest concentration of 4.29 μg L–1 in February and the lowest concentration of 0.01 μg L–1 during the ice-covered polar night (April–October) in 2015. The highest protein concentration coincided with the peak Chl-a concentration in February and decreased rapidly relative to the carbohydrate and lipid concentrations in the early part of polar night. Among the different biochemical components, carbohydrates were the predominant constituent, accounting for 69% (SD = ± 14%) of the total particulate organic matter (POM) during the entire study period. The carbohydrate contributions to the total POM markedly increased from 39 ± 8% during the ice-free period to 73 ± 9% during the polar night period. In comparison, while we found a significant negative correlation (r2 = 0.92, p < 0.01) between protein contributions and carbohydrate contributions, lipid contributions did not show any particular trend with relatively small temporal variations during the entire observation period. The substantial decrease in the average weight ratio of proteins to carbohydrates from the ice-free period (mean ± SD = 1.0 ± 0.3) to the ice-covered period (mean ± SD = 0.1 ± 0.1) indicates a preferential loss of nitrogen-based proteins compared to carbohydrates during the polar night period. Overall, the average food material (FM) concentration and calorific contents of FM in this study were within the range reported previously from the Southern Ocean. The results from this study may serve as important background data for long-term monitoring of the regional and interannual variations in the physiological state and biochemical compositions of phytoplankton resulting from future climate change in Antarctica.
Collapse
Affiliation(s)
- Kwanwoo Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Jisoo Park
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Naeun Jo
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Sanghoon Park
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyeju Yoo
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Jaehong Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Sang Heon Lee
- Department of Oceanography, Pusan National University, Busan, South Korea
| |
Collapse
|
45
|
Effect of temperature, nitrate concentration, pH and bicarbonate addition on biomass and lipid accumulation in the sporulating green alga PW95. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102148] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
46
|
Schoenrock KM, McHugh TA, Krueger-Hadfield SA. Revisiting the 'bank of microscopic forms' in macroalgal-dominated ecosystems. JOURNAL OF PHYCOLOGY 2021; 57:14-29. [PMID: 33135166 DOI: 10.1111/jpy.13092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Theoretical ecological models, such as succession and facilitation, were defined in terrestrial habitats, and subsequently applied to marine and freshwater habitats in intertidal and then subtidal realms. One such model is the soil seed bank, defined as all viable seeds (or fruits) found near the soil surface that facilitate community restoration/recovery. "Banks of microscopic forms" have been hypothesized in aquatic habitats and recent work from aquaculture has highlighted dormancy in algal life cycle stages. To reinvigorate the discussions about these algal banks, we discuss differences in life cycles, dispersal, and summarize research on banks of macroalgal stages in aquatic ecosystems that may be easier to explore with modern advances in molecular technology. With focus on seminal work in global kelp forest ecosystems, we present a pilot study in northern California as proof of concept that Nereocystis luetkeana and Alaria marginata stages can be detected within kelp forests in the biofilm of rocks and bedrock using targeted primers long after zoospore release. Considering the increased interest in algae as an economic resource, [blue] carbon sink, and as ecosystem engineers, the potential for "banking" macroalgal forms could be a mechanism of resilience and recovery in aquatic populations that have complex life cycles and environmental cues for reproduction. Molecular barcoding is becoming an important tool for identifying banks of macroalgal forms in marine communities. Understanding banks of macroalgal stages, especially in deforested habitats with intense disturbance and grazer pressure, will allow researchers and marine resource managers to facilitate this natural process in recovery of the aquatic system.
Collapse
Affiliation(s)
- Kathryn M Schoenrock
- Department of Zoology, Ryan Institute, National University of Ireland, Galway, University Rd., Galway, H91 TK33, Ireland
| | - Tristin Anoush McHugh
- Long Marine Laboratory, Reef Check Foundation, 115 McAllister Road, Santa Cruz, California, 95060, USA
| | - Stacy A Krueger-Hadfield
- Department of Biology, University of Alabama at Birmingham, Campbell Hall, Room 464, Birmingham, Alabama, 35294, USA
| |
Collapse
|
47
|
Pelusi A, De Luca P, Manfellotto F, Thamatrakoln K, Bidle KD, Montresor M. Virus-induced spore formation as a defense mechanism in marine diatoms. THE NEW PHYTOLOGIST 2021; 229:2251-2259. [PMID: 32978816 PMCID: PMC7894508 DOI: 10.1111/nph.16951] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/09/2020] [Indexed: 05/03/2023]
Abstract
Algal viruses are important contributors to carbon cycling, recycling nutrients and organic material through host lysis. Although viral infection has been described as a primary mechanism of phytoplankton mortality, little is known about host defense responses. We show that viral infection of the bloom-forming, planktonic diatom Chaetoceros socialis induces the mass formation of resting spores, a heavily silicified life cycle stage associated with carbon export due to rapid sinking. Although viral RNA was detected within spores, mature virions were not observed. 'Infected' spores were capable of germinating, but did not propagate or transmit infectious viruses. These results demonstrate that diatom spore formation is an effective defense strategy against viral-mediated mortality. They provide a possible mechanistic link between viral infection, bloom termination, and mass carbon export events and highlight an unappreciated role of viruses in regulating diatom life cycle transitions and ecological success.
Collapse
Affiliation(s)
- Angela Pelusi
- Department of Integrative Marine EcologyStazione Zoologica Anton DohrnVilla ComunaleNaples80121Italy
| | - Pasquale De Luca
- Research Infrastructures for Marine Biological ResourcesStazione Zoologica Anton DohrnVilla ComunaleNaples80121Italy
| | - Francesco Manfellotto
- Department of Integrative Marine EcologyStazione Zoologica Anton DohrnVilla ComunaleNaples80121Italy
| | | | - Kay D. Bidle
- Department of Marine and Coastal SciencesRutgers UniversityNew BrunswickNJ08901‐8520USA
| | - Marina Montresor
- Department of Integrative Marine EcologyStazione Zoologica Anton DohrnVilla ComunaleNaples80121Italy
| |
Collapse
|
48
|
Cyanobacteria and Algae in Clouds and Rain in the Area of puy de Dôme, Central France. Appl Environ Microbiol 2020; 87:AEM.01850-20. [PMID: 33097513 DOI: 10.1128/aem.01850-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/10/2020] [Indexed: 01/04/2023] Open
Abstract
The atmosphere contains diverse living microbes, of which the heterotrophic community has been the best studied. Microbes with other trophic modes, such as photoautotrophy, have received much less attention. In this study, culture-independent and dependent methods were used to examine the presence and diversity of oxygenic photoautotrophic microbes in clouds and rain collected at or around puy de Dôme Mountain, central France. Cloud water was collected from the summit of puy de Dôme (1,465 m above sea level [a.s.l.]) for cultivation and metagenomic analysis. Cyanobacteria, diatoms, green algae, and other oxygenic photoautotrophs were found to be recurrent members of clouds, while green algae affiliated with the Chlorellaceae were successfully cultured from three different clouds. Additionally, rain samples were collected below the mountain from Opme meteorological station (680 m a.s.l.). The abundance of chlorophyll a-containing cells and the diversity of cyanobacteria and green algae in rain were assessed by flow cytometry and amplicon sequencing. The corresponding downward flux of chlorophyll a-containing organisms to the ground, entering surface ecosystems with rain, varied with time and was estimated to be between ∼1 and >300 cells cm-2 day-1 during the sampling period. Besides abundant pollen from Pinales and Rosales, cyanobacteria of the Chroococcidiopsidales and green algae of the Trebouxiales were dominant in rain samples. Certain members of these taxa are known to be ubiquitous and stress tolerant and could use the atmosphere for dispersal. Overall, our results indicate that the atmosphere carries diverse, viable oxygenic photoautotrophic microbes and acts as a dispersal vector for this microbial guild.IMPORTANCE Information regarding the diversity and abundance of oxygenic photoautotrophs in the atmosphere is limited. More information from diverse locations is needed. These airborne organisms could have important impacts upon atmospheric processes and on the ecosystems they enter after deposition. Oxygenic photoautotrophic microbes are integral to ecosystem functioning, and some have the potential to affect human health. A better understanding of the diversity and the movements of these aeolian dispersed organisms is needed to understand their ecology, as well as how they could affect ecosystems and human health.
Collapse
|
49
|
Laboratory Culture-Based Characterization of the Resting Stage Cells of the Brown-Tide-Causing Pelagophyte, Aureococcus anophagefferens. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8121027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Life history (life cycle) plays a vital role in the ecology of some microalgae; however, the well-known brown-tide-causing pelagophyte Aureococcus anophagefferens has been barely investigated in this regard. Recently, based mainly on detections in marine sediments from China, we proved that this organism has a resting stage. We, therefore, conducted a follow-up study to characterize the resting stage cells (RSCs) of A. anophagefferens using the culture CCMP1984. The RSCs were spherical, larger than the vegetative cells, and smooth in cell surface and contained more aggregated plastid but more vacuolar space than vegetative cells. RSCs contained a conspicuous lipid-enriched red droplet. We found a 9.9-fold decrease in adenosine triphosphate (ATP) content from vegetative cells to RSCs, indicative of a "resting" or dormant physiological state. The RSCs stored for 3 months (at 4 °C in darkness) readily reverted back to vegetative growth within 20 days after being transferred to the conditions for routine culture maintenance. Our results indicate that the RSCs of A. anophagefferens are a dormant state that differs from vegetative cells morphologically and physiologically, and that RSCs likely enable the species to survive unfavorable conditions, seed annual blooms, and facilitate its cosmopolitan distribution that we recently documented.
Collapse
|
50
|
Mestre M, Höfer J. The Microbial Conveyor Belt: Connecting the Globe through Dispersion and Dormancy. Trends Microbiol 2020; 29:482-492. [PMID: 33281016 DOI: 10.1016/j.tim.2020.10.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022]
Abstract
Despite the recent increase in knowledge concerning microorganisms, the processes determining their global distribution and functioning have not been disentangled. Microbial dormant stages are adapted to endure specific adverse conditions related to their dispersion path, suggesting that dispersion is not entirely a stochastic process. Long-term dormancy enhances microbial dispersion, promoting the ubiquity of microorganisms. The evidence leads us to propose that there is a global, recurrent, and spatially cyclical dispersion of microorganisms that we have called the Microbial Conveyor Belt. These dispersion cycles directly influence the distribution of microorganisms, the global cycling of inorganic and organic matter, and thus the Earth system's functioning.
Collapse
Affiliation(s)
- Mireia Mestre
- Centro de Investigación Oceanográfica COPAS Sur-Austral, Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile; Centro FONDAP de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile.
| | - Juan Höfer
- Centro FONDAP de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile; Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile; Centro de Investigación y Formación San Ignacio de Huinay, Huinay, Chile.
| |
Collapse
|