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Jesus B, Jauffrais T, Trampe E, Méléder V, Ribeiro L, Bernhard JM, Geslin E, Kühl M. Microscale imaging sheds light on species-specific strategies for photo-regulation and photo-acclimation of microphytobenthic diatoms. Environ Microbiol 2023; 25:3087-3103. [PMID: 37671646 DOI: 10.1111/1462-2920.16499] [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: 05/24/2023] [Accepted: 08/23/2023] [Indexed: 09/07/2023]
Abstract
Intertidal microphytobenthic (MPB) biofilms are key sites for coastal primary production, predominantly by pennate diatoms exhibiting photo-regulation via non-photochemical quenching (NPQ) and vertical migration. Movement is the main photo-regulation mechanism of motile (epipelic) diatoms and because they can move from light, they show low-light acclimation features such as low NPQ levels, as compared to non-motile (epipsammic) forms. However, most comparisons of MPB species-specific photo-regulation have used low light acclimated monocultures, not mimicking environmental conditions. Here we used variable chlorophyll fluorescence imaging, fluorescent labelling in sediment cores and scanning electron microscopy to compare the movement and NPQ responses to light of four epipelic diatom species from a natural MPB biofilm. The diatoms exhibited different species-specific photo-regulation features and a large NPQ range, exceeding that reported for epipsammic diatoms. This could allow epipelic species to coexist in compacted light niches of MPB communities. We show that diatom cell orientation within MPB can be modulated by light, where diatoms oriented themselves more perpendicular to the sediment surface under high light vs. more parallel under low light, demonstrating behavioural, photo-regulatory response by varying their light absorption cross-section. This highlights the importance of considering species-specific responses and understanding cell orientation and photo-behaviour in MPB research.
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Affiliation(s)
- Bruno Jesus
- Nantes Université, Institut des Substances et Organismes de la Mer, ISOMer, UR2160, Nantes, France
| | - Thierry Jauffrais
- Ifremer, IRD, Univ Nouvelle-Calédonie, Univ La Réunion, CNRS, UMR 9220 ENTROPIE, RBE/LEAD, Noumea, New Caledonia
- Université d'Angers, Nantes Université, Le Mans Université, Angers, France
| | - Erik Trampe
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Vona Méléder
- Nantes Université, Institut des Substances et Organismes de la Mer, ISOMer, UR2160, Nantes, France
| | - Lourenço Ribeiro
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network Associated Laboratory, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Joan M Bernhard
- Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Emmanuelle Geslin
- Université d'Angers, Nantes Université, Le Mans Université, Angers, France
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
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Kleptoplast distribution, photosynthetic efficiency and sequestration mechanisms in intertidal benthic foraminifera. THE ISME JOURNAL 2022; 16:822-832. [PMID: 34635793 PMCID: PMC8857221 DOI: 10.1038/s41396-021-01128-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/19/2021] [Accepted: 09/22/2021] [Indexed: 11/19/2022]
Abstract
Foraminifera are ubiquitously distributed in marine habitats, playing a major role in marine sediment carbon sequestration and the nitrogen cycle. They exhibit a wide diversity of feeding and behavioural strategies (heterotrophy, autotrophy and mixotrophy), including species with the ability of sequestering intact functional chloroplasts from their microalgal food source (kleptoplastidy), resulting in a mixotrophic lifestyle. The mechanisms by which kleptoplasts are integrated and kept functional inside foraminiferal cytosol are poorly known. In our study, we investigated relationships between feeding strategies, kleptoplast spatial distribution and photosynthetic functionality in two shallow-water benthic foraminifera (Haynesina germanica and Elphidium williamsoni), both species feeding on benthic diatoms. We used a combination of observations of foraminiferal feeding behaviour, test morphology, cytological TEM-based observations and HPLC pigment analysis, with non-destructive, single-cell level imaging of kleptoplast spatial distribution and PSII quantum efficiency. The two species showed different feeding strategies, with H. germanica removing diatom content at the foraminifer's apertural region and E. williamsoni on the dorsal site. All E. williamsoni parameters showed that this species has higher autotrophic capacity albeit both feeding on benthic diatoms. This might represent two different stages in the evolutionary process of establishing a permanent symbiotic relationship, or may reflect different trophic strategies.
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Blommaert L, Chafai L, Bailleul B. The fine-tuning of NPQ in diatoms relies on the regulation of both xanthophyll cycle enzymes. Sci Rep 2021; 11:12750. [PMID: 34140542 PMCID: PMC8211711 DOI: 10.1038/s41598-021-91483-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 05/05/2021] [Indexed: 11/09/2022] Open
Abstract
Diatoms possess an efficient mechanism to dissipate photons as heat in conditions of excess light, which is visualized as the Non-Photochemical Quenching of chlorophyll a fluorescence (NPQ). In most diatom species, NPQ is proportional to the concentration of the xanthophyll cycle pigment diatoxanthin formed from diadinoxanthin by the diadinoxanthin de-epoxidase enzyme. The reverse reaction is performed by the diatoxanthin epoxidase. Despite the xanthophyll cycle's central role in photoprotection, its regulation is not yet well understood. The proportionality between diatoxanthin and NPQ allowed us to calculate the activity of both xanthophyll cycle enzymes in the model diatom Phaeodactylum tricornutum from NPQ kinetics. From there, we explored the light-dependency of the activity of both enzymes. Our results demonstrate that a tight regulation of both enzymes is key to fine-tune NPQ: (i) the rate constant of diadinoxanthin de-epoxidation is low under a light-limiting regime but increases as photosynthesis saturates, probably due to the thylakoidal proton gradient ΔpH (ii) the rate constant of diatoxanthin epoxidation exhibits an optimum under low light and decreases in the dark due to an insufficiency of the co-factor NADPH as well as in higher light through an as yet unresolved inhibition mechanism, that is unlikely to be related to the ΔpH. We observed that the suppression of NPQ by an uncoupler was due to an accelerated diatoxanthin epoxidation enzyme rather than to the usually hypothesized inhibition of the diadinoxanthin de-epoxidation enzyme.
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Affiliation(s)
- Lander Blommaert
- Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de La Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Physico-Chimique, 75005, Paris, France. .,Department of Estuarine and Delta System, NIOZ Royal Netherlands Institute for Sea Research, PO Box 140, 4400 AC, Yerseke, The Netherlands.
| | - Lamia Chafai
- Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de La Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Physico-Chimique, 75005, Paris, France
| | - Benjamin Bailleul
- Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de La Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Physico-Chimique, 75005, Paris, France.
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An Under-Ice Hyperspectral and RGB Imaging System to Capture Fine-Scale Biophysical Properties of Sea Ice. REMOTE SENSING 2019. [DOI: 10.3390/rs11232860] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sea-ice biophysical properties are characterized by high spatio-temporal variability ranging from the meso- to the millimeter scale. Ice coring is a common yet coarse point sampling technique that struggles to capture such variability in a non-invasive manner. This hinders quantification and understanding of ice algae biomass patchiness and its complex interaction with some of its sea ice physical drivers. In response to these limitations, a novel under-ice sled system was designed to capture proxies of biomass together with 3D models of bottom topography of land-fast sea-ice. This system couples a pushbroom hyperspectral imaging (HI) sensor with a standard digital RGB camera and was trialed at Cape Evans, Antarctica. HI aims to quantify per-pixel chlorophyll-a content and other ice algae biological properties at the ice-water interface based on light transmitted through the ice. RGB imagery processed with digital photogrammetry aims to capture under-ice structure and topography. Results from a 20 m transect capturing a 0.61 m wide swath at sub-mm spatial resolution are presented. We outline the technical and logistical approach taken and provide recommendations for future deployments and developments of similar systems. A preliminary transect subsample was processed using both established and novel under-ice bio-optical indices (e.g., normalized difference indexes and the area normalized by the maximal band depth) and explorative analyses (e.g., principal component analyses) to establish proxies of algal biomass. This first deployment of HI and digital photogrammetry under-ice provides a proof-of-concept of a novel methodology capable of delivering non-invasive and highly resolved estimates of ice algal biomass in-situ, together with some of its environmental drivers. Nonetheless, various challenges and limitations remain before our method can be adopted across a range of sea-ice conditions. Our work concludes with suggested solutions to these challenges and proposes further method and system developments for future research.
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Méléder V, Jesus B, Barnett A, Barillé L, Lavaud J. Microphytobenthos primary production estimated by hyperspectral reflectance. PLoS One 2018; 13:e0197093. [PMID: 29758047 PMCID: PMC5951593 DOI: 10.1371/journal.pone.0197093] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 04/26/2018] [Indexed: 11/18/2022] Open
Abstract
The use of remote sensing techniques allows monitoring of photosynthesis at the ecosystem level and improves our knowledge of plant primary productivity. The main objective of the current study was to develop a remote sensing based method to measure microphytobenthos (MPB) primary production from intertidal mudflats. This was achieved by coupling hyperspectral radiometry (reflectance, ρ and second derivative, δδ) and PAM-fluorometry (non-sequential light curves, NSLC) measurements. The latter allowed the estimation of primary production using a light use efficiency parameter (LUE) and electron transport rates (ETR) whereas ρ allowed to estimate pigment composition and optical absorption cross-section (a*). Five MPB species representative of the main growth forms: epipelic (benthic motile), epipsammic (benthic motile and non motile) and tychoplanktonic (temporarily resuspended in the water column) were submitted to increasing light intensities from dark to 1950 μmol photons.m-2.s-1. Different fluorescence patterns were observed for the three growth-forms and were linked to their xanthophyll cycle (de-epoxydation state). After spectral reflectance measurements, a* was retrieved using a radiative transfer model and several radiometric indices were tested for their capacity to predict LUE and ETR measured by PAM-fluorometry. Only one radiometric index was not species or growth-form specific, i.e. δδ496/508. This index was named MPBLUE and could be used to predict LUE and ETR. The applicability of this index was tested with simulated bands of a wide variety of hyperspectral sensors at spectral resolutions between 3 and 15 nm of Full Width at Half Maximum (FWHM).
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Affiliation(s)
- Vona Méléder
- Mer Molécules Santé (MMS)–EA 21 60, Université de Nantes, Nates, France
- * E-mail:
| | - Bruno Jesus
- Mer Molécules Santé (MMS)–EA 21 60, Université de Nantes, Nates, France
- BioISI–Biosystems & Integrative Sciences Institute, Campo Grande University of Lisboa, Faculty of Sciences, Lisboa, Portugal
| | - Alexandre Barnett
- Littoral Environnement et Sociétés (LIENSs)–UMR 7266, CNRS/Université de La Rochelle, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, La Rochelle, France
- Botany and Plant Science–National University of Ireland, Galway, Ireland
| | - Laurent Barillé
- Mer Molécules Santé (MMS)–EA 21 60, Université de Nantes, Nates, France
| | - Johann Lavaud
- Littoral Environnement et Sociétés (LIENSs)–UMR 7266, CNRS/Université de La Rochelle, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, La Rochelle, France
- Takuvik–UMI 3376, CNRS/Université Laval, Département de Biologie, Pavillon Alexandre Vachon, Québec, Canada
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Barillé L, Le Bris A, Méléder V, Launeau P, Robin M, Louvrou I, Ribeiro L. Photosynthetic epibionts and endobionts of Pacific oyster shells from oyster reefs in rocky versus mudflat shores. PLoS One 2017; 12:e0185187. [PMID: 28934317 PMCID: PMC5608347 DOI: 10.1371/journal.pone.0185187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/07/2017] [Indexed: 11/18/2022] Open
Abstract
The Pacific oyster, Crassostrea gigas (Thunberg), is the main bivalve species cultivated in the world. With global warming enabling its reproduction and larval survival at higher latitudes, this species is now recognized as invasive and creates wild oyster reefs globally. In this study, the spatial distribution of photosynthetic assemblages colonizing the shells of wild C. gigas was investigated on both a large scale (two contrasting types of reefs found in mudflats and rocky areas) and a small scale (within individual shells) using a hyperspectral imager. The microspatial distribution of all phototrophs was obtained by mapping the Normalized Difference Vegetation Index (NDVI). Second derivative (δδ) analyses of hyperspectral images at 462, 524, 571 and 647 nm were subsequently applied to map diatoms, cyanobacteria, rhodophytes and chlorophytes, respectively. A concomitant pigment analysis was carried out by high performance liquid chromatography and completed by taxonomic observations. This study showed that there was high microalgal diversity associated with wild oyster shells and that there were differences in the structure of the phototropic assemblages depending on the type of reef. Namely, vertically-growing oysters in mudflat areas had a higher biomass of epizoic diatoms (hyperspectral proxy at δδ462 nm) and were mainly colonized by species of the genera Navicula, Nitzschia and Hippodonta, which are epipelic or motile epipsammic. The assemblages on the horizontal oysters contained more tychoplanktonic diatoms (e.g. Thalassiosira pseudonana, T. proschkinae and Plagiogrammopsis vanheurckii). Three species of boring cyanobacteria were observed for both types of reef: Mastigocoleus testarum, Leptolyngbya terrebrans, and Hyella caespistosa, but the second derivative analysis at 524 nm showed a significantly higher biomass for the horizontally-growing oysters. There was no biomass difference for the boring chlorophyte assemblages (δδ647 nm), with two species: Eugomontia testarum and Ostreobium quekettii observed for both types of reef. This study shows that oyster shells are an idiosyncratic but ubiquitous habitat for phototrophic assemblages. The contribution of these assemblages in terms of biomass and production to the functioning of coastal areas, and particularly to shellfish ecosystems, remains to be evaluated.
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Affiliation(s)
- Laurent Barillé
- Laboratoire Mer Molécules Santé (EA2160), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
- * E-mail:
| | - Anthony Le Bris
- Laboratoire Mer Molécules Santé (EA2160), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
- LETG-Geolittomer (UMR 6554, CNRS), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
| | - Vona Méléder
- Laboratoire Mer Molécules Santé (EA2160), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
| | - Patrick Launeau
- Laboratoire de Planétologie et Géodynamique (UMR 6112, CNRS), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
| | - Marc Robin
- LETG-Geolittomer (UMR 6554, CNRS), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
| | - Ioanna Louvrou
- Department of Ecology and Systematics, Faculty of Biology, Panepistimiopolis, University of Athens, Athens, Greece
| | - Lourenço Ribeiro
- Laboratoire Mer Molécules Santé (EA2160), Institut Universitaire Mer et Littoral (FR_C 3473), Université de Nantes, Nantes, France
- Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
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Ni G, Zimbalatti G, Murphy CD, Barnett AB, Arsenault CM, Li G, Cockshutt AM, Campbell DA. Arctic Micromonas uses protein pools and non-photochemical quenching to cope with temperature restrictions on Photosystem II protein turnover. PHOTOSYNTHESIS RESEARCH 2017; 131:203-220. [PMID: 27639727 PMCID: PMC5247552 DOI: 10.1007/s11120-016-0310-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/08/2016] [Indexed: 05/12/2023]
Abstract
Micromonas strains of small prasinophyte green algae are found throughout the world's oceans, exploiting widely different niches. We grew arctic and temperate strains of Micromonas and compared their susceptibilities to photoinactivation of Photosystem II, their counteracting Photosystem II repair capacities, their Photosystem II content, and their induction and relaxation of non-photochemical quenching. In the arctic strain Micromonas NCMA 2099, the cellular content of active Photosystem II represents only about 50 % of total Photosystem II protein, as a slow rate constant for clearance of PsbA protein limits instantaneous repair. In contrast, the temperate strain NCMA 1646 shows a faster clearance of PsbA protein which allows it to maintain active Photosystem II content equivalent to total Photosystem II protein. Under growth at 2 °C, the arctic Micromonas maintains a constitutive induction of xanthophyll deepoxidation, shown by second-derivative whole-cell spectra, which supports strong induction of non-photochemical quenching under low to moderate light, even if xanthophyll cycling is blocked. This non-photochemical quenching, however, relaxes during subsequent darkness with kinetics nearly comparable to the temperate Micromonas NCMA 1646, thereby limiting the opportunity cost of sustained downregulation of PSII function after a decrease in light.
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Affiliation(s)
- Guangyan Ni
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, CAS, Guangzhou, 510160, China
| | - Gabrielle Zimbalatti
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Cole D Murphy
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | | | - Christopher M Arsenault
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Gang Li
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, CAS, Guangzhou, 510301, China
| | - Amanda M Cockshutt
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Douglas A Campbell
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada.
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Perkins RG, Williamson CJ, Brodie J, Barillé L, Launeau P, Lavaud J, Yallop ML, Jesus B. Microspatial variability in community structure and photophysiology of calcified macroalgal microbiomes revealed by coupling of hyperspectral and high-resolution fluorescence imaging. Sci Rep 2016; 6:22343. [PMID: 26923719 PMCID: PMC4770322 DOI: 10.1038/srep22343] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/09/2016] [Indexed: 11/09/2022] Open
Abstract
Calcifying coralline macroalgae provide biogenic habitats colonised by epiphytic microalgae that contribute significantly to community productivity. Georeferenced hyperspectral and high-resolution fluorescence imaging were coupled to microspatially mapped community composition and relative biomass of macroalgal host and epiphyte microalgal groups, and their weighted contributions to productivity within host fronds of Corallina officinalis on upper and lower zones of a rocky shore were determined. Lower shore epiphytes were dominated by filamentous diatoms (Bacillariophyta), confined to the apex of the frond structure, which were low light acclimated but retained a high capacity for photoprotective down regulation and contributed up to 51% of total community productivity. Upper shore epiphytes were dominated by green algae (Chlorophyta) and single-celled diatoms (principally Cocconeis spp.), which were high light acclimated but present at far lower relative biomass and contributed negligibly to productivity. The host, C. officinalis was the main primary producer. Variation in light environment resulting from differences in shore height and shading within the host macroalga, likely play a large role in determining patterns in epiphyte community structure, biomass and productivity observed. Additionally, microspatial gradients in photophysiological parameters along the host macroalga likely resulted from age-dependent variation in pigments as well as the gradient in light environment.
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Affiliation(s)
- R G Perkins
- School of Earth and Ocean Sciences, Cardiff University, Cardiff, Glamorgan, CF10 3AT, UK
| | - C J Williamson
- School of Earth and Ocean Sciences, Cardiff University, Cardiff, Glamorgan, CF10 3AT, UK.,Natural History Museum, Department of Life Sciences, Cromwell Road, London SW7 5BD, UK
| | - J Brodie
- Natural History Museum, Department of Life Sciences, Cromwell Road, London SW7 5BD, UK
| | - L Barillé
- Université de Nantes, Labotoire de Mer Molécules Santé EA 2160, Faculté des Sciences et des Techniques, B.P. 92208, 44322 Nantes cedex 3, France
| | - P Launeau
- LUNAM Université, Université de Nantes, Laboratoire de Planétologie et Géodynamique UMR 6112, Faculté des Sciences et des Techniques, B.P. 92208, 44322 Nantes cedex 3, France
| | - J Lavaud
- UMR7266 LIENSs 'Littoral, Environnement et Sociétés', CNRS/Université de La Rochelle, Institut du Littoral et de l'Environnement, La Rochelle, France
| | - M L Yallop
- School of Biological Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - B Jesus
- Université de Nantes, Labotoire de Mer Molécules Santé EA 2160, Faculté des Sciences et des Techniques, B.P. 92208, 44322 Nantes cedex 3, France.,University of Lisboa, Faculty of Sciences, BioISI - Biosystems &Integrative Sciences Institute, Campo Grande, 1749-016 Lisboa, Portugal
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In vivo estimation of pigment composition and optical absorption cross-section by spectroradiometry in four aquatic photosynthetic micro-organisms. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2013; 129:115-24. [DOI: 10.1016/j.jphotobiol.2013.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 09/13/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022]
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10
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Salleh S, McMinn A. THE EFFECTS OF TEMPERATURE ON THE PHOTOSYNTHETIC PARAMETERS AND RECOVERY OF TWO TEMPERATE BENTHIC MICROALGAE, AMPHORA CF. COFFEAEFORMIS AND COCCONEIS CF. SUBLITTORALIS (BACILLARIOPHYCEAE)(1). JOURNAL OF PHYCOLOGY 2011; 47:1413-1424. [PMID: 27020365 DOI: 10.1111/j.1529-8817.2011.01079.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Temperature and irradiance are the most important factors affecting marine benthic microalgal photosynthetic rates in temperate intertidal areas. Two temperate benthic diatoms species, Amphora cf. coffeaeformis (C. Agardh) Kütz. and Cocconeis cf. sublittoralis Hendey, were investigated to determine how their photosynthesis responded to temperatures ranging from 5°C to 50°C after short-term exposure (1 h) to a range of irradiance levels (0, 500, and 1,100 μmol photons · m(-2 ) ·( ) s(-1) ). Significant differences were observed between the temperature responses of maximum relative electron transport rate (rETRmax), photoacclimation index (Ek ), photosynthetic efficiency (α), and effective quantum yield (ΔF/Fm' ) in both species. A. coffeaeformis had a greater tolerance to higher temperatures than C. sublittoralis, with nonphotochemical quenching (NPQ) activated at temperatures of 45°C and 50°C. C. sublittoralis, however, demonstrated a more rapid rate of recovery at ambient temperatures. Temperatures between 10°C and 20°C were determined to be optimal for photosynthesis for both species. High temperatures and irradiances caused a greater decrease in ΔF/Fm' values. These results suggest that the effects of temperature are species specific and that short-term exposure to adverse temperature slows the recovery process, which subsequently leads to photoinhibition.
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Affiliation(s)
- Sazlina Salleh
- Institute for Marine and Antarctic Studies, University of Tasmania, Box 252-77, Hobart 7001, Tasmania, Australia
| | - Andrew McMinn
- Institute for Marine and Antarctic Studies, University of Tasmania, Box 252-77, Hobart 7001, Tasmania, Australia
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11
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Hubas C, Jesus B, Passarelli C, Jeanthon C. Tools providing new insight into coastal anoxygenic purple bacterial mats: review and perspectives. Res Microbiol 2011; 162:858-68. [DOI: 10.1016/j.resmic.2011.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 03/16/2011] [Indexed: 10/18/2022]
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12
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Serôdio J, Pereira S, Furtado J, Silva R, Coelho H, Calado R. In vivo quantification of kleptoplastic chlorophyll a content in the “solar-powered” sea slug Elysia viridis using optical methods: spectral reflectance analysis and PAM fluorometry. Photochem Photobiol Sci 2010; 9:68-77. [DOI: 10.1039/b9pp00058e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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