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Kalvelage J, Wöhlbrand L, Senkler J, Schumacher J, Ditz N, Bischof K, Winklhofer M, Klingl A, Braun HP, Rabus R. Conspicuous chloroplast with light harvesting-photosystem I/II megacomplex in marine Prorocentrum cordatum. Plant Physiol 2024; 195:306-325. [PMID: 38330164 DOI: 10.1093/plphys/kiae052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 02/10/2024]
Abstract
Marine photosynthetic (micro)organisms drive multiple biogeochemical cycles and display a large diversity. Among them, the bloom-forming, free-living dinoflagellate Prorocentrum cordatum CCMP 1329 (formerly P. minimum) stands out with its distinct cell biological features. Here, we obtained insights into the structural properties of the chloroplast and the photosynthetic machinery of P. cordatum using microscopic and proteogenomic approaches. High-resolution FIB/SEM analysis revealed a single large chloroplast (∼40% of total cell volume) with a continuous barrel-like structure, completely lining the inner face of the cell envelope and enclosing a single reticular mitochondrium, the Golgi apparatus, as well as diverse storage inclusions. Enriched thylakoid membrane fractions of P. cordatum were comparatively analyzed with those of the well-studied model-species Arabidopsis (Arabidopsis thaliana) using 2D BN DIGE. Strikingly, P. cordatum possessed a large photosystem-light harvesting megacomplex (>1.5 MDa), which is dominated by photosystems I and II (PSI, PSII), chloroplast complex I, and chlorophyll a-b binding light harvesting complex proteins. This finding parallels the absence of grana in its chloroplast and distinguishes from the predominant separation of PSI and PSII complexes in A. thaliana, indicating a different mode of flux balancing. Except for the core elements of the ATP synthase and the cytb6f-complex, the composition of the other complexes (PSI, PSII, and pigment-binding proteins, PBPs) of P. cordatum differed markedly from those of A. thaliana. Furthermore, a high number of PBPs was detected, accounting for a large share of the total proteomic data (∼65%) and potentially providing P. cordatum with flexible adaptation to changing light regimes.
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Affiliation(s)
- Jana Kalvelage
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Lars Wöhlbrand
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Jennifer Senkler
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Julian Schumacher
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Noah Ditz
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Kai Bischof
- Faculty Biology/Chemistry, University of Bremen & MARUM, 28359 Bremen, Germany
| | - Michael Winklhofer
- School of Mathematics and Science, Institute of Biology and Environmental Sciences (IBU), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Center Neurosensory Science, School of Mathematics and Science, Carl von Ossietzky University of Oldenburg, 26129 Oldenburg, Germany
| | - Andreas Klingl
- Faculty of Biology, Botany, Ludwig-Maximilians-Universität LMU München, 82152 Planegg-Martinsried, Germany
| | - Hans-Peter Braun
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Ralf Rabus
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
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Diehl N, Li H, Scheschonk L, Burgunter-Delamare B, Niedzwiedz S, Forbord S, Sæther M, Bischof K, Monteiro C. The sugar kelp Saccharina latissima I: recent advances in a changing climate. Ann Bot 2024; 133:183-212. [PMID: 38109285 PMCID: PMC10921839 DOI: 10.1093/aob/mcad173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/26/2023] [Accepted: 11/07/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND The sugar kelp Saccharina latissima is a Laminariales species widely distributed in the Northern Hemisphere. Its physiology and ecology have been studied since the 1960s, given its ecological relevance on western temperate coasts. However, research interest has been rising recently, driven mainly by reports of negative impacts of anthropogenically induced environmental change and by the increased commercial interest in cultivating the species, with several industrial applications for the resulting biomass. SCOPE We used a variety of sources published between 2009 to May 2023 (but including some earlier literature where required), to provide a comprehensive review of the ecology, physiology, biochemical and molecular biology of S. latissima. In so doing we aimed to better understand the species' response to stressors in natural communities, but also inform the sustainable cultivation of the species. CONCLUSION Due to its wide distribution, S. latissima has developed a variety of physiological and biochemical mechanisms to adjust to environmental changes, including adjustments in photosynthetic parameters, modulation of osmolytes and antioxidants, reprogramming of gene expression and epigenetic modifications, among others summarized in this review. This is particularly important because massive changes in the abundance and distribution of S. latissima have already been observed. Namely, presence and abundance of S. latissima has significantly decreased at the rear edges on both sides of the Atlantic, and increased in abundance at the polar regions. These changes were mainly caused by climate change and will therefore be increasingly evident in the future. Recent developments in genomics, transcriptomics and epigenomics have clarified the existence of genetic differentiation along its distributional range with implications in the fitness at some locations. The complex biotic and abiotic interactions unraveled here demonstrated the cascading effects the disappearance of a kelp forest can have in a marine ecosystem. We show how S. latissima is an excellent model to study acclimation and adaptation to environmental variability and how to predict future distribution and persistence under climate change.
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Affiliation(s)
- Nora Diehl
- Marine Botany, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, Germany
| | - Huiru Li
- Key Laboratory of Mariculture (Ministry of Education), Fisheries College, Ocean University of China, Qingdao 266003, China
| | | | - Bertille Burgunter-Delamare
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Sarina Niedzwiedz
- Marine Botany, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, Germany
| | - Silje Forbord
- Department of Fisheries and New Biomarine Industry, SINTEF Ocean AS, 7465 Trondheim, Norway
| | - Maren Sæther
- Seaweed Solutions AS, Bynesveien 50C, 7018 Trondheim, Norway
| | - Kai Bischof
- Marine Botany, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, Germany
| | - Catia Monteiro
- CIBIO, Research Centre in Biodiversity and Genetic Resources – InBIO Associate Laboratory, Campus of Vairão, University of Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus of Vairão, Vairão, Portugal
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Scheschonk L, Bischof K, Kopp MEL, Jueterbock A. Differences by origin in methylome suggest eco-phenotypes in the kelp Saccharina latissima. Evol Appl 2023; 16:262-278. [PMID: 36793679 PMCID: PMC9923482 DOI: 10.1111/eva.13382] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 11/29/2022] Open
Abstract
Most kelp species are of high ecological and economic importance worldwide, but are highly susceptible to rising ocean temperatures due to their sessile lifestyle. Due to interference with reproduction, development and growth, natural kelp forests have vanished in multiple regions after extreme summer heat waves. Furthermore, increasing temperatures are likely to decrease biomass production and, thus, reduce production security of farmed kelp. Epigenetic variation, and cytosine methylation as a heritable epigenetic trait, is a rapid means of acclimation and adaptation to environmental conditions, including temperature. While the first methylome of brown macroalgae has been recently described in the kelp Saccharina japonica, its functional relevance and contribution to environmental acclimation is currently unknown. The main objective of our study was to identify the importance of the methylome in the congener kelp species Saccharina latissima for temperature acclimation. Our study is the first to compare DNA methylation in kelp between wild populations of different latitudinal origin, and the first to investigate the effect of cultivation and rearing temperature on genome-wide cytosine methylation. Origin appears to determine many traits in kelp, but it is unknown to what extent the effects of thermal acclimation may be overruled by lab-related acclimation. Our results suggest that seaweed hatchery conditions have strong effects on the methylome and, thus, putatively on the epigenetically controlled characteristics of young kelp sporophytes. However, culture origin could best explain epigenetic differences in our samples suggesting that epigenetic mechanisms contribute to local adaptation of eco-phenotypes. Our study is a first step to understand whether DNA methylation marks (via their effect on gene regulation) may be used as biological regulators to enhance production security and kelp restoration success under rising temperatures, and highlights the importance to match hatchery conditions to origin.
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Affiliation(s)
| | - Kai Bischof
- Marine Botany & MARUM University of Bremen Bremen Germany
| | | | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division Faculty of Biosciences and Aquaculture Nord University Bodø Norway
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Marambio J, Rosenfeld S, Bischof K. Hyposalinity affects diurnal photoacclimation patterns in the rhodophyte Palmaria palmata under mimicked Arctic summer conditions. Journal of Photochemistry and Photobiology 2022. [DOI: 10.1016/j.jpap.2022.100124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Camoying MG, Thoms S, Geuer JK, Koch BP, Bischof K, Trimborn S. In contrast to diatoms, cryptophytes are susceptible to iron limitation, but not to ocean acidification. Physiol Plant 2022; 174:e13614. [PMID: 35199361 DOI: 10.1111/ppl.13614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/09/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Previous field studies in the Southern Ocean (SO) indicated an increased occurrence and dominance of cryptophytes over diatoms due to climate change. To gain a better mechanistic understanding of how the two ecologically important SO phytoplankton groups cope with ocean acidification (OA) and iron (Fe) availability, we chose two common representatives of Antarctic waters, the cryptophyte Geminigera cryophila and the diatom Pseudo-nitzschia subcurvata. Both species were grown at 2°C under different pCO2 (400 vs. 900 μatm) and Fe (0.6 vs. 1.2 nM) conditions. For P. subcurvata, an additional high pCO2 level was applied (1400 μatm). At ambient pCO2 under low Fe supply, growth of G. cryophila almost stopped while it remained unaffected in P. subcurvata. Under high Fe conditions, OA was not beneficial for P. subcurvata, but stimulated growth and carbon production of G. cryophila. Under low Fe supply, P. subcurvata coped much better with OA than the cryptophyte, but invested more energy into photoacclimation. Our study reveals that Fe limitation was detrimental for the growth of G. cryophila and suppressed the positive OA effect. The diatom was efficient in coping with low Fe, but was stressed by OA while both factors together strongly impacted its growth. The distinct physiological response of both species to OA and Fe limitation explains their occurrence in the field. Based on our results, Fe availability is an important modulator of OA effects on SO phytoplankton, with different implications on the occurrence of cryptophytes and diatoms in the future.
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Affiliation(s)
- Marianne G Camoying
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Silke Thoms
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Jana K Geuer
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Boris P Koch
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Department of Technology, University of Applied Sciences Bremerhaven, Bremerhaven, Germany
| | - Kai Bischof
- Marine Botany & MARUM, University of Bremen, Bremen, Germany
| | - Scarlett Trimborn
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Marine Botany & MARUM, University of Bremen, Bremen, Germany
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6
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Laeseke P, Martínez B, Mansilla A, Bischof K. Invaders in waiting? Non-equilibrium in Southern Hemisphere seaweed distributions may lead to underestimation of Antarctic invasion potential. Frontiers of Biogeography 2021. [DOI: 10.21425/f5fbg50879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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7
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Krause-Jensen D, Archambault P, Assis J, Bartsch I, Bischof K, Filbee-Dexter K, Dunton KH, Maximova O, Ragnarsdóttir SB, Sejr MK, Simakova U, Spiridonov V, Wegeberg S, Winding MHS, Duarte CM. Imprint of Climate Change on Pan-Arctic Marine Vegetation. Front Mar Sci 2020; 7. [PMID: 0 DOI: 10.3389/fmars.2020.617324] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The Arctic climate is changing rapidly. The warming and resultant longer open water periods suggest a potential for expansion of marine vegetation along the vast Arctic coastline. We compiled and reviewed the scattered time series on Arctic marine vegetation and explored trends for macroalgae and eelgrass (Zostera marina). We identified a total of 38 sites, distributed between Arctic coastal regions in Alaska, Canada, Greenland, Iceland, Norway/Svalbard, and Russia, having time series extending into the 21st Century. The majority of these exhibited increase in abundance, productivity or species richness, and/or expansion of geographical distribution limits, several time series showed no significant trend. Only four time series displayed a negative trend, largely due to urchin grazing or increased turbidity. Overall, the observations support with medium confidence (i.e., 5–8 in 10 chance of being correct, adopting the IPCC confidence scale) the prediction that macrophytes are expanding in the Arctic. Species distribution modeling was challenged by limited observations and lack of information on substrate, but suggested a current (2000–2017) potential pan-Arctic brown macroalgal distribution area of 655,111 km2(140,433 km2intertidal, 514,679 km2subtidal), representing an increase of about 45% for subtidal- and 8% for intertidal macroalgae since 1940–1950, and associated polar migration rates averaging 18–23 km decade–1. Adjusting the potential macroalgal distribution area by the fraction of shores represented by cliffs halves the estimate (340,658 km2). Warming and reduced sea ice cover along the Arctic coastlines are expected to stimulate further expansion of marine vegetation from boreal latitudes. The changes likely affect the functioning of coastal Arctic ecosystems because of the vegetation’s roles as habitat, and for carbon and nutrient cycling and storage. We encourage a pan-Arctic science- and management agenda to incorporate marine vegetation into a coherent understanding of Arctic changes by quantifying distribution and status beyond the scattered studies now available to develop sustainable management strategies for these important ecosystems.
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Becker LR, Ehrenberg A, Feldrappe V, Kröncke I, Bischof K. The role of artificial material for benthic communities - Establishing different concrete materials as hard bottom environments. Mar Environ Res 2020; 161:105081. [PMID: 33070934 DOI: 10.1016/j.marenvres.2020.105081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/29/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
Concrete is used in marine coastal constructions worldwide. These structures are colonized by specialized hard-bottom biota consisting of macroalgae and benthic macrofauna. As concrete manufacturers face challenges such as limited natural resources and high CO2-emissions, the need for supplementary materials increases. Still, there has been little research on the reaction of species to the differences in concrete composition and what ecological impact these reactions could have. This study addresses the questions (1) if there are differences in settlement communities, depending on differences in concrete constitutes and (2) if so, what are the consequences for the usability of alternative concretes in marine constructions. For the experiment 15 cubes (15 × 15 × 15 cm) made of five different concretes, containing different cements (Portland cement and blast furnace cements) and aggregates (sand, gravel, iron ore and metallurgical slags) were deployed in a natural hard bottom experimental field near Helgoland Island (German Bight) in April 2016. After 12 months, all cubes were examined regarding species composition and coverage, followed by statistical analysis (PERMANOVA, SIMPER, DIVERSE). Results indicate differences in settlement communities for different surface orientation (Top, Front/Back) of the cubes. Significant differences in settlement communities of the Front/Back side were present depending on the used material type. However, the found differences in settlement between the concrete types tested are not sufficiently clear to provide recommendations for their usability in coastal constructions.
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Affiliation(s)
- Lydia R Becker
- University of Bremen, INTERCOAST Research Training Group, Leobener Strasse, 28359, Bremen, Germany; Senckenberg am Meer, Dept. for Marine Research, Südstrand 40, 26382, Wilhelmshaven, Germany; University of Bremen, Department of Marine Botany, Leobener Str. NW2, 28359, Bremen, Germany.
| | - Andreas Ehrenberg
- FEhS - Institut für Baustoff-Forschung e.V., Bliersheimer Straße 62, 47229, Duisburg, Germany
| | - Volkert Feldrappe
- FEhS - Institut für Baustoff-Forschung e.V., Bliersheimer Straße 62, 47229, Duisburg, Germany
| | - Ingrid Kröncke
- Senckenberg am Meer, Dept. for Marine Research, Südstrand 40, 26382, Wilhelmshaven, Germany; Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Schleusenstr 1, 26382, Wilhelmshaven, Germany
| | - Kai Bischof
- University of Bremen, Department of Marine Botany, Leobener Str. NW2, 28359, Bremen, Germany
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Liesner D, Fouqueau L, Valero M, Roleda MY, Pearson GA, Bischof K, Valentin K, Bartsch I. Heat stress responses and population genetics of the kelp Laminaria digitata (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations. Ecol Evol 2020; 10:9144-9177. [PMID: 32953052 PMCID: PMC7487260 DOI: 10.1002/ece3.6569] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 12/26/2022] Open
Abstract
To understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp Laminaria digitata in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold-temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural L. digitata populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common-garden heat stress experiment applying 15°C to 23°C over eight days. We assessed growth, photosynthetic quantum yield, carbon and nitrogen storage, and xanthophyll pigment contents as response traits. Population connectivity and genetic diversity were analyzed with microsatellite markers. Results from the heat stress experiment suggest that the upper temperature limit of L. digitata is nearly identical across its distribution range, but subtle differences in growth and stress responses were revealed for three populations from the species' ecological range margins. Two populations at the species' warm distribution limit showed higher temperature tolerance compared to other populations in growth at 19°C and recovery from 21°C (Quiberon, France), and photosynthetic quantum yield and xanthophyll pigment responses at 23°C (Helgoland, Germany). In L. digitata from the northernmost population (Spitsbergen, Norway), quantum yield indicated the highest heat sensitivity. Microsatellite genotyping revealed all sampled populations to be genetically distinct, with a strong hierarchical structure between southern and northern clades. Genetic diversity was lowest in the isolated population of the North Sea island of Helgoland and highest in Roscoff in the English Channel. All together, these results support the hypothesis of moderate local differentiation across L. digitata's European distribution, whereas effects are likely too weak to ameliorate the species' capacity to withstand ocean warming and marine heatwaves at the southern range edge.
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Affiliation(s)
- Daniel Liesner
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Louise Fouqueau
- UMI EBEA 3614, Evolutionary Biology and Ecology of Algae, CNRSSorbonne Université, UC, UACH, Station Biologique de RoscoffRoscoff CedexFrance
| | - Myriam Valero
- UMI EBEA 3614, Evolutionary Biology and Ecology of Algae, CNRSSorbonne Université, UC, UACH, Station Biologique de RoscoffRoscoff CedexFrance
| | - Michael Y. Roleda
- Norwegian Institute of Bioeconomy ResearchBodøNorway
- The Marine Science Institute, College of ScienceUniversity of the Philippines, DilimanQuezon CityPhilippines
| | | | - Kai Bischof
- Marine BotanyUniversity of BremenBremenGermany
| | - Klaus Valentin
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Inka Bartsch
- Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchBremerhavenGermany
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Véliz K, Chandía N, Bischof K, Thiel M. Geographic Variation of UV Stress Tolerance in Red Seaweeds Does Not Scale with Latitude Along the SE Pacific Coast. J Phycol 2020; 56:1090-1102. [PMID: 32348548 DOI: 10.1111/jpy.13009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
Geographic variation of phenotypic traits affects the capacity of species to withstand and adapt to environmental stress. Here, we examined how geographic origin influences UV stress tolerance of the red seaweeds Chondracanthus chamissoi and Gelidium lingulatum distributed along the South-East Pacific coast between 20° S and 42° S. Seaweeds from six (C. chamissoi) and five (G. lingulatum) populations were grown under common-garden conditions and then exposed to consecutive UV stress events and essential biological traits (e.g., growth, photosynthetic responses, antioxidant capacity, and UV-absorbing compounds) were analyzed. In C. chamissoi, a strong UV sensitivity occurred in populations from mid-latitudes (27° S and 29° S) where the lowest recovery of maximum quantum yield (Fv /Fm ; between 32.3% and 66.8% of control) and growth rate were observed. Likewise, the lowest amount of mycosporine-like amino acids (MAAs) and a significant decrease in phycobilins were registered in these populations. In G. lingulatum, recovery of Fv /Fm ranged from 82.0% to 97.7% of control, and antioxidant activity, carotenoid, and MAA contents were positively influenced by UV exposure. The multivariate analysis indicated a significant influence of PAR, cloud cover, and UV index on physiological traits, depending on species. The ecotypic differentiation index (EDI) indicated a higher phenotypic variation in C. chamissoi (EDI = 0.10) than G. lingulatum (EDI = 0.03). This study shows that the spatial distribution of UV stress tolerance in the studied seaweeds does not follow linear latitudinal or central-edge gradients. Instead, among-site variability of solar intensities driven by specific climatic conditions seems to act as driver of phenotypic variation.
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Affiliation(s)
- Karina Véliz
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Nancy Chandía
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Kai Bischof
- Marine Botany, University of Bremen, 28359, Bremen, Germany
| | - Martin Thiel
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Av. Ossandon 877, Coquimbo, Chile
- Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
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Diehl N, Karsten U, Bischof K. Impacts of combined temperature and salinity stress on the endemic Arctic brown seaweed Laminaria solidungula J. Agardh. Polar Biol 2020. [DOI: 10.1007/s00300-020-02668-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
AbstractMacroalgae such as kelp are important ecosystem engineers in the Polar Regions and potentially affected by freshening and ocean warming. The endemic Arctic kelp Laminaria solidungula might be particularly imperiled and become locally extinct from Arctic fjord systems in the future, since temperature increase is most pronounced in the Polar Regions. Additionally, increased temperatures cause glacier and sea ice melting and enhancing terrestrial run-off from snowfields, which eventually can result in hyposaline conditions in fjord systems. We conducted a multiple-stressor experiment at four temperatures (0, 5, 10, 15 °C) and two salinities (SA 25, 35) to investigate the combined effects of increasing temperature and decreasing salinities on the physiological and biochemical status of young L. solidungula sporophytes. Both drivers had significant and interacting impacts, either in an additive or antagonistic way, dependent on the respective response variable. The maximum quantum yield of photosystem II (Fv/Fm) significantly declined with temperature increase and low salinity. Even though the absolute pigment content was not affected, the deepoxydation state of the xanthophyll cycle increased with intensified stress. Higher temperatures affected the C:N ratio significantly, mainly due to reduced nitrogen uptake, while SA 25 supported the nitrogen uptake, resulting in an attenuation of the effect. The concentration of mannitol decreased at SA 25. At control SA 35 mannitol level remained steady between 0 and 10 °C but significantly decreased at 15 °C. Conclusively, our results show that L. solidungula is very susceptible to both drivers of climate change, especially when they are combined. Implications to species ecology are discussed.
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Li H, Monteiro C, Heinrich S, Bartsch I, Valentin K, Harms L, Glöckner G, Corre E, Bischof K. Responses of the kelp Saccharina latissima (Phaeophyceae) to the warming Arctic: from physiology to transcriptomics. Physiol Plant 2020; 168:5-26. [PMID: 31267544 DOI: 10.1111/ppl.13009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/31/2019] [Accepted: 06/27/2019] [Indexed: 06/09/2023]
Abstract
The Arctic region is currently facing substantial environmental changes due to global warming. Melting glaciers cause reduced salinity environments in coastal Arctic habitats, which may be stressful for kelp beds. To investigate the responses of the kelp Saccharina latissima to the warming Arctic, we studied the transcriptomic changes of S. latissima from Kongsfjorden (Svalbard, Norway) over a 24-hour exposure to two salinities (Absolute Salinity [SA ] 20 and 30) after a 7-day pre-acclimation at three temperatures (0, 8 and 15°C). In addition, corresponding physiological data were assessed during an 11-days salinity/temperature experiment. Growth and maximal quantum yield for photosystem II fluorescence were positively affected by increased temperature during acclimation, whereas hyposalinity caused negative effects at the last day of treatment. In contrast, hyposalinity induced marked changes on the transcriptomic level. Compared to the control (8°C - SA 30), the 8°C - SA 20 exhibited the highest number of differentially expressed genes (DEGs), followed by the 0°C - SA 20. Comparisons indicate that S. latissima tends to convert its energy from primary metabolism (e.g. photosynthesis) to antioxidant activity under hyposaline stress. The increase in physiological performance at 15°C shows that S. latissima in the Arctic region can adjust and might even benefit from increased temperatures. However, in Arctic fjord environments its performance might become impaired by decreased salinity as a result of ice melting.
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Affiliation(s)
- Huiru Li
- Fisheries College, Ocean University of China, Qingdao, 266003, China
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
| | - Cátia Monteiro
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), Roscoff, 29680, France
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, Roscoff, 29680, France
| | - Sandra Heinrich
- Molecular Plant Genetics, Institute for Plant Science and Microbiology, University of Hamburg, Hamburg, 22609, Germany
| | - Inka Bartsch
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Klaus Valentin
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Lars Harms
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Gernot Glöckner
- Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, 50931, Germany
| | - Erwan Corre
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), Roscoff, 29680, France
| | - Kai Bischof
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
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Machado Monteiro CM, Li H, Bischof K, Bartsch I, Valentin KU, Corre E, Collén J, Harms L, Glöckner G, Heinrich S. Is geographical variation driving the transcriptomic responses to multiple stressors in the kelp Saccharina latissima? BMC Plant Biol 2019; 19:513. [PMID: 31775614 PMCID: PMC6881991 DOI: 10.1186/s12870-019-2124-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Kelps (Laminariales, Phaeophyceae) are brown macroalgae of utmost ecological, and increasingly economic, importance on temperate to polar rocky shores. Omics approaches in brown algae are still scarce and knowledge of their acclimation mechanisms to the changing conditions experienced in coastal environments can benefit from the application of RNA-sequencing. Despite evidence of ecotypic differentiation, transcriptomic responses from distinct geographical locations have, to our knowledge, never been studied in the sugar kelp Saccharina latissima so far. RESULTS In this study we investigated gene expression responses using RNA-sequencing of S. latissima from environments with contrasting temperature and salinity conditions - Roscoff, in temperate eastern Atlantic, and Spitsbergen in the Arctic. Juvenile sporophytes derived from uniparental stock cultures from both locations were pre-cultivated at 8 °C and SA 30. Sporophytes acclimated to 0 °C, 8 °C and 15 °C were exposed to a low salinity treatment (SA 20) for 24 h. Hyposalinity had a greater impact at the transcriptomic level than the temperature alone, and its effects were modulated by temperature. Namely, photosynthesis and pigment synthesis were extensively repressed by low salinity at low temperatures. Although some responses were shared among sporophytes from the different sites, marked differences were revealed by principal component analysis, differential expression and GO enrichment. The interaction between low temperature and low salinity drove the largest changes in gene expression in sporophytes from Roscoff while specimens from Spitsbergen required more metabolic adjustment at higher temperatures. Moreover, genes related to cell wall adjustment were differentially expressed between Spitsbergen and Roscoff control samples. CONCLUSIONS Our study reveals interactive effects of temperature and salinity on transcriptomic profiles in S. latissima. Moreover, our data suggest that under identical culture conditions sporophytes from different locations diverge in their transcriptomic responses. This is probably connected to variations in temperature and salinity in their respective environment of origin. The current transcriptomic results support the plastic response pattern in sugar kelp which is a species with several reported ecotypes. Our data provide the baseline for a better understanding of the underlying processes of physiological plasticity and may help in the future to identify strains adapted to specific environments and its genetic control.
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Affiliation(s)
- Cátia Marina Machado Monteiro
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), 29680 Roscoff, France
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, France
| | - Huiru Li
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
- Fisheries College, Ocean University of China, Qingdao, China
| | - Kai Bischof
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, Germany
| | - Inka Bartsch
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Klaus Ulrich Valentin
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Erwan Corre
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), 29680 Roscoff, France
| | - Jonas Collén
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, France
| | - Lars Harms
- Alfred-Wegener-Institute, Helmholtz Centre for Marine and Polar Research, Bremerhaven, Germany
| | - Gernot Glöckner
- Institute for Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | - Sandra Heinrich
- Institute for Plant Science and Microbiology, University of Hamburg, Hamburg, Germany
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Laeseke P, Bartsch I, Bischof K. Effects of kelp canopy on underwater light climate and viability of brown algal spores in Kongsfjorden (Spitsbergen). Polar Biol 2019. [DOI: 10.1007/s00300-019-02537-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Heiden JP, Thoms S, Bischof K, Trimborn S, Raven J. Ocean acidification stimulates particulate organic carbon accumulation in two Antarctic diatom species under moderate and high natural solar radiation. J Phycol 2018; 54:505-517. [PMID: 29791031 PMCID: PMC6120492 DOI: 10.1111/jpy.12753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Impacts of rising atmospheric CO2 concentrations and increased daily irradiances from enhanced surface water stratification on phytoplankton physiology in the coastal Southern Ocean remain still unclear. Therefore, in the two Antarctic diatoms Fragilariopsis curta and Odontella weissflogii, the effects of moderate and high natural solar radiation combined with either ambient or future pCO2 on cellular particulate organic carbon (POC) contents and photophysiology were investigated. Results showed that increasing CO2 concentrations had greater impacts on diatom physiology than exposure to increasing solar radiation. Irrespective of the applied solar radiation regime, cellular POC quotas increased with future pCO2 in both diatoms. Lowered maximum quantum yields of photochemistry in PSII (Fv /Fm ) indicated a higher photosensitivity under these conditions, being counteracted by increased cellular concentrations of functional photosynthetic reaction centers. Overall, our results suggest that both bloom-forming Antarctic coastal diatoms might increase carbon contents under future pCO2 conditions despite reduced physiological fitness. This indicates a higher potential for primary productivity by the two diatom species with important implications for the CO2 sequestration potential of diatom communities in the future coastal Southern Ocean.
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Affiliation(s)
- Jasmin P. Heiden
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
| | - Silke Thoms
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227568BremerhavenGermany
| | - Kai Bischof
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
| | - Scarlett Trimborn
- Alfred Wegener Institute Helmholtz Center for Polar and Marine ResearchAm Handelshafen 1227570BremerhavenGermany
- Marine BotanyUniversity BremenLeobener Str. NW228359BremenGermany
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Trimborn S, Thoms S, Brenneis T, Heiden JP, Beszteri S, Bischof K. Two Southern Ocean diatoms are more sensitive to ocean acidification and changes in irradiance than the prymnesiophyte Phaeocystis antarctica. Physiol Plant 2017; 160:155-170. [PMID: 28019019 DOI: 10.1111/ppl.12539] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/24/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
To better understand the impact of ocean acidification (OA) and changes in light availability on Southern Ocean phytoplankton physiology, we investigated the effects of pCO2 (380 and 800 µatm) in combination with low and high irradiance (20 or 50 and 200 µmol photons m-2 s-1 ) on growth, particulate organic carbon (POC) fixation and photophysiology in the three ecologically relevant species Chaetoceros debilis, Fragilariopsis kerguelensis and Phaeocystis antarctica. Irrespective of the light scenario, neither growth nor POC per cell was stimulated by OA in any of the tested species and the two diatoms even displayed negative responses in growth (e.g. C. debilis) or POC content (e.g. F. kerguelensis) under OA in conjunction with high light. For both diatoms, also maximum quantum yields of photosystem II (Fv /Fm ) were decreased under these conditions, indicating lowered photochemical efficiencies. To counteract the negative effects by OA and high light, the two diatoms showed diverging photoacclimation strategies. While cellular chlorophyll a (Chl a) and fucoxanthin contents were enhanced in C. debilis to potentially maximize light absorption, F. kerguelensis exhibited reduced Chl a per cell, increased disconnection of antennae from photosystem II reaction centers and strongly lowered absolute electron transport rates (ETR). The decline in ETRs in F. kerguelensis might be explained in terms of different species-specific strategies for tuning the available flux of adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. Overall, our results revealed that P. antarctica was more tolerant to OA and changes in irradiance than the two diatoms, which may have important implications for biogeochemical cycling.
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Affiliation(s)
- Scarlett Trimborn
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Silke Thoms
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Tina Brenneis
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Jasmin P Heiden
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Sara Beszteri
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Kai Bischof
- Marine Botany, University of Bremen, Bremen, Germany
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Koch K, Thiel M, Hagen W, Graeve M, Gómez I, Jofre D, Hofmann LC, Tala F, Bischof K. Short- and long-term acclimation patterns of the giant kelp Macrocystis pyrifera (Laminariales, Phaeophyceae) along a depth gradient. J Phycol 2016; 52:260-73. [PMID: 27037591 DOI: 10.1111/jpy.12394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
The giant kelp, Macrocystis pyrifera, is exposed to highly variable irradiance and temperature regimes across its geographic and vertical depth gradients. The objective of this study was to extend our understanding of algal acclimation strategies on different temporal scales to those varying abiotic conditions at various water depths. Different acclimation strategies to various water depths (0.2 and 4 m) between different sampling times (Jan/Feb and Aug/Sept 2012; long-term acclimation) and more rapid adjustments to different depths (0.2, 2 and 4 m; short-term acclimation) during 14 d of transplantation were found. Adjustments of variable Chl a fluorescence, pigment composition (Chl c, fucoxanthin), and the de-epoxidation state of the xanthophyll cycle pigments were responsible for the development of different physiological states with respect to various solar radiation and temperature climates. Interestingly, the results indicated that phlorotannins are important during long-term acclimation while antioxidants have a crucial role during short-term acclimation. Furthermore, the results suggested that modifications in total lipids and fatty acid compositions apparently also might play a role in depth acclimation. In Aug/Sept (austral winter), M. pyrifera responded to the transplantation from 4 m to 0.2 m depth with a rise in the degree of saturation and a switch from shorter- to longer-chain fatty acids. These changes seem to be essential for the readjustment of thylakoid membranes and might, thus, facilitate efficient photosynthesis under changing irradiances and temperatures. Further experiments are needed to disentangle the relative contribution of solar radiation, temperature and also other abiotic parameters in the observed physiological changes.
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Affiliation(s)
- Kristina Koch
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
| | - Martin Thiel
- Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Larrondo 1281, Coquimbo, Chile
- Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
| | - Wilhelm Hagen
- Marine Zoology and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, Bremen, 28359, Germany
| | - Martin Graeve
- Ecological Chemistry, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), Am Handelshafen 12, Bremerhaven, 27570, Germany
| | - Iván Gómez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
| | - David Jofre
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Laurie C Hofmann
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, 28359, Germany
| | - Fadia Tala
- Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Larrondo 1281, Coquimbo, Chile
| | - Kai Bischof
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
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Hofmann LC, Fink A, Bischof K, de Beer D. Microsensor studies on Padina from a natural CO2 seep: implications of morphology on acclimation to low pH. J Phycol 2015; 51:1106-1115. [PMID: 26987005 DOI: 10.1111/jpy.12347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 08/01/2015] [Indexed: 06/05/2023]
Abstract
Low seawater pH can be harmful to many calcifying marine organisms, but the calcifying macroalgae Padina spp. flourish at natural submarine carbon dioxide seeps where seawater pH is low. We show that the microenvironment created by the rolled thallus margin of Padina australis facilitates supersaturation of CaCO3 and calcifi-cation via photosynthesis-induced elevated pH. Using microsensors to investigate oxygen and pH dynamics in the microenvironment of P. australis at a shallow CO2 seep, we found that, under saturating light, the pH inside the microenvironment (pHME ) was higher than the external seawater (pHSW ) at all pHSW levels investigated, and the difference (i.e., pHME - pHSW ) increased with decreasing pHSW (0.9 units at pHSW 7.0). Gross photosynthesis (Pg ) inside the microenvironment increased with decreasing pHSW , but algae from the control site reached a threshold at pH 6.5. Seep algae showed no pH threshold with respect to Pg within the pHSW range investigated. The external carbonic anhydrase (CA) inhibitor, acetazolamide, strongly inhibited Pg of P. australis at pHSW 8.2, but the effect was diminished under low pHSW (6.4-7.5), suggesting a greater dependence on membrane-bound CA for the dehydration of HCO3 (-) ions during dissolved inorganic carbon uptake at the higher pHSW . In comparison, a calcifying green alga, Halimeda cuneata f. digitata, was not inhibited by AZ, suggesting efficient bicarbonate transport. The ability of P. australis to elevate pHME at the site of calcification and its strong dependence on CA may explain why it can thrive at low pHSW .
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Affiliation(s)
- Laurie C Hofmann
- Marine Botany, University of Bremen, Leobener Str. NW2, Bremen, 28359, Germany
| | - Artur Fink
- Microsensor Group, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, Bremen, 28359, Germany
| | - Kai Bischof
- Marine Botany, University of Bremen, Leobener Str. NW2, Bremen, 28359, Germany
| | - Dirk de Beer
- Microsensor Group, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, Bremen, 28359, Germany
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Hassenrück C, Hofmann LC, Bischof K, Ramette A. Seagrass biofilm communities at a naturally CO2 -rich vent. Environ Microbiol Rep 2015; 7:516-25. [PMID: 25727314 PMCID: PMC4677816 DOI: 10.1111/1758-2229.12282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/20/2015] [Indexed: 05/25/2023]
Abstract
Seagrass meadows are a crucial component of tropical marine reef ecosystems. Seagrass plants are colonized by a multitude of epiphytic organisms that contribute to broadening the ecological role of seagrasses. To better understand how environmental changes like ocean acidification might affect epiphytic assemblages, the microbial community composition of the epiphytic biofilm of Enhalus acroides was investigated at a natural CO2 vent in Papua New Guinea using molecular fingerprinting and next-generation sequencing of 16S and 18S rRNA genes. Both bacterial and eukaryotic epiphytes formed distinct communities at the CO2 -impacted site compared with the control site. This site-related CO2 effect was also visible in the succession pattern of microbial epiphytes. We further found an increased relative sequence abundance of bacterial types associated with coral diseases at the CO2 -impacted site (Fusobacteria, Thalassomonas), whereas eukaryotes such as certain crustose coralline algae commonly related to healthy reefs were less diverse. These trends in the epiphytic community of E. acroides suggest a potential role of seagrasses as vectors of coral pathogens and may support previous predictions of a decrease in reef health and prevalence of diseases under future ocean acidification scenarios.
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MESH Headings
- Aquatic Organisms/microbiology
- Bacteria/classification
- Bacteria/genetics
- Biofilms/growth & development
- Biota
- Carbon Dioxide/metabolism
- DNA, Algal/chemistry
- DNA, Algal/genetics
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- DNA-Directed DNA Polymerase
- Eukaryota/classification
- Eukaryota/genetics
- Hydrocharitaceae/microbiology
- Papua New Guinea
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 18S/genetics
- Sequence Analysis, DNA
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Affiliation(s)
- Christiane Hassenrück
- HGF MPG Group for Deep-Sea Ecology and Technology, Max Planck Institute for Marine MicrobiologyCelsiusstrasse 1, Bremen, 28359, Germany
| | - Laurie C Hofmann
- BreMarE, FB 02, University of BremenLeobener Str. NW2, Bremen, 28359, Germany
| | - Kai Bischof
- BreMarE, FB 02, University of BremenLeobener Str. NW2, Bremen, 28359, Germany
| | - Alban Ramette
- HGF MPG Group for Deep-Sea Ecology and Technology, Max Planck Institute for Marine MicrobiologyCelsiusstrasse 1, Bremen, 28359, Germany
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Lütz C, Di Piazza L, Fredersdorf J, Bischof K. The effect of ultraviolet radiation on cellular ultrastructure and photosystem II quantum yield of Alaria esculenta (L.) Greville from Spitsbergen (Norway). Polar Biol 2015. [DOI: 10.1007/s00300-015-1659-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Hofmann LC, Bischof K, Baggini C, Johnson A, Koop-Jakobsen K, Teichberg M. CO₂ and inorganic nutrient enrichment affect the performance of a calcifying green alga and its noncalcifying epiphyte. Oecologia 2015; 177:1157-69. [PMID: 25648647 DOI: 10.1007/s00442-015-3242-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 01/16/2015] [Indexed: 11/26/2022]
Abstract
Ocean acidification studies in the past decade have greatly improved our knowledge of how calcifying organisms respond to increased surface ocean CO2 levels. It has become evident that, for many organisms, nutrient availability is an important factor that influences their physiological responses and competitive interactions with other species. Therefore, we tested how simulated ocean acidification and eutrophication (nitrate and phosphate enrichment) interact to affect the physiology and ecology of a calcifying chlorophyte macroalga (Halimeda opuntia (L.) J.V. Lamouroux) and its common noncalcifying epiphyte (Dictyota sp.) in a 4-week fully crossed multifactorial experiment. Inorganic nutrient enrichment (+NP) had a strong influence on all responses measured with the exception of net calcification. Elevated CO2 alone significantly decreased electron transport rates of the photosynthetic apparatus and resulted in phosphorus limitation in both species, but had no effect on oxygen production or respiration. The combination of CO2 and +NP significantly increased electron transport rates in both species. While +NP alone stimulated H. opuntia growth rates, Dictyota growth was significantly stimulated by nutrient enrichment only at elevated CO2, which led to the highest biomass ratios of Dictyota to Halimeda. Our results suggest that inorganic nutrient enrichment alone stimulates several aspects of H. opuntia physiology, but nutrient enrichment at a CO2 concentration predicted for the end of the century benefits Dictyota sp. and hinders its calcifying basibiont H. opuntia.
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Affiliation(s)
- Laurie C Hofmann
- Marine Botany, Bremen Marine Ecology Centre for Research and Education, University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany,
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Hofmann LC, Heiden J, Bischof K, Teichberg M. Nutrient availability affects the response of the calcifying chlorophyte Halimeda opuntia (L.) J.V. Lamouroux to low pH. Planta 2014; 239:231-242. [PMID: 24158465 DOI: 10.1007/s00425-013-1982-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 10/13/2013] [Indexed: 06/02/2023]
Abstract
Atmospheric carbon dioxide emissions cause a decrease in the pH and aragonite saturation state of surface ocean water. As a result, calcifying organisms are expected to suffer under future ocean conditions, but their physiological responses may depend on their nutrient status. Because many coral reefs experience high inorganic nutrient loads or seasonal changes in nutrient availability, reef organisms in localized areas will have to cope with elevated carbon dioxide and changes in inorganic nutrients. Halimeda opuntia is a dominant calcifying primary producer on coral reefs that contributes to coral reef accretion. Therefore, we investigated the carbon and nutrient balance of H. opuntia exposed to elevated carbon dioxide and inorganic nutrients. We measured tissue nitrogen, phosphorus and carbon content as well as the activity of enzymes involved in inorganic carbon uptake and nitrogen assimilation (external carbonic anhydrase and nitrate reductase, respectively). Inorganic carbon content was lower in algae exposed to high CO₂, but calcification rates were not significantly affected by CO₂ or inorganic nutrients. Organic carbon was positively correlated to external carbonic anhydrase activity, while inorganic carbon showed the opposite correlation. Carbon dioxide had a significant effect on tissue nitrogen and organic carbon content, while inorganic nutrients affected tissue phosphorus and N:P ratios. Nitrate reductase activity was highest in algae grown under elevated CO₂ and inorganic nutrient conditions and lowest when phosphate was limiting. In general, we found that enzymatic responses were strongly influenced by nutrient availability, indicating its important role in dictating the local responses of the calcifying primary producer H. opuntia to ocean acidification.
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Affiliation(s)
- Laurie C Hofmann
- Marine Botany Department, Bremen Marine Ecology Center for Research and Education, University of Bremen, Leobener Straße NW2, 28359, Bremen, Germany,
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Stamenković M, Bischof K, Hanelt D. Xanthophyll cycle pool size and composition in several Cosmarium strains (Zygnematophyceae, Streptophyta) are related to their geographic distribution patterns. Protist 2013; 165:14-30. [PMID: 24334196 DOI: 10.1016/j.protis.2013.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 10/20/2013] [Accepted: 10/27/2013] [Indexed: 12/20/2022]
Abstract
The photosynthetic behaviour and composition of photosynthetic pigments of four Cosmarium strains collected from different geographic areas were examined under moderate and photoinhibitory white light by means of PAM fluorometry and high-performance liquid chromatography. Generally, all of the Cosmarium strains displayed the photosynthetic performance and the composition of xanthophyll cycle pigments corresponding to that of high-light adapted plants and algae, when grown under the standard laboratory conditions. However, photoinhibitory treatments provoked several strain- and species-specific characteristics despite the long-term cultivation in laboratory conditions. The typical arctic taxon, C. crenatum var. boldtianum, displayed an incomplete violaxanthin cycle yielding an accumulation of antheraxanthin during high light stress, which is considered as an adaptation to occasional high irradiances in the polar zone due to the albedo. So far, the violaxanthin/antheraxanthin turnover was known only in some prasinophycean algae. Antheraxanthin actively participated in the heat dissipation from PSII centres in C. crenatum, as concluded from a significant positive correlation between non-photochemical quenching (NPQ) and the quantity of antheraxanthin. In contrast, all the other Cosmarium strains displayed a complete violaxanthin de-epoxidase action during the high light treatments, as judged from the relatively high production of zeaxanthin which participated in thermal dissipation of excess energy.
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Affiliation(s)
- Marija Stamenković
- Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorst Str. 18, 22609 Hamburg, Germany.
| | - Kai Bischof
- Department of Marine Botany, Universität Bremen, Leobener Str. NW2, 28359 Bremen, Germany
| | - Dieter Hanelt
- Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorst Str. 18, 22609 Hamburg, Germany
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Hofmann LC, Straub S, Bischof K. Elevated CO2 levels affect the activity of nitrate reductase and carbonic anhydrase in the calcifying rhodophyte Corallina officinalis. J Exp Bot 2013; 64:899-908. [PMID: 23314813 PMCID: PMC3580807 DOI: 10.1093/jxb/ers369] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The concentration of CO(2) in global surface ocean waters is increasing due to rising atmospheric CO(2) emissions, resulting in lower pH and a lower saturation state of carbonate ions. Such changes in seawater chemistry are expected to impact calcification in calcifying marine organisms. However, other physiological processes related to calcification might also be affected, including enzyme activity. In a mesocosm experiment, macroalgal communities were exposed to three CO(2) concentrations (380, 665, and 1486 µatm) to determine how the activity of two enzymes related to inorganic carbon uptake and nutrient assimilation in Corallina officinalis, an abundant calcifying rhodophyte, will be affected by elevated CO(2) concentrations. The activity of external carbonic anhydrase, an important enzyme functioning in macroalgal carbon-concentrating mechanisms, was inversely related to CO(2) concentration after long-term exposure (12 weeks). Nitrate reductase, the enzyme responsible for reduction of nitrate to nitrite, was stimulated by CO(2) and was highest in algae grown at 665 µatm CO(2). Nitrate and phosphate uptake rates were inversely related to CO(2), while ammonium uptake was unaffected, and the percentage of inorganic carbon in the algal skeleton decreased with increasing CO(2). The results indicate that the processes of inorganic carbon and nutrient uptake and assimilation are affected by elevated CO(2) due to changes in enzyme activity, which change the energy balance and physiological status of C. officinalis, therefore affecting its competitive interactions with other macroalgae. The ecological implications of the physiological changes in C. officinalis in response to elevated CO(2) are discussed.
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Affiliation(s)
- Laurie C Hofmann
- Marine Botany, Bremen Marine Ecology Centre for Research and Education, University of Bremen, Leobener Str. NW2, Bremen, Germany.
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Steinhoff FS, Graeve M, Bartoszek K, Bischof K, Wiencke C. Phlorotannin production and lipid oxidation as a potential protective function against high photosynthetically active and UV radiation in gametophytes of Alaria esculenta (Alariales, Phaeophyceae). Photochem Photobiol 2012; 88:46-57. [PMID: 21958385 DOI: 10.1111/j.1751-1097.2011.01004.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Radiation damage can inter alia result in lipid peroxidation of macroalgal cell membranes. To prevent photo-oxidation within the cells, photoprotective substances such as phlorotannins are synthesized. In the present study, changes in total fatty acids (FA), FA composition and intra/extracellular phlorotannin contents were determined by gas chromatography and the Folin-Ciocalteu method to investigate the photoprotective potential of phlorotannins to prevent lipid peroxidation. Alaria esculenta juveniles (Phaeophyceae) were exposed over 20 days to high/low photosynthetically active radiation (PAR) in combination with UV radiation (UVR) in the treatments: PAB (low/high PAR + UV-B + UV-A), PA (low/high PAR + UV-A) or low/high PAR only. While extracellular phlorotannins increased after 10 days, intracellular phlorotannins increased with exposure time and PA and decreased under PAB. Interactive effects of time:radiation wavebands, time:PAR dose as well as radiation wavebands:PAR dose were observed. Low FA contents were detected in the PA and PAB treatments; interactive effects were observed between time:high PAR and PAB:high PAR. Total FA contents were correlated to extra/intracellular phlorotannin contents. Our results suggest that phlorotannins might play a role in intra/extracellular protection by absorption and oxidation processes. Changes in FA content/composition upon UVR and high PAR might be considered as an adaptive mechanism of the A. esculenta juveniles subjected to variations in solar irradiance.
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Krämer WE, Caamaño-Ricken I, Richter C, Bischof K. Dynamic Regulation of Photoprotection Determines Thermal Tolerance of Two Phylotypes of Symbiodinium Clade A at Two Photon Fluence Rates. Photochem Photobiol 2011; 88:398-413. [DOI: 10.1111/j.1751-1097.2011.01048.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Steinhoff FS, Graeve M, Wiencke C, Wulff A, Bischof K. Lipid content and fatty acid consumption in zoospores/developing gametophytes of Saccharina latissima (Laminariales, Phaeophyceae) as potential precursors for secondary metabolites as phlorotannins. Polar Biol 2011. [DOI: 10.1007/s00300-011-0960-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Müller R, Wiencke C, Bischof K, Krock B. Zoospores of three Arctic laminariales under different UV radiation and temperature conditions: exceptional spectral absorbance properties and lack of phlorotannin induction. Photochem Photobiol 2009; 85:970-7. [PMID: 19175751 DOI: 10.1111/j.1751-1097.2008.00515.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phlorotannins have often been considered to act as UV-protective compounds in zoospores of brown algae. However, only the absorption characteristics of zoospores under UV exposure have been determined and no data are available on the actual content of phlorotannins or on temperature-UV interactions. Therefore, we determined the absorbance spectra and the phlorotannin contents in zoospore suspensions of three Arctic species (Saccharina latissima, Laminaria digitata, Alaria esculenta), and in the media surrounding zoospores after exposure to different radiation (400-700, 320-700, 295-700 nm) and temperature (2-18 degrees C) conditions for 8 h. Absorption typical of phlorotannins with a maximum at 276 nm was monitored in zoospore suspensions as well as in the media surrounding zoospores, but the results depended strongly on radiation treatments and on zoospore densities. Surprisingly, the content of UV-absorbing phlorotannins subsequent to different exposures did not change in any of the three species. The observed exceptional absorption properties could, therefore, not be related to phlorotannin contents. These findings are discussed in light of a strong phlorotannin investment from sporophytes during spore release and a minor UV-protective role of phlorotannins for zoospores of Arctic kelp species.
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Affiliation(s)
- Ruth Müller
- Section Seaweed Biology, Alfred Wegener Institute for Marine and Polar Research, Bremerhaven, Germany.
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Fredersdorf J, Müller R, Becker S, Wiencke C, Bischof K. Interactive effects of radiation, temperature and salinity on different life history stages of the Arctic kelp Alaria esculenta (Phaeophyceae). Oecologia 2009; 160:483-92. [PMID: 19330357 DOI: 10.1007/s00442-009-1326-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 03/03/2009] [Indexed: 10/21/2022]
Abstract
To estimate the potential effects of climate change on polar marine macroalgae, studies on interactive stress effects of multiple climate-related parameters are essential. Interactions of temperature, radiation and salinity on two different life history stages of Alaria esculenta (L.) Greville from the Kongsfjord (Spitsbergen) were investigated for the first time within this study. Adult macroscopic sporophytes of A. esculenta were exposed to different temperatures between 4 and 21 degrees C combined with artificial irradiation conditions [photosynthetically active radiation, ultraviolet (UV) radiation: UV-A/UV-B, first experiment] and with different salinities [34, 28, 20 practical salinity units (p.s.u.) second experiment]. Effects of photosynthetic activity were determined by measuring variable chlorophyll fluorescence of photosystem II. Germination success of young microscopic zoospores of A. esculenta was studied under multifactorial stress. Zoospore suspensions were exposed to the three different salinities and irradiation conditions at four temperatures between 2 and 16 degrees C. Overall, A. esculenta exhibited a highly stage-specific susceptibility towards the experimental treatments. In both experiments using sporophytes, photosynthetic activity showed significant temperature effects and only very few significant radiation and salinity effects. Microscopic stages of A. esculenta were shown to be more sensitive than the adult macroscopic stages, since germination capacity of zoospores was significantly affected by temperature and salinity changes, and interactions of both. These results suggest that multiple stress factors interact synergistically. Temperature seems to be a predominant environmental parameter for the kelp A. esculenta. Overall, A. esculenta proved to be relatively tolerant and adaptable to increasing temperature and UV radiation, as well as to diluted salinities, but only up to a specific limit.
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Affiliation(s)
- Jana Fredersdorf
- Department of Marine Botany, University of Bremen, Bremen, Germany.
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Bischof K, Dörfler D, Sator K, Huber J. Kontrazeption für Frauen mit Behinderung. Geburtshilfe Frauenheilkd 2009. [DOI: 10.1055/s-0029-1225230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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31
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Steinhoff FS, Wiencke C, Müller R, Bischof K. Effects of ultraviolet radiation and temperature on the ultrastructure of zoospores of the brown macroalga Laminaria hyperborea. Plant Biol (Stuttg) 2008; 10:388-97. [PMID: 18426486 DOI: 10.1111/j.1438-8677.2008.00049.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interactive effects of an 8 h exposure to UV radiation and altered temperatures on the ultrastructure and germination of zoospores of the sublittoral brown alga Laminaria hyperborea (Gunn.) Foslie were investigated for the first time. Spores were exposed to four temperatures (2, 7, 12 and 17 degrees C) and three light regimes (PAR, PAR + UV-A, PAR + UV-A+UV-B). Freshly-released spores of L. hyperborea lack a cell wall and contain a nucleus with fine granular nucleoplasm and a nucleolus, one chloroplast, several mitochondria, dictyosomes and an endoplasmatic reticulum. Further, several kinds of so-called adhesive vesicles, lipid globuli and physodes containing UV-absorbing phlorotannins are embedded in the cytoplasm. No eye-spot is present. Physodes were found but they were rare and small. After an 8 h exposure to UV-B, the nucleoplasm had a mottled structure, chloroplasts contained plastoglobuli, the structure of the mitochondria changed from crista- to sacculus-type and germination was strongly inhibited at all temperatures. UV-A only had an impact on the ultrastructure at the highest temperature tested. The strongest effects were found at 17 degrees C, where germination was reduced to 35%, 32% and 9% after exposure to PAR, PAR+UV-A and PAR + UV-A + UV-B, respectively. This study indicates that UV-B radiation has strong damaging effects on the physiology and ultrastructure of zoospores of L. hyperborea. The results are important for developing scenarios for the effect of enhanced UV radiation and increasing temperatures caused by global climate changes.
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Affiliation(s)
- F S Steinhoff
- Alfred Wegener Institute for Polar and Marine Research, Section Seaweed Biology, Bremerhaven, Germany.
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Roleda MY, Wiencke C, Hanelt D, Bischof K. Sensitivity of the Early Life Stages of Macroalgae from the Northern Hemisphere to Ultraviolet Radiation†. Photochem Photobiol 2007; 83:851-62. [PMID: 17645656 DOI: 10.1562/2006-08-17-ir-1005] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The reproductive cells of macroalgae are regarded as the life history stages most susceptible to various environmental stresses, including UV radiation (UVR). UVR is proposed to determine the upper depth distribution limit of macroalgae on the shore. These hypotheses were tested by UV-exposure experiments, using spores and young thalli of the eulittoral Rhodophyceae Mastocarpus stellatus and Chondrus crispus and various sublittoral brown macroalgae (Phaeophyceae) with different depth distribution from Helgoland (German Bight) and Spitsbergen (Arctic). In spores, the degree of UV-induced inhibition of photosynthesis is lower in eulittoral species and higher in sublittoral species. After UV stress, recovery of photosynthetic capacity is faster in eulittoral compared to sublittoral species. DNA damage is lowest while repair of DNA damage is highest in eulittoral compared to sublittoral species. When the negative impact of UVR prevails, spore germination is inhibited. This is observed in deep water kelp species whereas the same UVR doses do not inhibit germination of shallow water kelp species. A potential acclimation mechanism to increase UV tolerance of brown algal spores is the species-specific ability to increase the content of UV-absorbing phlorotannins in response to UV-exposure. Growth rates of young Mastocarpus and Chondrus gametophytes exposed to experimental doses of UVR are not affected while growth rates of all young kelp sporophytes exposed to UVR are significantly lowered. Furthermore, morphological UV damage in Laminaria ochroleuca includes tissue deformation, lesion, blistering and thickening of the meristematic part of the lamina. The sensitivity of young sporophytes to DNA damage is correlated with thallus thickness and their optical characteristics. Growth rate is an integrative parameter of all physiological processes in juvenile plants. UV inhibition of growth may affect the upper distribution depth limit of adult life history stages. Juveniles possess several mechanisms to minimize UVR damage and, hence, are less sensitive but at the expense of growth. The species-specific susceptibility of the early life stages of macroalgae to UVR plays an important role for the determination of zonation patterns and probably also for shaping up community structure.
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Affiliation(s)
- Michael Y Roleda
- Biologische Anstalt Helgoland, Alfred Wegener Institute for Polar and Marine Research, Marine Station, Helgoland, Germany.
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Abstract
In our times, sexuality has become an essential part of life for aging people. For the aging, psychosocial and biological changes, as well as increasing morbidity present challenges to a satisfying sexual life. Hence, the demand grows for health-care providers with basic sexological knowledge and counseling abilities. This article discusses relationships between frequent sexual difficulties and aging related organic processes. A therapeutic concept, the "Sexocorporal Approach", is introduced. This approach is based on a model of ongoing sexual development throughout the lifetime enabling adaptation to new life phases and limiting circumstances through sexual learning processes. Aside from pharmacological treatment, the encouragement of sexual learning presents an effective therapeutic approach for practitioners that can be easily learned and applied.
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Affiliation(s)
- K Bischof
- Zürcher Institut für klinische Sexologie und Sexualtherapie ZISS, Zürich.
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Beller S, Sturm JD, Schöneberg O, Scherer T, Bischof K, Beller V, Szinicz G. Stellenwert der Laparoskopie in der Behandlung der perforierten Appendizitis – eine retrospektive Analyse von 142 konsekutiven Fällen. Visc Med 2004. [DOI: 10.1159/000083023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Van De Poll WH, Bischof K, Buma AGJ, Breeman AM. Habitat related variation in UV tolerance of tropical marine red macrophytes is not temperature dependent. Physiol Plant 2003; 118:74-83. [PMID: 12702016 DOI: 10.1034/j.1399-3054.2003.00090.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Because tropical marine macrophytes experience high ultraviolet-B radiation (UVBR: 280-320 nm) it is assumed that they have high UV tolerance. This was investigated by examining the relative UV sensitivity of five Caribbean red macrophytes. Furthermore, the possibility of temperature dependence of UV effects was examined over a tropical temperature range. Algal fragments of intertidally occurring Gelidiopsis planicaulis (Taylor) Taylor, Wurdemannia miniata (Duby) Feldman and Hamel, and Hypnea spinella (Agardh) Kützing, and the subtidal species Bryothamnion triquetrum (Gmelin) Howe and Heterosiphonia gibbesii (Harvey) Falkenberg were repeatedly subjected to artificial UVBR and ultraviolet-A radiation (UVAR: 320-400 nm) at 22, 26 and 30 degrees C, whereas exposure to photosynthetically active radiation (PAR) served as control. Growth rates, optimal quantum yield of PSII and accumulation of DNA damage were monitored for 10 days, whereas the relative abundance of the D1 reaction centre binding protein and the presence of UV absorbing compounds were investigated in some samples. UVAR and UVBR significantly depressed growth rates of all species. UVBR exposure caused accumulation of DNA damage and resulted in stronger growth reduction than UVAR. UVBR and UVAR caused a depression of optimal quantum yield and a lower D1 abundance. However, the former recovered fast and acclimated to the UV treatments. Some species produced UV absorbing compounds in response to UVAR. UV exposure caused less pronounced effects in intertidally occurring species than in subtidal species. UV effects on growth, the accumulation of DNA damage and UV induced depression of optimal quantum yield were independent of temperature in most species. We conclude that high UVBR in tropical regions may depress in situ growth rates of these intertidal and subtidal red macrophytes.
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Affiliation(s)
- Willem H. Van De Poll
- Department of Marine Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
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Bischof K, Peralta G, Kräbs G, Van De Poll WH, Pérez-Lloréns JL, Breeman AM. Effects of solar UV-B radiation on canopy structure of Ulva communities from southern Spain. J Exp Bot 2002; 53:2411-2421. [PMID: 12432033 DOI: 10.1093/jxb/erf091] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Within the sheltered creeks of Cádiz bay, Ulva thalli form extended mat-like canopies. The effect of solar ultraviolet radiation on photosynthetic activity, the composition of photosynthetic and xanthophyll cycle pigments, and the amount of RubisCO, chaperonin 60 (CPN 60), and the induction of DNA damage in Ulva aff. rotundata Bliding from southern Spain was assessed in the field. Samples collected from the natural community were covered by screening filters, generating different radiation conditions. During daily cycles, individual thalli showed photoinhibitory effects of the natural solar radiation. This inhibition was even more pronounced in samples only exposed to photosynthetically active radiation (PAR). Strongly increased heat dissipation in these samples indicated the activity of regulatory mechanisms involved in dynamic photoinhibition. Adverse effects of UV-B radiation on photosynthesis were only observed in combination with high levels of PAR, indicating the synergistic effects of the two wavelength ranges. In samples exposed either to PAR+UV-A or to UV-B+UV-A without PAR, no inhibition of photosynthetic quantum yield was found in the course of the day. At the natural site, the top layer of the mat-like canopies is generally completely bleached. Artificially designed Ulva canopies exhibited fast bleaching of the top layer under the natural solar radiation conditions, while this was not observed in canopies either shielded from UV or from PAR. The bleached first layer of the canopies acts as a selective UV-B filter, and thus prevents subcanopy thalli from exposure to harmful radiation. This was confirmed by the differences in photosynthetic activity, pigment composition, and the concentration of RubisCO in thalli with different positions within the canopy. In addition, the induction of the stress protein CPN 60 under UV exposure and the low accumulation of DNA damage indicate the presence of physiological protection mechanisms against harmful UV-B. A mechanism of UV-B-induced inhibition of photosynthesis under field conditions is proposed.
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Affiliation(s)
- Kai Bischof
- University of Groningen, Department of Marine Biology, Kerklaan 30, 9750 AA Haren, The Netherlands.
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Bischof K, Kräbs G, Wiencke C, Hanelt D. Solar ultraviolet radiation affects the activity of ribulose-1,5-bisphosphate carboxylase-oxygenase and the composition of photosynthetic and xanthophyll cycle pigments in the intertidal green alga Ulva lactuca L. Planta 2002; 215:502-509. [PMID: 12111234 DOI: 10.1007/s00425-002-0774-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2001] [Accepted: 03/12/2002] [Indexed: 05/23/2023]
Abstract
The effect of solar UV radiation on the physiology of the intertidal green macroalga Ulva lactuca L. was investigated. A natural Ulva community at the shore of Helgoland was covered with screening foils, excluding UV-B or UV-B + UV-A from the solar spectrum. In the sampled material, changes in the activity and concentration of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco), and the concentration of photosynthetic and xanthophyll cycle pigments were determined. Exclusion of UV radiation from the natural solar spectrum resulted in an elevated overall activity of Rubisco, related to an increase in its cellular concentration. Among the photosynthetic pigments, lutein concentration was substantially elevated under UV exclusion. In addition, marked UV effects on the xanthophyll cycle were found: exclusion of solar UV radiation (and particularly UV-B) resulted in an increased ratio of zeaxanthin concentration to the total xanthophyll content, indicating adverse effects of UV-B on the efficiency of photoprotection under high irradiances of photosynthetically active radiation. The results confirm a marked impact of present UV-B levels on macroalgal physiology under field conditions.
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Affiliation(s)
- Kai Bischof
- University of Groningen, Department of Marine Biology, Biological Centre, Kerklaan 30, 9750 AA Haren (Gn), The Netherlands.
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38
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Bayer M, Iberer R, Bischof K, Rassi E, Stabentheiner E, Zellnig G, Koraimann G. Functional and mutational analysis of p19, a DNA transfer protein with muramidase activity. J Bacteriol 2001; 183:3176-83. [PMID: 11325947 PMCID: PMC95219 DOI: 10.1128/jb.183.10.3176-3183.2001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein P19 encoded by the conjugative resistance plasmid R1 has been identified as being one member of a large family of muramidases encoded by bacteriophages and by type III and type IV secretion systems. We carried out a mutational analysis to investigate the function of protein P19 and used in vivo complementation assays to test those of several P19 mutants. The results indicated that conserved residues present in the presumed catalytic center of P19 are absolutely essential for its function in conjugation of plasmid R1 and infection by the RNA phage R17. Overexpression of protein P19 in an early growth phase resulted in a massive lysis of Escherichia coli cells in liquid culture, as indicated by a rapid and distinct decrease in cell culture densities after induction. Change of the proposed catalytic glutamate at position 44 to glutamine completely abolished this effect. P19-induced cell lysis was directly shown by transmission and scanning electron microscopy. Typically, P19-overexpressing cells showed bulges protruding from the cell surfaces. Our interpretation is that these protrusions arose from a localized and spatially confined disruption of the bacterial cell wall. To our knowledge such an effect has not previously been documented for any member of the lytic transglycosylase family. From the data presented here, we conclude that protein P19 possesses the proposed localized peptidoglycan-hydrolyzing activity. This activity would be a prerequisite for efficient penetration of the cell envelope by the DNA translocation complex encoded by the conjugative plasmid.
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Affiliation(s)
- M Bayer
- Institut für Molekularbiologie, Biochemie und Mikrobiologie, Karl-Franzens-Universität Graz, Universitätsplatz 2, A-8010 Graz, Austria
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39
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Karsten U, Bischof K, Wiencke C. Photosynthetic performance of Arctic macroalgae after transplantation from deep to shallow waters. Oecologia 2001; 127:11-20. [DOI: 10.1007/s004420000553] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2000] [Accepted: 10/01/2000] [Indexed: 10/27/2022]
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Bischof K, Hanelt D, Wiencke C. Effects of ultraviolet radiation on photosynthesis and related enzyme reactions of marine macroalgae. Planta 2000; 211:555-562. [PMID: 11030555 DOI: 10.1007/s004250000313] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Changes in physiological parameters related to photosynthesis were studied in five macroalgal species from Spitsbergen (Monostroma arcticum, Laminaria solidungula, Alaria esculenta, Palmaria palmata, Phycodrys rubens) during a 72-h exposure to UV radiation. Maximal quantum yield of photochemistry (Fv/Fm) and maximal electron transport rate (ETRmax) were measured with a pulse-amplitude-modulated fluorometer; the activity of the Calvin cycle enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) were estimated using a photometric test. Proteins of crude extracts were separated by SDS gel electrophoresis and changes in cellular concentrations of Rubisco were determined. Moreover, the concentration of chlorophyll a (Ch1 a), and protein content, were measured photometrically. In all species, Ch1 a content, maximal quantum yield as well as ETRmax decreased during the UV treatment. Changes in ETRmax were related to the changes in the overall activity of Rubisco. Analysis of SDS gels showed that in P. rubens, L. solidungula, M. arcticum and A. esculenta decreasing Rubisco activity partly resulted from a degradation of the enzyme. However, in A. esculenta, the formation of a high-molecular-weight polypeptide was observed. In all species, the activity of Rubisco was more strongly impaired than that of G3PDH. Exposure to UV resulted in loss of total protein only in the deepwater species L. solidungula and P. rubens. The different sensitivities to UV exposure of the species tested reflect their zonation pattern in the field.
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Affiliation(s)
- K Bischof
- Foundation Alfred Wegener Institute, Bremerhaven, Germany.
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41
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Abstract
Protein P19 encoded by the conjugative resistance plasmid R1, is essential for efficient conjugative DNA transfer and infection by the pilus-specific RNA phage R17. Based on sequence homologies P19 belongs to a family of lysozyme-like virulence factors which are found in type III and type IV secretion systems. In this report we describe the processing and subcellular localization of P19. Pulse-chase experiments were used to demonstrate the processing of P19 by the signal peptidase I of Escherichia coli. Translocation of P19 across the inner membrane was shown by gene 19-phoA fusions. Cell fractionation studies of P19 expressing cells showed the presence of P19 in the membrane compartment. P19 was solubilized with the detergent Sarkosyl indicating an inner membrane localization. Using sucrose density gradient centrifugation to separate inner and outer membranes, P19 was found in both membrane fractions. Taken together, our data suggest that mature P19 is a periplasmic protein which may be attached to the proposed membrane-spanning DNA transport complex.
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Affiliation(s)
- M Bayer
- Institut für Molekularbiologie, Biochemie und Mikrobiologie, Karl-Franzens-Universität Graz, Austria
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42
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Abstract
The TraM proteins encoded by F-like plasmids are sequence specific DNA binding proteins that are essential for conjugative DNA transfer. We investigated the quarternary structure and the DNA binding properties of the TraM wild-type protein of the resistance plasmid R1 and two mutant forms thereof. Size-exclusion chromatography and differential scanning calorimetry showed that purified TraM protein (amino acids 2-127) forms stable tetramers in solution. A truncated version of the protein termed TraMM26 (amino acids 2-56) forms dimers. Thus, the dimerization and tetramerization domains can be assigned to the N-terminal and C-terminal domains of TraM, respectively. Further analyses using chemical cross-linking and light scattering corroborated the preferentially tetrameric nature of the protein but also suggest that TraM has a tendency to form higher aggregates. Band-shift and fluorescence spectroscopy investigations of TraM-DNA complexes revealed that the TraM protein is also tetrameric when bound to its minimal DNA binding site. The deduced binding constant in the range of 10(8) M(-1) demonstrated a very strong binding of TraM to its preferred DNA sequence. Secondary structure analysis based on CD measurements showed that TraM is mainly alpha-helical with a significant increase in alpha-helicity (48 to 58%) upon DNA-binding, indicating an induced fit mechanism.
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Affiliation(s)
- P Verdino
- Institut für Physikalische Chemie, Karl-Franzens-Universität Graz, Heinrichstr. 28, A-8010 Graz, Austria
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43
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Abstract
It is sometimes stated that Wundt believed in the primacy of 'sensations of innervation' in the control of eye and limb position, to the exclusion of afferent feedback. Wundt's own statements on the subject are traced through the six editions of the Grundzüge: he believed that sensations of innervation were a contributory factor along with peripheral feedback; but in the fourth edition he dropped the term and subsumed them under 'central sensations of senses', because increased neurophysiological knowledge made a literal interpretation of the original term impossible. In the fifth edition he developed a more precise model of central processes, described as 'sensory costimulation', and an additional idea of 'reproduced' or conditioned sensations. He mentions clinical evidence on the perception of eye and limb position of weight by paralysed and other subjects. This evidence is discussed in relation to modern theories. It is concluded that Wundt's later theories have some similarities with modern "hybrid' theories of efference-contingent afference.
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44
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Abstract
Abstract
The investigation presented here, including detection of nitrogen, the viscometric investigation, melting point determinations, the ultraviolet and infrared spectra, allow of the qualitative statement that macroradicals are formed in the mechanochemical breakdown of polystyrene by vibromilling. The slight differences between N2 and NO milling may be ascribed in part to a more rapid deactivation of the radicals. On the foundation of the existing knowledge of mechanochemistry there result interesting prospects for science and technology, e.g., the use of macro-radicals as polymerization initiators and as active types of block copolymers and graft polymers by reactions both with monomers and with macroradicals of other polymer materials.
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Affiliation(s)
- H. Grohn
- 1Institut für Chemie und Technologie der Hochpolymeren an der Technischen Hochschule für Chemie, Levne-Merseburg, Germany
| | - K. Bischof
- 1Institut für Chemie und Technologie der Hochpolymeren an der Technischen Hochschule für Chemie, Levne-Merseburg, Germany
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