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Capó-Bauçà S, Iñiguez C, Galmés J. The diversity and coevolution of Rubisco and CO 2 concentrating mechanisms in marine macrophytes. THE NEW PHYTOLOGIST 2024; 241:2353-2365. [PMID: 38197185 DOI: 10.1111/nph.19528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024]
Abstract
The kinetic properties of Rubisco, the most important carbon-fixing enzyme, have been assessed in a small fraction of the estimated existing biodiversity of photosynthetic organisms. Until recently, one of the most significant gaps of knowledge in Rubisco kinetics was marine macrophytes, an ecologically relevant group including brown (Ochrophyta), red (Rhodophyta) and green (Chlorophyta) macroalgae and seagrasses (Streptophyta). These organisms express various Rubisco types and predominantly possess CO2 -concentrating mechanisms (CCMs), which facilitate the use of bicarbonate for photosynthesis. Since bicarbonate is the most abundant form of dissolved inorganic carbon in seawater, CCMs allow marine macrophytes to overcome the slow gas diffusion and low CO2 availability in this environment. The present review aims to compile and integrate recent findings on the biochemical diversity of Rubisco and CCMs in the main groups of marine macrophytes. The Rubisco kinetic data provided demonstrate a more relaxed relationship among catalytic parameters than previously reported, uncovering a variability in Rubisco catalysis that has been hidden by a bias in the literature towards terrestrial vascular plants. The compiled data indicate the existence of convergent evolution between Rubisco and biophysical CCMs across the polyphyletic groups of marine macrophytes and suggest a potential role for oxygen in shaping such relationship.
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Affiliation(s)
- Sebastià Capó-Bauçà
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, 07122, Palma, Balearic Islands, Spain
| | - Concepción Iñiguez
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, 07122, Palma, Balearic Islands, Spain
- Department of Ecology, Faculty of Sciences, University of Malaga, Boulevard Louis Pasteur s/n, 29010, Málaga, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, 07122, Palma, Balearic Islands, Spain
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Lee H, Depuydt S, Shin K, De Saeger J, Han T, Park J. Interactive Effects of Blue Light and Water Turbulence on the Growth of the Green Macroalga Ulva australis (Chlorophyta). PLANTS (BASEL, SWITZERLAND) 2024; 13:266. [PMID: 38256819 PMCID: PMC10820934 DOI: 10.3390/plants13020266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/06/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024]
Abstract
Macroalgal growth and yield are key to sustainable aquaculture. Although light and water turbulence are two important factors that affect algal productivity, research on their interaction is limited. Therefore, in this study, we investigated the effects of different wavelengths of light and the presence or absence of water turbulence on the growth of the green macroalga Ulva australis. Water turbulence was found to enhance the growth of U. australis irrespective of photosynthetic performance, but only in blue light cultures. The quantum dose of blue light required to induce 50% growth promotion was 1.02 mol m-2, which is comparable to the reported values for cryptochrome-mediated effects in other macroalgae. The combined effect of blue light and water turbulence led to the accumulation of photosynthesis-related proteins that support plastid differentiation and facilitate efficient photosynthesis and growth. Our findings thus highlight the potential of harnessing blue light and water turbulence to maximise macroalgal cultivation for sustainable and profitable algal aquaculture.
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Affiliation(s)
- Hojun Lee
- Bio Environmental Science and Technology (BEST) Lab, Ghent University Global Campus, 119-5, Songdomunhwa-ro, Incheon 21985, Republic of Korea
| | - Stephen Depuydt
- Erasmus Brussels University of Applied Sciences and Arts, Nijverheidskaai 170, 1070 Brussels, Belgium
| | - Kisik Shin
- Water Environmental Engineering Research Division, National Institute of Environmental Research (NIER), 42, Hwangyeong-ro, Incheon 22689, Republic of Korea
| | - Jonas De Saeger
- Bio Environmental Science and Technology (BEST) Lab, Ghent University Global Campus, 119-5, Songdomunhwa-ro, Incheon 21985, Republic of Korea
| | - Taejun Han
- Bio Environmental Science and Technology (BEST) Lab, Ghent University Global Campus, 119-5, Songdomunhwa-ro, Incheon 21985, Republic of Korea
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Coupure Links 653-Block F, B-9000 Gent, Belgium
| | - Jihae Park
- Bio Environmental Science and Technology (BEST) Lab, Ghent University Global Campus, 119-5, Songdomunhwa-ro, Incheon 21985, Republic of Korea
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Coupure Links 653-Block F, B-9000 Gent, Belgium
- Center for Environmental and Energy Research, Ghent University Global Campus, 119-5, Songdomunhwa-ro, Incheon 21985, Republic of Korea
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3
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Page HN, McCoy S, Spencer RGM, Burnham KA, Hewett C, Johnson M. Effects of ocean acidification on growth and photophysiology of two tropical reef macroalgae. PLoS One 2023; 18:e0286661. [PMID: 37976304 PMCID: PMC10655979 DOI: 10.1371/journal.pone.0286661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 05/21/2023] [Indexed: 11/19/2023] Open
Abstract
Macroalgae can modify coral reef community structure and ecosystem function through a variety of mechanisms, including mediation of biogeochemistry through photosynthesis and the associated production of dissolved organic carbon (DOC). Ocean acidification has the potential to fuel macroalgal growth and photosynthesis and alter DOC production, but responses across taxa and regions are widely varied and difficult to predict. Focusing on algal taxa from two different functional groups on Caribbean coral reefs, we exposed fleshy (Dictyota spp.) and calcifying (Halimeda tuna) macroalgae to ambient and low seawater pH for 25 days in an outdoor experimental system in the Florida Keys. We quantified algal growth, calcification, photophysiology, and DOC production across pH treatments. We observed no significant differences in the growth or photophysiology of either species between treatments, except for lower chlorophyll b concentrations in Dictyota spp. in response to low pH. We were unable to quantify changes in DOC production. The tolerance of Dictyota and Halimeda to near-future seawater carbonate chemistry and stability of photophysiology, suggests that acidification alone is unlikely to change biogeochemical processes associated with algal photosynthesis in these species. Additional research is needed to fully understand how taxa from these functional groups sourced from a wide range of environmental conditions regulate photosynthesis (via carbon uptake strategies) and how this impacts their DOC production. Understanding these species-specific responses to future acidification will allow us to more accurately model and predict the indirect impacts of macroalgae on coral health and reef ecosystem processes.
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Affiliation(s)
- Heather N. Page
- Elizabeth Moore International Center for Coral Reef Research and Restoration, Mote Marine Laboratory, Summerland Key, FL, United States of America
- Sea Education Association, Woods Hole, MA, United States of America
| | - Sophie McCoy
- University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | | | - Katherine A. Burnham
- Elizabeth Moore International Center for Coral Reef Research and Restoration, Mote Marine Laboratory, Summerland Key, FL, United States of America
| | - Clay Hewett
- Elizabeth Moore International Center for Coral Reef Research and Restoration, Mote Marine Laboratory, Summerland Key, FL, United States of America
- Jacksonville University, Jacksonville, Fl, United States of America
| | - Maggie Johnson
- Smithsonian Marine Station, Fort Pierce, FL, United States of America
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Summers N, Fragoso GM, Johnsen G. Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Sci Rep 2023; 13:17971. [PMID: 37863949 PMCID: PMC10589289 DOI: 10.1038/s41598-023-44026-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 10/03/2023] [Indexed: 10/22/2023] Open
Abstract
Arctic macroalgae species have developed different growth strategies to survive extreme seasonal changes in irradiance in polar regions. We compared photophysiological parameters such as the light saturation parameter (Ek) and pigment composition of green, red, and brown macroalgae collected in January (Polar Night) and October 2020 (end of the light season). Macroalgae in January appeared healthier (morphologically) and had longer lamina (new growth) than those in October. EK values for red, and brown algae were higher with lower maximum quantum yield of PS II fluorescence (Fv/Fm) in January versus October. Furthermore, in January, new tissues in kelp species had higher EK than the older tissue. Higher EK and lower Fv/Fm during the Polar Night indicates that the photosynthetic apparatus is active but slow. Furthermore, we discuss Chlorophyll (Chl) a emission spectra under blue and green excitation light to determine the ratio of Chl a in photosystem II (PS II) vs photosystem I (PS I). Absorbance spectra of P. palmata was used to interpret the emission spectra. The observed spectral shifts in the absorbance and reflectance spectra of different macroalgae is discussed. Photophysiological methods provide health information complementary to future mapping and monitoring of macroalgae. These results reveal that macroalgae grow new tissue in darkness.
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Affiliation(s)
- Natalie Summers
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim Biological Station, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
| | - Glaucia M Fragoso
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim Biological Station, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Geir Johnsen
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim Biological Station, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- University Centre in Svalbard (UNIS), Longyearbyen, Norway
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5
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Celis-Plá PSM, Trabal A, Navarrete C, Troncoso M, Moenne F, Zúñiga A, Figueroa FL, Sáez CA. Daily changes on seasonal ecophysiological responses of the intertidal brown macroalga Lessonia spicata: Implications of climate change. FRONTIERS IN PLANT SCIENCE 2022; 13:941061. [PMID: 36247624 PMCID: PMC9554264 DOI: 10.3389/fpls.2022.941061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/01/2022] [Indexed: 06/16/2023]
Abstract
Global climate change is expected to have detrimental effects on coastal ecosystems, with impacts observable at the local and regional levels, depending on factors such as light, temperature, and nutrients. Shifts in dominance between primary producers that can capitalize on carbon availability for photosynthesis will have knock-on effects on marine ecosystems, affecting their ecophysiological responses and biological processes. Here, we study the ecophysiological vulnerability, photoacclimation capacity, and tolerance responses as ecophysiological responses of the intertidal kelp Lessonia spicata (Phaeophyceae, Laminariales) during a year through different seasons (autumn, winter, spring, and summer) in the Pacific Ocean (central Chile). Six different daily cycle experiments were carried out within each season. A battery of different biochemical assays associated with antioxidant responses and in-vivo chlorophyll a fluorescence parameter showed that during spring and summer, there was an increase in photosynthetic capacity in the macroalgae, although their responses varied depending on light and nutrient availability in the course of the year. Lessonia spicata showed maximal photosynthesis and a similar photoinhibition pattern in summer compared to the other seasons, and the contents of nitrate and phosphorous in seawater were less in winter. Thus, high irradiance during spring and summer displayed a higher maximal electron transport rate (ETRmax), irradiance of saturation (Ek), non-photochemical quenching (NPQmax), nitrogen and carbon contents, and photoprotector compound levels. Antioxidant activity increased also in summer, the seasonal period with the highest oxidative stress conditions, i.e., the highest level of hydrogen peroxide (H2O2). In contrast, under low irradiance, i.e., wintertime conditions, L. spicata demonstrated lower concentrations of the photosynthetic pigments such as chlorophyll a and carotenoids. Our study suggests that macroalgae that are subjected to increased irradiance and water temperature under lower nutrient availability mediated by seasonal changes (expected to worsen under climate change) respond with higher values of productivity, pigment contents, and photoprotective compounds. Thus, our findings strengthen the available evidence to predict that algae in the order Laminariales, specifically L. spicata (kelp), could better proliferate, with lower vulnerability and greater acclimation, than other marine species subject to future expected conditions associated with climate change.
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Affiliation(s)
- Paula S. M. Celis-Plá
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
| | - Andres Trabal
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
- Escuela de Ciencias Agrarias y Veterinarias, Universidad de Viña del Mar, Viña del Mar, Chile
| | - Camilo Navarrete
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
- Doctorado Interdisciplinario en Ciencias Ambientales, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Valparaíso, Chile
| | - Macarena Troncoso
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
- Doctorado Interdisciplinario en Ciencias Ambientales, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Valparaíso, Chile
| | - Fabiola Moenne
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
| | - Antonio Zúñiga
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
| | - Félix L. Figueroa
- Ecology Department, Institute of Blue Biotechnology and Development (IBYDA), University of Malaga, Malaga, Spain
| | - Claudio A. Sáez
- Laboratory of Aquatic Environmental Research (LACER), Centro de Estudios Avanzados (CEA)/HUB Ambiental UPLA, Universidad de Playa Ancha, Valparaíso, Chile
- Departamento de Ciencias del Mar y Biología Aplicada, Facultad de Ciencias, Universidad de Alicante, Alicante, Spain
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Kotta J, Raudsepp U, Szava-Kovats R, Aps R, Armoskaite A, Barda I, Bergström P, Futter M, Gröndahl F, Hargrave M, Jakubowska M, Jänes H, Kaasik A, Kraufvelin P, Kovaltchouk N, Krost P, Kulikowski T, Kõivupuu A, Kotta I, Lees L, Loite S, Maljutenko I, Nylund G, Paalme T, Pavia H, Purina I, Rahikainen M, Sandow V, Visch W, Yang B, Barboza FR. Assessing the potential for sea-based macroalgae cultivation and its application for nutrient removal in the Baltic Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156230. [PMID: 35643144 DOI: 10.1016/j.scitotenv.2022.156230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
Marine eutrophication is a pervasive and growing threat to global sustainability. Macroalgal cultivation is a promising circular economy solution to achieve nutrient reduction and food security. However, the location of production hotspots is not well known. In this paper the production potential of macroalgae of high commercial value was predicted across the Baltic Sea region. In addition, the nutrient limitation within and adjacent to macroalgal farms was investigated to suggest optimal site-specific configuration of farms. The production potential of Saccharina latissima was largely driven by salinity and the highest production yields are expected in the westernmost Baltic Sea areas where salinity is >23. The direct and interactive effects of light availability, temperature, salinity and nutrient concentrations regulated the predicted changes in the production of Ulva intestinalis and Fucus vesiculosus. The western and southern Baltic Sea exhibited the highest farming potential for these species, with promising areas also in the eastern Baltic Sea. Macroalgal farming did not induce significant nutrient limitation. The expected spatial propagation of nutrient limitation caused by macroalgal farming was less than 100-250 m. Higher propagation distances were found in areas of low nutrient and low water exchange (e.g. offshore areas in the Baltic Proper) and smaller distances in areas of high nutrient and high water exchange (e.g. western Baltic Sea and Gulf of Riga). The generated maps provide the most sought-after input to support blue growth initiatives that foster the sustainable development of macroalgal cultivation and reduction of in situ nutrient loads in the Baltic Sea.
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Affiliation(s)
- Jonne Kotta
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia; Estonian Maritime Academy, Tallinn University of Technology, Kopli 101, EE-11712 Tallinn, Estonia.
| | - Urmas Raudsepp
- Marine Systems Institute, Tallinn University of Technology, Ehitajate tee 5, EE-12616 Tallinn, Estonia
| | - Robert Szava-Kovats
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Robert Aps
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | | | - Ieva Barda
- Latvian Institute of Aquatic Ecology, Voleru iela 2, LV-1007 Riga, Latvia
| | - Per Bergström
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, Tjärnö, Laboratorievägen 10, SE-45296 Strömstad, Sweden
| | - Martyn Futter
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-75007 Uppsala, Sweden
| | - Fredrik Gröndahl
- Royal Institute of Technology, KTH Stockholm, Teknikringen 10B, SE-10044 Stockholm, Sweden
| | - Matthew Hargrave
- Sven Lovén Centre for Marine Sciences, University of Gothenburg, Kristineberg 566, SE-45178 Fiskebäckskil, Sweden
| | - Magdalena Jakubowska
- National Marine Fisheries Research Institute, ul. Kołłątaja 1, PL-81332 Gdynia, Poland
| | - Holger Jänes
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Ants Kaasik
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Patrik Kraufvelin
- Kustlaboratoriet, Swedish University of Agricultural Sciences, Skolgatan 6, SE-74242 Öregrund, Sweden; Åland University of Applied Sciences, PB 1010, AX-221111 Mariehamn, Åland, Finland
| | - Nikolai Kovaltchouk
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Peter Krost
- Coastal Research and Management, Tiessenkai 12, D-24159 Kiel, Germany
| | - Tomasz Kulikowski
- National Marine Fisheries Research Institute, ul. Kołłątaja 1, PL-81332 Gdynia, Poland
| | - Anneliis Kõivupuu
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Ilmar Kotta
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Liisi Lees
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Sander Loite
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Ilja Maljutenko
- Marine Systems Institute, Tallinn University of Technology, Ehitajate tee 5, EE-12616 Tallinn, Estonia
| | - Göran Nylund
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, Tjärnö, Laboratorievägen 10, SE-45296 Strömstad, Sweden
| | - Tiina Paalme
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
| | - Henrik Pavia
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, Tjärnö, Laboratorievägen 10, SE-45296 Strömstad, Sweden
| | - Ingrida Purina
- Latvian Institute of Aquatic Ecology, Voleru iela 2, LV-1007 Riga, Latvia
| | - Moona Rahikainen
- Food Chemistry and Food Development, Department of Life Technologies, University of Turku, Tykistökatu 6, FI-20014 Turku, Finland
| | - Verena Sandow
- Coastal Research and Management, Tiessenkai 12, D-24159 Kiel, Germany
| | - Wouter Visch
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, TAS 7004, Australia
| | - Baoru Yang
- Food Chemistry and Food Development, Department of Life Technologies, University of Turku, Tykistökatu 6, FI-20014 Turku, Finland
| | - Francisco R Barboza
- Estonian Marine Institute, University of Tartu, Mäealuse 14, EE-12618 Tallinn, Estonia
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Nguyen HTT, Pritchard DW, Desmond MJ, Hepburn CD. Coralline photosynthetic physiology across a steep light gradient. PHOTOSYNTHESIS RESEARCH 2022; 153:43-57. [PMID: 35092556 DOI: 10.1007/s11120-022-00899-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Coralline algae (CA) are globally distributed and fulfil many important roles within coastal ecosystems. In this study, photosynthetically active radiation (PAR) measured for 616 days at 2 and 10 m in a temperate subtidal kelp forest in southern New Zealand provided context to photosynthesis vs. irradiance relationships for, and pigment concentrations of, an articulated coralline alga, Arthrocardia sp. and a crustose coralline species assemblage within the Hapalidiales order. The maximum photosynthetic rate Pmax of the Arthrocardia sp. (20.38 ± 2.38 µmol O2. gDW-1 h-1) was significantly higher than the Pmax of crustose coralline spp. (3.72 ± 0.74 µmol O2. gDW-1 h-1) at the same 2 m stratum. Pigment concentration of Arthrocardia sp. was significantly higher than that of crustose coralline spp. at the same depth, while pigment concentration of crustose coralline spp. at 2 and 10 m were not significantly affected by depth. The photosynthetic characteristics of these coralline algae represent a shade acclimated organism with low saturation irradiance (all Ek < 100 µmol photons m-2 s-1). Despite sevenfold difference in average daily dose between 2 and 10 m there was no significant effect of depth on the photosynthetic performance of crustose coralline algae measured. The lack of evidence for acclimation to low light could be because periods of clear water provide enough light to maintain photosynthesis, lower energetic requirements of species found at depth or constraints on the synthesis of photosynthetic pigments at greater depth.
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Affiliation(s)
- Hang T T Nguyen
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.
- University of Agriculture and Forestry, Hue University, 102 Phung Hung, Hue City, Vietnam.
| | - Daniel W Pritchard
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Coastal People Southern Skies, Centre of Research Excellence, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Te Ao Tūroa, Te Rūnanga O Ngāi Tahu, PO Box 799, Dunedin, 9054, New Zealand
| | - Matthew J Desmond
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Coastal People Southern Skies, Centre of Research Excellence, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Christopher D Hepburn
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Coastal People Southern Skies, Centre of Research Excellence, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
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8
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Bulychev AA, Alova AV. Microfluidic interactions involved in chloroplast responses to plasma membrane excitation in Chara. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 183:111-119. [PMID: 35576891 DOI: 10.1016/j.plaphy.2022.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Adaptation of plants to environmental changes involves the mechanisms of long-distance signaling. In characean algae, these mechanisms comprise the propagation of action potential (AP) and the rotational cytoplasmic streaming acting in cooperation with light-dependent exchange of ions and metabolites across the chloroplast envelope. Both excitability and cyclosis exert conspicuous effects on photosynthetic activity of chloroplasts but possible influence of cyclosis arrest on the coupling of AP stimulus to photosynthetic performance remained unexplored. In this study, fluidic interactions between anchored chloroplasts were allowed or restricted by illuminating the whole internode or a confined cell area (2 mm in diameter), respectively. Measurements of chlorophyll fluorescence parameters (F' and Fm') in cell regions located close to calcium crystal depositions revealed that the AP generation induced long-lasting Fm' oscillations that persisted in illuminated cells. The AP generation often induced the F' oscillations, whose number diminished upon the transfer of internodal cells from total to local background light. The results indicate that the AP-induced changes in photosynthetic parameters, F' in particular, have a complex origin and comprise the internal processes caused by the elevation of stromal Ca2+ concentration in the analyzed chloroplasts and the stages related to ion and metabolite exchange mediated by cytoplasmic streaming. It is supposed that the composition of flowing cytoplasm is heterogeneous due to the spatial alteration of calcified and noncalcified cell sites, but this heterogeneity is enhanced and can be visualized after the transient cessation and restoration of cytoplasmic streaming.
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Affiliation(s)
| | - Anna V Alova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
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9
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Hurd CL, Law CS, Bach LT, Britton D, Hovenden M, Paine ER, Raven JA, Tamsitt V, Boyd PW. Forensic carbon accounting: Assessing the role of seaweeds for carbon sequestration. JOURNAL OF PHYCOLOGY 2022; 58:347-363. [PMID: 35286717 DOI: 10.1111/jpy.13249] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
Carbon sequestration is defined as the secure storage of carbon-containing molecules for >100 years, and in the context of carbon dioxide removal for climate mitigation, the origin of this CO2 is from the atmosphere. On land, trees globally sequester substantial amounts of carbon in woody biomass, and an analogous role for seaweeds in ocean carbon sequestration has been suggested. The purposeful expansion of natural seaweed beds and aquaculture systems, including into the open ocean (ocean afforestation), has been proposed as a method of increasing carbon sequestration and use in carbon trading and offset schemes. However, to verify whether CO2 fixed by seaweeds through photosynthesis leads to carbon sequestration is extremely complex in the marine environment compared to terrestrial systems, because of the need to jointly consider: the comparatively rapid turnover of seaweed biomass, tracing the fate of carbon via particulate and dissolved organic carbon pathways in dynamic coastal waters, and the key role of atmosphere-ocean CO2 exchange. We propose a Forensic Carbon Accounting approach, in which a thorough analysis of carbon flows between the atmosphere and ocean, and into and out of seaweeds would be undertaken, for assessing the magnitude of CO2 removal and robust attribution of carbon sequestration to seaweeds.
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Affiliation(s)
- Catriona L Hurd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Cliff S Law
- National Institute of Water and Atmospheric Research, Wellington, 6021, New Zealand
- Department of Marine Science, University of Otago, Dunedin, 9016, New Zealand
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Damon Britton
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Mark Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
| | - Ellie R Paine
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - John A Raven
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Dundee, DD2 5DA, UK
- Climate Change Cluster, University of Technology, Sydney, Ultimo, New South Wales, 2006, Australia
- School of Biological Science, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Veronica Tamsitt
- University of South Florida College of Marine Science, 830 1st St S, St Petersburg, Florida, 33701, USA
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
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10
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Selection-enriched genomic loci (SEGL) reveals genetic loci for environmental adaptation and photosynthetic productivity in Chlamydomonas reinhardtii. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Quade BN, Parker MD, Hoepflinger MC, Phipps S, Bisson MA, Foissner I, Beilby MJ. The molecular identity of the characean OH - transporter: a candidate related to the SLC4 family of animal pH regulators. PROTOPLASMA 2022; 259:615-626. [PMID: 34232395 PMCID: PMC8738779 DOI: 10.1007/s00709-021-01677-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
Characeae are closely related to the ancient algal ancestors of all land plants. The long characean cells display a pH banding pattern to facilitate inorganic carbon import in the acid zones for photosynthetic efficiency. The excess OH-, generated in the cytoplasm after CO2 is taken into the chloroplasts, is disposed of in the alkaline band. To identify the transporter responsible, we searched the Chara australis transcriptome for homologues of mouse Slc4a11, which functions as OH-/H+ transporter. We found a single Slc4-like sequence CL5060.2 (named CaSLOT). When CaSLOT was expressed in Xenopus oocytes, an increase in membrane conductance and hyperpolarization of resting potential difference (PD) was observed with external pH increase to 9.5. These features recall the behavior of Slc4a11 in oocytes and are consistent with the action of a pH-dependent OH-/H+ conductance. The large scatter in the data might reflect intrinsic variability of CaSLOT transporter activation, inefficient expression in the oocyte due to evolutionary distance between ancient algae and frogs, or absence of putative activating factor present in Chara cytoplasm. CaSLOT homologues were found in chlorophyte and charophyte algae, but surprisingly not in related charophytes Zygnematophyceae or Coleochaetophyceae.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, NY, USA
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, NY, USA
| | - Marion C Hoepflinger
- Department of Biosciences, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria
| | - Shaunna Phipps
- Department of Biological Sciences and Program in Evolution, Ecology, and Behavior, The State University of New York: The University at Buffalo, Hochstetter 623, Buffalo, NY, USA
| | - Mary A Bisson
- Department of Biological Sciences and Program in Evolution, Ecology, and Behavior, The State University of New York: The University at Buffalo, Hochstetter 623, Buffalo, NY, USA
| | - Ilse Foissner
- Department of Biosciences, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria
| | - Mary J Beilby
- School of Physics, The University of NSW, Kensington, Sydney, NSW, 2052, Australia.
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12
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Bioelectricity generation from live marine photosynthetic macroalgae. Biosens Bioelectron 2022; 198:113824. [PMID: 34864244 DOI: 10.1016/j.bios.2021.113824] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/24/2022]
Abstract
The conversion of solar energy into electrical current by photosynthetic organisms has the potential to produce clean energy. Bio-photoelectrochemical cells (BPECs) utilizing unicellular photosynthetic microorganisms have been studied, however similar harvesting of electrons from more evolved intact photosynthetic organisms has not been previously reported. In this study, we describe for the first time BPECs containing intact live marine macroalgae (seaweeds) in natural seawater or saline buffer. The BPECs produce electrical currents of >50 mA/cm2, from both light-dependent (photosynthesis) and light-independent processes. These values are significantly greater than the current densities that have been reported for single-cell microorganisms. The photocurrent is inhibited by the Photosystem II inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, indicating that the source of light-driven electrons is from photosynthetic water oxidation. The current is mediated to the external anode via NADPH and possibly other reduced molecules. We show that intact macroalgae cultures can be used in large-scale BPECs containing seawater, to produce bias-free photocurrents, paving the way for the future development of low-cost energy solar energy conversion technologies using BPECs.
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13
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Zhukova NV, Yakovleva IM. Low light acclimation strategy of the brown macroalga Undaria pinnatifida: Significance of lipid and fatty acid remodeling for photosynthetic competence. JOURNAL OF PHYCOLOGY 2021; 57:1792-1804. [PMID: 34486722 DOI: 10.1111/jpy.13209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/10/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
Brown macroalgae, being important components of benthic communities in temperate regions, are frequently subjected to light limitation. To extend our understanding of their low light acclimation strategies to the regulation of membrane lipid environment, photosynthetic characteristics, lipid class, fatty acid profiles and chloroplast ultrastructure were compared in Undaria pinnatifida (Phaeophyceae, Ochrophyta) after long-term exposure to low and moderate light intensities (LL, 100 and ML, 280 µmol photons · m-2 · s-1 ). We show that light limitation significantly increased PSII quantum efficiency and photosynthetic electron transport rate, enhanced pigment contents and concentration of thylakoid membranes in chloroplasts but decreased the distance between the thylakoid stacks. These physiological alterations at LL were accompanied by a selective remodeling of thylakoid membrane lipids driven by increases in monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG) contents. Light limitation also induced active production of PG specific trans-Δ3 -hexadecenoic acid and accumulation of n-3 polyunsaturated fatty acids (PUFA) mostly in PG and MGDG at the expense of the rise in 18:3n-3 and 20:5n-3, 18:4n-3, respectively. These changes in lipid and FA profiles are apparently responsible for supporting thylakoid biogenesis and efficient photosynthesis at light limitation, thus contributing to photoacclimation strategies in brown algae. The content of triacylglycerols (TAG) and the level of their PUFA were decreased at LL, suggesting the consumption of TAG as a source of PUFA and energy reserves. Thus, U. pinnatifida is able to successfully overcome periods of low irradiance through the effective light harvesting and utilization that are provided by high flexibility of lipid biosynthesis.
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Affiliation(s)
- Natalia V Zhukova
- National Scientific Center of Marine Biology, Far East Branch of the Russian Academy of Sciences, Palchevskogo 17, Vladivostok, 690041, Russia
| | - Irina M Yakovleva
- National Scientific Center of Marine Biology, Far East Branch of the Russian Academy of Sciences, Palchevskogo 17, Vladivostok, 690041, Russia
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14
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Paine ER, Schmid M, Boyd PW, Diaz-Pulido G, Hurd CL. Rate and fate of dissolved organic carbon release by seaweeds: A missing link in the coastal ocean carbon cycle. JOURNAL OF PHYCOLOGY 2021; 57:1375-1391. [PMID: 34287891 DOI: 10.1111/jpy.13198] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/08/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Dissolved organic carbon (DOC) release by seaweeds (marine macroalgae) is a critical component of the coastal ocean biogeochemical carbon cycle but is an aspect of seaweed carbon physiology that we know relatively little about. Seaweed-derived DOC is found throughout coastal ecosystems and supports multiple food web linkages. Here, we discuss the mechanisms of DOC release by seaweeds and group them into passive (leakage, requires no energy) and active release (exudation, requires energy) with particular focus on the photosynthetic "overflow" hypothesis. The release of DOC from seaweeds was first studied in the 1960s, but subsequent studies use a range of units hindering evaluation: we convert published values to a common unit (μmol C · g DW-1 · h-1 ) allowing comparisons between seaweed phyla, functional groups, biogeographic region, and an assessment of the environmental regulation of DOC production. The range of DOC release rates by seaweeds from each phylum under ambient environmental conditions was 0-266.44 μmol C · g DW-1 · h-1 (Chlorophyta), 0-89.92 μmol C · g DW-1 · h-1 (Ochrophyta), and 0-41.28 μmol C · g DW-1 · h-1 (Rhodophyta). DOC release rates increased under environmental factors such as desiccation, high irradiance, non-optimal temperatures, altered salinity, and elevated dissolved carbon dioxide (CO2 ) concentrations. Importantly, DOC release was highest by seaweeds that were desiccated (<90 times greater DOC release compared to ambient). We discuss the impact of future ocean scenarios (ocean acidification, seawater warming, altered irradiance) on DOC release rates by seaweeds, the role of seaweed-derived DOC in carbon sequestration models, and how they inform future research directions.
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Affiliation(s)
- Ellie R Paine
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Matthias Schmid
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Guillermo Diaz-Pulido
- Griffith School of Environment, Australian Rivers Institute - Coast and Estuaries, Nathan Campus, Griffith University, Brisbane, Queensland, 4111, Australia
| | - Catriona L Hurd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
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15
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Agarwal PK, Dangariya M, Agarwal P. Seaweed extracts: Potential biodegradable, environmentally friendly resources for regulating plant defence. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Leal PP, Roleda MY, Fernández PA, Nitschke U, Hurd CL. Reproductive phenology and morphology of Macrocystis pyrifera (Laminariales, Ochrophyta) from southern New Zealand in relation to wave exposure 1. JOURNAL OF PHYCOLOGY 2021; 57:1619-1635. [PMID: 34153125 DOI: 10.1111/jpy.13190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Macrocystis pyrifera is a major habitat forming kelp in coastal ecosystems of temperate regions of the northern and southern hemispheres. We investigated the seasonal occurrence of adult sporophytes, morphological characteristics, and reproductive phenology at two sites within a wave-protected harbour and two wave-exposed sites in southern New Zealand every 3-4 months between 2012 and 2013. Seasonality in reproduction was assessed via the number of sporophylls, the occurrence of sori on sporophylls, and non-sporophyllous laminae (fertile pneumatocyst-bearing blades and fertile apical scimitars), meiospore release, and germination. We found that M. pyrifera was present and reproductive year-round in three of the four sites, and patterns were similar for the wave-exposure conditions. Sori were found on pneumatocyst-bearing blades and apical scimitars in addition to the sporophylls, and viable meiospores were released from all three types of laminae. Morphological variations between sites with different wave exposure indicate that sporophytes from wave-protected sites have bigger blades and holdfasts and are longer than those from wave-exposed sites. We discuss the implications of these biological variables for the ecology of M. pyrifera inhabiting different wave exposure environments in southern New Zealand.
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Affiliation(s)
- Pablo P Leal
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Departamento de Repoblación y Cultivo, Instituto de Fomento Pesquero (IFOP), Balmaceda 252, Casilla 665, Puerto Montt, Chile
| | - Michael Y Roleda
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Norwegian Institute of Bioeconomy Research, Kudalsveien 6, Bodø, 8027, Norway
- The Marine Science Institute, College of Science, University of the Philippines Diliman, Quezon City, Philippines
| | - Pamela A Fernández
- Centro i⁓mar & CeBiB, Universidad de Los Lagos, Camino a Chinquihue Km 6, Casilla 557, Puerto Montt, Chile
| | - Udo Nitschke
- Independent researcher, Jahnstraße 6, Vohburg, 85088, Germany
| | - Catriona L Hurd
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade Battery Point, Hobart, Tasmania, 7004, Australia
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17
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Baho DL, Arnott D, Myrstad KD, Schneider SC, Moe TF. Rapid colonization of aquatic communities in an urban stream after daylighting. Restor Ecol 2021. [DOI: 10.1111/rec.13394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Didier L. Baho
- Norwegian Institute for Water Research (NIVA), CIENS Science Park, Gaustadalléen 21 Oslo N‐0349 Norway
- Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences P.O. Box 7050 Uppsala SE‐750‐07 Sweden
| | - David Arnott
- Faculty of Environmental Sciences and Nature Conservation Norwegian University of Life Sciences P.O. Box 5003 Ås N‐1430 Norway
| | - Karoline D. Myrstad
- Faculty of Environmental Sciences and Nature Conservation Norwegian University of Life Sciences P.O. Box 5003 Ås N‐1430 Norway
| | - Susanne C. Schneider
- Norwegian Institute for Water Research (NIVA), CIENS Science Park, Gaustadalléen 21 Oslo N‐0349 Norway
- Faculty of Environmental Sciences and Nature Conservation Norwegian University of Life Sciences P.O. Box 5003 Ås N‐1430 Norway
| | - Therese F. Moe
- Norwegian Institute for Water Research (NIVA), CIENS Science Park, Gaustadalléen 21 Oslo N‐0349 Norway
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18
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Resende DI, Ferreira M, Magalhães C, Sousa Lobo J, Sousa E, Almeida IF. Trends in the use of marine ingredients in anti-aging cosmetics. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102273] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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19
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Zuñiga-Rios D, Vásquez-Elizondo RM, Caamal E, Robledo D. Photosynthetic responses of Halimeda scabra (Chlorophyta, Bryopsidales) to interactive effects of temperature, pH, and nutrients and its carbon pathways. PeerJ 2021; 9:e10958. [PMID: 33717694 PMCID: PMC7938779 DOI: 10.7717/peerj.10958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/27/2021] [Indexed: 12/04/2022] Open
Abstract
In this study, we evaluated the interactive effects of temperature, pH, and nutrients on photosynthetic performance in the calcareous tropical macroalga Halimeda scabra. A significant interaction among these factors on gross photosynthesis (Pgross) was found. The highest values of Pgross were reached at the highest temperature, pH, and nutrient enrichment tested and similarly in the control treatment (no added nutrients) at 33 °C at the lowest pH. The Q10Pgross values confirmed the effect of temperature only under nutrient enrichment scenarios. Besides the above, bicarbonate (HCO3−) absorption was assessed by the content of carbon stable isotope (δ13C) in algae tissue and by its incorporation into photosynthetic products, as well as by carbonic anhydrase (CA) inhibitors (Acetazolamide, AZ and Ethoxyzolamide, EZ) assays. The labeling of δ13C revealed this species uses both, CO2 and HCO3− forms of Ci relying on a CO2 Concentration Mechanism (CCM). These results were validated by the EZ-AZ inhibition assays in which photosynthesis inhibition was observed, indicating the action of internal CA, whereas AZ inhibitor did not affect maximum photosynthesis (Pmax). The incorporation of 13C isotope into aspartate in light and dark treatments also confirmed photosynthetic and non-photosynthetic the HCO3−uptake.
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Affiliation(s)
| | | | - Edgar Caamal
- Department of Marine Resources, Cinvestav, Merida, Yucatan, Mexico
| | - Daniel Robledo
- Department of Marine Resources, Cinvestav, Merida, Yucatan, Mexico
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20
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Bi YH, Du AY, Li JL, Zhou ZG. Isolation and characterization of a γ-carbonic anhydrase localized in the mitochondria of Saccharina japonica. CHEMOSPHERE 2021; 266:129162. [PMID: 33310361 DOI: 10.1016/j.chemosphere.2020.129162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 11/28/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
Saccharina japonica is an ecologically and economically important seaweed that is dominant in the rocky shores of cold-temperate regions, forms the major component of productive beds, and affects marine environments. S. japonica exhibits a high photosynthetic efficiency in natural seawater with low dissolved CO2 concentration, thus suggesting the presence of its carbon-concentrating mechanism (CCM). However, the genes, proteins, and pathways involved in the CCM of S. japonica have not been fully identified and characterized. Carbonic anhydrase (CA) is a crucial component of CCM in macroalgae. In this study, the cloning, characterization, and subcellular localization of a specific CA were described. Multisequence alignment and phylogenetic analysis indicated that this CA belonged to the gamma (Sjγ-CA) class. This enzyme has a full-length cDAN of 1370 bp, encodes a protein with 246 amino acids (aa; ca. 25.7 kDa), and contains the mitochondrial transit peptide of 16 aa and LbH_gama_CA_like domain of 159 aa that defined the γ-CA region. The Sjγ-CA was successfully expressed in E. coli BL21 and purified as an active recombinant CA. Immunogold electron microscopy and fluorescence localization illustrated that this enzyme is localized in the mitochondria, and its transcription level is up-regulated by low CO2 concentration. These findings showed that Sjγ-CA is a possible component of the CCM in S. japonica. This work is the first to report about the mtCA of macroalgae and provides a basis for further analysis on seaweed CCM.
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Affiliation(s)
- Yan-Hui Bi
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; National Demonstration Center for the Experimental Teaching of Fisheries Science, Shanghai Ocean University, Shanghai, 201306, China
| | - An-Ying Du
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Jia-Li Li
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Zhi-Gang Zhou
- International Research Center for Marine Biosciences Conferred By Ministry of Science and Technology, Shanghai Ocean University, Shanghai, 201306, China.
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21
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Gabara SS, Konar BH, Edwards MS. Biodiversity loss leads to reductions in community‐wide trophic complexity. Ecosphere 2021. [DOI: 10.1002/ecs2.3361] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Scott S. Gabara
- Department of Biology & Coastal Marine Institute Laboratory San Diego State University San Diego California92182USA
- Department of Environmental Science and Policy University of California Davis California95616USA
| | - Brenda H. Konar
- College of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks Alaska99775USA
| | - Matthew S. Edwards
- Department of Biology & Coastal Marine Institute Laboratory San Diego State University San Diego California92182USA
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22
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Noisette F, Depetris A, Kühl M, Brodersen KE. Flow and epiphyte growth effects on the thermal, optical and chemical microenvironment in the leaf phyllosphere of seagrass ( Zostera marina). J R Soc Interface 2020; 17:20200485. [PMID: 33050780 DOI: 10.1098/rsif.2020.0485] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Intensified coastal eutrophication can result in an overgrowth of seagrass leaves by epiphytes, which is a major threat to seagrass habitats worldwide, but little is known about how epiphytic biofilms affect the seagrass phyllosphere. The physico-chemical microenvironment of Zostera marina L. leaves with and without epiphytes was mapped with electrochemical, thermocouple and scalar irradiance microsensors as a function of four irradiance conditions (dark, low, saturating and high light) and two water flow velocities (approx. 0.5 and 5 cm s-1), which resemble field conditions. The presence of epiphytes led to the build up of a diffusive boundary layer and a thermal boundary layer which impeded O2 and heat transfer between the leaf surface and the surrounding water, resulting in a maximum increase of 0.8°C relative to leaves with no epiphytes. Epiphytes also reduced the quantity and quality of light reaching the leaf, decreasing plant photosynthesis. In darkness, epiphyte respiration exacerbated hypoxic conditions, which can lead to anoxia and the production of potential phytotoxic nitric oxide in the seagrass phyllosphere. Epiphytic biofilm affects the local phyllosphere physico-chemistry both because of its metabolic activity (i.e. photosynthesis/respiration) and its physical properties (i.e. thickness, roughness, density and back-scattering properties). Leaf tissue warming can lead to thermal stress in seagrasses living close to their thermal stress threshold, and thus potentially aggravate negative effects of global warming.
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Affiliation(s)
- Fanny Noisette
- Department of Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research, Hohenbergstraße 2, 24105 Kiel, Germany.,Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, 7004 TAS Hobart, Australia
| | - Anna Depetris
- École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne, Switzerland
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Kasper Elgetti Brodersen
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
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23
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Bergstrom E, Ordoñez A, Ho M, Hurd C, Fry B, Diaz-Pulido G. Inorganic carbon uptake strategies in coralline algae: Plasticity across evolutionary lineages under ocean acidification and warming. MARINE ENVIRONMENTAL RESEARCH 2020; 161:105107. [PMID: 32890983 DOI: 10.1016/j.marenvres.2020.105107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/29/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Dissolved inorganic carbon (DIC) assimilation is essential to the reef-building capacity of crustose coralline algae (CCA). Little is known, however, about the DIC uptake strategies and their potential plasticity under ongoing ocean acidification (OA) and warming. The persistence of CCA lineages throughout historical oscillations of pCO2 and temperature suggests that evolutionary history may play a role in selecting for adaptive traits. We evaluated the effects of pCO2 and temperature on the plasticity of DIC uptake strategies and associated energetic consequences in reef-building CCA from different evolutionary lineages. We simulated past, present, moderate (IPCC RCP 6.0) and high pCO2 (RCP 8.5) and present and high (RCP 8.5) temperature conditions and quantified stable carbon isotope fractionation (13ε), organic carbon content, growth and photochemical efficiency. All investigated CCA species possess CO2-concentrating mechanisms (CCMs) and assimilate CO2 via diffusion to varying degrees. Under OA and warming, CCA either increased or maintained CCM capacity, which was associated with overall neutral effects on metabolic performance. More basal taxa, Sporolithales and Hapalidiales, had greater capacity for diffusive CO2 use than Corallinales. We suggest that CCMs are an adaptation that supports a robust carbon physiology and are likely responsible for the endurance of CCA in historically changing oceans.
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Affiliation(s)
- Ellie Bergstrom
- School of Environment & Science and Australian Rivers Institute - Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, Nathan, Queensland, 4111, Australia.
| | - Alexandra Ordoñez
- School of Environment & Science and Australian Rivers Institute - Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, Nathan, Queensland, 4111, Australia
| | - Maureen Ho
- School of Environment & Science and Australian Rivers Institute - Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, Nathan, Queensland, 4111, Australia
| | - Catriona Hurd
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, 28 Morrison St., Hobart, TAS, 7000, Australia
| | - Brian Fry
- School of Environment & Science and Australian Rivers Institute - Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, Nathan, Queensland, 4111, Australia
| | - Guillermo Diaz-Pulido
- School of Environment & Science and Australian Rivers Institute - Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, Nathan, Queensland, 4111, Australia.
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24
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How Does the Sexual Reproduction of Marine Life Respond to Ocean Acidification? DIVERSITY 2020. [DOI: 10.3390/d12060241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent research indicates that synchronicity of sexual reproduction in coral spawning events is breaking down, leading to aging populations and decreased recruitment success. In this perspective, we develop a hypothesis that this phenomenon could be caused by ongoing ocean acidification (OA). We hypothesize, that the underlying physiological machinery could be the carbon concentrating mechanism (CCM). The endosymbiotic zooxanthellae of corals could use this mechanism to sense calm water motion states in a comparable way to that known from macroalgae. In macroalgae, it is well-established that dissolved inorganic carbon (DIC) acts as the trigger for signaling low water motion. Hence, evolutionarily developed signals of low water motion, suited for gamete-release, may be misleading in the future, potentially favoring opportunistic species in a broad range of marine organisms.
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25
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Algal density mediates the photosynthetic responses of a marine macroalga Ulva conglobata (Chlorophyta) to temperature and pH changes. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101797] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Wade R, Augyte S, Harden M, Nuzhdin S, Yarish C, Alberto F. Macroalgal germplasm banking for conservation, food security, and industry. PLoS Biol 2020; 18:e3000641. [PMID: 32058997 PMCID: PMC7046291 DOI: 10.1371/journal.pbio.3000641] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/27/2020] [Indexed: 01/02/2023] Open
Abstract
Ex situ seed banking was first conceptualized and implemented in the early 20th century to maintain and protect crop lines. Today, ex situ seed banking is important for the preservation of heirloom strains, biodiversity conservation and ecosystem restoration, and diverse research applications. However, these efforts primarily target microalgae and terrestrial plants. Although some collections include macroalgae (i.e., seaweeds), they are relatively few and have yet to be connected via any international, coordinated initiative. In this piece, we provide a brief introduction to macroalgal germplasm banking and its application to conservation, industry, and mariculture. We argue that concerted effort should be made globally in germline preservation of marine algal species via germplasm banking with an overview of the technical advances for feasibility and ensured success. Seaweed germplasm banking is an important resource for biodiversity conservation, human food security, and industry innovation. This Perspective article maintains that an international, coordinative initiative is needed to fully develop and capitalize on this resource.
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Affiliation(s)
- Rachael Wade
- University of Wisconsin Milwaukee, Milwaukee, Wisconsin, United States of America
- * E-mail:
| | - Simona Augyte
- University of Connecticut Stamford, Stamford, Connecticut, United States of America
| | - Maddelyn Harden
- University of Southern California, Los Angeles, California, United States of America
| | - Sergey Nuzhdin
- University of Southern California, Los Angeles, California, United States of America
| | - Charles Yarish
- University of Connecticut Stamford, Stamford, Connecticut, United States of America
| | - Filipe Alberto
- University of Wisconsin Milwaukee, Milwaukee, Wisconsin, United States of America
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27
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Desmond MJ, Pajusalu L, Pritchard DW, Stephens TA, Hepburn CD. Whole community estimates of macroalgal pigment concentration within two southern New Zealand kelp forests 1. JOURNAL OF PHYCOLOGY 2019; 55:936-947. [PMID: 31074500 DOI: 10.1111/jpy.12884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 02/26/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
Light availability is a fundamental factor that controls the productivity and distribution of macroalgae and is highly variable, both spatially and temporally, in subtidal coastal systems. Our comprehension of how macroalgae respond to such variability is a significant knowledge gap that limits our understanding of how light influences the structure and productivity of these environments. Here, we examined the pigment characteristics of individual species, and for the first time the whole community, within one low-light, and one high-light kelp-forest system in southern New Zealand. The aim was to quantify the range of pigmentation seen within the two kelp-forests which differed in irradiance regime. Light availability was 33% and 64% greater at the high-light compared to the low-light site at 2 and 10 m depth, respectively. Results suggested Phaeophyceae species at deeper depths in the low-light site may be living at the edge of their photosynthetic ability and pigment synthesis appeared significantly restricted. Even with greater investment in the pigment fucoxanthin, biomass of Phaeophyceae species was significantly lower in the low-light site. Highly pigmented Rhodophyceae species made a greater proportional contribution to community biomass within the low-light site where they likely possessed a photosynthetic advantage. This work helps explain discrepancies in community structure between the two study sites and explores the complex relationship between irradiance and photoacclimation. The comparison of community pigment concentration holds potential as a tool for assessing the relative degree of photoacclimation occurring between sites and provides a proxy of photosynthetic cost under a specific light regime.
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Affiliation(s)
- Matthew J Desmond
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Liina Pajusalu
- Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618, Tallinn, Estonia
| | - Daniel W Pritchard
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Te Ao Tūroa, Te Rūnanga o Ngāi Tahu, PO Box 799, Dunedin, 9054, New Zealand
| | - Tiffany A Stephens
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Christopher D Hepburn
- Department of Marine Science, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
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Briggs AA, Carpenter RC. Contrasting responses of photosynthesis and photochemical efficiency to ocean acidification under different light environments in a calcifying alga. Sci Rep 2019; 9:3986. [PMID: 30850681 PMCID: PMC6408467 DOI: 10.1038/s41598-019-40620-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 02/20/2019] [Indexed: 12/02/2022] Open
Abstract
Ocean acidification (OA) is predicted to enhance photosynthesis in many marine taxa. However, photophysiology has multiple components that OA may affect differently, especially under different light environments, with potentially contrasting consequences for photosynthetic performance. Furthermore, because photosynthesis affects energetic budgets and internal acid-base dynamics, changes in it due to OA or light could mediate the sensitivity of other biological processes to OA (e.g. respiration and calcification). To better understand these effects, we conducted experiments on Porolithon onkodes, a common crustose coralline alga in Pacific coral reefs, crossing pCO2 and light treatments. Results indicate OA inhibited some aspects of photophysiology (maximum photochemical efficiency), facilitated others (α, the responsiveness of photosynthesis to sub-saturating light), and had no effect on others (maximum gross photosynthesis), with the first two effects depending on treatment light level. Light also exacerbated the increase in dark-adapted respiration under OA, but did not alter the decline in calcification. Light-adapted respiration did not respond to OA, potentially due to indirect effects of photosynthesis. Combined, results indicate OA will interact with light to alter energetic budgets and potentially resource allocation among photosynthetic processes in P. onkodes, likely shifting its light tolerance, and constraining it to a narrower range of light environments.
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Affiliation(s)
- Amy A Briggs
- Department of Biology, California State University, Northridge, Northridge, CA, USA. .,Odum School of Ecology, University of Georgia, Athens, GA, USA.
| | - Robert C Carpenter
- Department of Biology, California State University, Northridge, Northridge, CA, USA
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29
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Hofmann LC, Schoenrock K, de Beer D. Arctic Coralline Algae Elevate Surface pH and Carbonate in the Dark. FRONTIERS IN PLANT SCIENCE 2018; 9:1416. [PMID: 30319676 PMCID: PMC6167962 DOI: 10.3389/fpls.2018.01416] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 09/06/2018] [Indexed: 05/30/2023]
Abstract
Red coralline algae are projected to be sensitive to ocean acidification, particularly in polar oceans. As important ecosystem engineers, their potential sensitivity has broad implications, and understanding their carbon acquisition mechanisms is necessary for making reliable predictions. Therefore, we investigated the localized carbonate chemistry at the surface of Arctic coralline algae using microsensors. We report for the first time carbonate ion concentration and pH measurements ([CO3 2-]) at and above the algal surface in the microenvironment. We show that surface pH and [CO3 2-] are higher than the bulk seawater in the light, and even after hours of darkness. We further show that three species of Arctic coralline algae have efficient carbon concentrating mechanisms including direct bicarbonate uptake and indirect bicarbonate use via a carbonic anhydrase enzyme. Our results suggest that Arctic corallines have strong biological control over their surface chemistry, where active calcification occurs, and that net dissolution in the dark does not occur. We suggest that the elevated pH and [CO3 2-] in the dark could be explained by a high rate of light independent carbon fixation that reduces respiratory CO2 release. This mechanism could provide a potential adaptation to ocean acidification in Arctic coralline algae, which has important implications for future Arctic marine ecosystems.
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Affiliation(s)
- Laurie C. Hofmann
- Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany
| | - Kathryn Schoenrock
- Department of Geographical and Earth Science, University of Glasgow, Glasgow, United Kingdom
| | - Dirk de Beer
- Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany
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30
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Poschenrieder C, Fernández JA, Rubio L, Pérez L, Terés J, Barceló J. Transport and Use of Bicarbonate in Plants: Current Knowledge and Challenges Ahead. Int J Mol Sci 2018; 19:E1352. [PMID: 29751549 PMCID: PMC5983714 DOI: 10.3390/ijms19051352] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 04/27/2018] [Accepted: 04/28/2018] [Indexed: 01/09/2023] Open
Abstract
Bicarbonate plays a fundamental role in the cell pH status in all organisms. In autotrophs, HCO₃− may further contribute to carbon concentration mechanisms (CCM). This is especially relevant in the CO₂-poor habitats of cyanobacteria, aquatic microalgae, and macrophytes. Photosynthesis of terrestrial plants can also benefit from CCM as evidenced by the evolution of C₄ and Crassulacean Acid Metabolism (CAM). The presence of HCO₃− in all organisms leads to more questions regarding the mechanisms of uptake and membrane transport in these different biological systems. This review aims to provide an overview of the transport and metabolic processes related to HCO₃− in microalgae, macroalgae, seagrasses, and terrestrial plants. HCO₃− transport in cyanobacteria and human cells is much better documented and is included for comparison. We further comment on the metabolic roles of HCO₃− in plants by focusing on the diversity and functions of carbonic anhydrases and PEP carboxylases as well as on the signaling role of CO₂/HCO₃− in stomatal guard cells. Plant responses to excess soil HCO₃− is briefly addressed. In conclusion, there are still considerable gaps in our knowledge of HCO₃− uptake and transport in plants that hamper the development of breeding strategies for both more efficient CCM and better HCO₃− tolerance in crop plants.
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Affiliation(s)
- Charlotte Poschenrieder
- Plant Physiology Lab., Bioscience Faculty, Universidad Autónoma de Barcelona, 08193 Barcelona, Spain.
| | - José Antonio Fernández
- Department Biologia. Vegetal, Campus Teatinos, Universidad de Málaga, 29071 Málaga, Spain.
| | - Lourdes Rubio
- Department Biologia. Vegetal, Campus Teatinos, Universidad de Málaga, 29071 Málaga, Spain.
| | - Laura Pérez
- Plant Physiology Lab., Bioscience Faculty, Universidad Autónoma de Barcelona, 08193 Barcelona, Spain.
| | - Joana Terés
- Plant Physiology Lab., Bioscience Faculty, Universidad Autónoma de Barcelona, 08193 Barcelona, Spain.
| | - Juan Barceló
- Plant Physiology Lab., Bioscience Faculty, Universidad Autónoma de Barcelona, 08193 Barcelona, Spain.
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Connell SD, Doubleday ZA, Foster NR, Hamlyn SB, Harley CDG, Helmuth B, Kelaher BP, Nagelkerken I, Rodgers KL, Sarà G, Russell BD. The duality of ocean acidification as a resource and a stressor. Ecology 2018; 99:1005-1010. [PMID: 29714829 DOI: 10.1002/ecy.2209] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/02/2018] [Accepted: 03/02/2018] [Indexed: 12/19/2022]
Abstract
Ecologically dominant species often define ecosystem states, but as human disturbances intensify, their subordinate counterparts increasingly displace them. We consider the duality of disturbance by examining how environmental drivers can simultaneously act as a stressor to dominant species and as a resource to subordinates. Using a model ecosystem, we demonstrate that CO2 -driven interactions between species can account for such reversals in dominance; i.e., the displacement of dominants (kelp forests) by subordinates (turf algae). We established that CO2 enrichment had a direct positive effect on productivity of turfs, but a negligible effect on kelp. CO2 enrichment further suppressed the abundance and feeding rate of the primary grazer of turfs (sea urchins), but had an opposite effect on the minor grazer (gastropods). Thus, boosted production of subordinate producers, exacerbated by a net reduction in its consumption by primary grazers, accounts for community change (i.e., turf displacing kelp). Ecosystem collapse, therefore, is more likely when resource enrichment alters competitive dominance of producers, and consumers fail to compensate. By recognizing such duality in the responses of interacting species to disturbance, which may stabilize or exacerbate change, we can begin to understand how intensifying human disturbances determine whether or not ecosystems undergo phase shifts.
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Affiliation(s)
- Sean D Connell
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Zoë A Doubleday
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Nicole R Foster
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Sarah B Hamlyn
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Christopher D G Harley
- Department of Zoology and Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian Helmuth
- Marine Science Center, Northeastern University, Nahant, Massachusetts, 01908, USA
| | - Brendan P Kelaher
- National Marine Science Centre & Marine Ecology Research Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Ivan Nagelkerken
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Kirsten L Rodgers
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Auckland, New Zealand
| | - Gianluca Sarà
- Ecology Lab, Dipartimento di Scienze della Terra e del Mare, Università degli Studi di Palermo, Palermo, Italy
| | - Bayden D Russell
- The Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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32
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Absolonova M, Beilby MJ, Sommer A, Hoepflinger MC, Foissner I. Surface pH changes suggest a role for H +/OH - channels in salinity response of Chara australis. PROTOPLASMA 2018; 255:851-862. [PMID: 29247277 PMCID: PMC5904247 DOI: 10.1007/s00709-017-1191-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/27/2017] [Indexed: 05/16/2023]
Abstract
To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H+/OH- channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl2, the main known blocker of animal H+ channels. The cells were imaged with confocal microscopy, using fluorescein isothiocyanate (FITC) coupled to dextran 70 to illuminate the pH changes outside the cell wall in artificial fresh water (AFW) and in saline medium. In the early saline exposure, we observed alkaline patches (bright fluorescent spots) appearing transiently in random spatial distribution. After longer exposure, some of the spots became fixed in space. Saline also abolished or diminished the pH banding pattern observed in the untreated control cells. ZnCl2 suppressed the alkaline spot formation in saline and the pH banding pattern in AFW. The osmotic component of the saline stress did not produce transient bright spots or affect banding. The displacement of H+ from the cell wall charges, the H+/OH- channel conductance/density, and self-organization are discussed. No homologies to animal H+ channels were found. Salinity activation of the H+/OH- channels might contribute to saline response in roots of land plants and leaves of aquatic angiosperms.
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Affiliation(s)
- Marketa Absolonova
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Mary J Beilby
- School of Physics, The University of NSW, Sydney, NSW, 2052, Australia.
| | - Aniela Sommer
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Marion C Hoepflinger
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Ilse Foissner
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
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33
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Noisette F, Hurd C. Abiotic and biotic interactions in the diffusive boundary layer of kelp blades create a potential refuge from ocean acidification. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13067] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fanny Noisette
- Institute for Marine and Antarctic StudiesUniversity of Tasmania Hobart Tasmania Australia
| | - Catriona Hurd
- Institute for Marine and Antarctic StudiesUniversity of Tasmania Hobart Tasmania Australia
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34
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Rubio L, García D, García-Sánchez MJ, Niell FX, Felle HH, Fernández JA. Direct uptake of HCO 3- in the marine angiosperm Posidonia oceanica (L.) Delile driven by a plasma membrane H + economy. PLANT, CELL & ENVIRONMENT 2017; 40:2820-2830. [PMID: 28815648 DOI: 10.1111/pce.13057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Seagrasses access HCO3- for photosynthesis by 2 mechanisms, apoplastic carbonic anhydrase-mediated dehydration of HCO3- to CO2 and direct HCO3- uptake. Here, we have studied plasma membrane energization and the mechanism for HCO3- import in Posidonia oceanica. Classical electrophysiology and ion-selective microelectrodes were used to measure the membrane potential, cytosolic pH, and the cytosolic concentrations of Na+ and Cl- upon the addition of HCO3- . The photosynthetic response to HCO3- and to inhibitors was also measured. Results indicate that the primary pump of P. oceanica plasma membrane is a fusicoccin-sensitive H+ -ATPase. Bicarbonate depolarizes the plasma membrane voltage and transiently acidifies the cytosol, indicating that HCO3- is transported into the cells by an H+ -symport. Initial cytosolic acidification is followed by an alkalinization, suggesting an internal dehydration of HCO3- . The lack of cytosolic Na+ and Cl- responses rules out the contribution of these ions to HCO3- transport. The energetics of nH+ /HCO3- symport allows, for n = 1, an estimate of cytosolic accumulation of 0.22 mM HCO3- . Because this transporter could permit accumulation of HCO3- up to 100 times above the equilibrium concentration, it would be a significant component of a carbon-concentrating mechanism in this species.
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Affiliation(s)
- Lourdes Rubio
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
| | - Delia García
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
| | - María J García-Sánchez
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
| | - F Xavier Niell
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
| | - Hubert H Felle
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
| | - José A Fernández
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos S/N, Málaga, 29071, Spain
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35
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Raven JA, Giordano M. Acquisition and metabolism of carbon in the Ochrophyta other than diatoms. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160400. [PMID: 28717026 PMCID: PMC5516109 DOI: 10.1098/rstb.2016.0400] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2017] [Indexed: 11/12/2022] Open
Abstract
The acquisition and assimilation of inorganic C have been investigated in several of the 15 clades of the Ochrophyta other than diatoms, with biochemical, physiological and genomic data indicating significant mechanistic variation. Form ID Rubiscos in the Ochrophyta are characterized by a broad range of kinetics values. In spite of relatively high K0.5CO2 and low CO2 : O2 selectivity, diffusive entry of CO2 occurs in the Chrysophyceae and Synurophyceae. Eustigmatophyceae and Phaeophyceae, on the contrary, have CO2 concentrating mechanisms, usually involving the direct or indirect use of [Formula: see text] This variability is possibly due to the ecological contexts of the organism. In brown algae, C fixation generally takes place through a classical C3 metabolism, but there are some hints of the occurrence of C4 metabolism and low amplitude CAM in a few members of the Fucales. Genomic data show the presence of a number of potential C4 and CAM genes in Ochrophyta other than diatoms, but the other core functions of many of these genes give a very limited diagnostic value to their presence and are insufficient to conclude that C4 photosynthesis is present in these algae.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- John A Raven
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona 60131, Italy
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Trěboň 37901, Czech Republic
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36
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Celis-Plá PSM, Martínez B, Korbee N, Hall-Spencer JM, Figueroa FL. Photoprotective responses in a brown macroalgae Cystoseira tamariscifolia to increases in CO 2 and temperature. MARINE ENVIRONMENTAL RESEARCH 2017; 130:157-165. [PMID: 28764959 DOI: 10.1016/j.marenvres.2017.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 07/04/2017] [Accepted: 07/18/2017] [Indexed: 05/16/2023]
Abstract
Global warming and ocean acidification are increasingly affecting coastal ecosystems, with impacts that vary regionally depending upon local biogeography. Ocean acidification drives shifts in seaweed community dominance that depend on interactions with other factors such as light and nutrients. In this study, we investigated the photophysiological responses in the brown macroalgae species Cystoseira tamariscifolia (Hudson) Papenfuss with important structural role in the coastal Mediterranean communities. These algae were collected in the Cabo de Gata-Nijar Natural Park in ultraoligotrophic waters (algae exposed under high irradiance and less nutrient conditions) vs. those collected in the La Araña beach in oligotrophic waters (algae exposed at middle nutrient and irradiance conditions) in the Mediterranean Sea. They were incubated in mesocosms, under two levels of CO2; ambient (400-500 ppm) and high CO2 (1200-1300 ppm), combined with two temperatures (ambient temperature; 20 °C and ambient temperature + 4 °C; 24 °C) and the same nutrient conditions of the waters of the origin of macroalgae. Thalli from two sites on the Spanish Mediterranean coast were significantly affected by increases in pCO2 and temperature. The carotenoids (fucoxanthin, violaxanthin and β-carotene) contents were higher in algae from oligotrophic than that from ultraoligotrophic water, i.e., algae collected under higher nutrient conditions respect to less conditions, increase photoprotective pigments content. Thalli from both locations upregulated photosynthesis (as Fv/Fm) at increased pCO2 levels. Our study shows that ongoing ocean acidification and warming can increase photoprotection and photosynthesis in intertidal macroalgae.
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Affiliation(s)
- Paula S M Celis-Plá
- Laboratory of Costal Environmental Research, Centre of Advanced Studies, University of Playa Ancha, 2581782 Viña del Mar, Chile; Department of Ecology, Faculty of Sciences, University of Malaga, 29071 Malaga, Spain.
| | - Brezo Martínez
- Biodiversity and Conservation Unit, Rey Juan Carlos University, 28933 Mostoles, Spain
| | - Nathalie Korbee
- Department of Ecology, Faculty of Sciences, University of Malaga, 29071 Malaga, Spain
| | - Jason M Hall-Spencer
- Marine Biology and Ecology Research Centre, Plymouth University, UK; Shimoda Marine Research Centre, Tsukuba University, Japan
| | - Félix L Figueroa
- Department of Ecology, Faculty of Sciences, University of Malaga, 29071 Malaga, Spain
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37
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Desmond MJ, Pritchard DW, Hepburn CD. Light dose versus rate of delivery: implications for macroalgal productivity. PHOTOSYNTHESIS RESEARCH 2017; 132:257-264. [PMID: 28389747 DOI: 10.1007/s11120-017-0381-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 04/01/2017] [Indexed: 06/07/2023]
Abstract
The role of how light is delivered over time is an area of macroalgal photosynthesis that has been overlooked but may play a significant role in controlling rates of productivity and the structure and persistence of communities. Here we present data that quantify the relative influence of total quantum dose and delivery rate on the photosynthetic productivity of five ecologically important Phaeophyceae species from southern New Zealand. Results suggested that greater net oxygen production occurs when light is delivered at a lower photon flux density (PFD) over a longer period compared to a greater PFD over a shorter period, given the same total dose. This was due to greater efficiency (α) at a lower PFD which, for some species, meant a compensatory effect can occur. This resulted in equal or greater productivity even when the total quantum dose of the lower PFD was significantly reduced. It was also shown that light limitation at Huriawa Peninsula, where macroaglae were sourced, may be restricting the acclimation potential of species at greater depths, and that even at shallow depth periods of significant light limitation are likely to occur. This research is of particular interest as the variability of light delivery to coastal reef systems increases as a result of anthropogenic disturbances, and as the value of in situ community primary productivity estimates is recognised.
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Affiliation(s)
- Matthew J Desmond
- Department of Marine Science, University of Otago, P. O. Box 56, Dunedin, 9054, New Zealand.
| | - Daniel W Pritchard
- Department of Marine Science, University of Otago, P. O. Box 56, Dunedin, 9054, New Zealand
- Te Ao Tūroa, Te Rūnanga o Ngāi Tahu, P. O. Box 799, Dunedin, 9054, New Zealand
| | - Christopher D Hepburn
- Department of Marine Science, University of Otago, P. O. Box 56, Dunedin, 9054, New Zealand
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38
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Larkum AWD, Davey PA, Kuo J, Ralph PJ, Raven JA. Carbon-concentrating mechanisms in seagrasses. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3773-3784. [PMID: 28911056 DOI: 10.1093/jxb/erx206] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Seagrasses are unique angiosperms that carry out growth and reproduction submerged in seawater. They occur in at least three families of the Alismatales. All have chloroplasts mainly in the cells of the epidermis. Living in seawater, the supply of inorganic carbon (Ci) to the chloroplasts is diffusion limited, especially under unstirred conditions. Therefore, the supply of CO2 and bicarbonate across the diffusive boundary layer on the outer side of the epidermis is often a limiting factor. Here we discuss the evidence for mechanisms that enhance the uptake of Ci into the epidermal cells. Since bicarbonate is plentiful in seawater, a bicarbonate pump might be expected; however, the evidence for such a pump is not strongly supported. There is evidence for a carbonic anhydrase outside the outer plasmalemma. This, together with evidence for an outward proton pump, suggests the possibility that local acidification leads to enhanced concentrations of CO2 adjacent to the outer tangential epidermal walls, which enhances the uptake of CO2, and this could be followed by a carbon-concentrating mechanism (CCM) in the cytoplasm and/or chloroplasts. The lines of evidence for such an epidermal CCM are discussed, including evidence for special 'transfer cells' in some but not all seagrass leaves in the tangential inner walls of the epidermal cells. It is concluded that seagrasses have a CCM but that the case for concentration of CO2 at the site of Rubisco carboxylation is not proven.
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Affiliation(s)
- Anthony William D Larkum
- Plant Functional Biology and Global Climate Change Cluster, University of Technology Sydney, NSW 2009, Australia
| | - Peter A Davey
- Plant Functional Biology and Global Climate Change Cluster, University of Technology Sydney, NSW 2009, Australia
| | - John Kuo
- Electron Microscope Centre, University of Western Australia, WA 6900, Australia
| | - Peter J Ralph
- Plant Functional Biology and Global Climate Change Cluster, University of Technology Sydney, NSW 2009, Australia
| | - John A Raven
- Plant Functional Biology and Global Climate Change Cluster, University of Technology Sydney, NSW 2009, Australia
- University of Dundee at JHI, Invergowrie, Dundee, UK
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Maberly SC, Gontero B. Ecological imperatives for aquatic CO2-concentrating mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3797-3814. [PMID: 28645178 DOI: 10.1093/jxb/erx201] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In aquatic environments, the concentration of inorganic carbon is spatially and temporally variable and CO2 can be substantially oversaturated or depleted. Depletion of CO2 plus low rates of diffusion cause inorganic carbon to be more limiting in aquatic than terrestrial environments, and the frequency of species with a CO2-concentrating mechanism (CCM), and their contribution to productivity, is correspondingly greater. Aquatic photoautotrophs may have biochemical or biophysical CCMs and exploit CO2 from the sediment or the atmosphere. Though partly constrained by phylogeny, CCM activity is related to environmental conditions. CCMs are absent or down-regulated when their increased energy costs, lower CO2 affinity, or altered mineral requirements outweigh their benefits. Aquatic CCMs are most widespread in environments with low CO2, high HCO3-, high pH, and high light. Freshwater species are generally less effective at inorganic carbon removal than marine species, but have a greater range of ability to remove carbon, matching the environmental variability in carbon availability. The diversity of CCMs in seagrasses and marine phytoplankton, and detailed mechanistic studies on larger aquatic photoautotrophs are understudied. Strengthening the links between ecology and CCMs will increase our understanding of the mechanisms underlying ecological success and will place mechanistic studies in a clearer ecological context.
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Affiliation(s)
- Stephen C Maberly
- Lake Ecosystems Group, Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK
| | - Brigitte Gontero
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR 3479, 31 Chemin J. Aiguier, 13 402 Marseille, Cedex 20, France
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Bulychev AA, Komarova AV. Photoregulation of photosystem II activity mediated by cytoplasmic streaming in Chara and its relation to pH bands. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:386-395. [PMID: 28257779 DOI: 10.1016/j.bbabio.2017.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/23/2017] [Accepted: 02/27/2017] [Indexed: 11/26/2022]
Abstract
Chloroplasts in vivo exposed to strong light export assimilates and excess reducing power to the cytoplasm for metabolic conversions and allocation to neighboring and distant organelles. The cytoplasmic streaming, being particularly fast in characean internodes, distributes the exported metabolites from brightly illuminated cell spots to light-limited regions, which is evident from the transient increase in chlorophyll fluorescence of shaded areas in response to illumination of distant cell regions situated upstream the liquid flow. It is not yet known whether long-distance communications between anchored chloroplasts are interfered by pH banding that commonly arises in characean internodes under the action of continuous or fluctuating light. In this study, microfluorometry, pH-microsensors, and local illumination were combined to examine long-distance transport and subsequent reentry of photosynthetic metabolites, including triose phosphates, into chloroplasts of cell regions producing external alkaline and acid bands. The lateral transmission of metabolic signals between distant chloroplasts was found to operate effectively in cell areas underlying acid zones but was almost fully blocked under alkaline zones. The rates of linear electron flow in chloroplasts of these regions were nearly equal under dim background light, but differed substantially at high light when availability of CO2, rather than irradiance, was the rate-limiting factor. Different productions of assimilates by chloroplasts underlying CO2-sufficient acid and CO2-deficient alkaline zones were a cause for contrasting manifestations of long-distance transport of photosynthetic metabolites. Nonuniform cytoplasmic pH in cells exhibiting pH bands might contribute to different activities of metabolic translocators under high and low pH zones.
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Affiliation(s)
- Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow 119991, Russia.
| | - Anna V Komarova
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow 119991, Russia.
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Drobnitch ST, Nickols K, Edwards M. Abiotic influences on bicarbonate use in the giant kelp, Macrocystis pyrifera, in the Monterey Bay. JOURNAL OF PHYCOLOGY 2017; 53:85-94. [PMID: 27861900 DOI: 10.1111/jpy.12480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 09/02/2016] [Indexed: 05/16/2023]
Abstract
In the Monterey Bay region of central California, the giant kelp Macrocystis pyrifera experiences broad fluctuations in wave forces, temperature, light availability, nutrient availability, and seawater carbonate chemistry, all of which may impact their productivity. In particular, current velocities and light intensity may strongly regulate the supply and demand of inorganic carbon (Ci) as substrates for photosynthesis. Macrocystis pyrifera can acquire and utilize both CO2 and bicarbonate (HCO3- ) as Ci substrates for photosynthesis and growth. Given the variability in carbon delivery (due to current velocities and varying [DIC]) and demand (in the form of saturating irradiance), we hypothesized that the proportion of CO2 and bicarbonate utilized is not constant for M. pyrifera, but a variable function of their fluctuating environment. We further hypothesized that populations acclimated to different wave exposure and irradiance habitats would display different patterns of bicarbonate uptake. To test these hypotheses, we carried out oxygen evolution trials in the laboratory to measure the proportion of bicarbonate utilized by M. pyrifera via external CA under an orthogonal cross of velocity, irradiance, and acclimation treatments. Our Monterey Bay populations of M. pyrifera exhibited proportionally higher external bicarbonate utilization in high irradiance and high flow velocity conditions than in sub-saturating irradiance or low flow velocity conditions. However, there was no significant difference in proportional bicarbonate use between deep blades and canopy blades, nor between individuals from wave-exposed versus wave-protected sites. This study contributes a new field-oriented perspective on the abiotic controls of carbon utilization physiology in macroalgae.
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Affiliation(s)
- Sarah Tepler Drobnitch
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, 95060, USA
| | - Kerry Nickols
- School of Natural Sciences, California State University, Monterey Bay, Seaside, California, 93955, USA
| | - Matthew Edwards
- Department of Biology, San Diego State University, San Diego, California, 92101, USA
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Fernández PA, Roleda MY, Leal PP, Hurd CL. Seawater pH, and not inorganic nitrogen source, affects pH at the blade surface of Macrocystis pyrifera: implications for responses of the giant kelp to future oceanic conditions. PHYSIOLOGIA PLANTARUM 2017; 159:107-119. [PMID: 27293117 DOI: 10.1111/ppl.12478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 05/16/2016] [Accepted: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Ocean acidification (OA), the ongoing decline in seawater pH, is predicted to have wide-ranging effects on marine organisms and ecosystems. For seaweeds, the pH at the thallus surface, within the diffusion boundary layer (DBL), is one of the factors controlling their response to OA. Surface pH is controlled by both the pH of the bulk seawater and by the seaweeds' metabolism: photosynthesis and respiration increase and decrease pH within the DBL (pHDBL ), respectively. However, other metabolic processes, especially the uptake of inorganic nitrogen (Ni ; NO3- and NH4+ ) may also affect the pHDBL . Using Macrocystis pyrifera, we hypothesized that (1) NO3- uptake will increase the pHDBL , whereas NH4+ uptake will decrease it, (2) if NO3- is cotransported with H+ , increases in pHDBL would be greater under an OA treatment (pH = 7.65) than under an ambient treatment (pH = 8.00), and (3) decreases in pHDBL will be smaller at pH 7.65 than at pH 8.00, as higher external [H+ ] might affect the strength of the diffusion gradient. Overall, Ni source did not affect the pHDBL . However, increases in pHDBL were greater at pH 7.65 than at pH 8.00. CO2 uptake was higher at pH 7.65 than at pH 8.00, whereas HCO3- uptake was unaffected by pH. Photosynthesis and respiration control pHDBL rather than Ni uptake. We suggest that under future OA, Macrocystis pyrifera will metabolically modify its surface microenvironment such that the physiological processes of photosynthesis and Ni uptake will not be affected by a reduced pH.
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Affiliation(s)
| | - Michael Y Roleda
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
| | - Pablo P Leal
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
| | - Catriona L Hurd
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
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Abstract
It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3(-). The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3(-) use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3(-) active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3(-) can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3(-) pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3(-). Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation.
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Affiliation(s)
- John A Raven
- Division of Plant Sciences, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK†, and School of Plant Biology, University of Western Australia, M084, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - John Beardall
- School of Biological Sciences, Monash University, VIC 3800, Australia
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Hurd CL. Slow-flow habitats as refugia for coastal calcifiers from ocean acidification. JOURNAL OF PHYCOLOGY 2015; 51:599-605. [PMID: 26986784 DOI: 10.1111/jpy.12307] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/09/2015] [Indexed: 05/20/2023]
Abstract
The pH of the oceans' surface water is dropping, termed ocean acidification (OA), and the 0.4 unit reduction in pH by 2100 is projected to negatively impact benthic coastal organisms that produce calcium carbonate "skeletons." Research has focussed on identifying species that are susceptible to OA, but there is an urgent need to discover refuge habitats that will afford protection to vulnerable species. The susceptibility of calcium carbonate skeletons to dissolution by OA depends on the pH at their surface, and this is controlled by the interaction between seawater velocity and organismal metabolism. This perspective considers how seawater velocity modifies the responses of calcifying organisms (seaweed, shellfish, and tropical corals) to OA through its action on controlling diffusion boundary layer thickness and thereby the pH and calcium carbonate saturation state (Ω) at the organisms' surface. Evidence is presented to support the idea that slow-flow habitats, such as wave-sheltered bays or the within canopies of seaweed/seagrass beds, might provide inexpensive refugia from OA for vulnerable coastal calcifiers.
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Affiliation(s)
- Catriona L Hurd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
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45
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Species interactions can maintain resistance of subtidal algal habitats to an increasingly modified world. Glob Ecol Conserv 2015. [DOI: 10.1016/j.gecco.2015.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Fernández PA, Roleda MY, Hurd CL. Effects of ocean acidification on the photosynthetic performance, carbonic anhydrase activity and growth of the giant kelp Macrocystis pyrifera. PHOTOSYNTHESIS RESEARCH 2015; 124:293-304. [PMID: 25869634 DOI: 10.1007/s11120-015-0138-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/31/2015] [Indexed: 06/04/2023]
Abstract
Under ocean acidification (OA), the 200 % increase in CO2(aq) and the reduction of pH by 0.3-0.4 units are predicted to affect the carbon physiology and growth of macroalgae. Here we examined how the physiology of the giant kelp Macrocystis pyrifera is affected by elevated pCO2/low pH. Growth and photosynthetic rates, external and internal carbonic anhydrase (CA) activity, HCO3 (-) versus CO2 use were determined over a 7-day incubation at ambient pCO2 400 µatm/pH 8.00 and a future OA treatment of pCO2 1200 µatm/pH 7.59. Neither the photosynthetic nor growth rates were changed by elevated CO2 supply in the OA treatment. These results were explained by the greater use of HCO3 (-) compared to CO2 as an inorganic carbon (Ci) source to support photosynthesis. Macrocystis is a mixed HCO3 (-) and CO2 user that exhibits two effective mechanisms for HCO3 (-) utilization; as predicted for species that possess carbon-concentrating mechanisms (CCMs), photosynthesis was not substantially affected by elevated pCO2. The internal CA activity was also unaffected by OA, and it remained high and active throughout the experiment; this suggests that HCO3 (-) uptake via an anion exchange protein was not affected by OA. Our results suggest that photosynthetic Ci uptake and growth of Macrocystis will not be affected by elevated pCO2/low pH predicted for the future, but the combined effects with other environmental factors like temperature and nutrient availability could change the physiological response of Macrocystis to OA. Therefore, further studies will be important to elucidate how this species might respond to the global environmental change predicted for the ocean.
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Affiliation(s)
- Pamela A Fernández
- Department of Botany, University of Otago, PO box 56, Dunedin, 9054, New Zealand,
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47
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Apel AC, Weuster-Botz D. Engineering solutions for open microalgae mass cultivation and realistic indoor simulation of outdoor environments. Bioprocess Biosyst Eng 2015; 38:995-1008. [PMID: 25627468 DOI: 10.1007/s00449-015-1363-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/15/2015] [Indexed: 01/27/2023]
Abstract
Microalgae could become an important renewable source for chemicals, food, and energy if process costs can be reduced. In the past 60 years, relevant factors in open outdoor mass cultivation of microalgae were identified and elaborate solutions regarding bioprocesses and bioreactors were developed. An overview of these solutions is presented. Since the cost of most microalgal products from current mass cultivation systems is still prohibitively high, further development is required. The application of complex computational techniques for cost-effective process and reactor development will become more important if experimental validation of simulation results can easily be achieved. Due to difficulties inherent to outdoor experimentation, it can be useful to conduct validation experiments indoors. Considerations and approaches for realistic indoor reproduction of the most important environmental conditions in microalgae cultivation experiments-light, temperature, and substance concentrations, are discussed.
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Affiliation(s)
- Andreas Christoph Apel
- Lehrstuhl für Bioverfahrenstechnik, Technische Universität München, Boltzmannstr. 15, 85748, Garching, Germany,
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48
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Raven JA, Beardall J, Giordano M. Energy costs of carbon dioxide concentrating mechanisms in aquatic organisms. PHOTOSYNTHESIS RESEARCH 2014; 121:111-24. [PMID: 24390639 DOI: 10.1007/s11120-013-9962-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/18/2013] [Indexed: 05/19/2023]
Abstract
Minimum energy (as photon) costs are predicted for core reactions of photosynthesis, for photorespiratory metabolism in algae lacking CO2 concentrating mechanisms (CCMs) and for various types of CCMs; in algae, with CCMs; allowance was made for leakage of CO2 from the internal pool. These predicted values are just compatible with the minimum measured photon costs of photosynthesis in microalgae and macroalgae lacking or expressing CCMs. More energy-expensive photorespiration, for example for organisms using Rubiscos with lower CO2-O2 selectivity coefficients, would be less readily accommodated within the lowest measured photon costs of photosynthesis by algae lacking CCMs. The same applies to the cases of CCMs with higher energy costs of active transport of protons or inorganic carbon species, or greater allowance for significant leakage from the accumulated intracellular pool of CO2. High energetic efficiency can involve a higher concentration of catalyst to achieve a given rate of reaction, adding to the resource costs of growth. There are no obvious mechanistic interpretations of the occurrence of CCMs algae adapted to low light and low temperatures using the rationales adopted for the occurrence of C4 photosynthesis in terrestrial flowering plants. There is an exception for cyanobacteria with low-selectivity Form IA or IB Rubiscos, and those dinoflagellates with low-selectivity Form II Rubiscos, for which very few natural environments have high enough CO2:O2 ratios to allow photosynthesis in the absence of CCMs.
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Affiliation(s)
- John A Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, DD2 5DQ, UK,
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Kato A, Hikami M, Kumagai NH, Suzuki A, Nojiri Y, Sakai K. Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples. MARINE ENVIRONMENTAL RESEARCH 2014; 94:1-6. [PMID: 24239067 DOI: 10.1016/j.marenvres.2013.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/25/2013] [Accepted: 10/25/2013] [Indexed: 06/02/2023]
Abstract
We evaluated acidification effects on two crustose coralline algal species common to Pacific coral reefs, Lithophyllum kotschyanum and Hydrolithon samoense. We used genetically homogeneous samples of both species to eliminate misidentification of species. The growth rates and percent calcification of the walls of the epithallial cells (thallus surface cells) of both species decreased with increasing pCO₂. However, elevated pCO₂ more strongly inhibited the growth of L. kotschyanum versus H. samoense. The trend of decreasing percent calcification of the cell wall did not differ between these species, although intercellular calcification of the epithallial cells in L. kotschyanum was apparently reduced at elevated pCO₂, a result that might indicate that there are differences in the solubility or density of the calcite skeletons of these two species. These results can provide knowledge fundamental to future studies of the physiological and genetic mechanisms that underlie the response of crustose coralline algae to environmental stresses.
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Affiliation(s)
- Aki Kato
- Takehara Marine Science Station, Setouchi Field Science Center, Hiroshima University, Minato-machi, Takehara, Hiroshima 725-0024, Japan.
| | - Mana Hikami
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Naoki H Kumagai
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Atsushi Suzuki
- Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8567, Japan
| | - Yukihiro Nojiri
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan
| | - Kazuhiko Sakai
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa 905-0227, Japan
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50
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Bender D, Diaz-Pulido G, Dove S. The impact of CO2 emission scenarios and nutrient enrichment on a common coral reef macroalga is modified by temporal effects. JOURNAL OF PHYCOLOGY 2014; 50:203-215. [PMID: 26988019 DOI: 10.1111/jpy.12153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 10/10/2013] [Indexed: 06/05/2023]
Abstract
Future coral reefs are expected to be subject to higher pCO2 and temperature due to anthropogenic greenhouse gas emissions. Such global stressors are often paired with local stressors thereby potentially modifying the response of organisms. Benthic macroalgae are strong competitors to corals and are assumed to do well under future conditions. The present study aimed to assess the impact of past and future CO2 emission scenarios as well as nutrient enrichment on the growth, productivity, pigment, and tissue nutrient content of the common tropical brown alga Chnoospora implexa. Two experiments were conducted to assess the differential impacts of the manipulated conditions in winter and spring. Chnoospora implexa's growth rate averaged over winter and spring declined with increasing pCO2 and temperature. Furthermore, nutrient enrichment did not affect growth. Highest growth was observed under spring pre-industrial (PI) conditions, while slightly reduced growth was observed under winter A1FI ("business-as-usual") scenarios. Productivity was not a good proxy for growth, as net O2 flux increased under A1FI conditions. Nutrient enrichment, whilst not affecting growth, led to luxury nutrient uptake that was greater in winter than in spring. The findings suggest that in contrast with previous work, C. implexa is not likely to show enhanced growth under future conditions in isolation or in conjunction with nutrient enrichment. Instead, the results suggest that greatest growth rates for this species appear to be a feature of the PI past, with A1FI winter conditions leading to potential decreases in the abundance of this species from present day levels.
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Affiliation(s)
- Dorothea Bender
- School of Biological Sciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia
- ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, Queensland, 4072, Australia
| | - Guillermo Diaz-Pulido
- Griffith School of Environment & Australian Rivers Institute, Griffith University, Nathan, Queensland, 4111, Australia
| | - Sophie Dove
- School of Biological Sciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia
- ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St. Lucia, Queensland, 4072, Australia
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