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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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Quintano E, Celis-Plá PSM, Martínez B, Díez I, Muguerza N, Figueroa FL, Gorostiaga JM. Ecophysiological responses of a threatened red alga to increased irradiance in an in situ transplant experiment. MARINE ENVIRONMENTAL RESEARCH 2019; 144:166-177. [PMID: 30683559 DOI: 10.1016/j.marenvres.2019.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/12/2018] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
The red alga Gelidium corneum is a dominant foundation species in the south-eastern Bay of Biscay, where a decline in its populations has been documented in the few last decades. We investigated the ecophysiological responses of G. corneum to different light conditions by means of an in situ transplant experiment. We found that the stress response measured by physiological and biochemical approaches was higher in G. corneum at higher irradiance levels, for both transplanted and control specimens, than under lower light intensities. In the former case the specimens showed a decrease in maximum quantum yield (Fv/Fm), maximum electron transport rate (ETRmax), photosynthetic efficiency (αETR), photosynthetic pigment contents, nitrogen content and thallus length, whereas the C:N ratio, MAAs and bleaching cover increased. In general terms, these responses were more evident in the apical parts of the thallus than in middle ones. Our results suggest that high light stress at depths of 3 m triggered photobiological changes in G. corneum, involving ineffective photoprotection and the occurrence of chronic photoinhibition. Therefore, considering the upward trend in summer mean surface solar radiation in the study area since the 80s, high light conditions may have played a role in the declines observed in G. corneum beds from the south-eastern Bay of Biscay.
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Affiliation(s)
- Endika Quintano
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain.
| | - Paula S M Celis-Plá
- Laboratory of Coastal Environmental Research, Centre of Advanced Studies, University of Playa Ancha, Calle Traslaviña 450, 2581782, Viña del Mar, Chile
| | - Brezo Martínez
- Department of Ecology, Faculty of Sciences, University of Málaga, 29071, Málaga, Spain
| | - Isabel Díez
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
| | - Nahiara Muguerza
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
| | - Félix L Figueroa
- Biodiversity and Conservation Unit, Rey Juan Carlos University, 28933, Móstoles, Spain
| | - José M Gorostiaga
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), PO Box 644, 48080, Bilbao, Spain
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Cruz JA, Savage LJ, Zegarac R, Hall CC, Satoh-Cruz M, Davis GA, Kovac WK, Chen J, Kramer DM. Dynamic Environmental Photosynthetic Imaging Reveals Emergent Phenotypes. Cell Syst 2018; 2:365-77. [PMID: 27336966 DOI: 10.1016/j.cels.2016.06.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/29/2016] [Accepted: 06/01/2016] [Indexed: 10/21/2022]
Abstract
Understanding and improving the productivity and robustness of plant photosynthesis requires high-throughput phenotyping under environmental conditions that are relevant to the field. Here we demonstrate the dynamic environmental photosynthesis imager (DEPI), an experimental platform for integrated, continuous, and high-throughput measurements of photosynthetic parameters during plant growth under reproducible yet dynamic environmental conditions. Using parallel imagers obviates the need to move plants or sensors, reducing artifacts and allowing simultaneous measurement on large numbers of plants. As a result, DEPI can reveal phenotypes that are not evident under standard laboratory conditions but emerge under progressively more dynamic illumination. We show examples in mutants of Arabidopsis of such "emergent phenotypes" that are highly transient and heterogeneous, appearing in different leaves under different conditions and depending in complex ways on both environmental conditions and plant developmental age. These emergent phenotypes appear to be caused by a range of phenomena, suggesting that such previously unseen processes are critical for plant responses to dynamic environments.
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Affiliation(s)
- Jeffrey A Cruz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Linda J Savage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Robert Zegarac
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Christopher C Hall
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Mio Satoh-Cruz
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Geoffry A Davis
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Cell and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - William Kent Kovac
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Jin Chen
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Computer Science and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
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54
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Levasseur W, Taidi B, Lacombe R, Perré P, Pozzobon V. Impact of seconds to minutes photoperiods on Chlorella vulgaris growth rate and chlorophyll a and b content. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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55
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Long M, Tallec K, Soudant P, Le Grand F, Donval A, Lambert C, Sarthou G, Jolley DF, Hégaret H. Allelochemicals from Alexandrium minutum induce rapid inhibition of metabolism and modify the membranes from Chaetoceros muelleri. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.09.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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56
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Livshits MY, Razgoniaev AO, Arbulu RC, Shin J, McCullough BJ, Qin Y, Ostrowski AD, Rack JJ. Generating Photonastic Work from Irradiated Dyes in Electrospun Nanofibrous Polymer Mats. ACS APPLIED MATERIALS & INTERFACES 2018; 10:37470-37477. [PMID: 30272433 DOI: 10.1021/acsami.8b11294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
For solar-driven macroscopic motions, we assert that there is a local heating that facilitates large-scale deformations in anisotropic morphologic materials caused by thermal gradients. This report specifically identifies the fate of heat generation in photonastic materials and demonstrates how heat can perform work following excitation of a nonisomerizing dye. Utilizing the electrospinning technique, we have created a series of anisotropic nanofibrous polymer mats that comprise nonisomerizing dyes. Polymers are chosen because of their relative glass transition temperatures, elastic moduli, and melting temperatures. Light irradiation of these polymer mats with an excitation wavelength matching the absorption characteristics of the dye leads to macroscopic deformation of the mat. Analysis of still images extracted from digital videos provides plots of angular displacement vs power. The data were analyzed in terms of a photothermal model. Analyses of scanning electron microscopy micrographs for all samples are consistent to local melting in low Tg polymers and softening in high Tg polymers. Dynamic mechanical analysis allowed for quantification of the modulus change under a given light fluence. We employ these data to calculate a energy conversion efficiency. These efficiencies for the polymer mats are compared to other nonmuscular systems, including a few natural, biological samples.
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Affiliation(s)
- Maksim Y Livshits
- Department of Chemistry and Chemical Biology , The University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Department of Chemistry and Biochemistry , Ohio University , Athens , Ohio 45701 , United States
| | - Anton O Razgoniaev
- Department of Chemistry, Center for Photochemical Sciences , Bowling Green State University , Bowling Green , Ohio 43403 , United States
| | - Roberto C Arbulu
- Department of Chemistry and Chemical Biology , The University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Jisoo Shin
- Department of Chemistry and Chemical Biology , The University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Brad J McCullough
- Department of Chemistry and Biochemistry , Ohio University , Athens , Ohio 45701 , United States
| | - Yang Qin
- Department of Chemistry and Chemical Biology , The University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Alexis D Ostrowski
- Department of Chemistry, Center for Photochemical Sciences , Bowling Green State University , Bowling Green , Ohio 43403 , United States
| | - Jeffrey J Rack
- Department of Chemistry and Chemical Biology , The University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Department of Chemistry and Biochemistry , Ohio University , Athens , Ohio 45701 , United States
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57
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The evolution of the photoprotective antenna proteins in oxygenic photosynthetic eukaryotes. Biochem Soc Trans 2018; 46:1263-1277. [DOI: 10.1042/bst20170304] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 12/24/2022]
Abstract
Photosynthetic organisms require rapid and reversible down-regulation of light harvesting to avoid photodamage. Response to unpredictable light fluctuations is achieved by inducing energy-dependent quenching, qE, which is the major component of the process known as non-photochemical quenching (NPQ) of chlorophyll fluorescence. qE is controlled by the operation of the xanthophyll cycle and accumulation of specific types of proteins, upon thylakoid lumen acidification. The protein cofactors so far identified to modulate qE in photosynthetic eukaryotes are the photosystem II subunit S (PsbS) and light-harvesting complex stress-related (LHCSR/LHCX) proteins. A transition from LHCSR- to PsbS-dependent qE took place during the evolution of the Viridiplantae (also known as ‘green lineage’ organisms), such as green algae, mosses and vascular plants. Multiple studies showed that LHCSR and PsbS proteins have distinct functions in the mechanism of qE. LHCX(-like) proteins are closely related to LHCSR proteins and found in ‘red lineage’ organisms that contain secondary red plastids, such as diatoms. Although LHCX proteins appear to control qE in diatoms, their role in the mechanism remains poorly understood. Here, we present the current knowledge on the functions and evolution of these crucial proteins, which evolved in photosynthetic eukaryotes to optimise light harvesting.
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58
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Caplin N, Willey N. Ionizing Radiation, Higher Plants, and Radioprotection: From Acute High Doses to Chronic Low Doses. FRONTIERS IN PLANT SCIENCE 2018; 9:847. [PMID: 29997637 PMCID: PMC6028737 DOI: 10.3389/fpls.2018.00847] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/31/2018] [Indexed: 05/09/2023]
Abstract
Understanding the effects of ionizing radiation (IR) on plants is important for environmental protection, for agriculture and horticulture, and for space science but plants have significant biological differences to the animals from which much relevant knowledge is derived. The effects of IR on plants are understood best at acute high doses because there have been; (a) controlled experiments in the field using point sources, (b) field studies in the immediate aftermath of nuclear accidents, and (c) controlled laboratory experiments. A compilation of studies of the effects of IR on plants reveals that although there are numerous field studies of the effects of chronic low doses on plants, there are few controlled experiments that used chronic low doses. Using the Bradford-Hill criteria widely used in epidemiological studies we suggest that a new phase of chronic low-level radiation research on plants is desirable if its effects are to be properly elucidated. We emphasize the plant biological contexts that should direct such research. We review previously reported effects from the molecular to community level and, using a plant stress biology context, discuss a variety of acute high- and chronic low-dose data against Derived Consideration Reference Levels (DCRLs) used for environmental protection. We suggest that chronic low-level IR can sometimes have effects at the molecular and cytogenetic level at DCRL dose rates (and perhaps below) but that there are unlikely to be environmentally significant effects at higher levels of biological organization. We conclude that, although current data meets only some of the Bradford-Hill criteria, current DCRLs for plants are very likely to be appropriate at biological scales relevant to environmental protection (and for which they were intended) but that research designed with an appropriate biological context and with more of the Bradford-Hill criteria in mind would strengthen this assertion. We note that the effects of IR have been investigated on only a small proportion of plant species and that research with a wider range of species might improve not only the understanding of the biological effects of radiation but also that of the response of plants to environmental stress.
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Affiliation(s)
| | - Neil Willey
- Centre for Research in Biosciences, University of the West of England, Bristol, Bristol, United Kingdom
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59
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Robakowski P, Pers-Kamczyc E, Ratajczak E, Thomas PA, Ye ZP, Rabska M, Iszkuło G. Photochemistry and Antioxidative Capacity of Female and Male Taxus baccata L. Acclimated to Different Nutritional Environments. FRONTIERS IN PLANT SCIENCE 2018; 9:742. [PMID: 29922316 PMCID: PMC5996056 DOI: 10.3389/fpls.2018.00742] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/15/2018] [Indexed: 06/08/2023]
Abstract
In dioecious woody plants, females often make a greater reproductive effort than male individuals at the cost of lower growth rate. We hypothesized that a greater reproductive effort of female compared with male Taxus baccata individuals would be associated with lower female photochemical capacity and higher activity of antioxidant enzymes. Differences between the genders would change seasonally and would be more remarkable under nutrient deficiency. Electron transport rate (ETRmax), saturation photosynthetic photon flux corresponding to maximum electron transport rate (PPFsat), quantum yield of PSII photochemistry at PPFsat (ΦPPFsat), and chlorophyll a fluorescence and activity of antioxidant enzymes were determined in needles of T. baccata female and male individuals growing in the experiment with or without fertilization. The effects of seasonal changes and fertilization treatment on photochemical parameters, photosynthetic pigments concentration, and antioxidant enzymes were more pronounced than the effects of between-sexes differences in reproductive efforts. Results showed that photosynthetic capacity expressed as ETRmax and ΦPPFsat and photosynthetic pigments concentrations decreased and non-photochemical quenching of fluorescence (NPQ) increased under nutrient deficiency. Fertilized individuals were less sensitive to photoinhibition than non-fertilized ones. T. baccata female and male individuals did not differ in photochemical capacity, but females showed higher maximum quantum yield of PSII photochemistry (Fv/Fm) than males. The activity of guaiacol peroxidase (POX) was also higher in female than in male needles. We concluded that larger T. baccata female reproductive effort compared with males was not at the cost of photochemical capacity, but to some extent it could be due to between-sexes differences in ability to protect the photosynthetic apparatus against photoinhibition with antioxidants.
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Affiliation(s)
- Piotr Robakowski
- Department of Forestry, Poznan University of Life Sciences, Poznań, Poland
| | | | | | - Peter A. Thomas
- School of Life Sciences, Keele University, Keele, United Kingdom
| | - Zi-Piao Ye
- College of Maths & Physics, Jinggangshan University, Ji'an, China
| | - Mariola Rabska
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Grzegorz Iszkuło
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
- Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra, Poland
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60
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Liu T, Ren T, White PJ, Cong R, Lu J. Storage nitrogen co-ordinates leaf expansion and photosynthetic capacity in winter oilseed rape. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2995-3007. [PMID: 29669007 PMCID: PMC5972566 DOI: 10.1093/jxb/ery134] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/06/2018] [Indexed: 05/20/2023]
Abstract
Storage nitrogen (N) is a buffer pool for maintaining leaf growth and synthesizing photosynthetic proteins, but the dynamics of its forms within the life cycle of a single leaf and how it is influenced by N supply remain poorly understood. A field experiment was conducted to estimate the influence of N supply on leaf growth, photosynthetic characteristics, and N partitioning inthe sixth leaf of winter oilseed rape (Brassica napus L.) from emergence through senescence. Storage N content (Nstore) decreased gradually along with leaf expansion. The relative growth rate based on leaf area (RGRa) was positively correlated with Nstore during leaf expansion. The water-soluble protein form of storage N was the main N source for leaf expansion. After the leaves fully expanded, the net photosynthetic rate (An) followed a linear-plateau response to Nstore, with An stabilizing at the highest value above a threshold and declining below the threshold. Non-protein and SDS (detergent)-soluble protein forms of storage N were the main N sources for maintaining photosynthesis. For the leaf N economy, storage N is used for co-ordinating leaf expansion and photosynthetic capacity. N supply can improve Nstore, thereby promoting leaf growth and biomass.
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Affiliation(s)
- Tao Liu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
| | - Tao Ren
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
| | | | - Rihuan Cong
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
| | - Jianwei Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
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61
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Cardona T, Shao S, Nixon PJ. Enhancing photosynthesis in plants: the light reactions. Essays Biochem 2018; 62:85-94. [PMID: 29563222 PMCID: PMC5897789 DOI: 10.1042/ebc20170015] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 01/23/2018] [Accepted: 01/29/2018] [Indexed: 12/20/2022]
Abstract
In this review, we highlight recent research and current ideas on how to improve the efficiency of the light reactions of photosynthesis in crops. We note that the efficiency of photosynthesis is a balance between how much energy is used for growth and the energy wasted or spent protecting the photosynthetic machinery from photodamage. There are reasons to be optimistic about enhancing photosynthetic efficiency, but many appealing ideas are still on the drawing board. It is envisioned that the crops of the future will be extensively genetically modified to tailor them to specific natural or artificial environmental conditions.
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Affiliation(s)
- Tanai Cardona
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Shengxi Shao
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Peter J Nixon
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
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62
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Davis GA, Rutherford AW, Kramer DM. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δ ψ and ΔpH. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0381. [PMID: 28808100 DOI: 10.1098/rstb.2016.0381] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching (qE), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δψ) induce photosystem II recombination reactions that produce damaging singlet oxygen (1O2). Both qE and FRIP are directly linked to the thylakoid proton motive force (pmf), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δψ and formation of ΔpH. This would result in increased rates for the formation and decay of qE while resulting in a more rapid decline in the amplitudes of Δψ-spikes and decreasing 1O2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo, while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis researchers to further explore and test specific hypotheses.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | | | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA .,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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63
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Identifying a marine microalgae with high carbohydrate productivities under stress and potential for efficient flocculation. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.02.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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64
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Hubbart S, Smillie IRA, Heatley M, Swarup R, Foo CC, Zhao L, Murchie EH. Enhanced thylakoid photoprotection can increase yield and canopy radiation use efficiency in rice. Commun Biol 2018; 1:22. [PMID: 30271909 PMCID: PMC6123638 DOI: 10.1038/s42003-018-0026-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/01/2018] [Indexed: 11/09/2022] Open
Abstract
High sunlight can raise plant growth rates but can potentially cause cellular damage. The likelihood of deleterious effects is lowered by a sophisticated set of photoprotective mechanisms, one of the most important being the controlled dissipation of energy from chlorophyll within photosystem II (PSII) measured as non-photochemical quenching (NPQ). Although ubiquitous, the role of NPQ in plant productivity remains uncertain because it momentarily reduces the quantum efficiency of photosynthesis. Here we used plants overexpressing the gene encoding a central regulator of NPQ, the protein PsbS, within a major crop species (rice) to assess the effect of photoprotection at the whole canopy scale. We accounted for canopy light interception, to our knowledge for the first time in this context. We show that in comparison to wild-type plants, psbS overexpressors increased canopy radiation use efficiency and grain yield in fluctuating light, demonstrating that photoprotective mechanisms should be altered to improve rice crop productivity.
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Affiliation(s)
- Stella Hubbart
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Ian R A Smillie
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Matthew Heatley
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Ranjan Swarup
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Chuan Ching Foo
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Liang Zhao
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Erik H Murchie
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK.
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65
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Adams MA, Buckley TN, Salter WT, Buchmann N, Blessing CH, Turnbull TL. Contrasting responses of crop legumes and cereals to nitrogen availability. THE NEW PHYTOLOGIST 2018; 217:1475-1483. [PMID: 29178286 DOI: 10.1111/nph.14918] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 10/21/2017] [Indexed: 06/07/2023]
Abstract
In nonagricultural systems, the relationship between intrinsic water-use efficiency (WUEi ) and leaf nitrogen (Narea ) is known to be stronger for legumes than for nonlegumes. We tested whether these relationships are retained for major agricultural legumes and nonlegumes. We compared the response to N nutrition of WUEi (and its component parts, photosynthesis (Asat ) and stomatal conductance (gs )) for legumes Cicer arietinum, Glycine max, Lupinus alba and Vicia faba, nonlegume dicots Brassica napus and Helianthus annus, and nonlegume cereals Hordeum vulgare and Triticum aestivum. Surprisingly, and in contrast to studied cereals and nonlegume dicots, Narea was positively related to photosynthesis in the legumes, explaining nearly half of the variance in Asat . WUEi was tightly coupled to Narea for agricultural legumes and nonlegume dicots, but not for cereal crops. Our analysis suggests that breeding efforts to reduce gs in legumes could increase WUEi by 120-218% while maintaining Asat at nonlegume values. Physiologically informed breeding of legumes can enhance sustainable agriculture by reducing requirements for water and N.
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Affiliation(s)
- Mark A Adams
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University, PO Box 218, Hawthorn, Vic, 3122, Australia
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA
| | - William T Salter
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, 380 Werombi Rd, Camden, NSW, 2570, Australia
| | - Nina Buchmann
- ETH Zurich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Carola H Blessing
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, 380 Werombi Rd, Camden, NSW, 2570, Australia
| | - Tarryn L Turnbull
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, 380 Werombi Rd, Camden, NSW, 2570, Australia
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Murata N, Nishiyama Y. ATP is a driving force in the repair of photosystem II during photoinhibition. PLANT, CELL & ENVIRONMENT 2018; 41:285-299. [PMID: 29210214 DOI: 10.1111/pce.13108] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 05/15/2023]
Abstract
Repair of photosystem II (PSII) during photoinhibition involves replacement of photodamaged D1 protein by newly synthesized D1 protein. In this review, we summarize evidence for the indispensability of ATP in the degradation and synthesis of D1 during the repair of PSII. Synthesis of one molecule of the D1 protein consumes more than 1,300 molecules of ATP equivalents. The degradation of photodamaged D1 by FtsH protease also consumes approximately 240 molecules of ATP. In addition, ATP is required for several other aspects of the repair of PSII, such as transcription of psbA genes. These requirements for ATP during the repair of PSII have been demonstrated by experiments showing that the synthesis of D1 and the repair of PSII are interrupted by inhibitors of ATP synthase and uncouplers of ATP synthesis, as well as by mutation of components of ATP synthase. We discuss the contribution of cyclic electron transport around photosystem I to the repair of PSII. Furthermore, we introduce new terms relevant to the regulation of the PSII repair, namely, "ATP-dependent regulation" and "redox-dependent regulation," and we discuss the possible contribution of the ATP-dependent regulation of PSII repair under environmental stress.
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Affiliation(s)
- Norio Murata
- National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
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Marchin RM, Turnbull TL, Deheinzelin AI, Adams MA. Does triacylglycerol (TAG) serve a photoprotective function in plant leaves? An examination of leaf lipids under shading and drought. PHYSIOLOGIA PLANTARUM 2017; 161:400-413. [PMID: 28664534 PMCID: PMC5877405 DOI: 10.1111/ppl.12601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 06/20/2017] [Indexed: 05/22/2023]
Abstract
Plant survival in many ecosystems requires tolerance of large radiation loads, unreliable water supply and suboptimal soil fertility. We hypothesized that increased production of neutral lipids (triacylglycerols, TAGs) in plant leaves is a mechanism for dissipating excess radiation energy. In a greenhouse experiment, we combined drought and shade treatments and examined responses among four species differing in life form, habitat, and drought- and shade-tolerance. We also present a lipid extraction protocol suitable for sclerophyllous leaves of native Australian trees (e.g. Acacia, Eucalyptus). Fluorescence measurements indicated that plants exposed to full sunlight experienced mild photoinhibition during our experiment. Accumulation of TAGs did not follow photosynthetic capacity, but instead, TAG concentration increased with non-photochemical quenching. This suggests that plants under oxidative stress may increase biosynthesis of TAGs. Moderate drought stress resulted in a 60% reduction in TAG concentration in wheat (Triticum aestivum). Shading had no effect on TAGs, but increased concentrations of polar lipids in leaves; for example, acclimation to shade in Austrodanthonia spp., a native Australian grass, resulted in a 60% increase in associated polar lipids and higher foliar chlorophyll concentrations. Shading also reduced the digalactosyldiacylglycerol:monogalactosyldiacylglycerol (DGDG:MGDG) ratio in leaves, with a corresponding increase in the degree of unsaturation and thus fluidity of thylakoid membranes of chloroplasts. Our results suggest that prevention of photodamage may be coordinated with accumulation of TAGs, although further research is required to determine if TAGs serve a photoprotective function in plant leaves.
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Affiliation(s)
- Renée M. Marchin
- Centre for Carbon, Water and Food, University of Sydney, Camden, NSW, 2570, Australia
| | - Tarryn L. Turnbull
- Centre for Carbon, Water and Food, University of Sydney, Camden, NSW, 2570, Australia
| | - Audrey I. Deheinzelin
- Centre for Carbon, Water and Food, University of Sydney, Camden, NSW, 2570, Australia
| | - Mark A. Adams
- Centre for Carbon, Water and Food, University of Sydney, Camden, NSW, 2570, Australia
- I.A. Watson Grains Research Centre, University of Sydney, Narrabri, NSW, 2390, Australia
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Mayers JJ, Ekman Nilsson A, Albers E, Flynn KJ. Nutrients from anaerobic digestion effluents for cultivation of the microalga Nannochloropsis sp. — Impact on growth, biochemical composition and the potential for cost and environmental impact savings. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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69
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Ramírez-Valiente JA, Cavender-Bares J. Evolutionary trade-offs between drought resistance mechanisms across a precipitation gradient in a seasonally dry tropical oak (Quercus oleoides). TREE PHYSIOLOGY 2017; 37:889-901. [PMID: 28419347 DOI: 10.1093/treephys/tpx040] [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] [Received: 10/14/2016] [Accepted: 03/29/2017] [Indexed: 05/07/2023]
Abstract
In seasonally dry tropical forest regions, drought avoidance during the dry season coupled with high assimilation rates in the wet season is hypothesized to be an advantageous strategy for forest trees in regions with severe and long dry seasons. In contrast, where dry seasons are milder, drought tolerance coupled with a conservative resource-use strategy is expected to maximize carbon assimilation throughout the year. Tests of this hypothesis, particularly at the intraspecific level, have been seldom conducted. In this study, we tested the extent to which drought resistance mechanisms and rates of carbon assimilation have evolved under climates with varying dry season length and severity within Quercus oleoidesCham. and Schlect., a tropical dry forest species that is widely distributed in Central America. For this purpose, we conducted a greenhouse experiment where seedlings originating from five populations that vary in rainfall patterns were grown under different watering treatments. Our results revealed that populations from xeric climates with more severe dry seasons exhibited large mesophyllous leaves (with high specific leaf area, SLA), and leaf abscission in response to drought, consistent with a drought-avoidance strategy. In contrast, populations from more mesic climates with less severe dry seasons had small and thick sclerophyllous leaves with low SLA and reduced water potential at the turgor loss point (πtlp), consistent with a drought-tolerance strategy. Mesic populations also showed high plasticity in πtlp in response to water availability, indicating that osmotic adjustment to drought is an important component of this strategy. However, populations with mesophyllous leaves did not have higher maximum carbon assimilation rates under well-watered conditions. Furthermore, SLA was negatively associated with mass-based photosynthetic rates, contrary to expectations of the leaf economics spectrum, indicating that drought-resistance strategies are not necessarily tightly coupled with resource-use strategies. Overall, our study demonstrates the importance of considering intraspecific variation in analyses of the vulnerability of tropical trees to climate change.
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Affiliation(s)
- Jose A Ramírez-Valiente
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Avenue, Saint Paul, MN 55108, USA
- Department of Integrative Ecology, Doñana Biological Station (EBD-CSIC), Avda Americo Vespucio s/n, 41092 Seville, Spain
| | - Jeannine Cavender-Bares
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Avenue, Saint Paul, MN 55108, USA
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Cantrell M, Peers G. A mutant of Chlamydomonas without LHCSR maintains high rates of photosynthesis, but has reduced cell division rates in sinusoidal light conditions. PLoS One 2017. [PMID: 28644828 PMCID: PMC5482440 DOI: 10.1371/journal.pone.0179395] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment. We found that a mutant of Chlamydomonas reinhardtii lacking LHCSR, npq4lhcsr1, displays minimal photoinhibition of photosystem II and minimal inhibition of short term oxygen evolution when grown in constant excess light compared to a wild type strain. We also investigated the impact of no LHCSR during growth in a sinusoidal light regime, which mimics daily changes in photosynthetically active radiation. The absence of LHCSR correlated with a slight reduction in the quantum efficiency of photosystem II and a stimulation of the maximal rates of photosynthesis compared to wild type. However, there was no reduction in carbon accumulation during the day. Another novel finding was that npq4lhcsr1 cultures underwent fewer divisions at night, reducing the overall growth rate compared to the wild type. Our results show that the rapid regulation of light harvesting mediated by LHCSR is required for high growth rates, but it is not required for efficient carbon accumulation during the day in a sinusoidal light environment. This finding has direct implications for engineering strategies directed at increasing photosynthetic productivity in mass cultures.
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Affiliation(s)
- Michael Cantrell
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
- * E-mail:
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71
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Stoichiometric Network Analysis of Cyanobacterial Acclimation to Photosynthesis-Associated Stresses Identifies Heterotrophic Niches. Processes (Basel) 2017. [DOI: 10.3390/pr5020032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Fenollosa E, Munné-Bosch S, Pintó-Marijuan M. Contrasting phenotypic plasticity in the photoprotective strategies of the invasive species Carpobrotus edulis and the coexisting native species Crithmum maritimum. PHYSIOLOGIA PLANTARUM 2017; 160:185-200. [PMID: 28058723 DOI: 10.1111/ppl.12542] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/17/2016] [Accepted: 01/03/2017] [Indexed: 06/06/2023]
Abstract
Photoprotective strategies vary greatly within the plant kingdom and reflect a plant's physiological status and capacity to cope with environment variations. The plasticity and intensity of these responses may determine plant success. Invasive species are reported to show increased vigor to displace native species. Describing the mechanisms that confer such vigor is essential to understanding the success of invasive species. We performed an experiment whereby two species were monitored: Carpobrotus edulis, an aggressive invasive species in the Mediterranean basin, and Crithmum maritimum, a coexisting native species in the Cap de Creus Natural Park (NE Spain). We analyzed their photoprotective responses to seasonal environmental dynamics by comparing the capacity of the invader to respond to the local environmental stresses throughout the year. Our study analyses ecophysiological markers and photoprotective strategies to gain an insight into the success of invaders. We found that both species showed completely different but effective photoprotective strategies: in summer, C. edulis took special advantage of the xanthophyll cycle, whereas the success of C. maritimum in summer stemmed from morphological changes and alterations on β-carotene content. Winter also presented differences between the species, as the native showed reduced Fv /Fm ratios. Our experimental design allowed us to introduce a new approach to compare phenotypic plasticity: the integrated phenotypic plasticity index (PPint ), defined as the maximum Euclidian distance between phenotypes, using a combination of different variables to describe them. This index revealed significantly greater phenotypic plasticity in the invasive species compared to the native species.
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Affiliation(s)
- Erola Fenollosa
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Marta Pintó-Marijuan
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
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Araniti F, Scognamiglio M, Chambery A, Russo R, Esposito A, D'Abrosca B, Fiorentino A, Lupini A, Sunseri F, Abenavoli MR. Highlighting the effects of coumarin on adult plants of Arabidopsis thaliana (L.) Heynh. by an integrated -omic approach. JOURNAL OF PLANT PHYSIOLOGY 2017; 213:30-41. [PMID: 28315793 DOI: 10.1016/j.jplph.2017.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/22/2017] [Accepted: 02/22/2017] [Indexed: 05/22/2023]
Abstract
In this study, the effects of the allelochemical coumarin through a metabolomic, proteomic and morpho-physiological approach in Arabidopsis adult plants (25days old) were investigated. Metabolomic analysis evidenced an increment of amino acids and a high accumulation of soluble sugars, after 6days of coumarin treatment. This effect was accompanied by a strong decrease on plant fresh and dry weights, as well as on total protein content. On the contrary, coumarin did not affect leaf number but caused a reduction in leaf area. An alteration of water status was confirmed by a reduction of relative water content and an increase in leaf osmotic potential. Moreover, coumarin impaired plant bio-membranes through an increase of lipid peroxidation and H2O2 content suggesting that coumarin treatment might induce oxidative stress. Coumarin reduced the effective quantum yield of the photosystem II, the energy dissipation in the form of heat, the maximum PSII efficiency, the coefficient of the photochemical quenching and the estimated electron transport rate, while it significantly stimulated the fluorescence emission and the coefficient of the non photochemical quenching. Finally, the proteomic characterization of coumarin-treated plants revealed a down-regulation of the ROS detoxifying proteins, responsible of oxidative damage and consequently of physiological cascade effects.
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Affiliation(s)
- Fabrizio Araniti
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy.
| | - Monica Scognamiglio
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Angela Chambery
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Rosita Russo
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Assunta Esposito
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Brigida D'Abrosca
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Antonio Fiorentino
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Antonio Lupini
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Francesco Sunseri
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy
| | - Maria Rosa Abenavoli
- Department of AGRARIA, University Mediterranea of Reggio Calabria, Località Feo di Vito, I-89122 Reggio Calabria, RC, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, via Vivaldi 43, I-81100 Caserta, Italy.
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Trimborn S, Thoms S, Brenneis T, Heiden JP, Beszteri S, Bischof K. Two Southern Ocean diatoms are more sensitive to ocean acidification and changes in irradiance than the prymnesiophyte Phaeocystis antarctica. PHYSIOLOGIA PLANTARUM 2017; 160:155-170. [PMID: 28019019 DOI: 10.1111/ppl.12539] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/24/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
To better understand the impact of ocean acidification (OA) and changes in light availability on Southern Ocean phytoplankton physiology, we investigated the effects of pCO2 (380 and 800 µatm) in combination with low and high irradiance (20 or 50 and 200 µmol photons m-2 s-1 ) on growth, particulate organic carbon (POC) fixation and photophysiology in the three ecologically relevant species Chaetoceros debilis, Fragilariopsis kerguelensis and Phaeocystis antarctica. Irrespective of the light scenario, neither growth nor POC per cell was stimulated by OA in any of the tested species and the two diatoms even displayed negative responses in growth (e.g. C. debilis) or POC content (e.g. F. kerguelensis) under OA in conjunction with high light. For both diatoms, also maximum quantum yields of photosystem II (Fv /Fm ) were decreased under these conditions, indicating lowered photochemical efficiencies. To counteract the negative effects by OA and high light, the two diatoms showed diverging photoacclimation strategies. While cellular chlorophyll a (Chl a) and fucoxanthin contents were enhanced in C. debilis to potentially maximize light absorption, F. kerguelensis exhibited reduced Chl a per cell, increased disconnection of antennae from photosystem II reaction centers and strongly lowered absolute electron transport rates (ETR). The decline in ETRs in F. kerguelensis might be explained in terms of different species-specific strategies for tuning the available flux of adenosine triphosphate and nicotinamide adenine dinucleotide phosphate. Overall, our results revealed that P. antarctica was more tolerant to OA and changes in irradiance than the two diatoms, which may have important implications for biogeochemical cycling.
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Affiliation(s)
- Scarlett Trimborn
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Silke Thoms
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Tina Brenneis
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Jasmin P Heiden
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
- Marine Botany, University of Bremen, Bremen, Germany
| | - Sara Beszteri
- Department of Biogeosciences, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27515, Germany
| | - Kai Bischof
- Marine Botany, University of Bremen, Bremen, Germany
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Indirect Interspecies Regulation: Transcriptional and Physiological Responses of a Cyanobacterium to Heterotrophic Partnership. mSystems 2017; 2:mSystems00181-16. [PMID: 28289730 PMCID: PMC5340862 DOI: 10.1128/msystems.00181-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/30/2017] [Indexed: 02/06/2023] Open
Abstract
This study elucidates how a cyanobacterial primary producer acclimates to heterotrophic partnership by modulating the expression levels of key metabolic genes. Heterotrophic bacteria can indirectly regulate the physiology of the photoautotrophic primary producers, resulting in physiological changes identified here, such as increased intracellular ROS. Some of the interactions inferred from this model system represent putative principles of metabolic coupling in phototrophic-heterotrophic partnerships. The mechanisms by which microbes interact in communities remain poorly understood. Here, we interrogated specific interactions between photoautotrophic and heterotrophic members of a model consortium to infer mechanisms that mediate metabolic coupling and acclimation to partnership. This binary consortium was composed of a cyanobacterium, Thermosynechococcus elongatus BP-1, which supported growth of an obligate aerobic heterotroph, Meiothermus ruber strain A, by providing organic carbon, O2, and reduced nitrogen. Species-resolved transcriptomic analyses were used in combination with growth and photosynthesis kinetics to infer interactions and the environmental context under which they occur. We found that the efficiency of biomass production and resistance to stress induced by high levels of dissolved O2 increased, beyond axenic performance, as a result of heterotrophic partnership. Coordinated transcriptional responses transcending both species were observed and used to infer specific interactions resulting from the synthesis and exchange of resources. The cyanobacterium responded to heterotrophic partnership by altering expression of core genes involved with photosynthesis, carbon uptake/fixation, vitamin synthesis, and scavenging of reactive oxygen species (ROS). IMPORTANCE This study elucidates how a cyanobacterial primary producer acclimates to heterotrophic partnership by modulating the expression levels of key metabolic genes. Heterotrophic bacteria can indirectly regulate the physiology of the photoautotrophic primary producers, resulting in physiological changes identified here, such as increased intracellular ROS. Some of the interactions inferred from this model system represent putative principles of metabolic coupling in phototrophic-heterotrophic partnerships.
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Ni G, Zimbalatti G, Murphy CD, Barnett AB, Arsenault CM, Li G, Cockshutt AM, Campbell DA. Arctic Micromonas uses protein pools and non-photochemical quenching to cope with temperature restrictions on Photosystem II protein turnover. PHOTOSYNTHESIS RESEARCH 2017; 131:203-220. [PMID: 27639727 PMCID: PMC5247552 DOI: 10.1007/s11120-016-0310-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/08/2016] [Indexed: 05/12/2023]
Abstract
Micromonas strains of small prasinophyte green algae are found throughout the world's oceans, exploiting widely different niches. We grew arctic and temperate strains of Micromonas and compared their susceptibilities to photoinactivation of Photosystem II, their counteracting Photosystem II repair capacities, their Photosystem II content, and their induction and relaxation of non-photochemical quenching. In the arctic strain Micromonas NCMA 2099, the cellular content of active Photosystem II represents only about 50 % of total Photosystem II protein, as a slow rate constant for clearance of PsbA protein limits instantaneous repair. In contrast, the temperate strain NCMA 1646 shows a faster clearance of PsbA protein which allows it to maintain active Photosystem II content equivalent to total Photosystem II protein. Under growth at 2 °C, the arctic Micromonas maintains a constitutive induction of xanthophyll deepoxidation, shown by second-derivative whole-cell spectra, which supports strong induction of non-photochemical quenching under low to moderate light, even if xanthophyll cycling is blocked. This non-photochemical quenching, however, relaxes during subsequent darkness with kinetics nearly comparable to the temperate Micromonas NCMA 1646, thereby limiting the opportunity cost of sustained downregulation of PSII function after a decrease in light.
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Affiliation(s)
- Guangyan Ni
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, CAS, Guangzhou, 510160, China
| | - Gabrielle Zimbalatti
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Cole D Murphy
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | | | - Christopher M Arsenault
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Gang Li
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, CAS, Guangzhou, 510301, China
| | - Amanda M Cockshutt
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada
| | - Douglas A Campbell
- Department of Chemistry & Biochemistry, Mount Allison University, 63B York St., Sackville, NB, E4L3M7, Canada.
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77
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Murphy CD, Roodvoets MS, Austen EJ, Dolan A, Barnett A, Campbell DA. Photoinactivation of Photosystem II in Prochlorococcus and Synechococcus. PLoS One 2017; 12:e0168991. [PMID: 28129341 PMCID: PMC5271679 DOI: 10.1371/journal.pone.0168991] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/10/2016] [Indexed: 01/15/2023] Open
Abstract
The marine picocyanobacteria Synechococcus and Prochlorococcus numerically dominate open ocean phytoplankton. Although evolutionarily related they are ecologically distinct, with different strategies to harvest, manage and exploit light. We grew representative strains of Synechococcus and Prochlorococcus and tracked their susceptibility to photoinactivation of Photosystem II under a range of light levels. As expected blue light provoked more rapid photoinactivation than did an equivalent level of red light. The previous growth light level altered the susceptibility of Synechococcus, but not Prochlorococcus, to this photoinactivation. We resolved a simple linear pattern when we expressed the yield of photoinactivation on the basis of photons delivered to Photosystem II photochemistry, plotted versus excitation pressure upon Photosystem II, the balance between excitation and downstream metabolism. A high excitation pressure increases the generation of reactive oxygen species, and thus increases the yield of photoinactivation of Photosystem II. Blue photons, however, retained a higher baseline photoinactivation across a wide range of excitation pressures. Our experiments thus uncovered the relative influences of the direct photoinactivation of Photosystem II by blue photons which dominates under low to moderate blue light, and photoinactivation as a side effect of reactive oxygen species which dominates under higher excitation pressure. Synechococcus enjoyed a positive metabolic return upon the repair or the synthesis of a Photosystem II, across the range of light levels we tested. In contrast Prochlorococcus only enjoyed a positive return upon synthesis of a Photosystem II up to 400 μmol photons m-2 s-1. These differential cost-benefits probably underlie the distinct photoacclimation strategies of the species.
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Affiliation(s)
- Cole D. Murphy
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Mitchell S. Roodvoets
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Emily J. Austen
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Allison Dolan
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Audrey Barnett
- Michigan Technological University, Houghton, Michigan, United States of America
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Olischläger M, Iñiguez C, Koch K, Wiencke C, Gordillo FJL. Increased pCO 2 and temperature reveal ecotypic differences in growth and photosynthetic performance of temperate and Arctic populations of Saccharina latissima. PLANTA 2017; 245:119-136. [PMID: 27654952 DOI: 10.1007/s00425-016-2594-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 09/05/2016] [Indexed: 06/06/2023]
Abstract
MAIN CONCLUSION The Arctic population of the kelp Saccharina latissima differs from the Helgoland population in its sensitivity to changing temperature and CO 2 levels. The Arctic population does more likely benefit from the upcoming environmental scenario than its Atlantic counterpart. The previous research demonstrated that warming and ocean acidification (OA) affect the biochemical composition of Arctic (Spitsbergen; SP) and cold-temperate (Helgoland; HL) Saccharina latissima differently, suggesting ecotypic differentiation. This study analyses the responses to different partial pressures of CO2 (380, 800, and 1500 µatm pCO2) and temperature levels (SP population: 4, 10 °C; HL population: 10, 17 °C) on the photophysiology (O2 production, pigment composition, D1-protein content) and carbon assimilation [Rubisco content, carbon concentrating mechanisms (CCMs), growth rate] of both ecotypes. Elevated temperatures stimulated O2 production in both populations, and also led to an increase in pigment content and a deactivation of CCMs, as indicated by 13C isotopic discrimination of algal biomass (ε p) in the HL population, which was not observed in SP thalli. In general, pCO2 effects were less pronounced than temperature effects. High pCO2 deactivated CCMs in both populations and produced a decrease in the Rubisco content of HL thalli, while it was unaltered in SP population. As a result, the growth rate of the Arctic ecotype increased at elevated pCO2 and higher temperatures and it remained unchanged in the HL population. Ecotypic differentiation was revealed by a significantly higher O2 production rate and an increase in Chl a, Rubisco, and D1 protein content in SP thalli, but a lower growth rate, in comparison to the HL population. We conclude that both populations differ in their sensitivity to changing temperatures and OA and that the Arctic population is more likely to benefit from the upcoming environmental scenario than its Atlantic counterpart.
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Affiliation(s)
- Mark Olischläger
- Department of Functional Ecology, Alfred-Wegener-Institute, Helmholtz Center for Marine and Polar Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Concepción Iñiguez
- Department of Ecology, Faculty of Sciences, University of Malaga, Bulevar Louis Pasteur s/n, 29010, Malaga, Spain
| | - Kristina Koch
- Marine Botany and Bremen Marine Ecology-Center for Research and Education (BreMarE), University of Bremen, LeobenerStr. NW2, 28359, Bremen, Germany
| | - Christian Wiencke
- Department of Functional Ecology, Alfred-Wegener-Institute, Helmholtz Center for Marine and Polar Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
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79
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016. [PMID: 27697149 DOI: 10.7554/elife.16921.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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80
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016; 5. [PMID: 27697149 PMCID: PMC5050024 DOI: 10.7554/elife.16921] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/08/2016] [Indexed: 12/20/2022] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field. DOI:http://dx.doi.org/10.7554/eLife.16921.001
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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81
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Ritchie RJ, Mekjinda N. Arsenic toxicity in the water weed Wolffia arrhiza measured using Pulse Amplitude Modulation Fluorometry (PAM) measurements of photosynthesis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 132:178-85. [PMID: 27318559 DOI: 10.1016/j.ecoenv.2016.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/02/2016] [Accepted: 06/03/2016] [Indexed: 05/13/2023]
Abstract
Accumulation of arsenic in plants is a serious South-east Asian environmental problem. Photosynthesis in the small aquatic angiosperm Wolffia arrhiza is very sensitive to arsenic toxicity, particularly in water below pH 7 where arsenite (As (OH)3) (AsIII) is the dominant form; at pH >7 AsO4(2-) (As(V) predominates). A blue-diode PAM (Pulse Amplitude Fluorometer) machine was used to monitor photosynthesis in Wolffia. Maximum gross photosynthesis (Pgmax) and not maximum yield (Ymax) is the most reliable indicator of arsenic toxicity. The toxicity of arsenite As(III) and arsenate (H2AsO4(2-)) As(V) vary with pH. As(V) was less toxic than As(III) at both pH 5 and pH 8 but both forms of arsenic were toxic (>90% inhibition) at below 0.1molm(-3) when incubated in arsenic for 24h. Arsenite toxicity was apparent after 1h based on Pgmax and gradually increased over 7h but there was no apparent effect on Ymax or photosynthetic efficiency (α0).
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Affiliation(s)
- Raymond J Ritchie
- Tropical Plant Biology, Technology and Environment, Prince of Songkla University Phuket, Vichitsongkram Rd, Kathu, Phuket 83120, Thailand.
| | - Nutsara Mekjinda
- Chemi Nano Biotech, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
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82
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Unlocking the Constraints of Cyanobacterial Productivity: Acclimations Enabling Ultrafast Growth. mBio 2016; 7:mBio.00949-16. [PMID: 27460798 PMCID: PMC4981716 DOI: 10.1128/mbio.00949-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Harnessing the metabolic potential of photosynthetic microbes for next-generation biotechnology objectives requires detailed scientific understanding of the physiological constraints and regulatory controls affecting carbon partitioning between biomass, metabolite storage pools, and bioproduct synthesis. We dissected the cellular mechanisms underlying the remarkable physiological robustness of the euryhaline unicellular cyanobacterium Synechococcus sp. strain PCC 7002 (Synechococcus 7002) and identify key mechanisms that allow cyanobacteria to achieve unprecedented photoautotrophic productivities (~2.5-h doubling time). Ultrafast growth of Synechococcus 7002 was supported by high rates of photosynthetic electron transfer and linked to significantly elevated transcription of precursor biosynthesis and protein translation machinery. Notably, no growth or photosynthesis inhibition signatures were observed under any of the tested experimental conditions. Finally, the ultrafast growth in Synechococcus 7002 was also linked to a 300% expansion of average cell volume. We hypothesize that this cellular adaptation is required at high irradiances to support higher cell division rates and reduce deleterious effects, corresponding to high light, through increased carbon and reductant sequestration. Efficient coupling between photosynthesis and productivity is central to the development of biotechnology based on solar energy. Therefore, understanding the factors constraining maximum rates of carbon processing is necessary to identify regulatory mechanisms and devise strategies to overcome productivity constraints. Here, we interrogate the molecular mechanisms that operate at a systems level to allow cyanobacteria to achieve ultrafast growth. This was done by considering growth and photosynthetic kinetics with global transcription patterns. We have delineated putative biological principles that allow unicellular cyanobacteria to achieve ultrahigh growth rates through photophysiological acclimation and effective management of cellular resource under different growth regimes.
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83
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Grudzinski W, Krzeminska I, Luchowski R, Nosalewicz A, Gruszecki WI. Strong-light-induced yellowing of green microalgae Chlorella: A study on molecular mechanisms of the acclimation response. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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84
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Karsten U, Herburger K, Holzinger A. Living in biological soil crust communities of African deserts-Physiological traits of green algal Klebsormidium species (Streptophyta) to cope with desiccation, light and temperature gradients. JOURNAL OF PLANT PHYSIOLOGY 2016; 194:2-12. [PMID: 26422081 PMCID: PMC4710676 DOI: 10.1016/j.jplph.2015.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 05/20/2023]
Abstract
Green algae of the genus Klebsormidium (Klebsormidiales, Streptophyta) are typical members of biological soil crusts (BSCs) worldwide. The phylogeny and ecophysiology of Klebsormidium has been intensively studied in recent years, and a new lineage called superclade G, which was isolated from BSCs in arid southern Africa and comprising undescribed species, was reported. Three different African strains, that have previously been isolated from hot-desert BSCs and molecular-taxonomically characterized, were comparatively investigated. In addition, Klebsormidium subtilissimum from a cold-desert habitat (Alaska, USA, superclade E) was included in the study as well. Photosynthetic performance was measured under different controlled abiotic conditions, including dehydration and rehydration, as well as under a light and temperature gradient. All Klebsormidium strains exhibited optimum photosynthetic oxygen production at low photon fluence rates, but with no indication of photoinhibition under high light conditions pointing to flexible acclimation mechanisms of the photosynthetic apparatus. Respiration under lower temperatures was generally much less effective than photosynthesis, while the opposite was true for higher temperatures. The Klebsormidium strains tested showed a decrease and inhibition of the effective quantum yield during desiccation, however with different kinetics. While the single celled and small filamentous strains exhibited relatively fast inhibition, the uniserate filament forming isolates desiccated slower. Except one, all other strains fully recovered effective quantum yield after rehydration. The presented data provide an explanation for the regular occurrence of Klebsormidium strains or species in hot and cold deserts, which are characterized by low water availability and other stressful conditions.
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Affiliation(s)
- Ulf Karsten
- University of Rostock, Institute of Biological Sciences, Applied Ecology & Phycology, Albert-Einstein-Strasse 3, D-18059 Rostock, Germany.
| | - Klaus Herburger
- University of Innsbruck, Institute of Botany, Functional Plant Biology, Sternwartestrasse 15, A-6020 Innsbruck, Austria
| | - Andreas Holzinger
- University of Innsbruck, Institute of Botany, Functional Plant Biology, Sternwartestrasse 15, A-6020 Innsbruck, Austria
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85
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Abu-Ghosh S, Fixler D, Dubinsky Z, Iluz D. Flashing light in microalgae biotechnology. BIORESOURCE TECHNOLOGY 2016; 203:357-363. [PMID: 26747205 DOI: 10.1016/j.biortech.2015.12.057] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/17/2015] [Accepted: 12/19/2015] [Indexed: 06/05/2023]
Abstract
Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera.
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Affiliation(s)
- Said Abu-Ghosh
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; The Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Dror Fixler
- Faculty of Engineering, Bar-Ilan University, Ramat-Gan 5290002, Israel; The Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Zvy Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - David Iluz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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86
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Lavaud J, Six C, Campbell DA. Photosystem II repair in marine diatoms with contrasting photophysiologies. PHOTOSYNTHESIS RESEARCH 2016; 127:189-99. [PMID: 26156125 DOI: 10.1007/s11120-015-0172-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/25/2015] [Indexed: 05/23/2023]
Abstract
Skeletonema costatum and Phaeodactylum tricornutum are model marine diatoms with differing strategies for non-photochemical dissipation of excess excitation energy within photosystem II (PSII). We showed that S. costatum, with connectivity across the pigment bed serving PSII, and limited capacity for induction of sustained non-photochemical quenching (NPQ), maintained a large ratio of [PSII(Total)]/[PSII(Active)] to buffer against fluctuations in light intensity. In contrast, P. tricornutum, with a larger capacity to induce sustained NPQ, could maintain a lower [PSII(Total)]/[PSII(Active)]. Induction of NPQ was correlated with an active PSII repair cycle in both species, and inhibition of chloroplastic protein synthesis with lincomycin leads to run away over-excitation of remaining PSII(Active), particularly in S. costatum. We discuss these distinctions in relation to the differing capacities, induction and relaxation rates for NPQ, and as strain adaptations to the differential light regimes of their originating habitats. The present work further confirms the important role for the light-dependent fast regulation of photochemistry by NPQ interacting with PSII repair cycle capacity in the ecophysiology of both pennate and centric diatoms.
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Affiliation(s)
- Johann Lavaud
- UMRi 7266 'LIENSs', Institut du Littoral et de l'Environnement (ILE), CNRS-University of La Rochelle, 2 rue Olympe de Gouges, 17000, La Rochelle Cedex, France.
| | - Christophe Six
- Department of Biology, Mount Allison University, Sackville, NB E4L 1G7, Canada
- UMR 7144 'Adaptation et Diversité en Milieu Marin', 'Marine Phototrophic Prokaryotes' group, Centre National pour la Recherche Scientifique (CNRS), Station Biologique de Roscoff, Place George Teissier, 29680, Roscoff, France
- UMR 7144 'Adaptation et Diversité en Milieu Marin', 'Marine Phototrophic Prokaryotes' group, Université Pierre et Marie Curie (Paris 06), Station Biologique de Roscoff, Place George Teissier, 29680, Roscoff, France
| | - Douglas A Campbell
- Department of Biology, Mount Allison University, Sackville, NB E4L 1G7, Canada
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87
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Fan F, Ding G, Wen X. Proteomic analyses provide new insights into the responses of Pinus massoniana seedlings to phosphorus deficiency. Proteomics 2016; 16:504-15. [PMID: 26603831 DOI: 10.1002/pmic.201500140] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 10/02/2015] [Accepted: 11/17/2015] [Indexed: 02/04/2023]
Abstract
Phosphorus is an essential macronutrient for plant growth and development. Plants can respond defensively to phosphorus deficiency by modifying their morphology and metabolic pathways via the differential expression of low phosphate responsive genes. To better understand the mechanisms by which the Masson pine (Pinus massoniana) adapts to phosphorus deficiency, we conducted comparative proteomic analysis using an elite line exhibiting high tolerance to phosphorus deficiency. The selected seedlings were treated with 0.5 mM KH2PO4 (control), 0.01 mM KH2PO4 (P1), or 0.06 mM KH2PO4 (P2) for 48 days. Total protein samples were separated via 2DE. A total of 98 differentially expressed proteins, which displayed at least 1.7-fold change expression compared to the control levels (p ≤ 0.05), were identified by MALDI-TOF/TOF MS. These phosphate starvation responsive proteins were implicated in photosynthesis, defense, cellular organization, biosynthesis, energy metabolism, secondary metabolism, signal transduction etc. Therefore, these proteins might play important roles in facilitating internal phosphorus homeostasis. Additionally, the obtained data may be useful for the further characterization of gene function and may provide a foundation for a more comprehensive understanding of the adaptations of the Masson pine to phosphorus-deficient conditions.
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Affiliation(s)
- Fuhua Fan
- The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, Guizhou, P. R. China.,Research Center for Forest Resources and Environment of Guizhou Province, Guizhou University, Guiyang, Guizhou, P. R. China
| | - Guijie Ding
- Research Center for Forest Resources and Environment of Guizhou Province, Guizhou University, Guiyang, Guizhou, P. R. China
| | - Xiaopeng Wen
- The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang, Guizhou, P. R. China.,Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICEAB), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang, Guizhou, P. R. China
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88
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The Photoinhibistat: Operating Microalgae Culture under Photoinhibition for Strain Selection**This work was supported by the French ANR Facteur 4 (ANR-12-BIME-0004) and Purple Sun (ANR-13-BIME-0004) projects. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.ifacol.2016.07.344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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89
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Murchie EH, Ali A, Herman T. Photoprotection as a Trait for Rice Yield Improvement: Status and Prospects. RICE (NEW YORK, N.Y.) 2015; 8:31. [PMID: 26424004 PMCID: PMC4589542 DOI: 10.1186/s12284-015-0065-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 09/19/2015] [Indexed: 05/25/2023]
Abstract
Solar radiation is essential for photosynthesis and global crop productivity but it is also variable in space and time, frequently being limiting or in excess of plant requirements depending on season, environment and microclimate. Photoprotective mechanisms at the chloroplast level help to avoid oxidative stress and photoinhibition, which is a light-induced reduction in photosynthetic quantum efficiency often caused by damage to photosystem II. There is convincing evidence that photoinhibition has a large impact on biomass production in crops and this may be especially high in rice, which is typically exposed to high tropical light levels. Thus far there has been little attention to photoinhibition as a target for improvement of crop yield. However, we now have sufficient evidence to examine avenues for alleviation of this particular stress and the physiological and genetic basis for improvement in rice and other crops. Here we examine this evidence and identify new areas for attention. In particular we discuss how photoprotective mechanisms must be optimised at both the molecular and the canopy level in order to coordinate with efficient photosynthetic regulation and realise an increased biomass and yield in rice.
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Affiliation(s)
- Erik H Murchie
- Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK.
| | - Asgar Ali
- School of Biosciences, University of Nottingham Malaysia Campus, Semenyih, 43500, Selangor Darul Ehsan, Malaysia
| | - Tiara Herman
- School of Biosciences, University of Nottingham Malaysia Campus, Semenyih, 43500, Selangor Darul Ehsan, Malaysia
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90
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Discerning the effects of photoinhibition and photoprotection on the rate of oxygen evolution in Arabidopsis leaves. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:272-8. [DOI: 10.1016/j.jphotobiol.2015.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/18/2015] [Accepted: 09/11/2015] [Indexed: 12/26/2022]
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91
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Segovia M, Mata T, Palma A, García-Gómez C, Lorenzo R, Rivera A, Figueroa FL. Dunaliella tertiolecta(Chlorophyta) Avoids Cell Death Under Ultraviolet Radiation By Triggering Alternative Photoprotective Mechanisms. Photochem Photobiol 2015. [DOI: 10.1111/php.12502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- María Segovia
- Department of Ecology; Faculty of Sciences; University of Málaga; Málaga Spain
| | - Teresa Mata
- Department of Ecology; Faculty of Sciences; University of Málaga; Málaga Spain
| | - Armando Palma
- Department of Ecology; Faculty of Sciences; University of Málaga; Málaga Spain
| | | | - Rosario Lorenzo
- Department of Ecology; Faculty of Sciences; University of Málaga; Málaga Spain
| | - Alicia Rivera
- Department of Cell Biology; Faculty of Sciences; University of Málaga; Málaga Spain
| | - Félix L. Figueroa
- Department of Ecology; Faculty of Sciences; University of Málaga; Málaga Spain
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92
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Hoppe CJM, Holtz L, Trimborn S, Rost B. Ocean acidification decreases the light-use efficiency in an Antarctic diatom under dynamic but not constant light. THE NEW PHYTOLOGIST 2015; 207:159-171. [PMID: 25708812 PMCID: PMC4950296 DOI: 10.1111/nph.13334] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/12/2015] [Indexed: 05/07/2023]
Abstract
There is increasing evidence that different light intensities strongly modulate the effects of ocean acidification (OA) on marine phytoplankton. The aim of the present study was to investigate interactive effects of OA and dynamic light, mimicking natural mixing regimes. The Antarctic diatom Chaetoceros debilis was grown under two pCO2 (390 and 1000 μatm) and light conditions (constant and dynamic), the latter yielding the same integrated irradiance over the day. To characterize interactive effects between treatments, growth, elemental composition, primary production and photophysiology were investigated. Dynamic light reduced growth and strongly altered the effects of OA on primary production, being unaffected by elevated pCO2 under constant light, yet significantly reduced under dynamic light. Interactive effects between OA and light were also observed for Chl production and particulate organic carbon quotas. Response patterns can be explained by changes in the cellular energetic balance. While the energy transfer efficiency from photochemistry to biomass production (Φe,C ) was not affected by OA under constant light, it was drastically reduced under dynamic light. Contrasting responses under different light conditions need to be considered when making predictions regarding a more stratified and acidified future ocean.
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Affiliation(s)
- Clara J. M. Hoppe
- Alfred Wegener Institute – Helmholtz Centre for Polar and Marine ResearchAm Handelshafen 12Bremerhaven27570Germany
| | - Lena‐Maria Holtz
- Alfred Wegener Institute – Helmholtz Centre for Polar and Marine ResearchAm Handelshafen 12Bremerhaven27570Germany
| | - Scarlett Trimborn
- Alfred Wegener Institute – Helmholtz Centre for Polar and Marine ResearchAm Handelshafen 12Bremerhaven27570Germany
- University BremenLeobener Straße NW2‐ABremen28359Germany
| | - Björn Rost
- Alfred Wegener Institute – Helmholtz Centre for Polar and Marine ResearchAm Handelshafen 12Bremerhaven27570Germany
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93
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Zheng Y, Giordano M, Gao K. The impact of fluctuating light on the dinoflagellate Prorocentrum micans depends on NO3(-) and CO2 availability. JOURNAL OF PLANT PHYSIOLOGY 2015; 180:18-26. [PMID: 25899727 DOI: 10.1016/j.jplph.2015.01.020] [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: 04/01/2014] [Revised: 11/18/2014] [Accepted: 01/10/2015] [Indexed: 06/04/2023]
Abstract
Increasing atmospheric pCO2 and its dissolution into oceans leads to ocean acidification and warming, which reduces the thickness of upper mixing layer (UML) and upward nutrient supply from deeper layers. These events may alter the nutritional conditions and the light regime to which primary producers are exposed in the UML. In order to better understand the physiology behind the responses to the concomitant climate changes factors, we examined the impact of light fluctuation on the dinoflagellate Prorocentrum micans grown at low (1 μmol L(-1)) or high (800 μmol L(-1)) [NO3(-)] and at high (1000 μatm) or low (390 μatm, ambient) pCO2. The light regimes to which the algal cells were subjected were (1) constant light at a photon flux density (PFD) of either 100 (C100) or 500 (C500) μmol m(-2) s(-1) or (2) fluctuating light between 100 or 500 μmol photons m(-2) s(-1) with a frequency of either 15 (F15) or 60 (F60) min. Under continuous light, the initial portion of the light phase required the concomitant presence of high CO2 and NO3(-) concentrations for maximum growth. After exposure to light for 3h, high CO2 exerted a negative effect on growth and effective quantum yield of photosystem II (F'(v)/F'(m)). Fluctuating light ameliorated growth in the first period of illumination. In the second 3h of treatment, higher frequency (F15) of fluctuations afforded high growth rates, whereas the F60 treatment had detrimental consequences, especially when NO3(-) concentration was lower. F'(v)/F'(m) respondent differently from growth to fluctuating light: the fluorescence yield was always lower than at continuous light at 100 μmol m(-2) s(-1), and always higher at 500 μmol m(-2) s(-1). Our data show that the impact of atmospheric pCO2 increase on primary production of dinoflagellate depends on the availability of nitrate and the irradiance (intensity and the frequency of irradiance fluctuations) to which the cells are exposed. The impact of global change on oceanic primary producers would therefore be different in waters with different chemical and physical (mixing) properties.
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Affiliation(s)
- Ying Zheng
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy; Institute of Microbiology ASCR, Algatech, Trebon 37981, Czech Republic
| | - Kunshan Gao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China.
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94
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Derks A, Schaven K, Bruce D. Diverse mechanisms for photoprotection in photosynthesis. Dynamic regulation of photosystem II excitation in response to rapid environmental change. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:468-485. [DOI: 10.1016/j.bbabio.2015.02.008] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/03/2015] [Accepted: 02/07/2015] [Indexed: 12/26/2022]
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95
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Abu-Ghosh S, Fixler D, Dubinsky Z, Iluz D. Continuous background light significantly increases flashing-light enhancement of photosynthesis and growth of microalgae. BIORESOURCE TECHNOLOGY 2015; 187:144-148. [PMID: 25846184 DOI: 10.1016/j.biortech.2015.03.119] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 06/04/2023]
Abstract
Under specific conditions, flashing light enhances the photosynthesis rate in comparison to continuous illumination. Here we show that a combination of flashing light and continuous background light with the same integrated photon dose as continuous or flashing light alone can be used to significantly enhance photosynthesis and increase microalgae growth. To test this hypothesis, the green microalga Dunaliella salina was exposed to three different light regimes: continuous light, flashing light, and concomitant application of both. Algal growth was compared under three different integrated light quantities; low, intermediate, and moderately high. Under the combined light regime, there was a substantial increase in all algal growth parameters, with an enhanced photosynthesis rate, within 3days. Our strategy demonstrates a hitherto undescribed significant increase in photosynthesis and algal growth rates, which is beyond the increase by flashing light alone.
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Affiliation(s)
- Said Abu-Ghosh
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; The Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Dror Fixler
- Faculty of Engineering, Bar-Ilan University, Ramat-Gan 5290002, Israel; The Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Zvy Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - David Iluz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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96
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Darwish M, Vidal V, Lopez-Lauri F, Alnaser O, Junglee S, El Maataoui M, Sallanon H. Tolerance to clomazone herbicide is linked to the state of LHC, PQ-pool and ROS detoxification in tobacco (Nicotiana tabacum L.). JOURNAL OF PLANT PHYSIOLOGY 2015; 175:122-30. [PMID: 25544589 DOI: 10.1016/j.jplph.2014.11.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 05/11/2023]
Abstract
In this study, plantlets of two tobacco (Nicotiana tabacum L.) varieties that are clomazone-tolerant (cv. Xanthi) and clomazone-sensitive (cv. Virginie vk51) were subjected to low concentration of clomazone herbicide. The oxygen-evolving rate of isolated chloroplasts, chlorophyll a fluorescence transients, JIP-test responses, hydrogen peroxide contents, antioxidant enzyme activities, cytohistological results and photosynthetic pigment contents were recorded. The results indicated that the carotenoid content was 2-fold higher in Virginie, which had greater clomazone sensitivity than Xanthi. Virginie exhibited noticeable decreases in the LHC content (Chl a/b ratio), the maximum photochemical quantum efficiency of PSII (Fv/Fm), the performance index on the absorption basis (PIabs), and the electron flux beyond the first PSII QA evaluated as (1-VJ) with VJ=(FJ-F0)/(Fm-F0) as well as increases in the rate of photon absorption (ABS/RC) and the energy dissipation as heat (DI0/RC). These results suggest that PSII photoinhibition occurred as a consequence of more reduced PQ-pool and accumulated QA(-). The oxygen evolution measurements indicate that PSI electron transport activity was not affected by clomazone. The more significant accumulation of H2O2 in Virginie compared to Xanthi was due to the absence of ROS-scavenging enzymes, and presumably induced programmed cell death (PCD). The symptoms of PCD were observed by cytohistological analysis, which also indicated that the leaf tissues of clomazone-treated Virginie exhibited significant starch accumulation compared to Xanthi. Taken together, these results indicate that the variable tolerance to clomazone observed between Virginie and Xanthi is independent of the carotenoid content and could be related to the state of the LHC, the redox state of the PQ-pool, and the activity of detoxification enzymes.
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Affiliation(s)
- Majd Darwish
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France.
| | - Véronique Vidal
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
| | - Félicie Lopez-Lauri
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
| | - Osama Alnaser
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
| | - Sanders Junglee
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
| | - Mohamed El Maataoui
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
| | - Huguette Sallanon
- Laboratoire Physiologie des Fruits et Légumes (EA 4279), Université d'Avignon et des Pays de Vaucluse, Bât Agrosciences, 301 rue Baruch de Spinoza, BP 21239, F-84916 Avignon cedex 9, France
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97
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Li G, Brown CM, Jeans JA, Donaher NA, McCarthy A, Campbell DA. The nitrogen costs of photosynthesis in a diatom under current and future pCO2. THE NEW PHYTOLOGIST 2015; 205:533-43. [PMID: 25256155 DOI: 10.1111/nph.13037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/10/2014] [Indexed: 05/23/2023]
Abstract
With each cellular generation, oxygenic photoautotrophs must accumulate abundant protein complexes that mediate light capture, photosynthetic electron transport and carbon fixation. In addition to this net synthesis, oxygenic photoautotrophs must counter the light-dependent photoinactivation of Photosystem II (PSII), using metabolically expensive proteolysis, disassembly, resynthesis and re-assembly of protein subunits. We used growth rates, elemental analyses and protein quantitations to estimate the nitrogen (N) metabolism costs to both accumulate the photosynthetic system and to maintain PSII function in the diatom Thalassiosira pseudonana, growing at two pCO2 levels across a range of light levels. The photosynthetic system contains c. 15-25% of total cellular N. Under low growth light, N (re)cycling through PSII repair is only c. 1% of the cellular N assimilation rate. As growth light increases to inhibitory levels, N metabolite cycling through PSII repair increases to c. 14% of the cellular N assimilation rate. Cells growing under the assumed future 750 ppmv pCO2 show higher growth rates under optimal light, coinciding with a lowered N metabolic cost to maintain photosynthesis, but then suffer greater photoinhibition of growth under excess light, coincident with rising costs to maintain photosynthesis. We predict this quantitative trait response to light will vary across taxa.
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Affiliation(s)
- Gang Li
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, E4L 1G7, Canada; Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, CAS, Guangzhou, 510301, China
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98
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Peers G. Increasing algal photosynthetic productivity by integrating ecophysiology with systems biology. Trends Biotechnol 2014; 32:551-555. [PMID: 25306192 DOI: 10.1016/j.tibtech.2014.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 08/22/2014] [Accepted: 09/09/2014] [Indexed: 11/26/2022]
Abstract
Oxygenic photosynthesis is the process by which plants, algae, and cyanobacteria convert sunlight and CO2 into chemical energy and biomass. Previously published estimates suggest that algal photosynthesis is, at best, able to convert approximately 5-7% of incident light energy to biomass and there is opportunity for improvement. Recent analyses of in situ photophysiology in mass cultures of algae and cyanobacteria show that cultivation methods can have detrimental effects on a cell's photophysiology - reinforcing the need to understand the complex responses of cell biology to a highly variable environment. A systems-based approach to understanding the stresses and efficiencies associated with light-energy harvesting, CO2 fixation, and carbon partitioning will be necessary to make major headway toward improving photosynthetic yields.
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Affiliation(s)
- Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
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99
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García-Sánchez M, Korbee N, Pérez-Ruzafa IM, Marcos C, Figueroa FL, Pérez-Ruzafa Á. Living in a coastal lagoon environment: photosynthetic and biochemical mechanisms of key marine macroalgae. MARINE ENVIRONMENTAL RESEARCH 2014; 101:8-21. [PMID: 25164017 DOI: 10.1016/j.marenvres.2014.07.012] [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: 04/11/2014] [Revised: 07/22/2014] [Accepted: 07/29/2014] [Indexed: 06/03/2023]
Abstract
The physiological status of Cystoseira compressa, Padina pavonica and Palisada tenerrima was studied by in vivo chlorophyll fluorescence, pigment content, stoichiometry (C:N), accumulation of UV photoprotectors and antioxidant activity; comparing their photosynthetic response in a coastal lagoon (Mar Menor) and in Mediterranean coastal waters. In general, the specimens reached their highest ETRmax in spring in the Lagoon, but in summer in the Mediterranean, coinciding with their maximum biomass peak. The species exhibited a dynamic photoinhibition. Except C. compressa, they showed a lower decrease in Fv/Fm and higher recovery rates in the Mediterranean populations when exposed to high irradiance. The higher salinity and temperature of the lagoon could impair the photoprotection mechanisms. The acclimation to lagoon environments is species-specific and involves complex regulatory mechanisms. The results underline the importance of N in repair, avoidance, quenching and scavenging mechanisms. In general, Lagoon specimens showed higher pigment concentration. Although xanthophylls play important photo-protective and antioxidant roles, the observed trend is more likely to be explained by the higher temperatures reached in the lagoon compared to Mediterranean. Therefore the studied photosynthetic and biochemical mechanisms can be effective not only for high irradiance, but also for higher temperatures in a climate change scenario, but are highly dependent on nutrient availability.
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Affiliation(s)
- Marta García-Sánchez
- Departamento de Ecología e Hidrología, Facultad de Biología, Campus de Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia 30100, Spain.
| | - Nathalie Korbee
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga 29071, Spain
| | - Isabel María Pérez-Ruzafa
- Departamento de Biología Vegetal I, Facultad de Biología, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Concepción Marcos
- Departamento de Ecología e Hidrología, Facultad de Biología, Campus de Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia 30100, Spain
| | - Félix L Figueroa
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga 29071, Spain
| | - Ángel Pérez-Ruzafa
- Departamento de Ecología e Hidrología, Facultad de Biología, Campus de Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia 30100, Spain
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100
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Campos H, Trejo C, Peña-Valdivia CB, García-Nava R, Conde-Martínez FV, Cruz-Ortega MDR. Photosynthetic acclimation to drought stress in Agave salmiana Otto ex Salm-Dyck seedlings is largely dependent on thermal dissipation and enhanced electron flux to photosystem I. PHOTOSYNTHESIS RESEARCH 2014; 122:23-39. [PMID: 24798124 DOI: 10.1007/s11120-014-0008-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 04/14/2014] [Indexed: 05/08/2023]
Abstract
Agave salmiana Otto ex Salm-Dyck, a crassulacean acid metabolism plant that is adapted to water-limited environments, has great potential for bioenergy production. However, drought stress decreases the requirement for light energy, and if the amount of incident light exceeds energy consumption, the photosynthetic apparatus can be injured, thereby limiting plant growth. The objective of this study was to evaluate the effects of drought and re-watering on the photosynthetic efficiency of A. salmiana seedlings. The leaf relative water content and leaf water potential decreased to 39.6 % and -1.1 MPa, respectively, over 115 days of water withholding and recovered after re-watering. Drought caused a direct effect on photosystem II (PSII) photochemistry in light-acclimated leaves, as indicated by a decrease in the photosynthetic electron transport rate. Additionally, down-regulation of photochemical activity occurred mainly through the inactivation of PSII reaction centres and an increased thermal dissipation capacity of the leaves. Prompt fluorescence kinetics also showed a larger pool of terminal electron acceptors in photosystem I (PSI) as well as an increase in some JIP-test parameters compared to controls, reflecting an enhanced efficiency and specific fluxes for electron transport from the plastoquinone pool to the PSI terminal acceptors. All the above parameters showed similar levels after re-watering. These results suggest that the thermal dissipation of excess energy and the increased energy conservation from photons absorbed by PSII to the reduction of PSI end acceptors may be an important acclimation mechanism to protect the photosynthetic apparatus from over-excitation in Agave plants.
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Affiliation(s)
- Huitziméngari Campos
- Posgrado en Recursos Genéticos y Productividad-Fisiología Vegetal, Colegio de Postgraduados, Carretera México-Texcoco, km 36.5, Montecillo, 56230, México, México,
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