Photosynthesis Research - Current Research Articles
Current research articles: Photosynthesis
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Photosynthesis Research - published by Springer
... is an international journal open to papers of merit dealing with both basic and applied aspects of photosynthesis.
Stable carbon isotope signatures are often used as tracers for environmentally driven changes in photosynthetic ?13C discrimination. However, carbon isotope signatures downstream from carboxylation by Rubisco are altered within metabolic
pathways, transport and respiratory processes, leading to differences in ?13C between carbon pools along the plant axis and in respired CO2. Little is known about the within-plant variation in ?13C under different environmental conditions or between species. We analyzed spatial, diurnal, and environmental variations
in ?13C of water soluble organic matter (?13CWSOM) of leaves, phloem and roots, as well as dark-respired ?13CO2 (?13Cres) in leaves and roots. We selected distinct light environments (forest understory and an open area), seasons (Mediterranean
spring and summer drought) and three functionally distinct understory species (two native shrubs—Halimium halimifolium and Rosmarinus officinalis—and a woody invader—Acacia longifolia). Spatial patterns in ?13CWSOM along the plant vertical axis and between respired ?13CO2 and its putative substrate were clearly species specific and the most ?13C-enriched and depleted values were found in ?13C of leaf dark-respired CO2 and phloem sugars, ~?15 and ~?33 ‰, respectively. Comparisons between study sites and seasons revealed that spatial and diurnal
patterns were influenced by environmental conditions. Within a species, phloem ?13CWSOM and ?13Cres varied by up to 4 ‰ between seasons and sites. Thus, careful characterization of the magnitude and environmental dependence
of apparent post-carboxylation fractionation is needed when using ?13C signatures to trace changes in photosynthetic discrimination.
Content Type Journal Article
Category Regular Paper
Pages 1-13
DOI 10.1007/s11120-012-9748-3
Authors
Maren Dubbert, Experimental and System Ecology, University of Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany
Katherine G. Rascher, Experimental and System Ecology, University of Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany
Christiane Werner, Experimental and System Ecology, University of Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany
The N-terminal 1E?6L domain of the manganese-stabilizing protein (PsbO) from spinach prevents non-specific binding of the subunit to photosystem
II (PSII) and deletions of the 1E?7T or 1E?15T sequences from the PsbO N-terminus reduce or impair, respectively, functional binding of PsbO to PSII (Popelkova et al.,
Biochemistry 42:6193–6200, 2003). The work presented here provides deeper insights into the interaction of PsbO with PSII. The data show that a single mutation,
15T ? A in mature PsbO from spinach reduces the stoichiometry of its functional binding from two to one subunit per PSII and
decreases reconstitution of activity to about 45 % of the wild-type control. Replacement of the 1E?6L domain with 6M in the T15A PsbO mutant has no additional negative effect on recovery of O2 evolution activity, but it significantly weakens both functional and nonspecific binding of the truncated mutant to PSII.
These results suggest that the 15T side-chain by itself is essential for binding of one of two PsbO subunits to eukaryotic PSII and that specific PSII-binding
sites for PsbO are distinguishable; one PSII-binding site does not require PsbO–15T and probably interacts with the other N-terminal domain of PsbO. Identity of the latter domain is revealed by a requirement
for the presence of the 1E?6L sequence that is shown here to be necessary for high-affinity binding of PsbO to PSII. When combined with previous results,
the data presented here lead to a more detailed model for PsbO binding in eukaryotic PSII.
Content Type Journal Article
Category Regular Paper
Pages 1-12
DOI 10.1007/s11120-012-9745-6
Authors
Hana Popelka, Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA
Charles Yocum, Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA
We provide here insights on the life and work of Berger C. Mayne (1920—2011). We remember and honor Berger, whose study of
photosynthesis began with the most basic processes of intersystem electron transport and oxygen evolution, continued with
application of fluorescence techniques to the study of photophosphorylation and the unique features of photosystems in specialized
cells, and concluded with collaborative study of photosynthesis in certain nitrogen fixing symbioses. Berger loved the outdoors
and was dedicated to preserving the environment and to social justice, and was a wonderful friend.
Content Type Journal Article
Category Tribute
Pages 1-9
DOI 10.1007/s11120-012-9742-9
Authors
Darrell Fleischman, Department of Biochemistry and Molecular Biology, Wright State University, Dayton, OH 45435-0001, USA
Gerald E. Edwards, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
Govindjee, Department of Plant Biology, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA
Leland Mayne, Department of Biochemistry and Biophysics, E. R. Johnson Foundation, University of Pennsylvania, Philadelphia, PA 19104, USA
Vijai Tyagi, G. E. Healthcare Life Sciences, Head Office, 800 Centennial Ave., Piscataway, NJ 08854, USA
Karen Jacobsen-Mispagel, University of Georgia College of Veterinary Medicine, Athens, GA, USA
Plants experiencing herbivory suffer indirect costs beyond direct loss of leaf area, but differentially so based on the herbivore
involved. We used a combination of chlorophyll fluorescence imaging and gas exchange techniques to quantify photosynthetic
performance, the efficiency of photochemistry, and heat dissipation to examine immediate and longer-term physiological responses
in the desert perennial Datura wrightii to herbivory by tobacco hornworm, Manduca sexta. Herbivory by colony-reared larvae yielded no significant reduction in carbon assimilation, whereas herbivory by wild larvae
induced a fast and spreading down-regulation of photosynthetic efficiency, resulting in significant losses in carbon assimilation
in eaten and uneaten leaves. We found both an 89 % reduction in net photosynthetic rates in herbivore-damaged leaves and a
whole-plant response (79 % decrease in undamaged leaves from adjacent branches). Consequently, herbivory costs are higher
than previously estimated in this well-studied plant–insect interaction. We used chlorophyll fluorescence imaging to elucidate
the mechanisms of this down-regulation. Quantum yield decreased up to 70 % in a small concentric band surrounding the feeding
area within minutes of the onset of herbivory. Non-photochemical energy dissipation by the plant to avoid permanent damage
was elevated near the wound, and increased systematically in distant areas of the leaf away from the wound over subsequent
hours. Together, the results underscore not only potential differences between colony-reared and wild-caught herbivores in
experimental studies of herbivory but also the benefits of quantifying physiological responses of plants in unattacked leaves.
Content Type Journal Article
Category Regular Paper
Pages 1-12
DOI 10.1007/s11120-012-9741-x
Authors
Greg A. Barron-Gafford, B2 Earthscience, University of Arizona, Tucson, AZ 85721, USA
Uwe Rascher, IBG-2: Plant Sciences, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Leo-Brandt-Str., 52425 Jülich, Germany
Judith L. Bronstein, Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
Goggy Davidowitz, Department of Entomology, University of Arizona, Tucson, AZ 85721, USA
Brian Chaszar, B2 Earthscience, University of Arizona, Tucson, AZ 85721, USA
Travis E. Huxman, B2 Earthscience, University of Arizona, Tucson, AZ 85721, USA
We undertook a series of measurements of photophysiological parameters of sea ice algae over 12 days of early spring growth
in a West Greenland Fjord, by variable chlorophyll fluorescence imaging. Imaging of the ice–water interface showed the development
of ice algae in 0.3–0.4 mm wide brine channels between laminar ice crystals in the lower 4–6 mm of the ice, with a several-fold
spatial variation in inferred biomass on cm scales. The maximum quantum yield of photosynthesis, Fv/Fm, was initially low (~0.1), though this increased rapidly to ~0.5 by day 6. Day 6 also saw the onset of biomass increase,
the cessation of ice growth and the time at which brine had reached <50 psu and >?2 °C. We interpret this as indicating that
the establishment of stable brine channels at close to ambient salinity was required to trigger photosynthetically active
populations. Maximum relative electron transport rate (rETRmax), saturation irradiance (Ek) and photosynthetic efficiency (?) had also stabilised by day 6 at 5–6 relative units, ~30 ?mol photons m?2 s?1 and 0.4–0.5 ?mol photons m?2 s?1, respectively. Ek was consistent with under-ice irradiance, which peaked at a similar value, confirming that daytime irradiance was adequate
to facilitate photosynthetic activity throughout the study period. Photosynthetic parameters showed no substantial differences
with depth within the ice, nor variation between cores or brine channels suggesting that during this early phase of ice algal
growth cells were unaffected by gradients of environmental conditions within the ice. Variable chlorophyll fluorescence imaging
offers a tool to determine how this situation may change over time and as brine channels and algal populations evolve.
Content Type Journal Article
Category Regular Paper
Pages 1-13
DOI 10.1007/s11120-012-9736-7
Authors
Ian Hawes, Gateway Antarctica, Private Bag 4800, Christchurch, New Zealand
Lars Chresten Lund-Hansen, Department of Bioscience, Marine Ecology, Aarhus University, 8000 Aarhus C, Denmark
Brian K. Sorrell, Department of Bioscience, Plant Biology, Aarhus University, 8000 Aarhus C, Denmark
Morten Holtegaard Nielsen, Department of Civil Engineering, Arctic Technology Centre, Technical University of Denmark, Kemitorvet, 2800 Kgs Lyngby, Denmark
Réka Borzák, Department of Bioscience, Marine Ecology, Aarhus University, 8000 Aarhus C, Denmark
Inge Buss, Department of Bioscience, Marine Ecology, Aarhus University, 8000 Aarhus C, Denmark
Conservation of light energy in photosynthesis is possible only in hydrated photoautotrophs. It requires complex biochemistry
and is limited in capacity. Charge separation in reaction centres of photosystem II initiates energy conservation but opens
also the path to photooxidative damage. A main mechanism of photoprotection active in hydrated photoautotrophs is controlled
by light. This is achieved by coupling light flux to the protonation of a special thylakoid protein which activates thermal
energy dissipation. This mechanism facilitates the simultaneous occurrence of energy conservation and energy dissipation but
cannot completely prevent damage by light. Continuous metabolic repair is required to compensate damage. More efficient photoprotection
is needed by desiccation-tolerant photoautotrophs. Loss of water during desiccation activates ultra-fast energy dissipation
in mosses and lichens. Desiccation-induced energy dissipation neither requires a protonation reaction nor light but photoprotection
often increases when light is present during desiccation. Two different mechanisms contribute to photoprotection of desiccated
photoautotrophs. One facilitates energy dissipation in the antenna of photosystem II which is faster than energy capture by
functional reaction centres. When this is insufficient for full photoprotection, the other one permits energy dissipation
in the reaction centres themselves.
Content Type Journal Article
Category Minireview
Pages 1-9
DOI 10.1007/s11120-012-9738-5
Authors
Ulrich Heber, Julius-von-Sachs-Institute, University of Würzburg, 97082 Würzburg, Germany
The temporal profile of the phosphorescence of singlet oxygen endogenously photosensitized by photosystem II (PSII) reaction
centre (RC) in an aqueous buffer has been recorded using laser excitation and a near infrared photomultiplier tube. A weak
emission signal was discernible, and could be fitted to the functional form
a[exp( - t/t2 ) - exp( - t/t1 )]
, with $$ a > 0 $$ and $$ \tau_{2} > \tau_{1} $$. The value of
t2
decreased from 11.6 ± 0.5 ?s under aerobic conditions to 4.1 ± 0.2 ?s in oxygen-saturated samples, due to enhanced bimolecular
quenching of the donor triplet by oxygen, whereas that of
t1
, identifiable with the lifetime of singlet oxygen, was close to 3 ?s in both cases. Extrapolations based on the low amplitude
of the emission signal of singlet oxygen formed by PSII RC in the aqueous buffer and the expected values of
t1
and
t2
in chloroplasts indicate that attempts to analyse the temporal profile of singlet oxygen in chloroplasts are unlikely to
be rewarded with success without a significant advance in the sensitivity of the detection equipment.
Content Type Journal Article
Category Technical Communication
Pages 75-79
DOI 10.1007/s11120-012-9739-4
Authors
Heng Li, Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
Thor Bernt Melø, Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
Juan B. Arellano, Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
K. Razi Naqvi, Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
Our previous work has demonstrated the isolation of photosystem I (PSI) from spinach using ultrafiltration with a final purity
of 84 %. In order to get a higher purity of PSI and more importantly to develop a practical bioseparation process, key physiochemical
properties of PSI and their dependence on operational parameters must be assessed. In this study, the effect of solution pH,
one of the most important operating parameters for membrane process, on the property of PSI was examined. Following the isolation
of crude PSI from spinach using n-dodecyl-beta-d-maltoside as detergent, the isoelectric point, aggregation size, zeta potential, low-temperature fluorescence, atomic force
microscopy imaging, secondary structure, and thermal stability were determined. Solution pH was found to have a significant
effect on the activity, aggregation size and thermal stability of PSI. The results also suggested that the activity of PSI
was related to its aggregation size.
Content Type Journal Article
Category Regular Paper
Pages 63-70
DOI 10.1007/s11120-012-9737-6
Authors
Jianguo Liu, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266555 People’s Republic of China
Xuefang Zhang, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266555 People’s Republic of China
Meng Wang, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266555 People’s Republic of China
Jing Liu, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266555 People’s Republic of China
Meiwen Cao, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266555 People’s Republic of China
Jianren Lu, School of Physics and Astronomy, Manchester University, Manchester, M13 9PL UK
Zhanfeng Cui, Department of Engineering Science, University of Oxford, Oxford, OX1 3PJ UK
High solar radiation in the tropics is known to cause transient reduction in photosystem II (PSII) efficiency and CO2 assimilation in sun-exposed leaves, but little is known how these responses affect the actual growth performance of tropical
plants. The present study addresses this question. Seedlings of five woody neotropical forest species were cultivated under
full sunlight and shaded conditions. In full sunlight, strong photoinhibition of PSII at midday was documented for the late-successional
tree species Ormosia macrocalyx and Tetragastris panamensis and the understory/forest gap species, Piper reticulatum. In leaves of O. macrocalyx, PSII inhibition was accompanied by substantial midday depression of net CO2 assimilation. Leaves of all species had increased pools of violaxanthin-cycle pigments. Other features of photoacclimation,
such as increased Chl a/b ratio and contents of lutein, ?-carotene and tocopherol varied. High light caused strong increase of tocopherol in leaves
of T. panamensis and another late-successional species, Virola surinamensis. O. macrocalyx had low contents of tocopherol and UV-absorbing substances. Under full sunlight, biomass accumulation was not reduced in
seedlings of T. panamensis, P. reticulatum, and V. surinamensis, but O. macrocalyx exhibited substantial growth inhibition. In the highly shade-tolerant understory species Psychotria marginata, full sunlight caused strongly reduced growth of most individuals. However, some plants showed relatively high growth rates
under full sun approaching those of seedlings at 40 % ambient irradiance. It is concluded that shade-tolerant tropical tree
seedlings can achieve efficient photoacclimation and high growth rates in full sunlight.
Content Type Journal Article
Category Regular Paper
Pages 1-13
DOI 10.1007/s11120-012-9731-z
Authors
G. Heinrich Krause, Smithsonian Tropical Research Institute, Apartado Postal, 0843-03092 Panama, Republic of Panama
Klaus Winter, Smithsonian Tropical Research Institute, Apartado Postal, 0843-03092 Panama, Republic of Panama
The Fenna–Matthews–Olson antenna protein from the green bacterium Pelodictyon phaeum mediates the energy transfer from a peripheral antenna complex to the membrane-bound reaction center. The three-dimensional
structure of this protein has been previously modeled using X-ray diffraction to a resolution limit of 2.0 Å, with Rwork and Rfree values of 16.6 and 19.9 %, respectively (Larson et al., Photosynth Res 107:139–150, 2011). This model shows the protein as consisting of ?-sheets surrounding several bacteriochlorophyll cofactors. While most of
the model clearly matches the electron density maps, in this paper we re-examine the electron density for a specific feature,
namely the eighth bacteriochlorophyll a cofactor. This electron density is now interpreted as arising primarily from the end of an otherwise disordered polyethylene
glycol molecule. Additional electron density is present but the density is weak and cannot be unambiguously assigned. The
new model has Rwork and Rfree values of 16.2 and 19.0 %, respectively.
Content Type Journal Article
Category Technical Communication
Pages 71-74
DOI 10.1007/s11120-012-9735-8
Authors
Dale E. Tronrud, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
James P. Allen, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA
Vascular plants use two pathways to synthesize galactolipids, the predominant lipid species in chloroplasts—a prokaryotic
pathway that resides entirely in the chloroplast, and a eukaryotic pathway that involves assembly in the endoplasmic reticulum.
Mutants deficient in the endoplasmic reticulum pathway, trigalactosyldiacylglycerol (tgd1-1 and tgd2-1) mutants, had been previously identified with reduced contents of monogalactosyldiacylglycerol and digalactosyldiacylglycerol,
and altered lipid molecular species composition. Here, we report that the altered lipid composition affected photosynthesis
in lipid trafficking mutants. It was found that proton motive force as measured by electrochromic shift was reduced by ~40
% in both tgd mutants. This effect was accompanied by an increase in thylakoid conductance attributable to ATPase activity and so the rate
of ATP synthesis was nearly unchanged. Thylakoid conductance to ions also increased in tgd mutants. However, gross carbon assimilation in tgd mutants as measured by gas exchange was only marginally affected. Rubisco activity, electron transport rate, and photosystem
I and II oxidation status were not altered. Despite the large differences in proton motive force, responses to heat and high
light stress were similar between tgd mutants and the wild type.
Content Type Journal Article
Category Regular Paper
Pages 49-61
DOI 10.1007/s11120-012-9734-9
Authors
Ziru Li, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
Jinpeng Gao, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
Christoph Benning, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
Thomas D. Sharkey, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
This study demonstrates unequivocally the presence of crassulacean acid metabolism (CAM) in a species of the Rubiaceae, the
fourth largest angiosperm plant family. The tropical Australian endemic epiphytic ant-plant, Myrmecodia beccarii Hook.f., exhibits net CO2 uptake in the dark and a concomitant accumulation of titratable acidity in plants in the field and in cultivation. Plants
growing near Cardwell, in a north Queensland coastal seasonally dry forest of Melaleuca viridiflora Sol. ex Gaertn., accumulated ~50 % of their 24 h carbon gain in the dark during the warm wet season. During the transition
from the wet season to the dry season, 24 h carbon gain was reduced whilst the proportion of carbon accumulated during the
dark increased. By mid dry season many plants exhibited zero net carbon uptake over 24 h, but CO2 uptake in the dark was observed in some plants following localised rainfall. In a shade-house experiment, droughted plants
in which CO2 uptake in the light was absent and dark CO2 uptake was reduced, were able to return to relatively high rates of CO2 uptake in the light and dark within 12 h of rewatering.
Content Type Journal Article
Category Regular Paper
Pages 1-10
DOI 10.1007/s11120-012-9732-y
Authors
Edward W. J. Tsen, Tropical Biology, James Cook University, Townsville, QLD 4811, Australia
Joseph A. M. Holtum, Tropical Biology, James Cook University, Townsville, QLD 4811, Australia
The Chlamydomonasreinhardtii DNA-insertional transformant truncated light-harvesting antenna 1 (tla1) mutant, helped identify the novel TLA1 gene (GenBank Accession # AF534570-71) as an important genetic determinant in the chlorophyll antenna size of photosynthesis.
Down-regulation in the amount of the TLA1 23 kDa protein in the cell resulted in smaller chlorophyll antenna size for both
photosystems (in Tetali et al. Planta 225:813–829, 2007). Specific polyclonal antibodies, raised against the recombinant TLA1 protein, showed a cross-reaction with the predicted 23
kDa TLA1 protein in C. reinhardtii protein extracts, but also showed a strong cross-reaction with a protein band migrating to 28.5 kDa. Questions of polymorphism,
or posttranslational modification of the TLA1 protein were raised as a result of the unexpected 28.5 kDa cross-reaction. Work
in this paper aimed to elucidate the nature of the unexpected 28.5 kDa cross-reaction, as this was deemed to be important
in terms of the functional role of the TLA1 protein in the regulation of the chlorophyll antenna size of photosynthesis. Immuno-precipitation
of the 28.5 kDa protein, followed by LC–mass spectrometry, showed amino acid sequences ascribed to the psbD/D2 reaction center protein of PSII. The common antigenic determinant between TLA1 and D2 was shown to be a stretch of nine
conserved amino acids V-F—L(V)LP-GNAL in the C-terminus of the two proteins, constituting a high antigenicity “GNAL” domain.
Antibodies raised against the TLA1 protein containing this domain recognized both the TLA1 and the D2 protein. Conversely,
antibodies raised against the TLA1 protein minus the GNAL domain specifically recognized the 23 kDa TLA1 protein and failed to recognize the 28.5 kDa D2 protein. D2 antibodies
raised against an oligopeptide containing this domain also cross-reacted with the TLA1 protein. It is concluded that the 28.5
kDa cross-reaction of C. reinhardtii protein extracts with antiTLA1 antibodies is due to antibody affinity for the GNAL domain of the D2 protein and has no bearing
on the identity or function of the TLA1 protein.
Content Type Journal Article
Category Regular Paper
Pages 39-47
DOI 10.1007/s11120-012-9733-x
Authors
Mautusi Mitra, Department of Biology, University of West Georgia, 1601 Maple Drive, Carrollton, GA 30118, USA
David Dewez, Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
Jose Gines García-Cerdán, Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
Anastasios Melis, Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
A mathematical formulation of the relationship between optical absorption coefficient of photosynthetic pigment molecules
and light intensity was developed. It showed that physical parameters of photosynthetic pigment molecule (i.e., light absorption
cross-section of photosynthetic pigment molecule, its average lifetime in the excited state, total photosynthetic pigment
molecules, the statistical weight, or degeneracy of energy level of photosynthetic pigment molecules in the ground state and
in the excited state) influenced on both the light absorption coefficient and effective light absorption cross-section of
photosynthetic pigment molecules. Moreover, it also showed that both the light absorption coefficient and effective light
absorption cross-section of photosynthetic pigment molecules were not constant, they decreased nonlinearly with light intensity
increasing. The occupation numbers of photosynthetic pigment molecules in the excited states increased nonlinearly with light
intensity increasing.
Content Type Journal Article
Category Regular Paper
Pages 31-37
DOI 10.1007/s11120-012-9730-0
Authors
Zi-Piao Ye, Research Center for Jinggangshan Eco-Environmental Sciences, Jinggangshan University, Ji’an, 343009 People’s Republic of China
Excitation–emission fluorescence matrices of phytoplankton communities were simulated from laboratory-grown algae and cyanobacteria
cultures, to define the optical configurations of theoretical fluorometers that either minimize or maximize the representation
of these phytoplankton groups in community variable fluorescence measurements. Excitation sources that match the photosystem
II (PSII) action spectrum of cyanobacteria do not necessarily lead to equal representation of cyanobacteria in community fluorescence.
In communities with an equal share of algae and cyanobacteria, inducible PSII fluorescence in algae can be retrieved from
community fluorescence under blue excitation (450–470 nm) with high accuracy (R2 = 1.00). The highest correlation between community and cyanobacterial variable fluorescence is obtained under orange-red
excitation in the 590–650 nm range (R2 = 0.54). Gaussian band decomposition reveals that in the presence of cyanobacteria, the emission detection slit must be narrow
(up to 10 nm) and centred on PSII chlorophyll-a emission (~683 nm) to avoid severe dampening of the signal by weakly variable phycobilisomal fluorescence and non-variable
photosystem I fluorescence. When these optimizations of the optical configuration of the fluorometer are followed, both cyanobacterial
and algal cultures in nutrient replete exponential growth exhibit values of the maximum quantum yield of charge separation
in PSII in the range of 0.65–0.7.
Content Type Journal Article
Category Regular Paper
Pages 13-30
DOI 10.1007/s11120-012-9729-6
Authors
Stefan G. H. Simis, Finnish Environment Institute SYKE, Marine Research Centre, Erik Palménin Aukio 1, 00560 Helsinki, Finland
Yannick Huot, Département de géomatique appliquée, Université de Sherbrooke, 2500 boulevard de l’Unversité, Sherbrooke, QC, Canada
Marcel Babin, Laboratoire d’Océanographie de Villefranche, B.P. 8, Villefranche-sur-Mer, Cedex, France
Jukka Seppälä, Finnish Environment Institute SYKE, Marine Research Centre, Erik Palménin Aukio 1, 00560 Helsinki, Finland
Liisa Metsamaa, Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Estonia
Can 50 years of research, performed between ignorance and the wish to know, and executed between hope, despair, satisfaction
and pain, be compressed into an abstract? What has been done in more than 50 years may be expressed in four words: it was
worth it. If I had another life, I would do it again. In the beginning of my career, life was an enigma. It still is. Molecular
details of the workings of life had been largely unknown when I began. Now, at the end, I still wish to know details: how
is light, master of life, manipulated to either support life, when photosynthesis is possible, or to protect it when light
endangers it. What is the molecular and the physical nature of the biological mechanisms which control both, energy conservation
and energy dissipation, in photosynthesis?
Content Type Journal Article
Category Personal Perspective
Pages 1-12
DOI 10.1007/s11120-012-9725-x
Authors
Ulrich Heber, Julius-von-Sachs-Institute, University of Würzburg, 97082 Würzburg, Germany
In order to obtain an improved understanding of the assembly of the bacterial photosynthetic apparatus, we have conducted
a proteomic analysis of pigment-protein complexes isolated from the purple bacterium Rhodobacter sphaeroides undergoing acclimation to reduced incident light intensity. Photoheterotrophically growing cells were shifted from 1,100
to 100 W/m2 and intracytoplasmic membrane (ICM) vesicles isolated over 24-h were subjected to clear native polyacrylamide gel electrophoresis.
Bands containing the LH2 and reaction center (RC)-LH1 complexes were excised and subjected to in-gel trypsin digestion followed
by liquid chromatography (LC)-mass spectroscopy (MS)/MS. The results revealed that the LH2 band contained distinct levels
of the LH2-? and -? polypeptides encoded by the two puc operons. Polypeptide subunits encoded by the puc2AB operon predominated under high light and in the early stages of acclimation to low light, while after 24 h, the puc1BAC components were most abundant. Surprisingly, the Puc2A polypeptide containing a 251 residue C-terminal extension not present
in Puc1A, was a protein of major abundance. A predominance of Puc2A components in the LH2 complex formed at high light intensity
is followed by a >2.5-fold enrichment in Puc1B levels between 3 and 24 h of acclimation, accompanied by a nearly twofold decrease
in Puc2A levels. This indicates that the puc1BAC operon is under more stringent light control, thought to reflect differences in the puc1 upstream regulatory region. In contrast, elevated levels of Puc2 polypeptides were seen 48 h after the gratuitous induction
of ICM formation at low aeration in the dark, while after 24 h of acclimation to low light, an absence of alterations in Puc
polypeptide distributions was observed in the upper LH2-enriched gel band, despite an approximate twofold increase in overall
LH2 levels. This is consistent with the origin of this band from a pool of LH2 laid down early in development that is distinct
from subsequently assembled LH2-only domains, forming the LH2 gel band.
Content Type Journal Article
Category Regular Paper
Pages 125-138
DOI 10.1007/s11120-011-9707-4
Authors
Kamil Woronowicz, Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, 604 Allison Road, Piscataway, NJ 08854-8082, USA
Oluwatobi B. Olubanjo, Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, 604 Allison Road, Piscataway, NJ 08854-8082, USA
Hee Chang Sung, Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, 604 Allison Road, Piscataway, NJ 08854-8082, USA
Joana L. Lamptey, Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, 604 Allison Road, Piscataway, NJ 08854-8082, USA
Robert A. Niederman, Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, 604 Allison Road, Piscataway, NJ 08854-8082, USA
We have developed a purification protocol for photoactive reaction centers (HbRC) from Heliobacterium modesticaldum. HbRCs were purified from solubilized membranes in two sequential chromatographic steps, resulting in the isolation of a
fraction containing a single polypeptide, which was identified as PshA by LC–MS/MS of tryptic peptides. All polypeptides reported
earlier as unknown proteins (in Heinnickel et al., Biochemistry 45:6756–6764, 2006; Romberger et al., Photosynth Res 104:293–303, 2010) are now identified by mass spectrometry to be the membrane-bound cytochrome c553 and four different ABC-type transporters. The purified PshA homodimer binds the following pigments: 20 bacteriochlorophyll
(BChl) g, two BChl g?, two 81-OH-Chl aF, and one 4,4?-diaponeurosporene. It lacks the PshB polypeptide binding the FA and FB [4Fe–4S] clusters. It is active in charge separation and exhibits a trapping time of 23 ps, as judged by time-resolved fluorescence
studies. The charge recombination rate of the P800+FX? state is 10–15 ms, as seen before. The purified HbRC core was able to reduce cyanobacterial flavodoxin in the light, exhibiting
a KM of 10 ?M and a kcat of 9.5 s?1 under near-saturating light. There are ~1.6 menaquinones per HbRC in the purified complex. Illumination of frozen HbRC in
the presence of dithionite can cause creation of a radical at g = 2.0046, but this is not a semiquinone. Furthermore, we show that high-purity HbRCs are very stable in anoxic conditions
and even remain active in the presence of oxygen under low light.
Content Type Journal Article
Category Regular Paper
Pages 291-302
DOI 10.1007/s11120-012-9726-9
Authors
Iosifina Sarrou, Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ 85287-1604, USA
Zahid Khan, Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ 85287-1604, USA
John Cowgill, Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ 85287-1604, USA
Su Lin, Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ 85287-1604, USA
Daniel Brune, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
Steven Romberger, Department of Biochemistry and Molecular Biology, and Department of Chemistry, The Pennsylvania State University, University Park, PA 16801, USA
John H. Golbeck, Department of Biochemistry and Molecular Biology, and Department of Chemistry, The Pennsylvania State University, University Park, PA 16801, USA
Kevin E. Redding, Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ 85287-1604, USA
Thalli of the foliose lichen species Parmelina tiliacea were studied to determine responses of the photosynthetic apparatus to high temperatures in the dry and wet state. The speed
with which dry thalli were activated by water following a 24 h exposure at different temperatures decreased as the temperature
was increased. But even following a 24 h exposure to 50°C the fluorescence induction kinetics OJIP reflecting the reduction
kinetics of the photosynthetic electron transport chain had completely recovered within 128 min. Exposure of dry thalli to
50°C for 24 h did not induce a K-peak in the fluorescence rise suggesting that the oxygen evolving complex had remained intact.
This contrasted strongly with wet thalli were submergence for 40 s in water of 45°C inactivated most of the photosystem II
reaction centres. In wet thalli, following the destruction of the Mn-cluster, the donation rate to photosystem II by alternative
donors (e.g. ascorbate) was lower than in higher plants. This is associated with the near absence of a secondary rise peak
(~1 s) normally observed in higher plants. Analysing the 820 nm and prompt fluorescence transients suggested that the M-peak
(occurs around 2–5 s) in heat-treated wet lichen thalli is related to cyclic electron transport around photosystem I. Normally,
heat stress in lichen thalli leads to desiccation and as consequence lichens may lack the heat-stress-tolerance-increasing
mechanisms observed in higher plants. Wet lichen thalli may, therefore, represent an attractive reference system for the evaluation
of processes related with heat stress in higher plants.
Content Type Journal Article
Category Regular Paper
Pages 303-314
DOI 10.1007/s11120-012-9728-7
Authors
Abdallah Oukarroum, Laboratories of Bioenergetics and Microbiology, Department of Botany and Plant Biology, University of Geneva, Chemin des Embrouchis 10, 1254 Jussy, Geneva, Switzerland
Reto J. Strasser, Laboratories of Bioenergetics and Microbiology, Department of Botany and Plant Biology, University of Geneva, Chemin des Embrouchis 10, 1254 Jussy, Geneva, Switzerland
Gert Schansker, Laboratories of Bioenergetics and Microbiology, Department of Botany and Plant Biology, University of Geneva, Chemin des Embrouchis 10, 1254 Jussy, Geneva, Switzerland
The light-harvesting complex, LH1, of thermophile purple bacteria Thermochromatium tepidum consists of an array of ?- and ?-polypeptides which assemble the photoactive bacteriochlorophyll and closely interact with
the membrane-lipids. In this study, we investigated the effect of calcium and manganese ions on the protein structure and
thermostability of the reaction centre (RC)–LH1/lipid complex. The binding of Ca2+, but not Mn2+ is shown to shift the LH1 Qy absorption maximum from ~889 to 915 nm and to significantly raise the thermostability of the RC–LH1 complex. The ATR–FTIR
spectra indicate that interaction of Ca2+ as monitored by the carboxylates’ vibration of aspartate residues, but not Mn2+ induces changes in the ?-helix packing arrangement. The reduced rate of 1H/2H exchange of proteins’ amide protons shows that the accessibility to 2H2O is significantly lowered in Ca2+-substituted RC–LH1/lipid complexes. In particular, exchange with the associated lipid molecules, is significantly retarded.
These results suggest that the thermostability of the RC–LH1 complex is raised by the distinct interaction with calcium cations
which reduces the RC–LH1/lipid dynamics, particularly, at the membrane–water interface.
Content Type Journal Article
Category Regular Paper
Pages 139-147
DOI 10.1007/s11120-012-9727-8
Authors
Selma Jakob-Grun, Department Biology I, Botany, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
Jara Radeck, Department Biology I, Botany, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
Paula Braun, Department Biology I, Botany, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
Fungicides are widely used to control pests in crop plants. However, it has been reported that these pesticides may have negative
effects on crop physiology, especially on photosynthesis. An alteration in photosynthesis might lead to a reduction in photoassimilate
production, resulting in a decrease in both growth and yield of crop plants. For example, a contact fungicide such as copper
inhibits photosynthesis by destroying chloroplasts, affecting photosystem II activity and chlorophyll biosynthesis. Systemic
fungicides such as benzimidazoles, anilides, and pyrimidine are also phytotoxic, whereas azoles stimulate photosynthesis.
This article focuses on the available information about toxic effects of fungicides on photosynthesis in crop plants, highlighting
the mechanisms of perturbation, interaction, and the target sites of different classes of fungicides.
Content Type Journal Article
Category Review
Pages 315-326
DOI 10.1007/s11120-012-9719-8
Authors
Anne-Noëlle Petit, Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
Florence Fontaine, Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
Parul Vatsa, Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
Christophe Clément, Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
Nathalie Vaillant-Gaveau, Laboratoire de Stress, Défenses et Reproduction des Plantes, URVVC EA 2069, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Bâtiment 18, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
Photoassimilated carbons are converted to sucrose in green plant leaves and distributed to non-phototropic tissues to provide
carbon and energy. In photosynthetic sucrose biosynthesis, the chloroplast envelope triose phosphate/phosphate translocator
(TPT) and cytosolic fructose-1,6-bisphosphatase (cFBPase) are key components in photosynthetic sucrose biosynthesis. The simultaneous
overexpression of TPT and cFBPase was utilized to increase the source capacity of Arabidopsis. The TPT and cFBPase overexpression lines exhibited enhanced growth with larger rosette sizes and increased fresh weights compared with wild-type
(WT) plants. The simultaneous overexpression of TPT and cFBPase resulted in enhanced photosynthetic CO2 assimilation rates in moderate and elevated light conditions. During the phototropic period, the soluble sugar (sucrose,
glucose, and fructose) levels in the leaves of these transgenic lines were also higher than those of the WT plants. These
results suggest that the simultaneous overexpression of TPT and cFBPase enhances source capacity and consequently leads to growth enhancement in transgenic plants.
Content Type Journal Article
Category Regular Paper
Pages 261-268
DOI 10.1007/s11120-012-9720-2
Authors
Man-Ho Cho, Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, 446-701 Korea
Areum Jang, Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, 446-701 Korea
Seong Hee Bhoo, Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, 446-701 Korea
Jong-Seong Jeon, Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, 446-701 Korea
Tae-Ryong Hahn, Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin, 446-701 Korea
Phototrophs of the family Heliobacteriaceae contain the simplest known Type I reaction center (RC), consisting of a homodimeric
(PshA)2 core devoid of bound cytochromes and antenna proteins. Unlike plant and cyanobacterial Photosystem I in which the FA/FB protein, PsaC, is tightly bound to P700–FX cores, the RCs of Heliobacterium modesticaldum contain two FA/FB proteins, PshBI and PshBII, which are loosely bound to P800–FX cores. These two 2[4Fe–4S] ferredoxins have been proposed to function as mobile redox proteins, reducing downstream metabolic
partners much in the same manner as does [2Fe–2S] ferredoxin or flavodoxin (Fld) in PS I. Using P800–FX cores devoid of PshBI and PshBII, we show that iron–sulfur cluster FX directly reduces Fld without the involvement of FA or FB (Fld is used as a proxy for soluble redox proteins even though a gene encoding Fld is not identified in the H. modesticaldum genome). The reduction of Fld is suppressed by the addition of PshBI or PshBII, an effect explained by competition for the
electron on FX. In contrast, P700–FX cores require the presence of the PsaC, and hence, the FA/FB clusters for Fld (or ferredoxin) reduction. Thus, in H. modesticaldum, the interpolypeptide FX cluster serves as the terminal bound electron acceptor. This finding implies that the homodimeric (PshA)2 cores should be capable of donating electrons to a wide variety of yet-to-be characterized soluble redox partners.
Content Type Journal Article
Category Regular Paper
Pages 285-290
DOI 10.1007/s11120-012-9723-z
Authors
Steven P. Romberger, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
John H. Golbeck, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
The future environment may be altered by high concentrations of salt in the soil and elevated [CO2] in the atmosphere. These have opposite effects on photosynthesis. Generally, salt stress inhibits photosynthesis by stomatal
and non-stomatal mechanisms; in contrast, elevated [CO2] stimulates photosynthesis by increasing CO2 availability in the Rubisco carboxylating site and by reducing photorespiration. However, few studies have focused on the
interactive effects of these factors on photosynthesis. To elucidate this knowledge gap, we grew the barley plant, Hordeum vulgare (cv. Iranis), with and without salt stress at either ambient or elevated atmospheric [CO2] (350 or 700 ?mol mol?1 CO2, respectively). We measured growth, several photosynthetic and fluorescence parameters, and carbohydrate content. Under saline
conditions, the photosynthetic rate decreased, mostly because of stomatal limitations. Increasing salinity progressively increased
metabolic (photochemical and biochemical) limitation; this included an increase in non-photochemical quenching and a reduction
in the PSII quantum yield. When salinity was combined with elevated CO2, the rate of CO2 diffusion to the carboxylating site increased, despite lower stomatal and internal conductance. The greater CO2 availability increased the electron sink capacity, which alleviated the salt-induced metabolic limitations on the photosynthetic
rate. Consequently, elevated CO2 partially mitigated the saline effects on photosynthesis by maintaining favorable biochemistry and photochemistry in barley
leaves.
Content Type Journal Article
Category Regular Paper
Pages 269-283
DOI 10.1007/s11120-012-9721-1
Authors
Usue Pérez-López, Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain
Anabel Robredo, Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain
Maite Lacuesta, Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad del País Vasco, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
Amaia Mena-Petite, Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain
Alberto Muñoz-Rueda, Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain
Chloroflexus aurantiacus J-10-fl is a thermophilic green bacterium, a filamentous anoxygenic phototroph, and the model organism of the phylum Chloroflexi.
We applied high-throughput, liquid chromatography–mass spectrometry in a global quantitative proteomics investigation of C. aurantiacus cells grown under oxic (chemoorganoheterotrophically) and anoxic (photoorganoheterotrophically) redox states. Our global
analysis identified 13,524 high-confidence peptides that matched to 1,286 annotated proteins, 242 of which were either uniquely
identified or significantly increased in abundance under photoheterotrophic culture condition. Fifty-four of the 242 proteins
are previously characterized photosynthesis-related proteins, including chlorosome proteins, proteins involved in the bacteriochlorophyll
biosynthesis, 3-hydroxypropionate (3-OHP) CO2 fixation pathway, and components of electron transport chains. The remaining 188 proteins have not previously been reported.
Of these, five proteins were found to be encoded by genes from a novel operon and observed only in photoheterotrophically
grown cells. These proteins candidates may prove useful in further deciphering the phototrophic physiology of C. aurantiacus and other filamentous anoxygenic phototrophs.
Content Type Journal Article
Category Regular Paper
Pages 153-168
DOI 10.1007/s11120-011-9711-8
Authors
Li Cao, Biological Separations and Mass Spectrometry, Pacific Northwest National Laboratory, Richland, WA 99352, USA
Donald A. Bryant, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
Athena A. Schepmoes, Biological Separations and Mass Spectrometry, Pacific Northwest National Laboratory, Richland, WA 99352, USA
Kajetan Vogl, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
Richard D. Smith, Biological Separations and Mass Spectrometry, Pacific Northwest National Laboratory, Richland, WA 99352, USA
Mary S. Lipton, Biological Separations and Mass Spectrometry, Pacific Northwest National Laboratory, Richland, WA 99352, USA
Stephen J. Callister, Biological Separations and Mass Spectrometry, Pacific Northwest National Laboratory, Richland, WA 99352, USA
Photosynthetic electron transfer has been examined in whole cells, isolated membranes and in partially purified reaction centers
(RCs) of Roseicyclus mahoneyensis, strain ML6 and Porphyrobacter meromictius, strain ML31, two species of obligate aerobic anoxygenic phototrophic bacteria. Photochemical activity in strain ML31 was
observed aerobically, but the photosynthetic apparatus was not functional under anaerobic conditions. In strain ML6 low levels
of photochemistry were measured anaerobically, possibly due to incomplete reduction of the primary electron acceptor (QA) prior to light excitation, however, electron transfer occurred optimally under low oxygen conditions. Photoinduced electron
transfer involves a soluble cytochrome c in both strains, and an additional reaction center (RC)-bound cytochrome c in ML6. The redox properties of the primary electron donor (P) and QA of ML31 are similar to those previously determined for other aerobic phototrophs, with midpoint redox potentials of +463 mV
and ?25 mV, respectively. Strain ML6 showed a very narrow range of ambient redox potentials appropriate for photosynthesis,
with midpoint redox potentials of +415 mV for P and +94 mV for QA. Cytoplasm soluble and photosynthetic complex bound cytochromes were characterized in terms of apparent molecular mass. Fluorescence
excitation spectra revealed that abundant carotenoids not intimately associated with the RC are not involved in photosynthetic
energy conservation.
Content Type Journal Article
Category Regular Paper
Pages 193-203
DOI 10.1007/s11120-011-9718-1
Authors
Christopher Rathgeber, Department of Microbiology, The University of Manitoba, 422 Buller Building, Winnipeg, MB R3T 2N2, Canada
Jean Alric, Institut de Biologie Physico-Chimique, CNRS UPR 1261, 13 rue P. et M. Curie, 75005 Paris, France
Elizabeth Hughes, Department of Microbiology, The University of Manitoba, 422 Buller Building, Winnipeg, MB R3T 2N2, Canada
André Verméglio, CEA-Cadarache DSV-DEVM Laboratoire de Bioénergétique Cellulaire, UMR 163 CEA-CNRS, Univ. Méditerranée-CEA 1000, 13108 Saint Paul lez Durance Cedex, France
Vladimir Yurkov, Department of Microbiology, The University of Manitoba, 422 Buller Building, Winnipeg, MB R3T 2N2, Canada
This News Report is a brief description of the 2010 Lifetime Achievement Award received by William (Bill) L. Ogren from the Rebeiz Foundation
for Basic Research, at Champaign, Illinois, on Sep 10, 2011. It focuses mainly on the presentations by two of us (ARP and
Gov), Christoph Benning (on behalf of Chris Somerville), David Krogmann and Jack Widholm, at this ceremony. It is enriched
by the testimonial received from George Bowes at the time of the preparation of this report.
Content Type Journal Article
Category News Report
Pages 213-220
DOI 10.1007/s11120-011-9716-3
Authors
Archie R. Portis, Departments of Crop Sciences and Plant Biology, University of Illinois, Urbana-Champaign, IL 61801, USA
Govindjee, Departments of Plant Biology and Biochemistry and Center of Biophysics & Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA
An interesting phenomenon is that some light-demanding plants fold their leaves when exposed to high light. Since high light
could induce selective photodamage to photosystem II (PSII), we suggest that the leaves fold themselves to diminish the absorption
of light energy and remedy the deficiency of physiological photoprotection for PSII. To test this hypothesis, we determined
light responses of non-photochemical quenching (NPQ) and cyclic electron flow (CEF) and the effect of high light on PSII activity
in Microcos paniculata (non-foldable species) and Bauhinia tenuiflora (foldable species). Under high light B. tenuiflora showed much lower NPQ and CEF than M. paniculata. Meanwhile, the excess light energy that cannot be harmlessly dissipated in B. tenuiflora was more compared with that in M. paniculata. After exposure to a high light of 1,900 ?mol photons m?2 s?1 for 2 h, the maximum quantum yield of PSII, as estimated by variable to maximal fluorescence (Fv/Fm) decreased from 0.7 to 0.52 in the foldable species B. tenuiflora but was stable at 0.7 in the nonfoldable species M. paniculata. These results indicate that the foldable species B. tenuiflora has more sensitivity of PSII to high light stress than the nonfoldable species M. paniculata, partly as a result of less CEF and NPQ in B. tenuiflora. Our results suggest that sun leaves fold themselves under high light to remedy the deficiency of physiological photoprotection
for PSII.
Content Type Journal Article
Category Regular Paper
Pages 185-191
DOI 10.1007/s11120-011-9717-2
Authors
Wei Huang, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
Shi-Bao Zhang, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
Kun-Fang Cao, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
The biogenesis and oxygen-evolving activity of cyanobacterial Photosystem II (PSII) is dependent on a number of accessory
proteins not found in the crystallised dimeric complex. These include Psb27, a small lipoprotein attached to the lumenal side
of PSII, which has been assigned a role in regulating the assembly of the Mn4Ca cluster catalysing water oxidation. To gain a better understanding of Psb27, we have determined in this study the crystal
structure of the soluble domain of Psb27 from Thermosynechococcus elongatus to a resolution of 1.6 Å. The structure is a four-helix bundle, similar to the recently published solution structures of
Psb27 from Synechocystis PCC 6803 obtained by nuclear magnetic resonance (NMR) spectroscopy. Importantly, the crystal structure presented here helps
us resolve the differences between the NMR-derived structural models. Potential binding sites for Psb27 within PSII are discussed
in light of recent biochemical data in the literature.
Content Type Journal Article
Category Regular Paper
Pages 169-175
DOI 10.1007/s11120-011-9712-7
Authors
Franck Michoux, Division of Molecular Biosciences, Imperial College London, Wolfson Biochemistry Building, South Kensington Campus, London, SW7 2AZ UK
Kenji Takasaka, Division of Molecular Biosciences, Imperial College London, Wolfson Biochemistry Building, South Kensington Campus, London, SW7 2AZ UK
Marko Boehm, Division of Molecular Biosciences, Imperial College London, Wolfson Biochemistry Building, South Kensington Campus, London, SW7 2AZ UK
Josef Komenda, Institute of Microbiology, Academy of Sciences, 379 81 T?ebo?, Czech Republic
Peter J. Nixon, Division of Molecular Biosciences, Imperial College London, Wolfson Biochemistry Building, South Kensington Campus, London, SW7 2AZ UK
James W. Murray, Division of Molecular Biosciences, Imperial College London, Wolfson Biochemistry Building, South Kensington Campus, London, SW7 2AZ UK
In this brief report, we provide a perspective on an international conference “Photosynthesis Research for Sustainability-2011”, held in Baku, Azerbaijan, during July 24–30, 2011 (http://www.photosynthesis2011.cellreg.org/). At this conference, awards were given to nine young investigators; they are recognized in this Report. We have also included here some photographs to show the pleasant ambiance at this conference. (See http://www.photosynthesis2011.cellreg.org/Photos.php and http://www.life.illinois.edu/govindjee/g/Photo/Baku.html for more photographs taken by the authors as well as by others.) We invite the readers to the next conference on “Photosynthesis
Research for Sustainability-2013” to be held in May or June 2013, in Baku, Azerbaijan. Information will be posted at: http://www.photosynthesis2013.cellreg.org/.
Content Type Journal Article
Category News Report
Pages 205-212
DOI 10.1007/s11120-011-9713-6
Authors
Suleyman I. Allakhverdiev, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276 Russia
Irada M. Huseynova, Institute of Botany, Azerbaijan National Academy of Sciences, 40 Badamdar Shosse, Baku, AZ 1073, Azerbaijan
Govindjee, Department of Plant Biology, Department of Biochemistry and Center of Biophysics & Computational Biology, University of Illinois, 265 Morrill Hall, MC-116, 505 South Goodwin Avenue, Urbana, IL 61801-3707, USA
Photosystem II is the oxygen-evolving enzyme of photosynthesis. It is a membrane-bound protein-pigment complex. The oxygen
is produced at the oxygen-evolving centre (OEC), a Mn4CaO5 metallocluster, which is largely ligated by amino acids of the D1 protein. The OEC-ligating residues are invariant between
most cyanobacteria and higher plants. In this study, a new class of cyanobacterial D1 proteins has been identified in which
the OEC metal-ligating residues are very different to the consensus. This new class of ‘rogue’ D1 proteins is associated with
diazotrophic cyanobacteria. Their function, activity and origins are discussed.
Content Type Journal Article
Category Regular Paper
Pages 177-184
DOI 10.1007/s11120-011-9714-5
Authors
James W. Murray, Division of Molecular Biosciences, Imperial College, Exhibition Road, London, SW7 2AZ UK
During the recent years, wide varieties of methodologies have been developed up to the level of commercial use to measure
photosynthetic electron transport by modulated chlorophyll a-in vivo fluorescence. It is now widely accepted that the ratio between electron transport rates and new biomass (PFl/BC) is not fixed and depends on many factors that are also taxonomically variable. In this study, the balance between photon
absorption and biomass production has been measured in two phycobilin-containing phototrophs, namely, a cyanobacterium and
a cryptophyte, which differ in their antenna organization. It is demonstrated that the different antenna organization exerts
influence on the regulation of the primary photosynthetic reaction and the dissipation of excessively absorbed radiation.
Although, growth rates and the quantum efficiency of biomass production of both phototrophs were comparable, the ratio PFl/BC was twice as high in the cryptophyte in comparison to the cyanobacterium. It is assumed that this discrepancy is because
of differences in the metabolic regulation of cell growth. In the cryptophyte, absorbed photosynthetic energy is used to convert
assimilated carbon directly into proteins and lipids, whereas in the cyanobacterium, the photosynthetic energy is preferentially
stored as carbohydrates.
Content Type Journal Article
Category Regular Paper
Pages 173-183
DOI 10.1007/s11120-011-9715-4
Authors
Christfried Kunath, Institute of Biology, Plant Physiology, University of Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany
Torsten Jakob, Institute of Biology, Plant Physiology, University of Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany
Christian Wilhelm, Institute of Biology, Plant Physiology, University of Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany
Chromera velia is a newly discovered photosynthetic eukaryotic alga that has functional chloroplasts closely related to the apicoplast of
apicomplexan parasites. Recently, the chloroplast in C. velia was shown to be derived from the red algal lineage. Light-harvesting protein complexes (LHC), which are a group of proteins
involved in photon capture and energy transfer in photosynthesis, are important for photosynthesis efficiency, photo-adaptation/accumulation
and photo-protection. Although these proteins are encoded by genes located in the nucleus, LHC peptides migrate and function
in the chloroplast, hence the LHC may have a different evolutionary history compared to chloroplast evolution. Here, we compare
the phylogenetic relationship of the C. velia LHCs to LHCs from other photosynthetic organisms. Twenty-three LHC homologues retrieved from C. velia EST sequences were aligned according to their conserved regions. The C.velia LHCs are positioned in four separate groups on trees constructed by neighbour-joining, maximum likelihood and Bayesian methods.
A major group of seventeen LHCs from C. velia formed a separate cluster that was closest to dinoflagellate LHC, and to LHC and fucoxanthin chlorophyll-binding proteins
from diatoms. One C. velia LHC sequence grouped with LI1818/LI818-like proteins, which were recently identified as environmental stress-induced protein
complexes. Only three LHC homologues from C. velia grouped with the LHCs from red algae.
Content Type Journal Article
Category Regular Paper
Pages 19-28
DOI 10.1007/s11120-011-9710-9
Authors
Hao Pan, School of Biological Sciences (A08), Faculty of Sciences, University of Sydney, Sydney, NSW 2006, Australia
Jan Šlapeta, Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
Dee Carter, Discipline of Microbiology, School of Molecular Biosciences, University of Sydney, Sydney, NSW 2006, Australia
Min Chen, School of Biological Sciences (A08), Faculty of Sciences, University of Sydney, Sydney, NSW 2006, Australia
Highly time-resolved photoacclimation patterns of the chlorophyte microalga Dunaliella tertiolecta during exposure to an off–on–off (block) light pattern of saturating photon flux, and to a regime of consecutive increasing
light intensities are presented. Non-photochemical quenching (NPQ) mechanisms unexpectedly responded with an initial decrease
during dark–light transitions. NPQ values started to rise after light exposure of approximately 4 min. State-transitions,
measured as a change of PSII:PSI fluorescence emission at 77 K, did not contribute to early NPQ oscillations. Addition of
the uncoupler CCCP, however, caused a rapid increase in fluorescence and showed the significance of qE for NPQ. Partitioning
of the quantum efficiencies showed that constitutive NPQ was (a) higher than qE-driven NPQ and (b) responded to light treatment
within seconds, suggesting an active role of constitutive NPQ in variable energy dissipation, although it is thought to contribute
statically to NPQ. The PSII connectivity parameter p correlated well with F?, Fm? and NPQ during the early phase of the dark–light transients in sub-saturating light, suggesting a plastic energy distribution
pattern within energetically connected PSII centres. In consecutive increasing photon flux experiments, correlations were
weaker during the second light increment. Changes in connectivity can present an early photoresponse that are reflected in
fluorescence signals and NPQ and might be responsive to the short-term acclimation state, and/or to the actinic photon flux.
Content Type Journal Article
Category Regular Paper
Pages 123-137
DOI 10.1007/s11120-011-9709-2
Authors
Sven Ihnken, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
Jacco C. Kromkamp, Netherlands Institute of Ecology, Centre for Estuarine and Marine Ecology (NIOO-CEME), P.O. Box 140, 4400 AC Yerseke, The Netherlands
John Beardall, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
Kärin Nickelsen and Govindjee: The Maximum Quantum Yield Controversy: Otto Warburg and the “Midwest-Gang”
Content Type Journal Article
Category Book Review
Pages 139-141
DOI 10.1007/s11120-011-9705-6
Authors
Howard Gest, Departments of Biology and History and Philosophy of Science, Indiana University, 1001 E. 3rd St., Jordan Hall 142, Bloomington, IN 47405-7005, USA
Energy transfer (ET) processes between chromophores in R-phycoerythrin (R-PE) from Polysiphonia urceolata were studied by use of ultrafast spectroscopic methods. Several primary ET pathways were elaborated. A fluorescence decay
component with a time constant of several hundred picoseconds observed by streak camera is tentatively assigned to the reversible
formation of exciton traps between ?84 and ?84 pigment pairs. In order to investigate much faster ET processes in R-PE, a
noncollinear optical parametric amplifier based femtosecond time-resolved transient fluorescence spectrometer was employed.
The results reveal that the ET between ?84 and ?84 pigment pair has a time constant of 1–2 ps; the energy migration between
?84 and ?84 pairs within the R-PE trimer has a time constant of 30–40 ps. We also demonstrated an ET process from phycourobilin
to phycoerythrobilin with a time constant as fast as 2.5–3.0 ps, which was directly observed in fluorescence kinetics by selective
excitation of the phycourobilin molecules acting as the energy donor.
Content Type Journal Article
Category Regular Paper
Pages 81-86
DOI 10.1007/s11120-011-9708-3
Authors
Hailong Chen, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijng, 100190 China
Wei Dang, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijng, 100190 China
Jie Xie, Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 China
Jingquan Zhao, Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 China
Yuxiang Weng, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijng, 100190 China
Erratum to: Electrochromism: a useful probe to study algal photosynthesis
Content Type Journal Article
Category Erratum
Pages 151-152
DOI 10.1007/s11120-011-9704-7
Authors
Benjamin Bailleul, UMR 7141, Centre National de la Recherche Scientifique, Institut de Biologie Physico-Chimique, Université Pierre et Marie Curie, 75005 Paris, France
Pierre Cardol, Laboratoire de Génétique des Microorganismes, Université de Liège, 4000 Liège, Belgium
Cécile Breyton, UMR 5075, Commissariat à l’Energie Atomique et aux Energies, Alternatives, Centre National de la Recherche Scientifique, Institut de Biologie Structurale, Université Joseph Fourier, 38027 Grenoble, France
Giovanni Finazzi, UMR 7141, Centre National de la Recherche Scientifique, Institut de Biologie Physico-Chimique, Université Pierre et Marie Curie, 75005 Paris, France
Using photographs taken at the conference site, we provide a perspective on (i) the awards that were given to four young investigators
at the 2011 Gordon Research Conference on Photosynthesis, and (ii) the ambiance at this conference, held at Davidson College,
North Carolina, during June 12–17, 2011.
Content Type Journal Article
Category News Report
Pages 143-149
DOI 10.1007/s11120-011-9706-5
Authors
Govindjee, Department of Plant Biology, Department of Biochemistry, and Center of Biophysics & Computational Biology, University of Illinois at Urbana-Champaign, 265 Morrill Hall, 505 South Goodwin Avenue, Urbana, IL 61801, USA
Gennady M. Ananyev, Department of Chemistry and Chemical Biology and Waksman Institute of Microbiology, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA
Sergei Savikhin, Department of Physics, Purdue University, West Lafayette, IN 47907, USA
Elastic incoherent neutron scattering (EINS), a non-invasive technique which is capable of measuring the mean square displacement
of atoms in the sample, has been widely used in biology for exploring the dynamics of proteins and lipid membranes but studies
on photosynthetic systems are scarce. In this study we investigated the dynamic characteristics of Photosystem II (PSII) membrane
fragments between 280 and 340 K, i.e., in the physiological temperature range and in the range of thermal denaturation of
some of the protein complexes. The mean square displacement values revealed the presence of a hydration-sensitive transition
in the sample between 310 and 320 K, suggesting that the oxygen evolving complex (OEC) plays an important role in the transition.
Indeed, in samples in which the OEC had been removed by TRIS- or heat-treatments (323 and 333 K) no such transition was found.
Further support on the main role of OEC in these reorganizations is provided by data obtained from differential scanning calorimetry
experiments, showing marked differences between the untreated and TRIS-treated samples. In contrast, circular dichroism spectra
exhibited only minor changes in the excitonic interactions below 323 K, showing that the molecular organization of the pigment-protein
complexes remains essentially unaffected. Our data, along with earlier incoherent neutron scattering data on PSII membranes
at cryogenic temperatures (Pieper et al., Biochemistry 46:11398–11409, 2007), demonstrate that this technique can be applied to characterize the dynamic features of PSII membranes, and can be used
to investigate photosynthetic membranes under physiologically relevant experimental conditions.
Content Type Journal Article
Category Regular Paper
Pages 113-124
DOI 10.1007/s11120-011-9701-x
Authors
Gergely Nagy, Institut Laue-Langevin, P.O. Box 156, 38042 Grenoble Cedex 9, France
Jörg Pieper, Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia
Sashka B. Krumova, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, G. Bontchev Str., bl. 21, 1113 Sofia, Bulgaria
László Kovács, Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, P.O. Box 521, 6701 Hungary
Marcus Trapp, Institut Laue-Langevin, P.O. Box 156, 38042 Grenoble Cedex 9, France
Gy?z? Garab, Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, P.O. Box 521, 6701 Hungary
The photosystem II (PSII) manganese-stabilizing protein (PsbO) is known to be the essential PSII extrinsic subunit for stabilization
and retention of the Mn and Cl? cofactors in the oxygen evolving complex (OEC) of PSII, but its function relative to Ca2+ is less clear. To obtain a better insight into the relationship, if any, between PsbO and Ca2+ binding in the OEC, samples with altered PsbO-PSII binding properties were probed for their potential to promote the ability
of Ca2+ to protect the Mn cluster against dark-inhibition by an exogenous artificial reductant, N,N-dimethylhydroxylamine. In the absence of the PsbP and PsbQ extrinsic subunits, Ca2+ and its surrogates (Sr2+, Cd2+) shield Mn atoms from inhibitory reduction (Kuntzleman et al., Phys Chem Chem Phys 6:4897, 2004). The results presented here show that PsbO exhibits a positive effect on Ca2+ binding in the OEC by facilitating the ability of the metal to prevent inhibition of activity by the reductant. The data
presented here suggest that PsbO may have a role in the formation of the OEC-associated Ca2+ binding site by promoting the equilibrium between bound and free Ca2+ that favors the bound metal.
Content Type Journal Article
Category Regular Paper
Pages 111-121
DOI 10.1007/s11120-011-9703-8
Authors
Hana Popelkova, Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA
Nicholas Boswell, Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA
Charles Yocum, Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA
Conventional linear and time-resolved spectroscopic techniques are often not appropriate to elucidate specific pigment–pigment
interactions in light-harvesting pigment-protein complexes (LHCs). Nonlinear (laser-) spectroscopic techniques, including
nonlinear polarization spectroscopy in the frequency domain (NLPF) as well as step-wise (resonant) and simultaneous (non-resonant) two-photon excitation spectroscopies may be advantageous in this regard. Nonlinear spectroscopies have been
used to elucidate substructure(s) of very complex spectra, including analyses of strong excitonic couplings between chlorophylls
and of interactions between (bacterio)chlorophylls and “optically dark” states of carotenoids in LHCs, including the major
antenna complex of higher plants, LHC II. This article shortly reviews our previous study and outlines perspectives regarding
the application of selected nonlinear laser-spectroscopic techniques to disentangle structure–function relationships in LHCs
and other pigment-protein complexes.
Content Type Journal Article
Category Review
Pages 227-235
DOI 10.1007/s11120-011-9700-y
Authors
Heiko Lokstein, Institut für Biochemie und Biologie/Pflanzenphysiologie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Haus 20, 14476 Potsdam-Golm, Germany
Alexander Betke, Institut für Physik und Astronomie/Photonik, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Haus 28, 14476 Potsdam-Golm, Germany
Maria Krikunova, Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
Klaus Teuchner, Institut für Physik und Astronomie/Photonik, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Haus 28, 14476 Potsdam-Golm, Germany
Bernd Voigt, Institut für Physik und Astronomie/Photonik, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Haus 28, 14476 Potsdam-Golm, Germany
Oxygen evolution per single-turnover flash (STF) or multiple-turnover pulse (MTP) was measured with a zirconium O2 analyzer from sunflower leaves at 22°C. STF were generated by Xe arc lamp, MTP by red LED light of up to 18000 ?mol quanta m?2 s?1. Ambient O2 concentration was 10–30 ppm, STF and MTP were superimposed on far-red background light in order to oxidize plastoquinone
(PQ) and randomize S-states. Electron (e?) flow was calculated as 4 times O2 evolution. QA ? QB electron transport was investigated firing double STF with a delay of 0 to 2 ms between the two. Total O2 evolution per two flashes equaled to that from a single flash when the delay was zero and doubled when the delay exceeded
2 ms. This trend was fitted with two exponentials with time constants of 0.25 and 0.95 ms, equal amplitudes. Illumination
with MTP of increasing length resulted in increasing O2 evolution per pulse, which was differentiated with an aim to find the time course of O2 evolution with sub-millisecond resolution. At the highest pulse intensity of 2.9 photons ms?1 per PSII, 3 e? initially accumulated inside PSII and the catalytic rate of PQ reduction was determined from the throughput rate of the fourth
and fifth e?. A light response curve for the reduction of completely oxidized PQ was a rectangular hyperbola with the initial slope of
1.2 PSII quanta per e? and Vm of 0.6 e? ms?1 per PSII. When PQ was gradually reduced during longer MTP, Vm decreased proportionally with the fraction of oxidized PQ. It is suggested that the linear kinetics with respect to PQ are
apparent, caused by strong product inhibition due to about equal binding constants of PQ and PQH2 to the QB site. The strong product inhibition is an appropriate mechanism for down-regulation of PSII electron transport in accordance
with rate of PQH2 oxidation by cytochrome b6f.
Content Type Journal Article
Category Regular Paper
Pages 99-109
DOI 10.1007/s11120-011-9702-9
Authors
Vello Oja, Tartu Ülikooli Molekulaar-ja Rakubioloogia Instituut, Riia tn. 23, Tartu, 51010 Estonia
Hillar Eichelmann, Tartu Ülikooli Molekulaar-ja Rakubioloogia Instituut, Riia tn. 23, Tartu, 51010 Estonia
Agu Laisk, Tartu Ülikooli Molekulaar-ja Rakubioloogia Instituut, Riia tn. 23, Tartu, 51010 Estonia
The procedure of isolating the thylakoids and the thylakoid membrane fragments enriched with either photosystem I or photosystem
II (PSI- and PSII-membranes) from Arabidopsis thaliana leaves was developed. It differed from the one used with pea and spinach in durations of detergent treatment and centrifugation,
and in concentrations of detergent and Mg2+ in the media. Both the thylakoid and the fragments preserved carbonic anhydrase (CA) activities. Using nondenaturing electrophoresis
followed by detection of CA activity in the gel stained with bromo thymol blue, one low molecular mass carrier of CA activity
was found in the PSI-membranes, and two carriers, a low molecular mass one and a high molecular mass one, were found in the
PSII-membranes. The proteins in the PSII-membranes differed in their sensitivity to acetazolamide (AA), a specific CA inhibitor.
AA at 5 × 10?7 M inhibited the CA activity of the high molecular mass protein but stimulated the activity of the low molecular mass carrier
in the PSII-membranes. At the same concentration, AA moderately inhibited, by 30%, the CA activity of PSI-membranes. CA activity
of the PSII-membranes was almost completely suppressed by the lipophilic CA inhibitor, ethoxyzolamide at 10?9 M, whereas CA activity of the PSI-membranes was inhibited by this inhibitor even at 5 × 10?7 M just the same as for AA. The observed distribution of CA activity in the thylakoid membranes from A. thaliana was close to the one found in the membranes of pea, evidencing the general pattern of CA activity in the thylakoid membranes
of C3-plants.
Content Type Journal Article
Category Regular Paper
Pages 89-98
DOI 10.1007/s11120-011-9699-0
Authors
Lyudmila K. Ignatova, Institute of Basic Biological Problems of Russian Academy of Sciences, Pushchino, Moscow, Russia 142290
Natalia N. Rudenko, Institute of Basic Biological Problems of Russian Academy of Sciences, Pushchino, Moscow, Russia 142290
Vilen A. Mudrik, Institute of Basic Biological Problems of Russian Academy of Sciences, Pushchino, Moscow, Russia 142290
Tat’yana P. Fedorchuk, Institute of Basic Biological Problems of Russian Academy of Sciences, Pushchino, Moscow, Russia 142290
Boris N. Ivanov, Institute of Basic Biological Problems of Russian Academy of Sciences, Pushchino, Moscow, Russia 142290
The multiexponential fluorescence decay of the CP29 complex in which the apoprotein and pigments were reconstituted in vitro
was examined. Of the three decay components observed only the two dominant ones, with about 3 and 5 ns lifetimes, were studied.
The main question addressed was whether the multicomponent decay was associated with sample optical heterogeneity. To this
end, we examined the optical absorption and fluorescence of the CP29 sample by means of two different and independent experimental
strategies. This approach was used as the wavelength positions of the absorption/fluorescence spectral forms has recently
been shown to be a sensitive indicator of the binding site-induced porphyrin ring deformation (Zucchelli et al. Biophys J
93:2240–2254, 2007) and hence of apoprotein conformational changes. The data indicate that this CP29 sample is optically homogeneous. It is
hypothesised that the different lifetimes are explained in terms of multiple detergent/CP29 interactions leading to different
quenching states, a suggestion that allows for optical homogeneity.
Content Type Journal Article
Category Regular Paper
Pages 53-62
DOI 10.1007/s11120-011-9696-3
Authors
Erica Belgio, CNR-Istituto di Biofisica, Sede di Milano, Via G. Celoria 26, 20133 Milan, Italy
Giorgio Tumino, CNR-Istituto di Biofisica, Sede di Milano, Via G. Celoria 26, 20133 Milan, Italy
Stefano Santabarbara, CNR-Istituto di Biofisica, Sede di Milano, Via G. Celoria 26, 20133 Milan, Italy
Giuseppe Zucchelli, CNR-Istituto di Biofisica, Sede di Milano, Via G. Celoria 26, 20133 Milan, Italy
Robert Jennings, CNR-Istituto di Biofisica, Sede di Milano, Via G. Celoria 26, 20133 Milan, Italy
This report describes a new method to measure the chloroplastic lumenal proton pool in leaves (tobacco and sunflower). The
method is based on measurement of CO2 outbursts from leaves caused by the shift in the CO2 + H2O ? HCO3? + H+ equilibrium in the chloroplast stroma as protons return from the lumen after darkening. Protons did not accumulate in the
lumen to a significant extent when photosynthesis was light-limited, but a large pool of >100 ?mol H+ m?2 accumulated in the lumen as photosynthesis became light-saturated. During thylakoid energization in the light, large amounts
of protons are moved from binding sites in the stroma to binding sites in the lumen. The transthylakoidal difference in the
chemical potential of free protons (?pH) is largely based on the difference in the chemical potential of bound protons in
the lumenal and stromal compartments (pK). Over the course of the dark-light induction of photosynthesis protons accumulate in the lumen during reduction of 3-phosphoglycerate.
The accumulation of electrons in reduced compounds of the stroma and cytosol is the natural cause for accumulation of a stoichiometric
pool of lumenal protons during this transient event.
Content Type Journal Article
Category Regular Paper
Pages 73-88
DOI 10.1007/s11120-011-9697-2
Authors
Vello Oja, Institute of Molecular and Cellular Biology, University of Tartu, Riia St. 23, 51010 Tartu, Estonia
Hillar Eichelmann, Institute of Molecular and Cellular Biology, University of Tartu, Riia St. 23, 51010 Tartu, Estonia
Agu Laisk, Institute of Molecular and Cellular Biology, University of Tartu, Riia St. 23, 51010 Tartu, Estonia
The trimeric fucoxanthin–chlorophyll a/c protein (FCP) was purified from a Japanese brown alga, Cladosiphon okamuranus TOKIDA. Its pigment stoichiometry was determined to be chlorophyll (Chl) a:Chl c1:Chl c2:fucoxanthin = 4.6:1.1:1.0:5.5 by a combination of binary HPLC and 1H NMR spectroscopy. No violaxanthin found bound to the FCP. The ratio of Chl c/Chl a in this FCP is amongst the highest so far reported.
Content Type Journal Article
Category Regular Paper
Pages 165-172
DOI 10.1007/s11120-011-9698-1
Authors
Ritsuko Fujii, The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
Mamiko Kita, CREST/JST, 4-1-8 Hon-cho Kawaguchi, Saitama, 332-0012 Japan
Matsumi Doe, The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
Yoshiro Iinuma, South Product Co. Ltd, 12-75 Suzaki, Uruma, Okinawa, 904-2234 Japan
Naohiro Oka, South Product Co. Ltd, 12-75 Suzaki, Uruma, Okinawa, 904-2234 Japan
Yuki Takaesu, South Product Co. Ltd, 12-75 Suzaki, Uruma, Okinawa, 904-2234 Japan
Tomonori Taira, South Product Co. Ltd, 12-75 Suzaki, Uruma, Okinawa, 904-2234 Japan
Masahiko Iha, South Product Co. Ltd, 12-75 Suzaki, Uruma, Okinawa, 904-2234 Japan
Tadashi Mizoguchi, Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
Richard J. Cogdell, Glasgow Biomedical Research Centre, University of Glasgow, 12 University Place, Glasgow, G12 8QQ Scotland, UK
Hideki Hashimoto, The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
We honor here Thomas (Tom) Roosevelt Punnett, Jr. (May 25, 1926–July 4, 2008), who was a pioneer of Biology, particularly
of biochemistry of plants and algae, having specialized in photosynthesis under Robert Emerson of the University of Illinois
at Urbana-Champaign. He did exciting work on regulation and control of various metabolic reactions. He was an innovator and
raconteur par excellence, and he prized critical thinking. His enthusiasm for basic science questions was matched by his grasp
of their “real-world” implications. His last project was a patent for anaerobic sewage treatment that he hoped would lead to solution of waste disposal and energy creation world wide, including
the clean-up of Lake Erie, where he had sailed as a boy. On the personal side, he had a strong sense of morality and a great
wit and humor.
Content Type Journal Article
Category Tribute
Pages 1-7
DOI 10.1007/s11120-011-9695-4
Authors
William Hagar, Department of Biology, College of Science and Mathematics, University of Massachusetts Boston, 100 Morressey Boulevard, Boston, MA 02125, USA
Hope Punnett, Department of Pediatrics, Temple University Medical School, Philadelphia, PA 19140, USA
Laura Punnett, Department of Work Environment, University of Massachusetts Lowell, Lowell, MA 01854, USA
Govindjee, Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
A time-resolved fluorescence study of living lichen thalli at 5 K was conducted to clarify the dynamics and mechanism of the
effective dissipation of excess light energy taking place in lichen under extreme drought conditions. The decay-associated
spectra obtained from the experiment at 5 K were characterized by a drastically sharpened spectral band which could not be
resolved by experiments at higher temperatures. The present results indicated the existence of two distinct dissipation components
of excess light energy in desiccated lichen; one is characterized as rapid fluorescence decay with a time constant of 27 ps
in the far-red region that was absent in wet lichen thalli, and the other is recognized as accelerated fluorescence decay
in the 685–700 nm spectral region. The former energy-dissipation component with extremely high quenching efficiency is most
probably ascribed to the emergence of a rapid quenching state in the peripheral-antenna system of photosystem II (PS II) on
desiccation. This is an extremely effective protection mechanism of PS II under desiccation, which lichens have developed
to survive in the severely desiccated environments. The latter, which is less efficient at 5 K, might have a supplementary
role and take place either in the core antenna of PS II or aggregated peripheral antenna of PS II.
Content Type Journal Article
Category Regular Paper
Pages 39-48
DOI 10.1007/s11120-011-9691-8
Authors
Hirohisa Miyake, Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya, 464-8602 Japan
Masayuki Komura, Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya, 464-8602 Japan
Shigeru Itoh, Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya, 464-8602 Japan
Makiko Kosugi, Graduate School of Life Science, University of Hyogo, Harima Science Garden City, Hyogo, 678-1297 Japan
Yasuhiro Kashino, Graduate School of Life Science, University of Hyogo, Harima Science Garden City, Hyogo, 678-1297 Japan
Kazuhiko Satoh, Graduate School of Life Science, University of Hyogo, Harima Science Garden City, Hyogo, 678-1297 Japan
Yutaka Shibata, Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya, 464-8602 Japan
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