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Clay, Christine Nicole. "Non-leaf chlorenchyma in Bienertia cycloptera and Suaeda aralocaspica (chenopodiaceae) exhibit single cell C₄ photosynthesis." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Spring2006/c%5Fclay%5F050506.pdf.
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Xu, Qingzhang. "Development of photosynthetic competency in tall fescue leaves /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924948.
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Edvardsson, Anna. "Peptidyl-prolyl cis-trans Isomerases in the Chloroplast Thylakoid Lumen." Doctoral thesis, Linköping : Univ, 2007. http://www.bibl.liu.se/liupubl/disp/disp2007/med983s.pdf.
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Bonatto, José Matheus Camargo. "Consequências da expressão constitutiva do gene Lhcb1*2 de Pisum sativum em plantas de Nicotiana tabacum: impactos no proteoma foliar, montagem dos fotossistemas e influência no desenvolvimento vegetal." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11137/tde-19042010-164936/.
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O complexo coletor de luz (LHC) do fotossistema II (PSII) é o principal complexo de proteínas associado a pigmentos situado na membrana dos tilacóides de cloroplastos em plantas. O LHCII funciona como uma antena de transferência de energia para a captura e direcionamento da energia luminosa do PSII para o PSI. A ação coordenada dos dois fotossistemas com o direcionamento do fluxo de elétrons gera a quebra da molécula de água, através da membrana do tilacóide, produzindo força assimilatória ATP e NADPH. A energia química produzida na fotossíntese é de suma importância para a assimilação de carbono, biossíntese de aminoácidos e metabólicos secundários. Portanto, este é um importante gene para estudos em biotecnologia. Linhagens transgênicas de tabaco (TR-1 e TR-2) as quais expressam constitutivamente o transgene Lhcb1*2 de ervilha obtidas por Labate e colaboradores (2004) foram utilizadas nesse trabalho. Estas plantas apresentaram diversos efeitos pleiotrópicos relacionados à anatomia, morfologia, bioquímica e fisiologia. Uma proteína pode não atuar isoladamente, mas freqüentemente interagindo com outras proteínas, influenciando diversos processos metabólicos. O perfil de proteômica dessas linhagens transformantes, em relação à planta selvagem (WT) foi investigado. As proteínas totais foram extraídas de folhas de plantas de três meses crescidas em câmaras de crescimento, então separadas por 2D-PAGE. As proteínas diferencialmente expressas foram identificadas por LC-MS/MS. Os resultados mostram que 244 spots apresentaram alterações significativas na expressão nas duas linhagens transgênicas em relação à WT. 122 spots são expressos exclusivamente nas linhagens transformantes, e 24 spots somente na selvagem. Muitas proteínas como ATP synthase e ribulose bisphosphate carboxylase/oxygenase activase foram mais expressas nas linhagens transgênicas, mas a glutamine synthetase, uma importante proteína na reciclagem de nitrogênio nos cloroplastos, teve sua expressão diminuída. Para analisar as alterações na expressãode genes relacionados ao ritmo circadiano entre outros, como a conformação do PSII, cotilédones de plântulas estioladas foram submetidas à luz e amostras coletadas depois de 0, 3, 6, 12 e 24 horas. O nível de transcritos foram analisados por PCR quantitativo. A diferenciação de plastídio à cloroplasto maduro foi analisado por microscopia eletrônica de transmissão, para se entender as diferenças entre os genótipos em estudo no desenvolvimento vegetal. A expressão constitutiva do gene Lhcb1*2 de ervilha em plantas transgênicas de tabaco acarretou a indução e repressão de várias proteínas e genes em distintos passos de vias metabólicas, estabilizando a homeostase celular, exercendo uma influência significativa no desenvolvimento vegetal e produção de biomassa.The light harvesting complex (LHC) of photosystem II (PSII) is the major ensemble of pigmet-biding proteins situated in the thylakoid membranes of the chloroplast in plants. The LHCbII functions as an energy-transferring antenna for capturing and delivering light energy to the photosystems PSII and PSI. The coordinated actions of the two photosystems in turn drive the flow of electrons, generated by the splitting of water, through the thylakoid membranes to produce the assimilatory force ATP and NADPH. The chemical energy produced by photosynthesis is very important for the assimilation of carbon, amino acids biosynthesis, and secundary metabolism. Therefore it is an important gene for biotechnological studies. Transgenic tobacco lines (TR-1 and TR-2) which express the pea Lhcb1*2 transgene constitutively obtained by Labate et al. (2004) were used in this work. These plants presented pleiotropic effects related to anatomy, morphology, biochemistry and physiology. As a protein may not act by itself, but it is, frequently interacting with other proteins, influencing a lot of metabolic processes. The proteomic profile of these transgenic lines, in relation to the wild type (WT), was investigated. The total proteins extracted from leaves of three-month old plants grown in growth chambers were separated by 2DPAGE. The differentially expressed proteins were identified by LC-MS/MS. The results showed that 225 spots displayed significant changes in the expression of the two transgenic lines in relation to the WT. 122 spots were exclusively expressed in the transgenic lines, and 24 only in the wild type. Many proteins as ATP synthase and ribulose bisphosphate carboxylase/oxygenase activase are overexpressed in the transgenic lines, but the glutamine synthetase, an important protein tor nitrogen recycling in the chloroplasts, showed a reducted level of expression. In order to analyse the alterations of the expression of genes related to the circadian rhythm among others, involved in the conformation of the PSII, cotyledons from etiolated seedlings were thenexposed to light and samples collected after 0, 3, 6, 12 and 24 hours. The level of transcripts were analysed by RT/RT-PCR. The PSII conformation were analysed by transmition electron microscopy, with the aim of verifying the evolution of plastids into the chloroplasts which could be leading to changes in plant development. The overexpression of the pea Lhcb1*2 gene in transgenic tobacco plants, lead to the induction and suppression of several proteins and genes in key metabolic pathways, as a way to establish a cellular homeostasis, exerting a significant influence on plant development and biomass production.
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Tomizioli, Martino. "Identification de nouveaux acteurs de la régulation de la photosyhthèse." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENV046/document.
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Chez les eucaryotes, la photosynthèse a lieu dans le chloroplaste, un organite spécifique de la cellule végétale et caractérisé par différents compartiments : (i) l'enveloppe, la double membrane qui délimite le chloroplaste ; (ii) le stroma, phase aqueuse principalement composée de protéines solubles et (iii) un système membranaire interne, les thylacoïdes, qui contiennent les complexes photosynthétiques. Les thylakoïdes forment un réseau tridimensionnel continu et sont différenciés en deux domaines physiques distincts : des empilements de vésicules de membrane (appelés granas ou BBY) et des extensions de membrane simple (lamelles stromales). Les complexes majeurs de la photosynthèse ne sont pas distribués de manière égale dans cette membrane à cause de contraintes électrostatiques et stériques. Ainsi, le photosystème I et l'ATP-synthétase sont enrichis dans les granas, le photosystème II dans les lamelles stromales alors que d'autres complexes, comme le cytochrome b6f, auraient une répartition équivalente entre granas et lamelles stromales. Pour faire face aux variations environnementales de lumière (en qualité et quantité), les plantes ont développé des processus pour moduler leur capacité d'absorption et d'utilisation de la lumière par les photosystèmes, processus regroupés sous le terme de « quenching non photosynthétique ou NPQ ». Dans le cadre de ma thèse, je me suis intéressé à deux composants du NPQ, les états de transition et la dissipation sous forme de chaleur (partie qE).Le premier objectif de ma thèse a été d'identifier de nouveaux acteurs impliqués dans les transitions d'état et ceci en étudiant la relocalisation de protéines au sein des sous-compartiments des thylacoïdes par une approche protéomique. En effet, il a été montré que certaines antennes collectrices de lumière sont réorganisées dans les membranes photosynthétiques lors des transitions d'état. Jusqu'à présent, aucune description exhaustive de la composition et distribution des protéines dans les sous-compartiments de thylacoïdes n'avait été réalisée. J'ai donc dans un premier temps développé des protocoles de purification des sous-compartiments des thylakoïdes (granas et lamelles stromales) à partir de chloroplastes de plantes sauvage d'Arabidopsis thaliana. Ensuite, grâce à une approche d'analyse protéomique semi-quantitative, nous avons pu déterminer la localisation d'environ 300 protéines des thylacoïdes. Les résultats suggèrent que la localisation de complexes photosynthétiques est beaucoup plus dynamique que celle jusqu'à lors proposée. En effet, même s'ils sont préférentiellement identifiés dans un sous-compartiment, certains complexes photosynthétiques présentent une double localisation qui était inattendue. De plus, la composition en sous-unités de ces complexes diffère selon leur localisation, dans les granas et dans les lamelles stromales, suggérant l'existence de processus de régulation de la photosynthèse jusqu'à lors insoupçonnés. Cette approche a ensuite été appliquée sur des plantes mutantes d'Arabidopsis affectées dans les transitions d'état afin d'identifier des protéines pouvant être impliquées dans ce processus d'adaptation. En parallèle, je me suis intéressé au qE . L'activation de ce mécanisme n'est pas constitutive et nécessite la formation d'un gradient de pH entre le stroma et le lumen des thylacoïdes (ΔpH). L'objectif de l'étude a été d'identifier des acteurs pouvant contrôler la formation de ce gradient de pH. Pour cela, nous nous somme focalisés sur le rôle d'un transporteur de potassium récemment caractérisé, TPK3. Grâce à des approches biophysiques et biochimiques, nous avons démontré que TPK3 est impliqué, in vivo, dans la modulation des deux composantes de la force proton motrice (pmf), le gradient de pH (ΔpH) et la différence de potentiel (Δψ). En contrôlant la répartition de la force proton motrice,TPK3, permet une utilisation correcte de la lumière en dissipant l'excès d'énergieWithin higher plants and algae, photosynthesis is carried out in the chloroplast. Structurally, chloroplasts are organized in (i) the envelope, a double membrane system surrounding the chloroplast (ii) the stroma, the aqueous space which mainly contains soluble proteins and the (iii) thylakoids, a three-dimensional membrane network where photosynthetic electron transport reactions occur. Thylakoids are non-homogeneously folded, and comprise two major domains: (i) the grana-BBY, which are stacks of thylakoids particularly enriched in photosystem II, LHCII (the antenna-protein complex responsible for light harvesting) and (ii) the stroma lamellae, which are unstacked thylakoids connecting grana stacks enriched in photosystem I and ATP synthase. Plants can respond to changes in the environmental light conditions by several means as those which are collectively called non-photochemical quenching or NPQ. During my thesis, I mainly focused on two components of the NPQ: state transition (qT) and high-energy state quenching (qE).State transitions is the process by which PSII-antenna proteins are re-organized between stroma-lamellae and grana-BBY following changes in ambient light both of intensity and spectral composition. State transitions play a key role in the plant adaptation but many aspects of this process remain unclear. The main objective of my thesis was to study the thylakoid protein re-localization between stroma-lamellae and grana-BBY during state transitions using a proteomic-based approach. At this aim I firstly focused on the sub-thylakoid protein localization in Arabidopsis WT and I developed different protocols for the purification of the two sub-compartments (stroma-lamellae and grana-BBY) starting from intact chloroplasts. Later, thanks to a semi-quantitative proteomic approach, I determined the precise localization of around 300 thylakoid proteins in Arabidopsis WT. Results suggested that the localization of the different photosynthetic complexes is much more dynamics than previously hypothesized. In fact, even if characterized by a preferential localization, some photosynthetic complexes displayed an unexpected double localization. Moreover the subunit composition of these complexes was found to vary according to their localization (BBY or stroma-lamellae) suggesting the existence of mechanisms of regulation which have never been evidenced before. Later, we used the same mass-spectrometry-based approach on two different Arabidopsis mutants unable to perform state transitions. The objective was to highlight the involvement of other proteins (other than LHCII) which could possibly be re-localized within the photosynthetic membrane during state transitions. In the second part of my thesis, I focused on the high-energy state quenching component of the NPQ. qE allows the plant to dissipate excessive light energy as heat. This process it's not constitutive but need to be activated by the formation of a difference in the pH between the stroma and the thylakoid lumen (ΔpH). The objective of the study was to identify new possible actors in the regulation of the ΔpH formation. At this purpose I focused on a recently characterized potassium channel, TPK3. Thanks to a biophysical and biochemical approach, we demonstrated that TPK3 is involved, in vivo, in the modulation of the two components of the proton motive force (pmf), the ΔpH and the difference in the electric field Δψ. By controlling the repartition of the pmf, TPK3, controls also the formation of the NPQ and directly affects light utilization and dissipation in vivo. This avoids serious damages to the photosynthetic chain when plants are exposed to high-light conditions
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Bailey, Shaun. "Acclimation of photosynthesis to irradiance in Arabidopsis thaliana." Thesis, University of Sheffield, 2002. http://etheses.whiterose.ac.uk/14630/.
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The work contained within this thesis describes the acclimation of photosynthesis in A.thaliana to growth over a broad range of irradiance. Using Pmax and Chl a/b as an index, the ability of A.thaliana to modulate the composition of the photosynthetic apparatus across a range of irradiance has been demonstrated. A non-linear response to growth irradiance was seen for both parameters, the shape of which was similar. In addition the overall magnitude of the response was large compared to other plant species. These changes took place with no alteration in overall chlorophyll content per unit leaf area. A detailed analysis of the changes in chloroplast composition followed. This revealed a good correlation between changes in Chl a/b and bulk LHCII as well as Pmax and Rubisco content. However measurement of the reaction centre content along with immunoblot analysis of all ten Chl a/b binding light harvesting polypeptides established that changes in other thylakoid components were also responsible for changes in Chl a/b. Significant changes in reaction centre content were seen at both the low and high extremes of growth irradiance with PSI content doubling at 35 umol m-2 s-1 and PSII content rising significantly at 600 umol m-2 S-I. The extent of the changes in reaction content is well beyond those previously reported for other plant species. Other previously unreported changes in thylakoid composition are also observed for A.thaliana. For example there was a doubling in the minor LHCII complexes, Lhca5 and 6, at very low growth irradiance. In addition a complex pattern of change was observed for all 4 LHCI polypeptides. The functional consequence of photosynthetic acclimation was also investigated using room temperature chlorophyll fluorescence. Measurements of the maximum rate of electron transport (ETR) for plants grown at all irradiance revealed a higher rate for plants grown at 400 umol m-2 S-I than would have been predicted from the maximum photosynthetic rate (Pmax). This discrepancy suggested an alternative fate for electrons (other than CO2 fixation) for plants grown at this irradiance. Since this electron sink must involve molecular oxygen it is suggested that enhanced Mehler reaction accounts for the increased ETR. Relaxation kinetics of chlorophyll a fluorescence quenching was used to resolve qN into two components, qE and ql. The maximum capacity for qE clearly increased withincreasing growth irradiance and correlated well with Chl a/b and the xanthophyll cycle pool size establishing that the capacity for short term photosynthetic regulation is itself subject to acclimation. Finally the dynamic nature of photosynthetic acclimation was demonstrated following transfers between high and low irradiance.
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Evertsen, Jussi. "Solar powered phycozoans : Herbivore sacoglossans with photosynthetic chloroplasts." Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2244.
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Torabi, Salar Abu-Torab. "Establishment of photosynthetic complexes in the chloroplast." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-183292.
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Martin, Sophie. "Photoelectrochemistry of immobilised photosynthetic components: From chlorophyll to intact chloroplasts." Thesis, University of Warwick, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487960.
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This thesis aims to explore the use of scanning electrochemical microscopy (SECM) to investigate a range of processes, in particular fundamental electron transfer processes, connected to photosynthesis. These studies focus on several model systems ranging from LB films of chI a to intact chloroplasts. Electrochemical and scanned probe microscopy (SPM) techniques will be invaluable for monitoring these electron transfer processes and the structure - activity relationships in the systems of interest. A study of the different methods of chlorophyll film formation on solid supports and characterisation of these films with regard to surface coverage and film thicknesses has been explored with a range of techniques. Dropcast, spincast and LB films are investigated using UV-visible spectroscopy and AFM in order to elucidate the most appropriate chlorophyll film formation techniques for use in the later studies of this thesis. SECM has combined with an inverted microscope setup to investigate electron transfer in thin films of chlorophyll, with the aim of correlating the photoelectrochemical activity of the chlorophyll layer with the spatial organisation of the film. Using LB techniques, monolayers and multilayer films of chi a have been prepared on solid inert supports. It is clarified that electron transfer occurs from photo-excited chlorophyll to reduce oxygen. This is observed using SEeM, to electrochemically follow the transient change in oxygen concentration close to chlorophyll films upon illumination. The data obtained have been simulated using a commercial software package and used to determine kinetic parameters for this electron transfer process. This work is extended by considering the effects of electron transport in chI a molecules when deposited onto conducting electrode surfaces, compared to inert glass surfaces. These studies present some contradictory results to those previously published in literature and these findings have been discussed. ' The photosynthetic activity and surface structure of chloroplast and 'thylakoid membranes using SPM techniques and CLSM has been investigated. Factors such as illumination conditions, O2 evolution and reactions with different redox mediators will be studied to probe key steps in the electron transport chain reaction. Finally, confocal microscopy has been combined with SECM to study lateral proton diffusion at different phospholipid monolayers under a range of surface pressures. Therefore, investigating key diffusional processes as a model for those processes occurring at biological membranes.
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Schubert, Maria. "The chloroplast lumen proteome of Arabidopsis thaliana /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-654-9/.
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Kindgren, Peter. "The chloroplast talks : Insights into the language of the chloroplast in Arabidopsis." Doctoral thesis, Umeå universitet, Institutionen för fysiologisk botanik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-36166.
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The chloroplast originates from an endosymbiotic event 1.5 billion years ago, when a free living photosynthetic bacteria was engulfed by a eukaryotic host. The chloroplastic genome has through evolution lost many genes to the nuclear genome of the host. To coordinate the gene expression between the two genomes, plants have evolved two types of communication, nucleus-to-plastid (anterograde) and plastid-to-nucleus (retrograde) signalling. This thesis will focus on retrograde communication with emphasis on redox and tetrapyrrole mediated signalling. In this thesis, we establish the tetrapyrrole Mg-ProtoIX as an important retrograde negative regulator of nuclear encoded plastid proteins. We show that Mg-ProtoIX accumulates in both artificial and natural stress conditions, and that the accumulation is tightly correlated to regulation of nuclear gene expression. Using confocal microscopy, we could visualize Mg-ProtoIX in the cytosol during stress conditions. In addition, exogenously applied Mg-ProtoIX stayed in the cytosol and was enough to trigger a signal to the nucleus. The results presented here indicate that Mg-ProtoIX is transported out of the chloroplast to control nuclear gene expression. Mg-ProtoIX mediated repression of the nuclear gene, COR15a, occurs via the transcription factor HY5. HY5 is influenced by both plastid signals and the photoreceptors. Here, we show that photoreceptors are part of Mg-ProtoIX mediated signalling as well as excess light adaptation. We identified the blue light receptor, CRY1, as a light intensity sensor that partly utilizes HY5 in the high light response. To further understand the high light regulation of nuclear genes, we isolated a mutant with redox insensitive (rin) high light response. The rin2 mutant has a mutated plastid protein with unknown function. Characterization of the rin2 mutant revealed that the protein is important in regulating plastid gene expression as well as nuclear gene expression. The rin2 mutant is the first characterized rin mutant and could prove important in elucidating the cross-talk between redox mediated coordination between the plastid and the nuclear genome.
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Turton, Janet Susan. "An investigation of chloroplast ATPase structure and function using anti-peptide antibodies." Thesis, Keele University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260303.
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Williams, R. S. "Studies on the peripheral light-harvesting chlorophyll-protein complex of photosystem I in Pisum sativum L." Thesis, University of Warwick, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380326.
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Knight, Julie Sylvia. "The isolation, characterization and expression of the gene encoding the chloroplast Rieske iron-sulphur protein of Arabidopsis thaliana." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338309.
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Bonavia-Fisher, Bruna. "Evidence that a chloroplast membrane protein is located in the mitochondria of photosynthetic and non-photosynthetic euglenoids." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36755.
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1. Distribution of the two photosystems (PS I and PS II) in the thylakoid membranes of the alga Euglena gracilis. The distribution of photosystem I and II (PS I and PS II) in the alga Euglena gracilis Z strain was studied by electron microscopic immunocytochemistry. In this alga, the thylakoids are not organized in gram structures, as they are in higher plants. Two different antibodies were used to identify PS I. One is directed against particles of PS I from maize and the other against the 60 and 62 kDa PS I reaction centre proteins of the cyanobacterium Synechococcus elongatus. Both antibodies demonstrated the presence of PS I in the two types of thylakoid membranes, appressed (AM) and non-appressed (NAM). Quantitative analysis showed that 60--74% of PS I is in the AM and 26--40% is in the NAM, and since about 80--90% of the membranes are AM, that PS I is more concentrated in the NAM. An antibody directed against the CP47 protein of PS II also revealed labelling in both types of thylakoid membranes (54% in AM and 46% in NAM). PS II is again more concentrated in the NAM. I demonstrated by the photo-oxidation of 3,3'-diaminobenzidine that there is PS I activity in the two types of membranes and, moreover, that there are changes in this activity during the light cycle of the cell. My results indicate that the distribution of PS I and PS II in Euglena gracilis Z strain is different from that of higher plants and is similar to that seen in green algae. The possible evolutionary significance of our observations are discussed.2. Localization of the protein CP47 (plastid protein) in the mitochondria of euglenoids. The localization of the CP47 protein to the mitochondria of euglenoids was studied by electron microscopic immunocytochemistry. My results demonstrate that this protein, which is coded by chloroplast DNA in all algae and plants, is present in whole or in part in the mitochondria of Euglena gracilis and related euglenoids. I used two different antibodies against the protein CP47 (anti-CP47 from Chlamydomonas reinhardtii and S. elongatus) to test wild-type, light-grown, cells of Euglena. Both antibodies selectively labelled the mitochondria. These results furthermore suggest that this labelling is particularly associated with mitochondrial cristae. Anti-CP47 from S. elongatus also labelled the mitochondria of other euglenoids, such as dark-grown cells of Euglena gracilis, the mutant Y9Z1NaL, and Astasia longa. Since the CP47 protein is present in dark-grown cells and in the mutant Y9Z1NaL, which are organisms that do not have an active psbB gene, I suggest that a gene transfer has occurred from the plastid to the mitochondria during evolution. Because our results show the presence of CP47 in the mitochondria of Astasia longa, I postulate that the transfer occurred before the branching of Astasia from Euglena.
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Jullesson, David. "Wiring liposomes and chloroplasts to the grid with an electronic polymer." Thesis, Linköpings universitet, Biomolekylär och Organisk Elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97517.
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We present a novel thylakoid based bio-solar cell capable of generating a photoelectric current of 0.7 µA/cm2. We have introduced an electro conductive polymer, PEDOT-S, to the thylakoid membrane. PEDOT-S intervenes in the photosynthesis, captures electrons from the electron transport chain and transfers them directly across the thylakoid membrane, thus generating a current. The incorporation of the electro conductive polymer into the thylakoid membrane is therefore vital for the function of the bio-solar cell. A liposomal model system based on liposomes formed by oleic acid was used to develop and study the incorporation of PEDOT-S to fatty acid membranes. The liposomes allow for a more controllable and easily manipulated system compared to the thylakoid membrane. In the model system, PEDOT-S could successfully be incorporated to the membrane, and the developed methods were applied to the real system of thylakoid membranes. We found that a bio-compatible electrolyte and redox couple was required for this system to function. The final thylakoid based bio-solar cell was evaluated according to performance and reproducibility. We found that this bio-solar system can generate a low but reproducible current.
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Shiki, Baluch Behrad. "Potassium channel AtTPK5 : An essential or redundant regulator of photosynthesis in Arabidopsis?" Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68756.
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It has previously been stated that K+-ions in a plant cell have a counter-balancing role in which the efflux of K+-ions from the thylakoid lumen charge-balance the light-induced proton pumping that is known to occur across the thylakoid membrane, and this in turn stabilizes photosynthetic activity. In the present study, two different types of plants of the same ecotype (Col-0) of Arabidopsis thaliana have been studied: a wild-type and a T-DNA exon-mutant (tpk5-e) that has lost the expression of the protein known as Tandem-pore K+- channel (AtTPK5). The plants were grown in a hydroponic system under normal light conditions with 70% humidity. Homozygous (HM) tpk5-e mutant plants were screened using PCR and gene specific primers. Further, the photosynthetic activity was measured in 4 hour light-adapted plants and the photosynthetic activity of the tpk5-e mutant proved not to be significantly different in comparison to the wild-type when measuring the electron transport rate (ETR). Furthermore, the O2-evolution was also measured in 4 hour light-adapted plants and the tpk5-e mutant's O2-evolution proved to be significantly lower in the tpk5-e mutant in comparison to the wild-type under high light conditions. The plant fitness of the wild-type and tpk5-e mutant was also different judging from phenotypic traits such as chlorophyll expression. However, the measured chlorophyll amount of pigments chlorophyll a and b proved not to be significantly different in the tpk5-e mutant in comparison to the wild-type.
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Hall, Michael. "The chloroplast lumen : New insights into thiol redox regulation and functions of lumenal proteins." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-58423.
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In higher plants oxygenic photosynthesis primarily takes place in the chloroplasts of leaves. Within the chloroplasts is an intricate membrane system, the thylakoid membrane, which is the site of light harvesting and photosynthetic electron transport. Enclosed by this membrane is the lumen space, which initially was believed to only contain a few proteins, but now is known to house a distinct set of >50 proteins, many for which there is still no proposed function. The work presented in this thesis is focused on understanding the functions of the proteins in the lumen space. Using proteomic methods, we investigated first the regulation of lumenal proteins by light and secondly by dithiol-disulphide exchange, mediated by the disulphide reductase protein thioredoxin. We furthermore performed structural and functional studies of the lumenal pentapeptide repeat proteins and of the PsbP-domain protein PPD6. When studying the diurnal expression pattern of the lumen proteins, using difference gel electrophoresis, we observed an increased abundance of fifteen lumen protein in light-adapted Arabidopsis thaliana plants. Among these proteins were subunits of the oxygen evolving complex, plastocyanin and proteins of unknown function. In our analysis of putative lumenal targets of thioredoxin, we identified nineteen proteins, constituting more than 40 % of the lumen proteins observable by our methods. A subset of these putative target proteins were selected for further studies, including structure determination by x-ray crystallography. The crystal structure of the pentapeptide repeat protein TL15 was solved to 1.3 Å resolution and further biochemical characterization suggested that it may function as a novel type of redox regulated molecular chaperone in the lumen. PPD6, a member of the PsbP-family of proteins, which is unique in that it possesses a conserved disulphide bond not found in any other PsbP-family protein, was also expressed, purified and crystallized. A preliminary x-ray analysis suggests that PPD6 exists as a dimer in the crystalline state and binds zinc ions. The high representation of targets of thioredoxin among the lumen proteins, along with the characterization of the pentapeptide repeat protein family, implies that dithiol-disulphide exchange reactions play an important role in the thylakoid lumen of higher plants, regulating processes such as photoprotection, protein turnover and protein folding.
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Allorent, Guillaume. "Expression du génome plastidial d'Arabidopsis thaliana pendant la formation des graines." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00680102.
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L'expression du génome plastidial, un des trois génomes (nucléaire, mitochondrial et plastidial) qui coexistent dans les cellules végétales, est assurée par trois ARN polymérases. Deux NEP (Nuclear-Encoded RNA Polymerase) transcrivent la plupart des gènes de ménage tandis que la PEP (Plastid-Encoded RNA Polymerase) transcrit principalement les gènes liés à la fonction photosynthétique en s'associant à des facteurs de transcription d'origine nucléaire (facteurs sigma) importés dans le plaste. De précédents travaux dans l'équipe ont montré que, contrairement aux observations généralement admises, les trois ARN polymérases sont nécessaires pour assurer une germination efficace des graines d'Arabidopsis. L'objectif de notre travail est de comprendre comment ces enzymes ont été mises en place au cours de la formation de la graine. Pour cela, nous avons analysé l'expression de l'appareil transcriptionnel et du transcriptome plastidial durant les trois phases de formation de la graine d'Arabidopsis thaliana, c'est à dire l'embryogenèse, la maturation (phase photosynthétique) et la dessiccation. L'expression globale du transcriptome plastidial montre que les changements quantitatifs des transcrits sont les plus élevés pour les transcrits des gènes liés à la fonction photosynthétique. Ils sont très fortement exprimés pendant la phase de la maturation et diminuent ensuite, comme leurs protéines correspondantes. Nous observons également une forte accumulation des protéines codant les NEP et les sous unités de la PEP pendant la période de maturation des graines, suivie d'une forte diminution pendant la dessiccation. Cependant, les ARNm correspondants augmentent pendant la dessiccation. Le stockage de ces ARNm codant l'appareil transcriptionnel constitue une étape cruciale pour l'efficacité de la germination de la graine. La quantité de matériel biologique disponible pour ces études étant très limitée, nous avons développé une nouvelle technique de détection des ADNc sur lame de quartz, utilisant la microscopie TIRF. Cette méthode augmente la résolution (elle permet la détection de molécules uniques) et diminue considérablement la quantité de matériel nécessaire à l'hybridation. Finalement, nous avons analysé les conditions sous lesquelles se déroule la photosynthèse embryonnaire. Ces études ont montré que la photosynthèse dans l'embryon se déroule dans un environnement particulier, hypoxique, et sous un éclairement enrichi en longueurs d'onde vertes. Cependant, la structure et le fonctionnement de l'appareil photosynthétique sont semblables à ceux d'une feuille. Nous avons également montré que l'étape transitoire de la photosynthèse embryonnaire est indispensable à la vigueur germinative des graines. Les résultats obtenus lors de ce travail apportent de nouvelles informations sur le fonctionnement de la transcription plastidiale au cours de la formation de la graine. L'importance de l'accumulation d'ARNm, de certaines protéines ainsi que celle de la photosynthèse embryonnaire dans la vigueur germinative ont été soulignées. Ces données permettent de comprendre comment l'efficacité de la germination est conditionnée par la phase de formation de la graine.
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Torabi, Salar Abu-Torab [Verfasser], and Jörg [Akademischer Betreuer] Meurer. "Establishment of photosynthetic complexes in the chloroplast / Salar Abu-Torab Torabi. Betreuer: Jörg Meurer." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1072376709/34.
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Gabilly, Stephane T. "A Disulfide-Reducing Pathway Required For Plastid Cytochrome c Assembly." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1339720233.
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Dorrell, Richard G. "Coevolution of plastid genomes and transcript processing pathways in photosynthetic alveolates." Thesis, University of Cambridge, 2014. https://www.repository.cam.ac.uk/handle/1810/246266.
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Following their endosymbiotic uptake, plastids undergo profound changes to genome content and to their associated biochemistry. I have investigated how evolutionary transitions in plastid genomes may impact on biochemical pathways associated with plastid gene expression, focusing on the highly unusual plastids found in one group of eukaryotes, the alveolates. The principal photosynthetic alveolate lineage is the dinoflagellate algae. Most dinoflagellate species harbour unusual plastids derived from red algae. The genome of this plastid has been fragmented into small, plasmid-like elements termed “minicircles”. Transcripts of this genome receive a 3’ poly(U) tail and, in some species, undergo extensive sequence editing. Some dinoflagellates have replaced their original plastids with others, in a process termed “serial endosymbiosis”. The major non-photosynthetic alveolates are the apicomplexans, which include the malaria parasite Plasmodium. Apicomplexans are descended from free-living algae and possess a vestigial plastid, which originated through the same endosymbiosis as the ancestral red dinoflagellate plastid. This plastid has lost all genes involved in photosynthesis and does not possess a poly(U) tail addition pathway. I have investigated the consequences of the fragmentation of the red algal dinoflagellate plastid genome on plastid transcription. I have characterised non-coding transcripts in plastids of the dinoflagellate Amphidinium carterae, including the first evidence for antisense transcripts in an algal plastid. Antisense transcripts in dinoflagellate plastids do not receive poly(U) tails, suggesting that poly(U) tail addition may play a role in strand discrimination during transcript processing. I have additionally characterised transcript processing in dinoflagellate plastids that were acquired through serial endosymbiosis. I have shown that poly(U) tail addition and editing occur in the haptophyte-derived serial endosymbionts of the fucoxanthin-containing dinoflagellates Karenia mikimotoi and Karlodinium veneficum. This is the first evidence that plastids acquired through serial endosymbiosis may be supported by pathways retained from previous symbioses. Transcript editing constrains the phenotypic consequences of divergent mutations in fucoxanthin plastid genomes, whereas poly(U) tail addition plays a central role in recognising and processing translationally functional fucoxanthin plastid mRNAs. I have additionally shown that certain genes within fucoxanthin plastids are located on minicircles. This demonstrates convergent evolution in the organisation of the fucoxanthin and red algal dinoflagellate plastid genomes since their endosymbiotic acquisition. Finally, I have investigated transcript processing in the algae Chromera velia and Vitrella brassicaformis. These species are closely related to apicomplexans but are still photosynthetic and apply poly(U) tails to plastid transcripts, as with dinoflagellates. I have shown that poly(U) tails in these species are preferentially associated with translationally functional mRNAs of photosynthesis genes. This is the first plastid transcript processing pathway documented to target a specific functional gene category. Poly(U) tail addition may direct transcript cleavage and allow photosynthesis gene transcripts to accumulate to high levels. The loss of this pathway from ancestors of apicomplexans may have contributed to their transition from photosynthesis to parasitism.
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Maai, Eri. "Factors inducing the chloroplast movement in C₄ plants underhigh light-stress conditions and effects of the response on photosynthesis." Doctoral thesis, Kyoto University, 2020. http://hdl.handle.net/2433/253468.
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京都大学0048
新制・論文博士
博士(農学)
乙第13360号
論農博第2891号
新制||農||1080(附属図書館)
学位論文||R2||N5299(農学部図書室)
(主査)教授 中﨑 鉄也, 教授 白岩 立彦, 教授 土井 元章
学位規則第4条第2項該当
Doctor of Agricultural Science
Kyoto University
DGAM
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Santos, Paula Cristina Bento Batista dos. "Molecular responses of Coffea spp. tolerance to low non-freezing temperatures." Doctoral thesis, ISA/UTL, 2010. http://hdl.handle.net/10400.5/3864.
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Doutoramento em Biologia - Instituto Superior de AgronomiaLow positive temperatures are of up most importance in tropical plant species, namely in Coffea spp., disturbing plant growth and metabolism, with impact on photosynthesis and yield. An integrated biochemical and molecular approach was used to analyze the cold impact and tolerance ability on photosynthesis of coffee plants, linked to modifications of the status of the antioxidative system, and chloroplast membrane lipids. Five coffee genotypes with contrasting cold sensitivity were used: Coffea canephora cv. Apoatã, C. arabica cv. Catuaí, C. dewevrei, Icatu (C. arabica x C. canephora) and Piatã (C. dewevrei x C. arabica). Determinations were performed along a slow cold imposition (to allow acclimation) from 25/20 ºC (day/night) down to 13/8 ºC, after exposure to 4o C (chilling) and in the rewarming period thereafter. Cold exposure strongly affected net photosynthesis in all genotypes, although stomatal limitations were not detected. Icatu revealed the lowest leaf loss, higher reinforcement of the antioxidative system, qualitative changes in chloroplast membrane lipids and regulation of some key genes. Altogether these responses indicate a better ability of this genotype to cope with low positive temperatures
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Bégot, Laurent. "Caractérisation du mutant dal1-2 d'Arabidopsis thaliana, affecté dans le développement précoce du chloroplaste." Université Joseph Fourier (Grenoble ; 1971-2015), 1999. http://www.theses.fr/1999GRE10054.
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Le mutant d'arabidopsis thaliana dal1-2, etiquete par un element transposable ac, est bloque precocement dans le developpement du chloroplaste. Son etude phenotypique a permit de mettre en evidence une couleur des feuilles variant du jaune au vert clair, au cours de son developpement. Morphologiquement, des coupes histologiques de feuilles montrent une desorganisation de la couche palissadique mesophyllienne. Le nombre de chloroplastes par cellule est plus important chez le mutant compare avec le sauvage mais leur taille est plus petite. La structure des chloroplastes par microscopie electronique a transmission montre une desorganisation et une quantite reduite des membranes thylacoidiennes. Les dosages realises sur les chlorophylles, carotenoides et lipides indiquent une forte reduction quantitative de ces molecules chez le mutant. La respiration chez le mutant est normale mais la photosynthese est residuelle pour un stade de developpement avance du mutant. Dal1-2 n'est pas affecte dans la skotomorphogenese. Au niveau genetique, l'isolement de l'adnc et du gene ont ete realises. L'expression du gene dal est absente chez le mutant. Une seule copie du gene dal est presente dans le genome nucleaire d'arabidopsis thaliana et celui-ci appartient a une famille de genes. L'expression de dal est elevee dans les boutons floraux et les fleurs. La proteine dal contient une sequence d'adressage chloroplastique et est importee dans le chloroplaste. L'analyse de l'expression de genes impliques dans le developpement des organites a permit de montrer clairement que la coordination de l'expression de genes nucleaires et chloroplastiques est toujours assuree chez le mutant dal1-2. L'expression des genes nucleaires de proteines ribosomiques est inchangee dans le mutant alors que l'expression des genes photosynthetiques cab et rbcs est reduite. Globalement, l'expression des genes mitochondriaux montre un niveau d'expression normal. Par contre, l'expression de tous les genes chloroplastiques testes est fortement reduite. L'analyse de l'expression de l'adnr 16s chloroplastique revele la presence de 50% d'arnr 16s non matures. Une explication possible etant que la proteine dal soit impliquee dans la maturation post-transcriptionnelle des arnr 16s. Ainsi, l'absence de la proteine dal conduirait a une chute de l'assemblage des ribosomes 70s, et par consequent a une perte de l'integrite chloroplastique.
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DUCHER, TARDY MIREILLE. "Role de la lumiere sur la morphogenese et le metabolisme du thalle de draparnaldia mutabilis (roth-cederg)." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2E386.
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Influence de differentes intensites d'eclairement sur la ramification du thalle, l'organisation et la differenciation du chloroplaste. Sur la croissance avec action du phytochisme, sur la photosynthese, le metabolisme du glycolate et glucides solubles et insolubles
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Upham, Brad Luther. "Interactions of paraquat and nitrodiphenylether herbicides with the chloroplast photosynthetic electron transport in the activation of toxic oxygen species." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/82614.
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The interactions of paraquat (methylviologen) and diphenylether herbicides with the Mehler reaction as investigated. Sera from two different rabbits (RS1 & RS2) were examined for their patterns of inhibition of the photosynthetic electron transport (PET) system. Serum from RS2 was greatly hemolyzed. Fifty ul of RS1 serum were required for 100% inhibition of a H₂O → methylviologen(MV)/O₂ reaction, whereas only 10 µl of a 1:10 dilution of RS2 were needed for 100% inhibition. The γ-globulin fraction from purified rabbit serum (RS1) did not inhibit PET, indicating that the antibody fraction of the rabbit serum does not contain the inhibitor. It appears that the inhibitor is from the hemolyzed red blood cells. Rabbit sera, added to chloroplast preparations prior illumination, caused no inhibition of a H₂O → MV/O₂ reaction while addition of rabbit sera during illumination inhibited the H₂O → MV/O₂ reaction within 1-3 s. Various Hill reactions were used to determine the site of inhibition. Rabbit sera inhibited photosystem I (PSI) Hill reactions, but did not inhibit a photosystem II (PSI II) Hill reaction indicating that inhibition is on the reducing side of PSI. It would be expected that a H₂O → Ferredoxin (Fd)/NADP Hill reaction should also be blocked. Surprisingly, rabbit sera did not inhibit this reaction. These results were interpreted as supportive evidence for parallel (branched) electron transport on the reducing side of PSI.
Six pyridyl derivatives {benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4-pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine} and five heme-iron derivatives {hemoglobin, hemin, hematin, ferritin, and ferrocene} were screened for their potential to counteract paraquat toxicity on pea (Pisum sativum L. cv. Little Marvel) isolated chloroplasts. H₂O → MV/O₂ and H₂O → Fd/NADP+ were the two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. None of the pyridyl derivatives examined inhibited the reaction H₂O → MV/O₂. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H₂O → MV/O₂ without inhibiting the reaction H₂O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. Hemin and hematin also inhibited H₂O → diaminodurene (ox) and durohydroquinone → MV/O₂ Hill reactions but not the dichlorophenylindolphenol(red) → MV/O₂ and diaminodurene(red) → MV/O₂ Hill reactions. These results indicate that hemin and hematin are inhibiting photosynthetic electron transport in the plastoquinone pool region.
Potential involvement of hydroxyl and alkoxyl radicals in the peroxidative action of the p-nitro diphenyl ether herbicides acifluorfen was evaluated under laboratory conditions. Methional was added to illuminated pea thylakoids and its oxidation to ethylene was used as an indicator of hydroxyl and alkoxyl radical synthesis. Oxyfluorfenstimulation of the rate of methional oxidation was dependent on light, photosynthetic electron transport and hydrogen peroxide since it was not observed under dark conditions or in the presence of DCMU and catalase. Addition of FeEDTA, a catalyst of the Fenton reaction, stimulated the oxyfluorfen-induced enhancement of methional oxidation six-fold suggesting that hydroxyl radicals are synthesized through a Fenton reaction. Acifluorfen, nitrofen and nitrofluorfen inhibited the rate of methional oxidation whereas, acifluorfen-methyl had no effect on the rate of methional oxidation even at high concentrations (1 mM). Nitrofluorfen at 1 mM was the only p-nitro diphenyl ether herbicide tested which inhibited photosynthetic electron transport of pea thylakoids. In experiments with pea leaf discs, acifluorfen at low concentrations stimulated the rate of methional oxidation, while acifluorfen-methyl, nitrofen and nitrofluorfen had no effect. These data indicate that hydroxyl and alkoxyl radicals could be involved in the mechanism of cellular damage caused by oxyfluorfen, but they are not important for the activity of the diphenyl ether herbicides acifluorfen, acifluorfen-methyl, nitrofen, and nitrofluorfen.
Diethyldithiocarbamate (DEDTC) does not accept electrons from the photosynthetic electron transport (PET), but can donate electrons to a photosystem I (PSI) Mehler reaction in the presence of the following PET inhibitors: diuron, dibromothymoquinone, and bathophenanthroline. It cannot photoreduce PSI in the presence of cyanide, a PET inhibitor. These data indicate that the site of electron donation is after the plastoquinone pool. Ascorbate is not required for the ability of DEDTC to donate electrons to PSI. There is no photoreductant activity by DEDTC in a ferredoxin/NADP Hill reaction. Superoxide dismutase inhibits DEDTC/diuron or bathophenanthroline → MV/O₂ Mehler reaction. Catalase does not restore the consumed O₂ from a DEDTC/diuron → MV/O₂ Mehler reaction, indicating O₂- has not been dissmutating into H₂O₂. These results indicate that superoxide is required for DEDTC ability to donate electrons, therefore DEDTC is limited only to Mehler-type reactions.Ph. D.
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Samnakay, Parwez. "An investigation into the chloroplast transformation of wheat, and the use of a cyanobacterial CCM gene for improving photosynthesis in a C3 plant." Thesis, Lancaster University, 2015. http://eprints.lancs.ac.uk/80974/.
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Wheat is a major component of the UK diet, and provides approximately 20% of global caloric intake. Wheat is grown on more land area than any other crop, and the continued supply of wheat is essential for global food security. Biotechnology is likely to play an important role in the sustainable increase of wheat yields, and the genetic manipulation of chloroplasts for photosynthetic improvement has many potential advantages over transformation of the nuclear genome. The genetic modification of the chloroplast genome via transformation was first demonstrated in the late 1980’s, and since then, chloroplast transformation of many Dicotyledonous (dicot) plant species such as Nicotiana tabaccum has been routinely performed. In comparison, the transformation of chloroplasts in Monocotyledons (monocot) plant species, which includes all cereal crops, has made far less progress. To date, there has been no reproducible homoplasmic plastid transformation event in the monocots. This study identifies a number of bottlenecks responsible for the prevention of chloroplast transformation in wheat. One such bottleneck is the lack of a suitable explant for plastid transformation, as traditional nuclear transformation targets are absent of metabolically active plastids. This study has developed a robust regeneration protocol for a previously undescribed tissue, termed the primary inflorescence leaf sheath (piLS), which is rich in active chloroplasts. Functional wheat specific chloroplast transformation vectors have been generated, and bombardment studies have been conducted with these on piLS and a second tissue, the immature embryosderived callus. Immature embryo callus (IEC) does not contain active plastids, however contains pro-plastids and is highly embryogenic. To uncover novel ways of increasing photosynthesis in C3 plants, a number of transplastomic tobacco lines expressing the Synechococcus elongatus PCC 7942 ictB gene were generated. Previous studies suggest that ictB may be an inorganic carbon transporter. In a number of transplastomic lines produced in this study, the intercellular carbon concentration (Ci) is significantly increased. This increased Ci did not result in an increased photosynthetic rate, however did cause a number of phenotypic differences, such as smaller plants, wider leaves, and earlier seed pod formation. The results, with regards to chloroplast transformation, and its implications in improving photosynthesis within C3 plants, are discussed in this thesis.
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Kuntz, Marcel. "Etude de la structure et de l'expression des genomes plastidiaux et du transport des proteines dans les chloroplastes." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13012.
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Etude des genes de trna d'organistes photosynthetiques et determination des sequences nucleotidiques des genes du trna**(t4r)(ggu), trna**(glu)(uuc) et trna**(tyr)(gua) chloroplastiques de feve et des genes des trna**(glu)(uuc), trna**(leu)(uaa), trna**(ser)(gga) et trna**(gly)(ggc) des cyanelles de cyanophora paradoxa. Un intron de classe i a ete mis en evidence dans le gene codant pour le trna**(leu)(uaa) de cyanelles. A l'aide des techniques de fusion de genes et de transformation des plantes, il est apparu que le peptide transit de la pente sous unite de la rubisco permet le transport efficace d'une proteine etrangere dans les chloroplastes. La regulation de l'expression des genes plastidiaux s'effectue donc au niveau de la traduction
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Ek, Louise. "The effect of nitrogen starvation on PSI and PSII activity in pea (Pisum sativum)." Thesis, Halmstad University, School of Business and Engineering (SET), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-143.
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This investigation addresses how photosynthetic efficiency is affected when pea (Pisum sativum) plants are restricted to a sole nitrogen source (i.e. ammonium or nitrate). The pea plants were watered with different nutrient solutions without NO3- or NH4+ for different time-periods in order to assay for nitrogen content. The soluble ammonium and nitrate content was measured throughout the entire growth period. No major differences were observed in nitrogen content during the starvation period up to 25 days. For technical reasons, cultivation of plants could not be extended beyond this time. The chloroplasts and thylakoids were isolated after 25 days and assayed for chlorophyll contents and photosynthetic activity.
The outcome of these tests indicates a small but unambiguous decrease in the photosynthesis activity for all treatments, relative the control.
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Adam, Véronique. "Etude des chloroplastes isoles de feuilles de kalanchoe blossfeldiana, plante a metabolisme crassulaceen : isolement, caracterisation enzymatique et proprietes photosynthetiques." Paris 6, 1988. http://www.theses.fr/1988PA066003.
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Mesure polarographique de l'activite photosynthetique des chloroplastes et des mitochondries isoles. Observation des inhibitions competitives entre phosphoenolpyruvate et le 3-phosphoglycerate d'une part et la malate dehydrogenase nadp**(+) dependante et la chaine de transfert d'electrons pour le nadp**(+). Ce modele devrait permettre d'etudier la regulation de la decarboxylation du malate par l'activite photosynthetique des chloroplastes
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Dionísio, Gisela João Ribeiro Lemos. "Effects of climate change on the physiology and photobiology of photosynthetic sea slugs." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22392.
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Doutoramento em BiologiaThe vulnerability of marine photosynthetic symbioses to climate-driven changes has deserved particular attention in recent years. However, while there is an increasing number of studies on emblematic species such as symbiotic corals, little is known about less charismatic groups such as solar-powered sea slugs. These organisms display one of the most puzzling features observed in the animal kingdom: the mollusc-plastid association, which results from their ability to retain photosynthetically active chloroplasts (kleptoplasts) “stolen” from their algal food sources. Given their peculiar biology, sea slugs have stood out as tool organisms for academic research on photobiology, biomedical studies and bioprospecting of new marine drugs, becoming also desired critters in the marine aquarium trade. In order to provide an overview of state-of-the-art on our knowledge on these fascinating organisms, and lay down the foundations for climate change research, the biological and ecological features of the mollusc-plastid association were reviewed and optimal culture conditions for their different life stages were identified. The impact of ocean acidification and warming was evaluated on early stages and adults of temperate (Elysia viridis) and tropical (Elysia clarki) sea slugs. In this context, new methodological approaches were developed to non-invasively assess the photophysiology of kleptoplasts under future ocean conditions. Our results have shown that acidification and warming may impact several biological features of solar-powered sea slugs, including survival, reproductive success, growth, incidence of deformities, kleptoplasts photosynthetic efficiency, metabolism, heat shock and antioxidant responses. However, sea slug tolerance to future ocean conditions was shown to be species-specific. The temperate sea slug E. viridis, in spite of their low survival, presented efficient heat shock and antioxidant defence mechanisms and high rates of photosynthesis and respiration when exposed to acidification and warming, suggesting the existence of a more tolerant mollusc-kleptoplast complex and capacity to cope with future scenarios. In contrast, the tropical sea slug E. clarki showed to be quite vulnerable to future ocean conditions. The reduced capacity or lack of mechanisms to deal with environmental stress may, in part, explain the metabolic depression of the holobiont and the reduced photosynthetic efficiency of kleptoplasts, leading to bleaching and a lower survival. This work is the first reporting the occurrence of bleaching under climate change in other photosynthetic symbiosis than the cnidarian-dinoflagellate association. These results have broad implications and may help us to anticipate potential negative impacts on the recruitment of solar-powered sea slugs in the oceans of tomorrow. However, it is worth noting that solar-powered sea slugs may have time and evolutionary opportunities to adapt to future ocean conditions.
A vulnerabilidade das simbioses fotossintéticas marinhas face às alterações climáticas tem recebido particular atenção nos últimos anos. Porém, enquanto existe um número crescente de estudos para as espécies emblemáticas, como os corais, pouco se sabe acerca dos grupos menos carismáticos como as lesmas do mar “movidas a energia solar”. Estes organismos possuem uma das particularidades mais intrigantes do reino animal: uma associação molusco-plasto, que resulta da sua capacidade de reter cloroplastos fotossinteticamente ativos (cleptoplastos) “roubados” às algas de que se alimentam. Dada a sua biologia peculiar, as lesmas do mar destacaram-se nos últimos anos como organismo “ferramenta” na investigação da fotobiologia, modelo nos estudos biomédicos e de bioprospeção de novos compostos marinhos, tornando-se ainda pretendidas para o comercio da aquariofilia marinha. Por forma a apresentar uma visão global acerca do conhecimento destes organismos fascinantes e estabelecer critérios para a investigação sobre as alterações climáticas, as características biológicas e ecológicas da associação molusco-plasto foram revistas e ainda identificadas as condições ótimas de cultivo para diferentes fases do seu ciclo de vida. O impacto da acidificação e o aquecimento dos oceanos foi avaliado nos estágios iniciais do desenvolvimento e nos adultos da lesma do mar temperada (Elysia viridis) e na tropical (Elysia clarki). Neste contexto, novas abordagens metodológicas foram desenvolvidas por forma a aceder de forma não invasiva à foto-fisiologia dos cleptoplastos de acordo com as futuras condições do oceano. Os resultados mostraram que a acidificação e o aquecimento do oceano podem influenciar as características biológicas das lesmas do mar “movidas a energia solar”, incluindo a sobrevivência, sucesso reprodutivo, crescimento, incidência de deformações, eficiência fotossintética dos cleptoplastos, metabolismo, e as respostas contra o choque térmico e de ação antioxidante. Contudo, a tolerância das lesmas do mar às condições futuras do oceano revelou ser especifica de cada espécie. A lesma do mar temperada E. viridis, apesar da baixa sobrevivência, apresentou mecanismos eficientes contra o choque térmico, defesa antioxidante e elevadas taxas de fotossíntese e respiração quando exposta à acidificação e ao aquecimento, sugerindo um complexo molusco-cleptoplasto mais tolerante e capacidade em lidar contra os cenários futuros. Por outro lado, a lesma do mar tropical E. clarki mostrou ser vulnerável às condições futuras do oceano. A reduzida capacidade e ausência de mecanismos para lidar com o stress ambiental pode, em parte, explicar a depressão metabólica do holobionte e a reduzida eficiência fotossintética dos cleptoplastos, que levaram ao branqueamento das lesmas do mar e a reduzida sobrevivência. Este trabalho é o primeiro a reportar a ocorrência de branqueamento em circunstâncias de alterações climáticas noutras simbioses marinhas que não as associações cnidário-dinoflagelado. Estes resultados têm amplas implicações e podem ajudar a antecipar os possíveis impactos negativos no recrutamento das lesmas do mar “movidas a energia solar” nos oceanos de amanhã. Contudo, é importante notar que as lesmas do mar “movidas a energia solar” poderão ter tempo e oportunidades evolutivas de adaptação às condições do futuro oceano.
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WITTEMER, GROTZINGER CHRISTIANNE. "Etude de genes nucleaires codant pour des proteines chloroplastiques d'euglena gracilis." Strasbourg 1, 1987. http://www.theses.fr/1987STR13229.
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Antonucci, Natalia Paganotti. "Estudos anatômicos, ultra-estruturais e bioquímicos da síndrome Kranz em folhas de duas espécies de Gomphrena L. (Amaranthaceae)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-19042010-115918/.
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A síndrome Kranz é um conjunto de características anatômicas, ultra-estruturais e bioquímicas que culminam na realização da fotossíntese C4. Tal síndrome apresenta grande diversidade dentre as Angiospermas, tornando-se conveniente seu estudo em todos os níveis acima citados para a completa caracterização da mesma. No presente trabalho foi investigada a síndrome Kranz de Gomphrena arborescens e G. scapigera (Amaranthaceae) com ênfase na origem ontogenética da bainha Kranz, na descrição ultra-estrutural e na confirmação bioquímica sobre o tipo de fotossíntese C4. O desenvolvimento foliar dessas espécies indica que a bainha Kranz é originada da camada mais interna do mesofilo, a endoderme foliar. Uma discussão sobre os termos presentes na literatura para a descrição dessa bainha, todos eles focados em sua função na fotossíntese C4, demonstra a importância de se utilizar termos que informem a origem ontogenética dessa bainha, como endoderme e periciclo. Na análise ultra-estrutural, foram identificados possíveis fatores que interferem na fotossíntese de ambas as espécies, como o espessamento e a composição da parede da bainha Kranz, o posicionamento centrípeto dos cloroplastos e a presença de retículo periférico nos mesmos. Embora a análise bioquímica tenha resultado em informações ainda não conclusivas, o dimorfismo dos cloroplastos sugere a realização da fotossíntese C4 do tipo NADP-ME. O presente trabalho, de uma forma geral, contribui ao conhecimento da síndrome Kranz dentre as Amaranthaceae s.s., um grupo em que a ultra-estrutura e a bioquímica ainda são pouco conhecidas, e ressalta a importância dos estudos anatômicos, principalmente com enfoque ontogenético, para o melhor conhecimento da diversidade da síndrome Kranz dentre as Angiospermas.The Kranz syndrome is a set of anatomical, ultrastructural and biochemical features that culminate in the C4 photosynthesis. This syndrome has a huge diversity among Angiosperms, so it became suitable to survey all the levels above cited for its complete characterization. In the present work the Kranz syndrome of Gomphrena arborescens and G. scapigera (Amaranthaceae) is studied, with emphasis on the ontogenetic origin of the Kranz sheath, on the ultrastructural description, and on the biochemical confirmation about the C4 photosynthesis kind. The foliar development of these species shows that the Kranz sheath is originated from the inner layer of the mesophyll, the foliar endodermis. A discussion about the literature terms used to describe the Kranz sheath, all of them referring to the function of this layer in C4 photosynthesis, demonstrates the importance of using terms that inform the ontogenetic origin of this layer, such as endodermis and perycicle. The ultrastructural analysis identified possible factors that interfere on the C4 photosynthesis of both species, such as wall thickening and composition of Kranz sheath cells, the centripetal position of chloroplasts and the peripheral reticulum in chloroplasts. Although biochemical analysis has resulted in no conclusive information, the chloroplast dimorphism suggests the NADP-ME C4 photosynthesis. This work, in a general way, contributes to the knowledge of the Kranz syndrome among Amaranthaceae s.s., a group that has the ultrastructure and the biochemistry of C4 photosynthesis poorly known. It also draws attention to the importance of anatomical surveys concerning the ontogenetic origin of Kranz sheath for a better understanding on the diversity of Kranz syndrome among Angiosperms.
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Erlinghäuser, Matthias [Verfasser]. "Identifizierung von Komponenten der single-cell C4 Photosynthese in Bienertia sinuspersici durch vergleichende Transkriptomik photosynthetischer Gewebe und proteomische Untersuchung der Hüllmembranen dimorpher Chloroplasten / Matthias Erlinghäuser." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2018. http://d-nb.info/1172414092/34.
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Aguettaz, Pierre. "Utilisation de cultures photomixotrophiques de cellules d'épinard : 1, pour la sélection de lignées résistantes à la streptomycine. 2, pour l'étude de la transcription de gènes plastidiaux au cours de la transformation d'amyloplastes en chloroplastes." Grenoble 1, 1987. http://www.theses.fr/1987GRE10008.
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La lignee cellulaire d'epinard g20 necessite une source de carbone organique pour croitre, en culture aerees, les celules perdent leur chlorophylle. En condition d'oxygene limitant, les chloroplastes se differencient et grace a l'oxygene produit par photosynthese, les cellules deviennent capables d'utiliser le sucre du milieu. Des cultures photomixotrophes, dont la croissance est dependante du fonctionnement des chloroplastes, ont ete ainsi etablies. Un protocole de mutagenese aux uv et de selection en milieu liquide ont ete mis au point pour obtenir des lignees resistantes a la streptomycine; ces lignees restent chlorophyliennes en presence de l'antibiotique, presentent une croissance ralentie, suggerent une action de l'antibiotique sur le fonctionnement mitochondrial. L'hybridation moleculaire des adn cellulaires a diverses sondes de genes plastidiaux revele l'evolution des teneurs cellulaires en transcrits de ces genes, et met en evidence le role preponderant du "gene-dosage" dans le controle de cette evolution (transformation des chloroplastes en amyloplastes)
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Middlebrooks, Michael Louis. "Consequences of Kleptoplasty on the Distribution, Ecology, and Behavior of the Sacoglossan Sea Slug, Elysia clarki." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4162.
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The sacoglossan sea slug Elysia clarki is able to photosynthesize for three to four months using chloroplasts sequestered from its algal food sources. Furthermore, the slug is able to store multiple chloroplasts from different algal species within the same cell. This research, consisting of several related studies, explores the role that provision of organic nutrients via photosynthesis plays in the biology of the slug. The first chapter demonstrates that, under conditions of starvation, photosynthetic activity in E. clarki remains fully functional for one month after which it then declines. During the first month of starvation the slug exhibits similar feeding behavior as slugs provided a continuous supply of food, suggesting that photosynthesis delays the onset of starvation-induced behavioral changes. The second chapter explores E. clarki's spatial relationships with algae known to be food sources in the field. In areas with high slug density, edible algal populations were very low. DNA barcoding was employed to demonstrate that the algae found near slugs were poor predictors of which foods were actually consumed by slugs. Generally, there was a mismatch between algae available in the field and slug diets. The third chapter explores how E. clarki is able to maintain photosynthesis. After labeling with a C14 ALA incubation process, then chlorophyll was extracted from slugs and purified using HPLC. Results indicate that recently collected E. clarki are able to synthesize chlorophyll, whereas slugs starved for 3 months were not. Photosynthesis plays a very important role for E. clarki and its relationships with food algae.
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Levavasseur, Guy. "Plasticité de l'appareil pigmentaire des algues marines : Macrophytes : regulation en fonction de l'environnement." Paris 6, 1986. http://www.theses.fr/1986PA066121.
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Méthode d'étude et matériel: Chlorophycées, Pheophycees et Rhodophycées de la région de Roscoff. Méthodes d'extraction des diloroplastes et de leur membranes et de complexes protéine-chl. Caractéristiques pigmentaires des algues et activités photosynthétiques, et relation avec la localisation des algues dans les zones médio- et infra-littorale. Effet des saisons et de la durée d' éclairement
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Cunha, de Pádua Mário Manuel. "Effets du cuivre sur le métabolisme des plantes supérieures." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10061.
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L'exposition de cellules d'érable à des concentrations sublétales de cuivre (50 m) s'accompagne d'un arrêt de l'augmentation de la masse fraîche au bout du 5#e#m#e jour de culture. Cet arrêt de croissance est précédé par une diminution de la respiration couplée et découplée, avec diminution concomitante des marqueurs mitochondriaux (fumarase, cytochrome oxydase, cardiolipide). Le cuivre provoque ainsi une dilution progressive des mitochondries dans la population cellulaire, due à un arrêt de la division des mitochondries précédent l'arrêt de la division des cellules. Lorsque le cuivre est soustrait du milieu, la division des mitochondries, puis des cellules, sont relancées. Nous disposons ainsi d'un levier pour analyser le contrôle du nombre de mitochondries dans les cellules. Par ailleurs, nous avons montré que l'oxydase alternative est étroitement contrôlée par le niveau de cuivre dans le milieu de culture des cellules (activité et quantité de protéine). Les effets de l'excès de cuivre sur la photosynthèse ont été étudiés en utilisant des chloroplastes purifiés présentant un haut degré d'intégrité morphologique et fonctionnelle (épinard et pois). La teneur de 1. 8 m de cuivre donne une inhibition (ic50) de 50% du dégagement d'oxygène, alors que sur les thylacoides purifiés on observe un ic50 apparent de 54 m. Ceci suggère que le cuivre agit essentiellement sur les enzymes du cycle de Benson. Enfin, nous avons observé une interférence entre le cuivre et le manganèse au niveau de la photosynthèse des chloroplastes intacts, et pas au niveau des thylacoides. Les analyses par oxygraphie et par fluorescence modulée suggèrent qu'il y a une compétition entre le cuivre et le manganèse au niveau de leur transport à travers l'enveloppe plastidiale.
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Gallois, Jean-Luc. "Recherches méthodologiques en vue de l'isolement de mutants d'expression du gène nucléaire RPL21." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10109.
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La differenciation des chloroplastes au sein des cellules vegetales est essentielle pour la photosynthese et donc la croissance autotrophique de la plante. Les genes nucleaires codant des proteines ribosomiques du plaste constituent des genes marqueurs precoces de la differenciation du proplaste indifferencie en chloroplaste fonctionnel. Deux genes nucleaires rpl21 d'arabidopsis ont ete caracterises. Ils codent pour deux proteines l21 d'origine procaryotiques. Une proteine l21 est localisee dans le ribosome plastidial, l'autre dans le ribosome mitochondrial. Ces deux proteines temoignent d'une origine evolutive commune, et distincte des proteines l21 codees dans le genome plastidial des plantes inferieures. L'etude du gene codant la proteine l21 chloroplastique montre la conservation de la structure et de l'expression de ce gene chez arabidopsis et chez l'epinard. Ces genes sont exprimes fortement au sein des feuilles jeunes, et cela independamment du developpement chloroplastique. Le gene de la luciferase a ete fusionne au promoteur rpl21 d'epinard et cette construction a ete inseree par transformation dans arabidopsis. 10000 plantes homozygotes pour cette construction ont ete mutagenisees par traitement ems. Une selection de plantules m2 presentant un defaut d'expression de la luciferase a ete menee a l'aide d'une camera ccd. Trois mutants putatifs, deux albinos sous-exprimant la luciferase sous controle du promoteur rpl21 et une au phenotype sauvage la surexprimant dans la racine, ont ete isoles. Leur etude devrait mener a la caracterisation de genes impliques dans le developpement chloroplastique. Notre etude montre les possibilites offertes par l'utilisation de la luciferase comme gene rapporteur. Par ailleurs, une nouvelle methode antisens assistee par la luciferase est presentee. Elle vise a suivre l'antisens insere par transformation dans arabidopsis et permet d'ecarter d'eventuels phenotypes independants de l'effet antisens.
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Troton, Didier. "Modifications de la composition lipidique des thylakoides intervenant au cours de l'adaptation d'euglena gracilis au diuron." Paris 7, 1987. http://www.theses.fr/1987PA077169.
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Ungrová, Anna. "Úloha chloroplastů ve středním válci kořenů epifytických orchidejí." Master's thesis, 2021. http://www.nusl.cz/ntk/nusl-446070.
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The photosynthesis of the aerial roots of epiphytic orchids has been the subject of numerous studies. However, the roots are always evaluated as a homogeneous structure, even though they actually consist of significantly different areas. This work deals for the first time with the possibility of the spatial distribution of photosynthesis between the root layers, specifically the cortex and the stele. A combination of various microscopic techniques, the histochemical characterization of the apoplastic barriers and the immunohistochemical localization of the photosynthetic enzyme phosphoenolpyruvate carboxylase has been used. The results show that well-developed chloroplasts in the stele probably occur in the subfamily Epidendroideae in all epiphytic representatives, while in the subfamily Vanilloideae they occur occasionally. The ultrastructure of chloroplasts from both areas is systematically different, so it is likely that their functions also differ. Apoplastic barriers are prominent in the roots and differentiate early during root development, which can effectively isolate chloroplasts in the stele from the cortex. Chloroplasts also occur in the sclerenchyma cells of the stele, where were identified hitherto unknown pits in cell walls that could provide gas exchange within the stele....
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"Effect of pesticides on proton flux through the CF0CF1 complex in chloroplasts." 1997. http://library.cuhk.edu.hk/record=b5889200.
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by Edwina Po Sau Man.The "0" & "1" in the title are subscripts.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.
Includes bibliographical references (leaves 81-86).
Abstract --- p.II
Acknowledgment --- p.IV
Abbreviations --- p.V
List of Tables --- p.VIII
List of Figures --- p.IX
Table of Contents --- p.XII
Chapter Section 1 --- Introduction --- p.1
Chapter 1.1 --- Photosynthesis --- p.1
Chapter 1.2 --- Site of Photosynthesis --- p.3
Chapter 1.3 --- The Structure of ATPase --- p.6
Chapter 1.3.1 --- Functions of the Subunits of CF1 --- p.9
Chapter 1.3.1.1 --- The ε - Subunit --- p.9
Chapter 1.3.1.2 --- The δ - Subunit --- p.9
Chapter 1.3.1.3 --- The γ- Subunit --- p.10
Chapter 1.3.1.4 --- The α- and β- Subunits --- p.10
Chapter 1.4 --- "Photosynthetic Electron Transport, Δ pH and Phosphorylation inside Chloroplasts" --- p.12
Chapter 1.5 --- Pesticides --- p.16
Chapter 1.5.1 --- Paraquat --- p.17
Chapter 1.5.2 --- Carbamates --- p.20
Chapter 1.6 --- Objectives of the Study --- p.21
Chapter Section 2 --- Materials and Methods --- p.22
Chapter 2.1 --- Apparatus --- p.22
Chapter 2.2 --- Materials --- p.24
Chapter 2.2.1 --- Reagents and Buffers for assay of Proton Transport --- p.25
Chapter 2.2.2 --- Pesticides --- p.26
Chapter 2.2.3 --- Buffers for SDS-PAGE --- p.27
Chapter 2.2.4 --- Reagents of Bradford Protein Assay --- p.31
Chapter 2.3 --- Methods --- p.32
Chapter 2.3.1 --- Determination of ChlorophyllContent --- p.32
Chapter 2.3.2 --- Determination of Protein Content in Chloroplast Thylakoids --- p.33
Chapter 2.3.3 --- Measurement of Proton Transport --- p.34
Chapter 2.3.3.1 --- Pesticide Concentration Study --- p.36
Chapter 2.3.3.2 --- Time Course Study --- p.36
Chapter 2.3.3.3 --- Kinetic Analysis of the Effects of Pesticides on Chloroplast Thylakoids Before and After Illumination --- p.37
Chapter 2.3.3.4 --- Study of the Combined Effects of Two Pesticides --- p.37
Chapter 2.3.4 --- Effect of Pesticides on Chloroplast Membranes by SDS-PAGE --- p.38
Chapter Section 3 --- Results --- p.39
Chapter 3.1 --- Pesticide Concentration Study --- p.39
Chapter 3.1.1 --- Paraquat Dichloride --- p.39
Chapter 3.1.2 --- Methyl Carbamate --- p.41
Chapter 3.1.3 --- Ethyl Carbamate --- p.43
Chapter 3.1.4 --- Pyridinol Carbamate --- p.45
Chapter 3.1.5 --- Pyrrolidinedithiocarbamate --- p.47
Chapter 3.1.6 --- Diethyldithiocarbamic Acid --- p.49
Chapter 3.1.7 --- Summary of the Pesticides Concentration Study --- p.51
Chapter 3.2 --- Time-course Study --- p.52
Chapter 3.3 --- Kinetic Analysis of the Effects of Pesticides on Chloroplast Thylakoids Before and After Illumination --- p.53
Chapter 3.3.1 --- Paraquat Dichloride --- p.53
Chapter 3.3.2 --- Methyl Carbamate --- p.56
Chapter 3.3.3 --- Ethyl Carbamate --- p.57
Chapter 3.3.4 --- Pyridinol Carbamate --- p.58
Chapter 3.3.5 --- Pyrrolidinedithiocarbamate --- p.59
Chapter 3.3.6 --- Diethyldithiocarbamic Acid --- p.60
Chapter 3.4 --- Combined Effects of Paraquat and Carbamates --- p.61
Chapter 3.4.1 --- Paraquat and Methyl Carbamate --- p.61
Chapter 3.4.2 --- Paraquat and Ethyl Carbamate --- p.64
Chapter 3.4.3 --- Paraquat and Pyridinol Carbamate --- p.66
Chapter 3.4.4 --- Paraquat and Pyrrolidinedithiocarbamate --- p.69
Chapter 3.4.5 --- Paraquat and Diethyldithiocarbamic Acid --- p.71
Chapter 3.5 --- Gel Electrophoresis --- p.73
Chapter Section 4 --- Discussion --- p.75
Chapter Section 5 --- Conclusion --- p.80
Chapter Section 6 --- References --- p.81
References --- p.81
Appendix I Kinetic Analysis of Pesticides with Chloroplast Thylakoids upon Illumination --- p.87
Appendix II Kinetic Analysis of Pesticides with Chloroplast Thylakoids in the Dark --- p.88
Appendix III The Initial Rate of Proton Transport in Chloroplast Thylakoids with Different Pesticides --- p.89
Appendix IV The Conversion of Equivalent Protons from pH Changes --- p.90
Appendix V Calculation of Proton Transport (%) --- p.91
Appendix VI Determination of Protein Content in Chloroplast Thylakoids --- p.92
Appendix VII Calculaiton of Relative Mobility (Rf) --- p.93
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Fan, Shu-Ting, and 范舒婷. "Effects of Ethylene during Storage and 1-Methylcyclopropene Pretreatment on Poststorage Quality, Photosynthesis, Chloroplasts, and Antioxidative Reaction in Aglaonema." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/95351197087763836781.
Full textAbstract:
博士國立臺灣大學
園藝學研究所
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Aglaonema is an important perennial herbaceous foliage plant. Taiwan has superior climate conditions, and thus has potential for export potted Aglaonema to Japan. Ethylene arising from anthropogenic and biological sources could occasionally accumulated to physiologically active concentrations inside enclosed areas during storage to alternate poststorage quality of foliage plants. This study investigated the effects of ethylene during storage and 1-methylcyclopropene (1-MCP) pretreatment on post-storage leaf senescence as measured by changes in quality, photosynthesis, chloroplasts, and antioxidative reaction of the fully developed leaves and the lowest leaves in Aglaonema cultivars. The purpose was to determine the cause of ethylene damage, and the effectiveness of 1-MCP protection. Potted plants of ‘Chalit’s Fantasy’, ‘Curtisii’ and ‘White Tip’ were treated with 0-4.5 μL‧L-1 ethylene during storage at 16℃ for 5 d. ‘Chalit’s Fantasy’ treated with 0 - 4.5 μL‧L-1 ethylene did not produce any chlorotic leaves and all stored plants were of excellent quality, with high SPAD-502 and Fv/Fm values. Increased number of chlorotic leaves and reduced quality rating were recorded in ‘Curtisii’ treated with 4.5 μL‧L-1 ethylene or ‘White Tip’ treated with 2.5 μL‧L-1 ethylene, as compared with 0 μL‧L-1 ethylene. Both the SPAD-502 value and Fv/Fm value of ‘Curtisii’ and ‘White Tip’ decreased as ethylene concentration increased from 0 to 4.5 μL‧L-1. Potted plants of ‘Chalit’s Fantasy’ and ‘White Tip’ were stored in a dark room at 16℃ for 5 d. Three treatments were employed in this study while plants were being stored. The first treatment (CK) was plants stored without ethylene or 1-MCP treatment. The second treatment (ET) was plants treated with 3.0 μL‧L-1 ethylene during storage. The third treatment (MCP/ET) was plants stored with 3.0 μL‧L-1 ethylene followed by pretreatment with 600 nL‧L-1 1-MCP for 6 h. Results showed that ET treatment did not affect the stomatal conductance in either cultivars or leaves. ET treatment reduced the net CO2 assimilation rate and potential photochemical efficiency of photosystem Ⅱ (Fv/Fm) in the lowest leaves of ‘White Tip’. MCP/ET treatment resulted in increased net CO2 assimilation rate and Fv/Fm in the lowest leaves of ‘White Tip’, as compared with ET treatment. Chloroplast number in a palisade or spongy mesophyll cell did not differ among treatments in the lowest leaves of ‘Chalit’s Fantasy’. However, the lowest leaves of ethylene-treated ‘White Tip’ had fewer chloroplasts in the mesophyll cells, had more and larger plastoglobules in the chloroplasts, and had looser granal stacking with enlarged thylakoid lumens. MCP/ET treatment prevented ethylene injury, and maintained the quantity and structural integrity of chloroplasts. Regardless of the fully developed or the lowest leaves, no differences were found in hydrogen peroxide (H2O2) and chlorophyll concentrations, and relative injury (RI) value among CK, ET and MCP/ET treatments in ‘Chalit’s Fantasy’. In ‘White Tip’, ET treatment resulted in increased H2O2 concentration and RI value, and reduced chlorophyll concentration, APX and CAT activity in the lowest leaves. There were no differences in H2O2 and chlorophyll concentrations and RI value between CK and ET treatments in the fully developed leaves of ‘White Tip’. Ehylene did not alter postharvest performance of ‘Chalit’s Fantasy’. In contrast, ethylene increased number of chlorotic leaves, decreased quality rating, the SPAD-502 value, and Fv/Fm value in ‘Silver Bay’, ‘Silver Queen’, ‘Pattaya Beauty’, ‘White Tip’, and ‘King of Siam’. ‘Silver Bay’ had fewer number of chlorotic leaves and higher quality rating, SPAD-502, and Fv/Fm values than ‘Silver Queen’, ‘Pattaya Beauty’, ‘White Tip’, and ‘King of Siam’. The number of chlorotic leaves decreased, and SPAD-502 and Fv/Fm values increased with increasing 1-MCP concentration × time. Treatment with 1-MCP concentration × time (300 nL‧L-1‧h) was effective in reducing the number of chlorotic leaves, and maintaining SPAD-502 and Fv/Fm values in ‘Silver Bay’. In other cultivars, higher 1-MCP concentration × time (400-900 nL‧L-1‧h) was required to maintain poststorage quality. This study also measured H2O2 concentration, CAT, APX, SOD, and GR activity and total ascorbate concentration in the lowest leaves of six cultivars before storage. H2O2 concentration, CAT and APX activity were higher in ‘Chalit’s Fantasy’ than other cultivars.
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CHARVÁT, Filip. "Efektivní velikost světlosběrných antén a její význam pro regulaci fotosyntézy." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-375728.
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Nonphotochemical quenching and state transitions are an important photoprotective mechanism against excessive irradiation. In this work I studied changes in the size of the effective crosssection of photosystem II antennae in regard to the level of nonphotochemical quenching (state transitions) under different levels of light induced stress.
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Palovská, Markéta. "Analýza primárních fotosyntetických procesů u jehličnanů: srovnání vybraných metod a možné využití při studiu genetické variability." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-267938.
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Conifers are important both ecologically and socioeconomically, however, same parts of their biology are not that well researched. This includes genetics and breeding and partly even physiology. Because quantitative genetic analyzes applied in breeding necessitate an analysis of a large number of samples, and conventional methods of analysis are quite time-consuming, certain parameters describing e.g. the activity of photosynthetic electron-transport chain (ETC) are considered for such use. Several methods of the measurement of the activity of photosynthetic ETC exist, but there are some problems with their usage in conifers. I studied this issue from different points of view in three parts of this thesis. 1) I compared the photosynthetic ETC activity in 8 species of conifers using chlorophyll (Chl) fluorescence measurements on intact needles and polarographic measurements in isolated chloroplasts. Each method brought different information. 2) I measured Chl fluorescence parameters, reflectance spectra and pigment content in 536 genetically defined trees of Pinus sylvestris L. Many parameters showed relatively high genetic variability and heritability. I have also determined the suitability of various reflectance indices to estimate pigment and water content of needles. 3) I have optimized the...
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Holtgrefe, Simone. "Untersuchungen zur Kurzzeit-Regulation und Adaptation von Photosynthese und Elektronenverteilung in Chloroplasten und transgenen Kartoffelpflanzen." Doctoral thesis, 2003. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2003061013.
Full textAbstract:
Die in dieser Arbeit durchgeführten Untersuchungen dienten zur Identifizierung von Faktoren, die das Zusammenspiel zwischen dem photosynthetischen Elektronentransport und den Reaktionen im Stroma koordinieren. Hierzu erfolgten Manipulationen von Elektronen- und/oder Metabolitverfügbarkeit im Chloroplasten. Als Untersuchungsmaterial dienten zunächst isolierte Spinat-Chloroplasten unter sättigendem CO2 und Pi. Durch die Herstellung transgener Kartoffelpflanzen, welche die zentralen Elektronenverteiler Fd I und FTR über- bzw. unterexprimieren, wurde die Elektronenverfügbarkeit im Chloroplasten dann dauerhaft verändert.
Auswirkungen von zusätzlichen Elektronenakzeptoren auf den Chloroplastenmetabolismus
Die Zugabe von verschieden „starken“ Elektronenakzeptoren zu Chloroplasten während der „steady state“-Photosynthese bei ausreichendem Lichtangebot hatte zwei Effekte zur Folge. Ein moderater Elektronenentzug (0,2 und 2 mM OAA, 0,2 mM Nitrit) beeinträchtigte ausschließlich den Aktivierungszustand der NADP-MDH, während die Aktivierungszustände von NAD(P)-GAPDH, FBPase und PRK nahezu unverändert waren. Auch qN, der stromale Metabolitgehalt und die [14CO2]-Fixierung waren nur geringfügig beeinflußt. qP hingegen war stark erhöht. Im Gegensatz dazu inhibierten Nitrit bzw. Methylviologen in höheren Konzentrationen die [14CO2]-Fixierung. Das ATP/ADP-Verhältnis stieg an und das NADPH/NADP-Verhältnis war nahezu unverändert. Eine extreme Erhöhung war im DHAP/PGA-Verhältnis und der stromalen FBP-Menge meßbar. Die Aktivierungszustände von FBPase und NADP-MDH nahmen nach Zugabe stark ab, während die Aktivierungszustände von NAD(P)-GAPDH und PRK unbeeinflußt blieben.
Zusammenspiel von Elektronenangebot und Effektoren auf die Redoxmodulation von Chloroplastenenzymen
Eine Veränderung im Elektronenangebot durch variierende Lichtintensitäten verdeutlichte, daß bei höheren Lichtintensitäten ein Großteil der Elektronen nicht für die CO2-Fixierung genutzt werden kann. Parallel zur Sättigung der CO2-Fixierung stiegen FBPase- und NADP-MDH-Aktivierungszustände an, während PRK und NAD(P)-GAPDH schon bei Intensitäten von 50 µE den maximalen Aktivierungszustand erreichten. Die Zugabe von Intermediaten, die positiv bzw. negativ auf den Aktivierungszustand der einzelnen Enzyme wirken, hatten wieder bei NADP-MDH und FBPase die deutlichsten Auswirkungen. Sowohl NAD(P)-GAPDH- als auch PRK-Aktivierungszustände waren nur unter Bedingungen erniedrigt, unter denen der Elektronenfluß stark herabgesetzt ist und im Stroma wenig ATP, Triosephosphate und 3PGA vorhanden sind. Demgegenüber reagiert NADP-MDH sehr sensitiv auf Umlenkung oder Erhöhung des Elektronenflusses. Im Fall der FBPase bestehen lineare Zusammenhänge zwischen FBP-Gehalt oder aktuellem Elektronendruck und dem Aktivierungszustand des Enzyms.
Die an Chloroplasten erhaltenen Ergebnisse zeigen:
Die Redoxmodulation im Licht spielt weder bei PRK noch bei NAD(P)-GAPDH eine herausragende Rolle. Die Bedeutung dieses grundlegenden Regulationsmechanismus liegt für beide Enzyme im Licht/Dunkel- und Dunkel/Licht-Übergang. Durch die „feed back“-Regulation der NADP-MDH durch NADP erfolgt bei diesem Enzym immer eine direkte Rückkopplung auf die Elektronenverfügbarkeit im Stroma. Aufgrund der sensitiven Reaktion auf Änderungen im NADPH/NADP-Verhältnis stellt das Enzym einen sehr guten Marker für den im Stroma vorherrschenden Elektrondruck dar. Die sensitiven Schritte im Calvin-Zyklus stellen die FBPase und die sehr ähnlich regulierte SBPase dar. Der aktivierende Effekt von FBP auf die FBPase wird durch den Elektronendruck in der Weise beeinflußt, daß eine Erhöhung der Lichtintensität in höheren Enzymaktivitäten unter vergleichbaren FBP-Konzentrationen resultieren. Bei einer Limitierung im Elektronenangebot scheint die Aktivierung dann unabhängig vom FBP-Gehalt zu sein. Restriktionen im Calvin-Zyklus, die zu einer verminderten FBP-Bereitstellung bei hohem Elektronenangebot führen, reichen für eine Aktivierung ebenfalls nicht aus. Somit stellt der aktuelle Aktivierungszustand des Enzyms einen kombinierten Effekt aus Elektronenverfügbarkeit und FBP-Gehalt dar.
Manipulation der Elektronenflüsse in vivo durch Veränderugen im Fd-Gehalt
Die Transformation von Kartoffelpflanzen mit dem homologen fed 1-cDNA-Klon (diese Arbeit) in „antisense“-Orientierung bewirkte eine maximal 50%ige Reduktion im Fd I-Proteingehalt. Eine weitere Reduktion im Fd I-Gehalt scheint für die Pflanze letal zu sein. Sowohl moderat supprimierte (80-100% des Wildtyp-Gehaltes) als auch stärker supprimierte Linien (50-80%) wiesen verstärkten zyklischen Elektronentransport und eine verringerte CO2-Assimilationsrate auf, zeigten aber kein Anzeichen von O2-Reduktion. Als Schutz gegen oxidativen Stress war in den „antisense“-Linien ein verminderter Elektronenfluß nachweisbar, indem die Effizienz der Lichtnutzung von PSI und PSII vermindert war. Dabei wurden zwei Strategien deutlich, die aber beide zu weniger funktionellem PS II und verringerten Quantenausbeuten führten: In den moderaten Linien war ein extremer DpH für diesen Effekt verantwortlich, während die stärker supprimierten Linien Photoinhibition zeigten. Weiterhin trat in den „antisense“-Linien eine bis zu 25%ige Reduktion im Chlorophyllgehalt bei erhöhten Chlorophyll a/b-Verhältnissen auf. Eine solche Akklimatisierung tritt bei Pflanzen auf, die an schwache Lichtintensitäten adaptiert sind und Starklicht ausgesetzt werden. Eine Überexpression des heterologen fed 1-cDNA-Klon aus Spinat in Kartoffelpflanzen hatte gegenteilige Effekte zur Folge. Die Elektronentransportketten zwischen den Photosystemen waren weniger reduziert, die Transformanten wiesen in Kurzzeitversuchen eine bis zu 10% höhere CO2-Assimilation auf und auch die Effizienz der Lichtnutzung war erhöht. Die im Vergleich zu Wildtyp-Pflanzen stark erhöhten Chlorophyllfluoreszenz-Endsignale deuten darauf hin, daß ein größerer Anteil stromaler Akzeptoren reduziert vorliegt. Gleichzeitig war das Chlorophyll a/b-Verhältnis erniedrigt. In Abhängigkeit von der Fd I-Menge, und im Endeffekt vermutlich durch die im Stroma verfügbare Akzeptor-Menge bedingt, erfolgt eine Erhöhung bzw. Erniedrigung von qP. Der permanent erhöhte Redoxstatus zwischen den Photosystemen scheint in den Fd I-Transformanten eine Adaptation des Chlorophyll a/b-Verhältnisses in die Richtung zu bewirken, daß im Fall der Unterexprimierer eine Anpassung in Richtung Starklicht erfolgt, während die Überexprimierer eine Schwachlichtanpassung zeigen. Ein Hinweis in diese Richtung ist die gute Korrelation zwischen qP und dem Chlorophyll a/b-Verhältnis.
Isolierung von ftr a- und ftr b-cDNA-Klonen aus Kartoffel und Herstellung transgener Kartoffelpflanzen
Für eine Manipulation der Elektronenflüsse in Richtung Td erfolgte eine „antisense“-Transformation mit dem ftr b-cDNA-Klon aus Kartoffelblatt (diese Arbeit). Die primären Transformanten wiesen keinen Phänotyp auf. Eine Transformation im heterologen System mit dem „antisense“-ftr b-cDNA-Klon aus Spinat erwies sich als ineffektiv. Eine Überexpression des ftr b-cDNA-Klons aus Spinat in Kartoffel war erfolgreich; Pflanzen mit Cosuppression wurden nicht gefunden. Auch erfolgte in diesen Pflanzen keine Coregulation in der Expression der FTR A-Untereineinheit. Für eine Überexpression von funktioneller FTR könnte der ftr a-cDNA-Klon aus Kartoffelblatt (diese Arbeit) zusammen mit dem ftr b-cDNA-Klon transformiert werden.
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Fan, Yi-Ting, and 范宜婷. "Studies on the molecular mechanisms of interactions between begomovirus C4 protein and chloroplast photosynthetic oxygen-evolving protein." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/73568965617815784891.
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碩士國立中興大學
生物科技學研究所
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Begomoviruses, whitefly-transmitted members of the family Geminiviridae, harbor single-stranded circular DNA genomes and cause serious economical damages in numerous important dicotyledonous crops worldwide. Our previous studies found that Nicotiana benthamiana plants infected by Agerayum yellow vein virus (AYVV) displayed severe upward leaf curling symptom. In ontrast, Tomato leaf curl virus (TLCV) and Squash leaf curl virus (SqLCV) caused downward leaf curling symptom on N. benthamiana. The C4 proteins of these viruses were found to be involved in the regulation of the directions of leaf curling symptoms. Several host factors, including Chloroplast photosynthetic oxygen-evolving protein (CPOEP), have been identified to interact with the C4 proteins of various begomoviruses. Among the host factors, CPOEP has been shown to be involved in the symptom expression of some RNA viruses. However, whether CPOEP plays any role in the modulation of symptoms inflicted by DNA viruses remains to be elucidated. Therefore, the objective of this study is to investigate the molecular interactions between CPOEP and C4 proteins of AYVV, TLCV, and SqLCV. The CPOEP gene of N. benthamiana was amplified and cloned in the pET21d vector. The CPOEP protein was then over-expressed in Escherichia coli, purified, and used as antigens to raise specific antisera. Far-western blot analysis using CPOEP or various C4 proteins as probes confirmed the differential interactions between viral C4 proteins and CPOEP. By using the yeast two-hybrid analyses, it was revealed that the middle portion and the C-terminus of CPOEP differentially interact with the C4 protein of AYVV and TLCV, which might also be involved in the modulation of leaf curling symptoms. In contrast, the N-terminus of CPOEP is not involved in the interactions. The examination of mRNA and protein expression levels of CPOEP in plants infected with different begomoviruses is currently underway. It is expected that the results will provide further insight into the mechanisms for the modulation of symptoms.
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Cheung, Melissa. "Investigating the Role of Alternative Oxidase in Nicotiana tabacum during Light Acclimation." Thesis, 2011. http://hdl.handle.net/1807/29513.
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Photosynthetic electron transport produces ATP and NADPH which support carbon fixation by the Calvin Cycle. To avoid over-reduction of the electron transport chain, plants must balance absorption and consumption of light energy. Mitochondrial alternative oxidase (AOX) is a non-energy-conserving electron sink, making it an ideal candidate to oxidize excess reductant and regulate chloroplastic redox state. Wild-type (WT) and transgenic Nicotiana tabacum lines with enhanced or suppressed AOX protein levels were grown under low light (LL) and moderate light (ML). LL-grown plants were also shifted to ML. AOX transcript and protein levels were enhanced in WT plants under ML. Chlorophyll fluorescence, gas exchange, and contents of chlorophyll, carbohydrate, and malondialdehyde were measured. Lack of AOX protein decreased Photosystem II (PSII) quantum efficiency and CO2 assimilation rates while enhancing PSII excitation pressure compared to WT. These findings suggest a role for AOX in mediating the chloroplast-mitochondrion relationship during acclimation to higher irradiance.
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Holtgrefe, Simone [Verfasser]. "Untersuchungen zur Kurzzeit-Regulation und Adaptation von Photosynthese und Elektronenverteilung in Chloroplasten und transgenen Kartoffelpflanzen / von Simone Holtgrefe." 2002. http://d-nb.info/970382677/34.
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