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412. PsbP-induced protein conformational changes around Cl- ions in the water oxidizing center of photosystem II
- Creator:
- Kondo, J. and Noguchi, T.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, Mn4CaO5 cluster, oxygen evolution, 2, and 581
- Language:
- Multiple languages
- Description:
- PsbP is an extrinsic protein of PSII having a function of Ca2+ and Cl- retention in the water-oxidizing center (WOC). In order to understand the mechanism how PsbP regulates the Cl- binding in WOC, we examined the effect of PsbP depletion on the protein structures around the Cl- sites using Fourier transform infrared (FTIR) spectroscopy. Light-induced FTIR difference spectra upon the S1-S2 transition were obtained using Cl--bound and NO3--substituted PSII membranes in the presence and absence of PsbP. A clear difference in the amide I band changes by PsbP depletion was observed between Cl--bound and NO3--substituted PSII samples, indicating that PsbP binding perturbed the protein conformations around the Cl-ion(s) in WOC. It is suggested that PsbP stabilizes the Cl- binding by regulating the dissociation constant of Cl- and/or an energy barrier of Cl- dissociation through protein conformational changes around the Cl- ion(s)., J. Kondo, T. Noguchi., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
413. PsbY is required for prevention of photodamage to photosystem II in a PsbM-lacking mutant of Synechocystis sp. PCC 6803
- Creator:
- Biswas, S. and Eaton-Rye, Julian J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- hydrogenuhličitan sodný, cytochromy, ochrana před ultrafialovým zářením, bicarbonate, cytochromes, photoprotection, assembly, chlorophyll fluorescence, cytochrome b559, repair, 2, and 581
- Language:
- Multiple languages
- Description:
- The PsbM (3.9 kDa) and PsbY (4.2 kDa) proteins are membrane-spanning, single-helix, subunits associated with the chlorophyll-binding CP47 pre-complex of photosystem II (PSII). Removal of PsbM resulted in accumulation of PSII pre-assembly complexes and impaired electron transfer between the primary (QA) and secondary (QB) plastoquinone electron acceptors of PSII indicating that the QB-binding site and bicarbonate binding to the non-heme iron were altered in this strain. Removal of PsbY alone had only a minor impact on PSII activity but deleting PsbY in the PsbM background led to additional modification of the acceptor side resulting in PsbM:PsbY cells being susceptible to photodamage and this required protein synthesis for recovery. Addition of bicarbonate was able to compensate for the light-induced damage in PsbM:PsbY cells potentially re-occupying the modified bicarbonate-binding site in the PsbM:PsbY strain and complementation of PsbM:PsbY cells with the psbY gene restored the PsbM phenotype., S. Biswas, J. J. Eaton-Rye., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
414. Pyl - včelí chléb
- Creator:
- Kitzberger, Ivan František
- Publisher:
- A. Neubert
- Format:
- print, text, regular print, and 168 s. : 47 obr. ; 8°
- Type:
- model:monograph and TEXT
- Subject:
- Obecná botanika, pyl, rostliny medonosné, včely, opylování, 638.138, 2, 581, and UF01
- Language:
- Czech
- Description:
- Ivan František Kitzberger and Se 47 obr.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
415. Quality of supplementary LED lighting effects on growth and photosynthesis of two different Lactuca recombinant inbred lines (RILs) grown in a tropical greenhouse
- Creator:
- Choong, T. W., He, J., Qin, L., and Lee, S. K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- pigmenty, světelné diody, fotosyntéza, pigments, light emitting diodes, photosynthesis, electron transport rate, leaf expansion, light- and CO2-saturated net photosynthetic rate, photochemical and nonphotochemical quenching, stomatal density, 2, and 581
- Language:
- Multiple languages
- Description:
- LED lamps with various combinations of red (R) and blue (B) wavelengths were used to supplement sunlight for the growth of a heat-resistant (HR) and heat-sensitive (HS) recombinant inbred lines (RIL) of lettuce. The RB-LED ratios were 100R:0B (0B), 92R:8B (8B), 84R:16B (16B), and 76R:24B (24B) with an equal PPFD of 100 μmol m-2 s-1. The greatest leaf expansion rates were observed at 8B for both genotypes. All HR-RILs had similar values of growth parameters and specific leaf area (SLA). However, higher values of growth parameters were observed in HS-RIL with 0B, 8B, and 16B than that under 24B and sunlight. Furthermore, HS-RIL had higher SLA under 0B compared to other conditions. Photosynthetic light-use efficiency and maximal oxygen evolution rate were the lowest under 8B for both genotypes. The quality of LED lighting, if provided, seemed to implicate genotype dependence, probably as a result of their different sensitivities to heat stress., T. W. Choong, J. He, L. Qin, S. K. Lee., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
416. Quantification of bound bicarbonate in photosystem II
- Creator:
- Tikhonov, K., Shevela, D., Klimov, V. V., and Messinger, J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- hmotnostní spektrometrie, mass spectroscopy, hydrogen carbonate, inorganic carbon, Mn-stabilizing protein, non-heme iron, oxygen-evolving complex, 2, and 581
- Language:
- Multiple languages
- Description:
- In this study, we presented a new approach for quantification of bicarbonate (HCO3-) molecules bound to PSII. Our method, which is based on a combination of membrane-inlet mass spectrometry (MIMS) and 18O-labelling, excludes the possibility of "non-accounted" HCO3- by avoiding (1) the employment of formate for removal of HCO3- from PSII, and (2) the extremely low concentrations of HCO3-/CO2 during online MIMS measurements. By equilibration of PSII sample to ambient CO2 concentration of dissolved CO2/HCO3-, the method ensures that all physiological binding sites are saturated before analysis. With this approach, we determined that in spinach PSII membrane fragments 1.1 ± 0.1 HCO3- are bound per PSII reaction center, while none was bound to isolated PsbO protein. Our present results confirmed that PSII binds one HCO3- molecule as ligand to the non-heme iron of PSII, while unbound HCO3- optimizes the water-splitting reactions by acting as a mobile proton shuttle., K. Tikhonov, D. Shevela, V. V. Klimov, J. Messinger., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
417. Řádky k pětašedesátinám vegetačního ekologa, počítačového instrumentalisty a muzikanta Eduarda Brabce
- Creator:
- Pavel Kovář
- Type:
- article, biography, jubilejní články, festschriften, model:article, and TEXT
- Subject:
- Obecná botanika, Brabec, Eduard, geobotanika, výročí, biografie, geobotany, anniversaries, biography, Česko, Czechia, 2, and 581
- Language:
- Czech
- Description:
- Pavel Kovář.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
418. Rearrangement of leaf traits with changing source-sink relationship in blueberry (Vaccinium corymbosum L.) leaves
- Creator:
- Jorquera-Fontena, E., Alberdi, M., Reyes-Díaz, M., and Franck, N.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- uhlík, karotenoidy, ovoce, pigmenty, carbon, carotenoids, fruit, pigments, výměna plynu, fotosyntetické pigmenty, rozpustné cukry, borůvky, list, brusnice chocholičnatá, gas exchange, photosynthetic pigments, soluble sugars, nitrogen, blueberries, dark respiration rate, girdling, leaf, stomatal conductance, source-sink relationship, 2, and 581
- Language:
- Multiple languages
- Description:
- The source-sink relationship is one of major determinants of plant performance. The influence of reproductive sink demand on light-saturated photosynthesis (Pmax), dark respiration (RD), stomatal conductance (gs), intrinsic water-use efficiency (WUEi), contents of soluble sugar (SSC), nitrogen, carbon, and photosynthetic pigments was examined in blueberry (Vaccinium corymbosum L. cv. ‘Brigitta’) during the final stage of rapid fruit growth. Measurements were performed three times per day on developed, sun-exposed leaves of girdled shoots with 0.1, 1, and 10 fruit per leaf (0.1F:L, 1F:L, and 10F:L, respectively) and nongirdled shoots bearing one fruit per leaf (NG). Girdling and lower fruit amount induced lower Pmax, gs, N, and total chlorophyll (Chl) and higher WUEi, SSC, RD, Chl a/b ratio and carotenoids-to-chlorophylls ratio (Car/Chl) for the 1F:L and 0.1F:L treatments. The impact of girdling was counterbalanced by 10F:L, with NG and 10F:L having similar values. Variables other than Pmax, RD, gs, WUEi, and SSC were unaffected throughout the course of the day. Pmax and gs decreased during the course of the day, but gs decreased more than Pmax in the afternoon, while WUEi was increasing in almost all treatments. SSC increased from the morning until afternoon, whereas RD peaked at noon regardless of the treatment. Generally, Pmax was closely and negatively correlated to SSC, indicating that sugar-sensing mechanisms played an important role in regulation of blueberry leaf photosynthesis. With respect to treatments, Pmax and N content were positively related, while RD was not associated to substrate availability. The enhanced Car/Chl ratio showed a higher photoprotection under the lower sink demand. Changes in the source-sink relationship in 'Brigitta' blueberry led to a rearrangement of physiological and structural leaf traits which allowed adjusting the daily balance between carbon assimilation and absorbed light energy., E. Jorquera-Fontena, M. Alberdi, M. Reyes-Díaz, N. Franck., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
419. Reduction of photosynthetic apparatus plays a key role in survival of the microalga Haematococcus pluvialis (Chlorophyceae) at freezing temperatures
- Creator:
- Chekanov, K., Vasilieva, S., Solovchenko, A., and Lobakova, E.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, cold stress, Haematococcys pluvialis, stress tolerance, 2, and 581
- Language:
- Multiple languages
- Description:
- The microalga Haematococcus pluvialis is a biotechnologically important microorganism producing a ketocarotenoid astaxanthin. Haematococcus exists either as metabolically active vegetative cells with a high chlorophyll content or astaxanthin-rich haematocysts (aplanospores). This microalga featuring outstanding tolerance to a wide range of adverse conditions is a highly suitable model for studies of freezing tolerance in phototrophs. The retention of H. pluvialis cell viability after freezing-thawing is ascribed to elevated antioxidant enzyme activity and high ketocarotenoid content. However, we report that only haematocysts characterized by a lower photosynthetic activity were resistant to freezing-thawing even without cryoprotectant addition. The key factors of haematocyst freezing tolerance were assumed to be a low water content, rigid cell walls, reduction of the membranous structures, photosynthesis downregulation, and low chlorophyll content. Collectively, viability of Haematoccus after freezing-thawing can be improved by forcing the transition of vegetative cells to freeze-tolerant haematocysts before freezing., K. Chekanov, S. Vasilieva, A. Solovchenko, E. Lobakova., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
420. Regulating photoprotection improves photosynthetic growth and biomass production in QC-site mutant cells of the cyanobacterium Synechocystis sp. PCC 6803
- Creator:
- Huang, J.-Y., Hung, N.-T., Lin, K.-M., Chiu, Y.-F., and Chu, H.-A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- cytochromy, fotosyntéza, ochrana před ultrafialovým zářením, cytochromes, photosynthesis, photoprotection, cytochrome b559, photosystem II, 2, and 581
- Language:
- Multiple languages
- Description:
- We characterized the photosynthetic growth of wild-type (WT) and QC-site mutant cells of the cyanobacterium Synechocystis sp. PCC 6803 grown in a photobioreactor under medium-intensity [~70 μmol(photon) m-2 s-1] and high-intensity [~200 μmol(photon) m-2 s-1] light conditions. Photosynthetic growth rate (the exponential phase) increased about 1.1-1.2 fold for the A16FJ, S28Aβ, and V32Fβ mutant compared with WT cells under medium-intensity light and about 1.2-1.3 fold under high-intensity light. Biomass production increased about 17-20% for A16FJ and S28Aβ mutant cells as compared with WT cells under medium-intensity light and about 14-17% for A16FJ and V32Fβ mutant cells under high-intensity light. The greater photosynthetic growth rate and biomass production of these QC-site mutant cells could be attributed to the increased photosynthesis efficiency and decreased dissipation of wasteful energy from phycobilisomes in mutants vs. WT cells. Our results support that manipulation of photoprotection may improve photosynthesis and biomass production of photosynthetic organisms., J.-Y. Huang, N.-T. Hung, K.-M. Lin, Y.-F. Chiu, H.-A. Chu., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public