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AbstractAbstract
[en] Highlights: • Photochemical Reflectance Index (PRI) as a photosynthetic parameter in physiology. • Real-time monitoring of photosynthesis behaviors under light condition. • PRI possesses a strong correlation with qZ rather than qE. Non-photochemical quenching (NPQ) is the most important photoprotective system in higher plants. NPQ can be divided into several steps according to the timescale of relaxation of chlorophyll fluorescence after reaching a steady state (i.e., the fast phase, qE; middle phase, qZ or qT; and slow phase, qI). The dissipation of excess energy as heat during the xanthophyll cycle, a large component of NPQ, is detectable during the fast to middle phase (sec to min). Although thermal dissipation is primarily investigated using indirect methods such as chlorophyll a fluorescence measurements, such analyses require dark adaptation or the application of a saturating pulse during measurement, making it difficult to continuously monitor this process. Here, we designed an unconventional technique for real-time monitoring of changes in thylakoid lumen pH (as reflected by changes in xanthophyll pigment content) based on the photochemical reflectance index (PRI), which we estimated by measuring light-driven leaf reflectance at 531 nm. We analyzed two Arabidopsis thaliana mutants, npq1 (unable to convert violaxanthin to zeaxanthin due to inhibited violaxanthin de-epoxidase [VDE] activity) and npq4 (lacking PsbS protein), to uncover the regulator of the PRI. The PRI was variable in wild-type and npq4 plants, but not in npq1, indicating that the PRI is related to xanthophyll cycle-dependent thermal energy quenching (qZ) rather than the linear electron transport rate or NPQ. In situ lumen pH substitution using a pH-controlled buffer solution caused a shift in PRI. These results suggest that the PRI reflects only xanthophyll cycle conversion and is therefore a useful parameter for monitoring thylakoid lumen pH (reflecting VDE activity) in vivo.
Primary Subject
Source
S0006291X18304388; Available from http://dx.doi.org/10.1016/j.bbrc.2018.02.192; Copyright (c) 2018 The Authors. Published by Elsevier Inc.; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Biochemical and Biophysical Research Communications; ISSN 0006-291X;
; CODEN BBRCA9; v. 498(1); p. 52-57

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Dedic, R.; Promnares, K.; Psencik, J.; Svoboda, A.; Korinek, M.; Tichy, M.; Komenda, J.; Funk, C.; Hala, J., E-mail: roman@kchf-43.karlov.mff.cuni.cz2004
AbstractAbstract
[en] This contribution presents low-temperature absorption, both broad-band and site-selective excited fluorescence, and persistent hole burning spectra of Photosystem II complexes from the Photosystem I-lacking strains of the cyanobacterium Synechocystis sp. PCC 6803 differing in the content of small putative chlorophyll-binding proteins (Scps). These proteins are homologous to light-harvesting complex of higher plants and may bind pigments. The excited state lifetimes of the complexes were determined from zero-phonon hole widths extrapolated to zero-burning dose. The area and spectral position of a phonon side-band with respect to the zero-phonon hole provided additional information concerning chlorophyll-protein coupling and the Stokes shift. Decrease of three absorption subbands at (670.0, 672.9, and 675.7 nm) in the Photosystem II isolated from the strain lacking ScpC and ScpD is in agreement with a hypothesis about the role of Scps in the chlorophyll binding. In addition, narrowing of the zero-phonon hole in Photosystem II without both Scps indicates slowering of the excitation energy transfer which may be explained by the absence of a protective excitation energy quenching related to the presence of Scps
Primary Subject
Source
S0022231303001947; Copyright (c) 2003 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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Dinh, Thanh-Chung; Busch, Marcel Schmidt am; Renger, Thomas
Joint Annual Meeting of the Austrian Physical Society and the Swiss Physical Society together with the Austrian and Swiss Societies for Astronomy and Astrophysics2013
Joint Annual Meeting of the Austrian Physical Society and the Swiss Physical Society together with the Austrian and Swiss Societies for Astronomy and Astrophysics2013
AbstractAbstract
[en] Full text: We present a theory of optical spectra of pigment-protein complexes that allows to include both the excitonic and the exciton-vibrational coupling on an equal footing. The theory is applied to two different types of the water soluble chlorophyll binding protein (WSCP) containing chlorophyll dimers. First, it is tested in simulation of optical spectra of class IIb WSCP with known crystal structure, and then it is applied to class IIa WSCP with unknown structure, in order to check whether a similar arrangement of chlorophylls as in type IIb WSCP can be assumed. Using a homology modeling of the unknown structure in combination with quantum chemical/ electrostatic calculations we propose an explanation of the 10 nm redshift observed of its optical bands with respect to class IIb WSCP. (author)
Primary Subject
Secondary Subject
Source
Austrian Physical Society (Austria); Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); vp; 2013; p. 125; Joint Annual Meeting of the Austrian Physical Society and the Swiss Physical Society together with the Austrian and Swiss Societies for Astronomy and Astrophysics; Gemeinsame Jahrestagung der Österreichischen Physikalischen Gesellschaft und der Schweizerischen Physikalischen Gesellschaft zusammen mit den Österreichischen und der Schweizerischen Gesellschaften für Astronomie und Astrophysik; Linz (Austria); 3-6 Sep 2013; Available in abstract form only, full text entered in this record. Available from: http://www.jku.at/conferences/content/e198715/; Available from: Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (AT)
Record Type
Miscellaneous
Literature Type
Conference
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Shimazaki, K.; Igarashi, T.; Kondo, N.
National Inst. for Environmental Studies, Tsukuba Ibaraki (Japan); Hohenheim Univ., Stuttgart (Germany)1988
National Inst. for Environmental Studies, Tsukuba Ibaraki (Japan); Hohenheim Univ., Stuttgart (Germany)1988
AbstractAbstract
No abstract available
Primary Subject
Source
FAO/AGRIS record; ARN: DK19890088332; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Physiologia Plantarum; ISSN 0031-9317;
; v. 74(1); p. 34-38

Country of publication
ANIMAL TISSUES, BODY, CARBOXYLIC ACIDS, CHEMICAL REACTIONS, EMISSION, EPITHELIUM, HETEROCYCLIC ACIDS, HETEROCYCLIC COMPOUNDS, LUMINESCENCE, ORGANIC ACIDS, ORGANIC COMPOUNDS, ORGANIC NITROGEN COMPOUNDS, ORGANS, PHOTOCHEMICAL REACTIONS, PHOTON EMISSION, PHYTOCHROMES, PIGMENTS, PORPHYRINS, PROTEINS, SKIN, SYNTHESIS
Reference NumberReference Number
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AbstractAbstract
[en] Seven newly developed rice cultivars i.e., KS-133, DR-83, DR-64, BR-601, Gomal, JP-5 and Gomal-6, were evaluated for salinity tolerance in a glass house along with three varieties of known salinity tolerance i.e., KS-282 (tolerant), IR-6 (medium tolerant) and Basmati-385 (susceptible). Based on the survival percentage at 50 mol/m3 sodium chloride salinity imposed at seedling stage, rice cultivars KS-133, Gomal, and DR-83 showed high survival comparable to that of salinity tolerant cultivars like KS-282, and were thus placed in tolerance range. Survival percentage of JP-5, Gomal-6 and DR-64 remained in medium tolerance range (35 to 38%) as that of IR-6. The rice cultivar BR-601 showed only 13% survival and was found to be as sensitive towards salinity as Basmati-385. The results of rice survival in saline medium showed good uniformity and the check varieties showed results corresponding to those found elsewhere. Sodium (Na/sup +/) and potassium (K/sup +/) concentrations in the third leaf showed variations among different rice cultivars under salinity. There was an inverse correlation between varietal leaf Na/sup +/ vs survival percentage (r = -0.808) and Na/sup +/ vs leaf chlorophyll (r -0.857). The correlation between K/sup +/ and final survival percentage was direct (r = 0.744) and also leaf chlorophyll vs survival (r = 0.952). The shoot fresh and dry weights were greater in the rice genotypes having higher final survival percentage under saline conditions. Therefore, in addition to final survival percentage, the higher shoot fresh and dry weight under salinity could be also used as criterion for evaluation of salinity tolerance of rice. (author)
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Journal Article
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Pakistan Journal of Scientific and Industrial Research; ISSN 0030-9885;
; v. 53(1); p. 37-41

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Li Linhai; Li Lin; Song Kaishan; Shi Kun; Li Zuchuan; Li Yunmei, E-mail: lil032@ucsd.edu2011
AbstractAbstract
[en] An analytical three-band algorithm for spectrally estimating chlorophyll-a (Chl-a) has been proposed recently and the model does not need to be trained. However, the model did not consider the effects of the absorption due to colored detritus matter (CDM) and backscattering of the water column, resulting in an overestimation when Chl-a < 50 mg m-3 and an underestimation when Chl-a ≥ 50 mg m-3. In this letter, an improved three-band algorithm is proposed by integrating both backscattering and CDM absorption coefficients into the model. The results demonstrate that the improved three-band model resulted in more accurate estimation of Chl-a than the previously used three-band model when they were applied to water samples collected from five highly turbid water bodies with Chl-a ranging from 2.54 to 285.8 mg m-3. The best results, after model modification, were observed in three Indiana reservoirs with R2 = 0.905 and relative root mean square error of 20.7%, respectively.
Primary Subject
Source
S1748-9326(11)87135-1; Available from http://dx.doi.org/10.1088/1748-9326/6/3/034037; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
Journal
Environmental Research Letters; ISSN 1748-9326;
; v. 6(3); [7 p.]

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AbstractAbstract
[en] The optimum gamma irradiation treatments for the inhibition of greening of unwashed Up-to-Date potatoes exposed to continuous fluorescent lighting were 0,15 and 0,20 kGy. The 0,15 and 0,20 kGy treated potatoes took 8,7 and 10,3 d longer respectively than the controls for 50% of the potatoes to turn green. The results were verified by chlorophyll determinations. The solanine content of the γ-irradiated potatoes did not differ significantly from that of the controls during the period of exposure. Gamma irradiated tubers which were removed from continuous fluorescent lighting after 7 d to 'household' conditions of daylight and fluorescent light alternated with darkness maintained the quality of day 7 for at least another 16 d. Factors such as washing, packaging, display temperature, post-irradiation pre-illumination storage and cultivar differences did not detract from the effectiveness of γ-irradiation in retarding the greening of potatoes. A comparison of γ-irradiation with dipping inedible oil showed the latter treatment to be more effective than irradiation in inhibiting greening but the treatment caused serious rotting. No difference in the taste or colour of irradiated and nonirradiated potatoes cooked in various ways could be detected
[af]
Die optimale gamma-bestralingsbehandelings vir die vergroeningsvertraging van ongewaste Up-to-Date-aartappels wat onafgebroke aan buislig blootgestel is, was 0,15 en 0,20 kGy. Die aartappels wat met dosisse van 0,15 en 0,20 kGy behandel is, het onderskeidelik 8,7 en 10,3 d langer as die kontroles geneem vir 50% van die aartappels om te vergroen. Hierdie resultate is met chlorofil-analises bevestig. Die solanieninhoud van die γ-bestraalde aartappels het gedurende die blootstellingstydperk nie betekenisvol van die kontroles verskil nie. Gammabestraalde knolle wat na blootstelling van 7 d aan onafgebroke buislig na 'huishoudelike' toestande van dag- en buislig afgewissel met donker oorgeplaas is, het die gehalte van dag 7 vir ten minste 'n verdere 16 d gehandhaaf. Faktore soos was, verpakking, uitstaltemperatuur, opberging na bestraling en voorafbeligting en cultivarverskille het nie afbreuk aan die doeltreffendheid van γ-bestraling gedoen om vergroening te vertraag nie. 'n Vergelyking van γ-bestraling met indompeling in eetbare olie het getoon dat laasgenoemde behandeling vergroening doeltreffender as γ-bestraling vertraag, maar die behandeling veroorsaak ernstige verrotting. Geen verskille kon in die smaak en kleur van bestraalde aartappels wat op verskeie maniere gaargemaak is, bespeur word niePrimary Subject
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Journal Article
Journal
Agroplantae; ISSN 0302-7139;
; v. 13(2); p. 29-38

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Kim, Jin-Hong; Kim, Jae-Sung; Moon, Yu Ran; Lee, Min Hee; Chung, Byung Yeoup, E-mail: jhongkim@kaeri.re.kr
Proceedings of the 8. LOWRAD: International conference on the effects of low doses and very low doses of ionizing radiation on human health and biotopes2009
Proceedings of the 8. LOWRAD: International conference on the effects of low doses and very low doses of ionizing radiation on human health and biotopes2009
AbstractAbstract
No abstract available
Primary Subject
Source
Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Associacao Brasileira de Energia Nuclear, Rio de Janeiro, RJ (Brazil); Low Radiation International Network, Paris (France); World Council of Nuclear Workers, Paris (France); 138 p; 2009; p. 55; LOWRAD: 8. International conference on the effects of low doses and very low doses of ionizing radiation on human health and biotopes; Rio de Janeiro (Brazil); 28-30 Sep 2009
Record Type
Miscellaneous
Literature Type
Conference
Report Number
Country of publication
CARBOXYLIC ACIDS, CELL CONSTITUENTS, CHEMICAL REACTIONS, ELECTROMAGNETIC RADIATION, EMISSION, HETEROCYCLIC ACIDS, HETEROCYCLIC COMPOUNDS, IONIZING RADIATIONS, LUMINESCENCE, MAGNOLIOPHYTA, MAGNOLIOPSIDA, ORGANIC ACIDS, ORGANIC COMPOUNDS, ORGANIC NITROGEN COMPOUNDS, PHOTOCHEMICAL REACTIONS, PHOTON EMISSION, PHOTOSYNTHETIC REACTION CENTERS, PHYTOCHROMES, PIGMENTS, PLANTS, PORPHYRINS, PROTEINS, RADIATION SOURCES, RADIATIONS, SYNTHESIS
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AbstractAbstract
[en] Gross primary production (GPP) estimation usually involves a priori assumptions about biome-specific rules or climate controls, which hampers an objective analysis of driving mechanisms. Observation-based methods that are biome-invariant and globally uniform are thus highly desirable. To facilitate this, a reflectance index representing the ratio of chlorophyll to total pigments (R chl) was proposed to consider the variation of energy conversion efficiency driven by different pigment contents in the canopy. Experiments based on simulated reflectance spectra showed that R chl could explain over 83% of chlorophyll ratio dynamics. A model was then developed which approximates GPP as the product of R chl, the normalized difference vegetation index, the near-infrared reflectance, and the photosynthetically active radiation. The model is simple, fast, with definite physical meaning and independent of climatic parameters such as temperature and humidity. Validated with over one hundred thousand field measurements, the model exhibited comparable accuracy to biome- and climate-based GPP models (r = 0.74 for both types of models), demonstrating satisfactory performance. It also achieved significantly better results compared with a regression model excluding R chl, which emphasizes the important role of R chl. By avoiding circular analyses in mechanism studies on GPP variations, this model may extend our previous understanding of global terrestrial carbon uptake. (letter)
Primary Subject
Source
Available from http://dx.doi.org/10.1088/1748-9326/abf3dc; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Environmental Research Letters; ISSN 1748-9326;
; v. 16(5); [11 p.]

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Martin Moreno, C.; Fernandez Gonzalez, J.
Junta de Energia Nuclear (JEN), Madrid (Spain)1983
Junta de Energia Nuclear (JEN), Madrid (Spain)1983
AbstractAbstract
[en] The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs
Original Title
Efecto de la radiacion gamma sobre la fotosintesis neta y la respiracion de Chlorella pyrenoidosa
Primary Subject
Source
1983; 60 p
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Report
Report Number
Country of publication
ALGAE, CARBOXYLIC ACIDS, CHEMICAL REACTIONS, CHLOROPHYCOTA, ELECTROMAGNETIC RADIATION, HETEROCYCLIC ACIDS, HETEROCYCLIC COMPOUNDS, IONIZING RADIATIONS, MICROORGANISMS, ORGANIC ACIDS, ORGANIC COMPOUNDS, ORGANIC NITROGEN COMPOUNDS, PHOTOCHEMICAL REACTIONS, PHYTOCHROMES, PIGMENTS, PLANTS, PORPHYRINS, PROTEINS, RADIATIONS, SYNTHESIS, UNICELLULAR ALGAE
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