Artículos de revistas: "Non photochemical quencing"

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Schreiber, Ulrich y Christian Neubauer. "The Polyphasic Rise of Chlorophyll Fluorescence upon Onset of Strong Continuous Illumination: II. Partial Control by the Photosystem II Donor Side and Possible Ways of Interpretation". Zeitschrift für Naturforschung C 42, n.º 11-12 (1 de diciembre de 1987): 1255–64. http://dx.doi.org/10.1515/znc-1987-11-1218.

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The fluorescence rise kinetics in saturating light display two well separated components with largely different properties. The rapid rise from F0 to a first intermediate level, I1 is photochemically controlled, while the following phases leading to a secondary intermediate level, I2 and to a peak level, P, are limited by thermal reactions. Treatments which primarily affect components at the photosystem II donor side are shown to increase quenching at I1 and/or to suppress the secondary fluorescence rise to I2. Preillumination by single turnover saturating flashes causes I1- quenching oscillating with period-4 in dependence of flash number. It is suggested that this quenching correlates with (S2 + S3) states of the watersplitting enzyme system. Suppression of the secondary, I1 - I2 rise component is invariably found with treatments which lower electron donation rate by the watersplitting system and are known to favor the low potential form of cyt b 559. Three different mechanisms are discussed on the basis of which donor-side dependent quenching could be interpreted: 1) Non-photochemical quenching by accumulation of the P 680+ radical cation. 2) Dissipative photochemical quenching at a special population of PS II centers (β- or non- B centers) displaying low donor capacity and high rates of charge recombination. 3) Dissipative photochemical quenching via cyclic electron flow around PS II, involving alternate donors to P 680+ (like cyt b 559 or carotenoid in their low potential forms), which can compete when donation rate from the water splitting system is slowed down. The possibility of donor-side limitation also being involved in “energy dependent” quenching is discussed.

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2

Bilger, W. y U. Schreiber. "Modulation of Millisecond Chlorophyll Luminescence by Non-Photochemical Fluorescence Quenching". Zeitschrift für Naturforschung C 44, n.º 11-12 (1 de diciembre de 1989): 966–70. http://dx.doi.org/10.1515/znc-1989-11-1215.

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Abstract By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring systems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenching at photosystem II reaction centers, thus allowing determination of the non-photochemical quenching component. The saturation pulse induction curves of luminescence are well correlated with the corresponding curves of fluorescence, suggesting that luminescence yield is lowered by the same type of non-photochemical quenching (mostly “energy dependent quenching”) as fluorescence. Hence, in order to evaluate luminescence signals in terms of the rate of charge recombination at photosystem II reaction centers, knowledge of fluorescence quenching is required.

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3

Correa-Galvis, Viviana, Petra Redekop, Katharine Guan, Annika Griess, Thuy B. Truong, Setsuko Wakao, Krishna K. Niyogi y Peter Jahns. "Photosystem II Subunit PsbS Is Involved in the Induction of LHCSR Protein-dependent Energy Dissipation in Chlamydomonas reinhardtii". Journal of Biological Chemistry 291, n.º 33 (29 de junio de 2016): 17478–87. http://dx.doi.org/10.1074/jbc.m116.737312.

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Non-photochemical quenching of excess excitation energy is an important photoprotective mechanism in photosynthetic organisms. In Arabidopsis thaliana, a high quenching capacity is constitutively present and depends on the PsbS protein. In the green alga Chlamydomonas reinhardtii, non-photochemical quenching becomes activated upon high light acclimation and requires the accumulation of light harvesting complex stress-related (LHCSR) proteins. Expression of the PsbS protein in C. reinhardtii has not been reported yet. Here, we show that PsbS is a light-induced protein in C. reinhardtii, whose accumulation under high light is further controlled by CO2 availability. PsbS accumulated after several hours of high light illumination at low CO2. At high CO2, however, PsbS was only transiently expressed under high light and was degraded after 1 h of high light exposure. PsbS accumulation correlated with an enhanced non-photochemical quenching capacity in high light-acclimated cells grown at low CO2. However, PsbS could not compensate for the function of LHCSR in an LHCSR-deficient mutant. Knockdown of PsbS accumulation led to reduction of both non-photochemical quenching capacity and LHCSR3 accumulation. Our data suggest that PsbS is essential for the activation of non-photochemical quenching in C. reinhardtii, possibly by promoting conformational changes required for activation of LHCSR3-dependent quenching in the antenna of photosystem II.

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4

Hashim, Mohd Akmal, Sharir Aizat Kamaruddin, Mun Fei Yam, Ahmad Suhail Khazali, Khairunnisa Ahmad Kamil, Nor Atikah Husna Ahmad Nasir y Murray T. Brown. "Effects of Diuron, Terbuthylazine and Isoproturon on Photochemical and Non-Photochemical Quenching of Ectocarpus siliculosus". IOP Conference Series: Earth and Environmental Science 1019, n.º 1 (1 de abril de 2022): 012015. http://dx.doi.org/10.1088/1755-1315/1019/1/012015.

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Abstract The influence of anthropogenic discharges on the environment is an increasing concern among environmental toxicologists. This investigation set out to analyse the impacts of selected herbicides; diuron, terbuthylazine and isoproturon on two strains of Ectocarpus siliculosus with different pollution histories, LIA4 and Es524. Evaluation of their effects on photochemical quenching (qP) and non-photochemical quenching (qN) indicators have demonstrated negative impacts of all herbicides on both strains. From the results, diuron shows to exert significant negative effect at concentration as low as 5 µg L−1 followed by terbuthylazine at 10 µg L−1 (qP) and 5 µg L−1 (qN), and isoproturon at 100 µg L−1 (qP) and 50 µg L−1 (qN). Non-photochemical quenching (qN) indicator was found to exhibit greater sensitivity to the herbicides compared to photochemical quenching (qP). In both strains of E. siliculosus, the three herbicides were ranked in order of toxicity: diuron > terbuthylazine > isoproturon. This investigation provides new information on ecotoxicology of herbicides towards brown algae.

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5

Kitao, Mitsutoshi, Hiroyuki Tobita, Satoshi Kitaoka, Hisanori Harayama, Kenichi Yazaki, Masabumi Komatsu, Evgenios Agathokleous y Takayoshi Koike. "Light Energy Partitioning under Various Environmental Stresses Combined with Elevated CO2 in Three Deciduous Broadleaf Tree Species in Japan". Climate 7, n.º 6 (3 de junio de 2019): 79. http://dx.doi.org/10.3390/cli7060079.

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Understanding plant response to excessive light energy not consumed by photosynthesis under various environmental stresses, would be important for maintaining biosphere sustainability. Based on previous studies regarding nitrogen (N) limitation, drought in Japanese white birch (Betula platyphylla var. japonica), and elevated O3 in Japanese oak (Quercus mongolica var. crispula) and Konara oak (Q. serrata) under future-coming elevated CO2 concentrations, we newly analyze the fate of absorbed light energy by a leaf, partitioning into photochemical processes, including photosynthesis, photorespiration and regulated and non-regulated, non-photochemical quenchings. No significant increases in the rate of non-regulated non-photochemical quenching (JNO) were observed in plants grown under N limitation, drought and elevated O3 in ambient or elevated CO2. This suggests that the risk of photodamage caused by excessive light energy was not increased by environmental stresses reducing photosynthesis, irrespective of CO2 concentrations. The rate of regulated non-photochemical quenching (JNPQ), which contributes to regulating photoprotective thermal dissipation, could well compensate decreases in the photosynthetic electron transport rate through photosystem II (JPSII) under various environmental stresses, since JNPQ+JPSII was constant across the treatment combinations. It is noteworthy that even decreases in JNO were observed under N limitation and elevated O3, irrespective of CO2 conditions, which may denote a preconditioning-mode adaptive response for protection against further stress. Such an adaptive response may not fully compensate for the negative effects of lethal stress, but may be critical for coping with non-lethal stress and regulating homeostasis. Regarding the three deciduous broadleaf tree species, elevated CO2 appears not to influence the plant responses to environmental stresses from the viewpoint of susceptibility to photodamage.

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6

Neubauer, Christian y Ulrich Schreiber. "Photochemical and Non-Photochemical Quenching of Chlorophyll Fluorescence Induced by Hydrogen Peroxide". Zeitschrift für Naturforschung C 44, n.º 3-4 (1 de abril de 1989): 262–70. http://dx.doi.org/10.1515/znc-1989-3-415.

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Abstract Chlorophyll Fluorescence. Fluorescence Quenching, Hydrogen Peroxide. Active Oxygen. Ascorbate Peroxidase Chlorophyll fluorescence quenching induced by H 20 2 in intact spinach chloroplasts was investigated with a modulation fluorometer which allows to distinguish between photochemical and non photochemical quenching components by the so-called saturation pulse method. Residual catalase activity was removed by washing and percoll gradient centrifugation. H2O2 was found to induce pronounced photochem ical and non-photochemical quenching, characteristic for the action of a Hill reagent, with a half-maximal rate already observed at 5 × 10-6 m . The saturation characteristics and maximal rate of H2O2-reduction were very similar to those of methylviologen reduction. H2O2-dependent quenching was stimulated by ascorbate and inhibited by cyanide and azide in agreement with previous findings by other researchers that H2O2-reduction involves the ascorbate peroxidase scavenging system and that the actual “Hill acceptor” is an oxidation product of ascorbate, i.e. monodehydroascorbate or dehydroascorbate. With well-coupled intact chloroplasts reducing CO2 at 150 (μmol (mg Chl)-1h-1, iodoacetamide stopped CO2-dependent O2-evolution and consequent addition of 10″3 m H2O2 produced an O2-Solution rate of 240 (μmol (mg Chl)-1h-1 .It is concluded that light-dependent H 20 2 reduction is a very efficient reaction in intact chloroplasts. As H2O2 formation and consequent reduction also occur in vivo, the corresponding quenching should be considered when assimilatory electron flow is estimated from quenching coefficients. It is suggested that proton flux associated with H2O2-formation and reduction may be important for the adjustment of appropriate ATP /NADPH ratios required for CO2-fixation in vivo. Furthermore, H2O2-reduction may serve as a valve reaction whenever Calvin cycle activity is limited by factors different from NADPH supply, thus protecting against photo-inhibitory damage.

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7

Laisk, A. y V. Oja. "Alteration of photosystem II properties with non-photochemical excitation quenching". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 355, n.º 1402 (29 de octubre de 2000): 1405–18. http://dx.doi.org/10.1098/rstb.2000.0702.

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Oxygen yield from single turnover flashes and multiple turnover pulses was measured in sunflower leaves differently pre–illuminated to induce either ‘energy–dependent type’ non–photochemical excitation quenching ( q E ) or reversible, inhibitory type non–photochemical quenching ( q I ). A zirconium O 2 analyser, combined with a flexible gas system, was used for these measurements. Oxygen yield from saturating single turnover flashes was the equivalent of 1.3–2.0 μmol e − m −2 in leaves pre–adapted to low light. It did not decrease when q E quenching was induced by a 1 min exposure to saturating light, but it decreased when pre–illumination was extended to 30–60 min. Oxygen evolution from saturating multiple turnover pulses behaved similarly: it did not decrease with the rapidly induced q E but decreased considerably when exposure to saturating light was extended or O 2 concentration was decreased to 0.4%. Parallel recording of chlorophyll fluorescence and O 2 evolution during multiple turnover pulses, interpreted with the help of a mathematical model of photosystem II (PS II) electron transport, revealed PS II donor and acceptor side resistances. These experiments showed that PS II properties depend on the type of non–photochemical quenching present. The rapidly induced and rapidly reversible q E type (photoprotective) quenching does not induce changes in the number of active PS II or in the PS II maximum turnover rate, thus confirming the antenna mechanism of q E. The more slowly induced but still reversible q I type quenching (photoinactivation) induced a decrease in the number of active PS II and in the maximum PS II turnover rate. Modelling showed that, mainly, the acceptor side resistance of PS II increased in parallel with the reversible q I. Oxygen yield from single turnover flashes and multiple turnover pulses was measured in sunflower leaves differently pre–illuminated to induce either ‘energy–dependent type’ non–photochemical excitation quenching ( q E ) or reversible, inhibitory type non–photochemical quenching ( q I ). A zirconium O 2 analyser, combined with a flexible gas system, was used for these measurements. Oxygen yield from saturating single turnover flashes was the equivalent of 1.3–2.0 μmol e − m −2 in leaves pre–adapted to low light. It did not decrease when q E quenching was induced by a 1 min exposure to saturating light, but it decreased when pre–illumination was extended to 30–60 min. Oxygen evolution from saturating multiple turnover pulses behaved similarly: it did not decrease with the rapidly induced q E but decreased considerably when exposure to saturating light was extended or O 2 concentration was decreased to 0.4%. Parallel recording of chlorophyll fluorescence and O 2 evolution during multiple turnover pulses, interpreted with the help of a mathematical model of photosystem II (PS II) electron transport, revealed PS II donor and acceptor side resistances. These experiments showed that PS II properties depend on the type of non–photochemical quenching present. The rapidly induced and rapidly reversible q E type (photoprotective) quenching does not induce changes in the number of active PS II or in the PS II maximum turnover rate, thus confirming the antenna mechanism of q E. The more slowly induced but still reversible q I type quenching (photoinactivation) induced a decrease in the number of active PS II and in the maximum PS II turnover rate. Modelling showed that, mainly, the acceptor side resistance of PS II increased in parallel with the reversible q I.

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8

Gruber, J. Michael, Pengqi Xu, Jevgenij Chmeliov, Tjaart P. J. Krüger, Maxime T. A. Alexandre, Leonas Valkunas, Roberta Croce y Rienk van Grondelle. "Dynamic quenching in single photosystem II supercomplexes". Physical Chemistry Chemical Physics 18, n.º 37 (2016): 25852–60. http://dx.doi.org/10.1039/c6cp05493e.

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9

Nosalewicz, Artur, Karolina Okoń y Maria Skorupka. "Non-Photochemical Quenching under Drought and Fluctuating Light". International Journal of Molecular Sciences 23, n.º 9 (6 de mayo de 2022): 5182. http://dx.doi.org/10.3390/ijms23095182.

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Plants grow in a variable environment in regard to soil water and light driving photochemical reactions. Light energy exceeding plant capability to use it for photochemical reactions must be dissipated by processes of non-photochemical quenching (NPQ). The aim of the study was to evaluate the impact of various components of NPQ on the response of Arabidopsis thaliana to fluctuating light and water availability. A laboratory experiment with Arabidopsis thaliana wild type (WT) and mutants npq1 and npq4 grown under optimum or reduced water availability was conducted. Dark-adapted plants were illuminated with fluctuating light (FL) of two intensities (55 and 530 μmol m−2 s−1) with each of the phases lasting for 20 s. The impact of water availability on the role of zeaxanthin and PsbS protein in NPQ induced at FL was analysed. The water deficit affected the dynamics of NPQ induced by FL. The lack of zeaxanthin or PsbS reduced plant capability to cope with FL. The synergy of both of these components was enhanced in regard to the amplitude of NPQ in the drought conditions. PsbS was shown as a component of primary importance in suiting plant response to FL under optimum and reduced water availability.

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10

Karapetyan, N. V. "Non-photochemical quenching of fluorescence in cyanobacteria". Biochemistry (Moscow) 72, n.º 10 (octubre de 2007): 1127–35. http://dx.doi.org/10.1134/s0006297907100100.

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11

Greer, Dennis H. "Photon flux density and temperature-dependent responses of photosynthesis and photosystem II performance of apple leaves grown in field conditions". Functional Plant Biology 42, n.º 8 (2015): 782. http://dx.doi.org/10.1071/fp15068.

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The process of photosynthesis depends on the light, and is modulated by leaf temperature and their interaction is important to understand how climate affects photosynthesis. Photosynthetic and PSII light responses at a range of leaf temperatures were measured on leaves of apple (Malus domestica Borkh. cv. Red Gala) trees growing in field conditions. The objective was to assess the interaction between photon flux density (PFD) and temperature on these processes. Results showed leaf temperature strongly modulated the PFD-dependent response of photosynthesis and PSII performance. An interaction on photosynthesis occurred, with temperature affecting saturated rates as well as PFDs saturating photosynthesis. The efficiency of PSII electron transport (operating and maximum in light) universally declined with increasing PFD but temperature strongly influenced the response. Rates of PSII electron transport at saturating PFDs were affected by temperatures. Both photochemical quenching and non-photochemical quenching also responded strongly to temperature but at high PFDs, photochemical quenching increased linearly with decreasing temperatures while non-photochemical quenching increased curvilinearly with increasing temperatures. Modelling revealed changes in photosynthesis were positively correlated with rates of electron transport. These results greatly enhance our understanding of photosynthesis and the underpinning processes and their responses to temperature and PFD.

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12

Yaghoubi Khanghahi, Mohammad, Sabrina Strafella y Carmine Crecchio. "Changes in Photo-Protective Energy Dissipation of Photosystem II in Response to Beneficial Bacteria Consortium in Durum Wheat under Drought and Salinity Stresses". Applied Sciences 10, n.º 15 (22 de julio de 2020): 5031. http://dx.doi.org/10.3390/app10155031.

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The present research aimed at evaluating the harmless dissipation of excess excitation energy by durum wheat (Triticum durum Desf.) leaves in response to the application of a bacterial consortium consisting of four plant growth-promoting bacteria (PGPB). Three pot experiments were carried out under non-stress, drought (at 40% field capacity), and salinity (150 mM NaCl) conditions. The results showed that drought and salinity affected photo-protective energy dissipation of photosystem II (PSII) increasing the rate of non-photochemical chlorophyll fluorescence quenching (NPQ (non-photochemical quenching) and qCN (complete non-photochemical quenching)), as well as decreasing the total quenching of chlorophyll fluorescence (qTQ), total quenching of variable chlorophyll fluorescence (qTV) and the ratio of the quantum yield of actual PSII photochemistry, in light-adapted state to the quantum yield of the constitutive non-regulatory NPQ (PQ rate). Our results also indicated that the PGPB inoculants can mitigate the adverse impacts of stresses on leaves, especially the saline one, in comparison with the non-fertilized (control) treatment, by increasing the fraction of light absorbed by the PSII antenna, PQ ratio, qTQ, and qTV. In the light of findings, our beneficial bacterial strains showed the potential in reducing reliance on traditional chemical fertilizers, in particular in saline soil, by improving the grain yield and regulating the amount of excitation energy.

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13

Ruban, Alexander V., Erica Belgio y Maxwell Ware. "Photoprotective effectiveness of non-photochemical chlorophyll fluorescence quenching". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1837 (julio de 2014): e124. http://dx.doi.org/10.1016/j.bbabio.2014.05.331.

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14

Demmig, B. y K. Winter. "Characterisation of Three Components of Non-photochemical Fluorescence Quenching and Their Response to Photoinhibition". Functional Plant Biology 15, n.º 2 (1988): 163. http://dx.doi.org/10.1071/pp9880163.

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Three components of non-photochemical fluorescence quenching were distinguished according to their response to irradiance and to their relaxation kinetics upon darkening. Two components of quenching were restricted to excessive irradiance and were interpreted to reflect radiationless dissipation. One relaxed rapidly upon darkening, and increased sharply when irradiance became excessive, i.e. as soon as net CO2 assimilation rate was no longer linearly related to irradiance, and attained a maximum value with only small further increases in irradiance. The second component relaxed slowly, increased mark- edly when the rapidly relaxing component had reached its maximum, and continued to increase linearly with increasing irradiance. The third component was already present at low irradiances, relaxed very slowly, and may be related to an altered distribution of excitation energy between PS II and PS I. Following exposure to weak illumination under conditions preventing photosynthetic electron transport (20 mbar O2, zero CO2), the reduction state of Q was initially high and decreased as non- photochemical fluorescence quenching indicative of radiationless dissipation developed. Subsequent to photoinhibitory treatments in high light and 20 mbar O2, zero CO2, an increased reduction state of Q as well as increased non-photochemical quenching of the two types indicative of increased heat dissipation was observed. In sunflower a lasting increase in the reduction state of Q was observed and fluorescence characteristics reflected photoinhibitory damage. In Nerium oleander, increased radiationless dissipation of the slowly relaxing type was the predominant response and the reduction state of Q was increased only transiently.

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15

Jamil, Muhammad, Shafiq ur Rehman, Kui Jae Lee, Jeong Man Kim, Hyun-Soon Kim y Eui Shik Rha. "Salinity reduced growth PS2 photochemistry and chlorophyll content in radish". Scientia Agricola 64, n.º 2 (2007): 111–18. http://dx.doi.org/10.1590/s0103-90162007000200002.

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When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L.) were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control), 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), non photochemical quenching coefficient (qN), leaf area and chlorophyll content (SPAD value) were also reduced (P < 0.001) by salt stress. In contrast, the Fo/Fm ratio increased with increasing salt concentration while salinity showed no effect on the efficiency of excitation captured by open PS2 (Fv'/Fm'), electron transport rate (ETR), and leaf water content. Linear regression shows that the photochemical efficiency of PS2 (Fv/Fm) had a positive relationship with the photochemical quenching coefficient (qP), leaf area and chlorophyll content but had no relation with Fv'/Fm', Fo/Fm, and qN.

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He, Jun Yu, Yan Fang Ren, Cheng Zhu y Dean Jiang. "Change of Photosynthetic Gas Exchange and Chlorophyll Fluorescence of Cd-Sensitive Mutant Rice in Response to Cd Stress". Advanced Materials Research 807-809 (septiembre de 2013): 336–41. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.336.

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The growth, photosynthetic gas exchange and chlorophyll fluorescence were investigated in wild type and mutant rice plants treated with 50 μmol L-1 Cd. The results showed that plant height, dry mass, and chlorophyll content decreased by Cd treatment, and the mutant showed more severe reduction than wild type rice. Net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (Gs), maximal photochemical efficiency of PSII (Fv/Fm), effective PSII quantum yield (ΦPS2), and photochemical quenching (qP) were decreased and intercellular CO2 concentration (Ci) and and non-photochemical quenching (qN) were enhanced in Cd-treated plants with the increasing of Cd exposure time, with changes in the mutant being more evident. The results suggest that Cd inhibits photosynthesis due to non-stomatal limitations and the response of PSII reaction centre and the mutant has less capacity of acclimation to Cd stress.

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17

Savitch, Leonid V., Alexander G. Ivanov, Loreta Gudynaite-Savitch, Norman P. A. Huner y John Simmonds. "Effects of low temperature stress on excitation energy partitioning and photoprotection in Zea mays". Functional Plant Biology 36, n.º 1 (2009): 37. http://dx.doi.org/10.1071/fp08093.

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Analysis of the partitioning of absorbed light energy within PSII into fractions utilised by PSII photochemistry (ΦPSII), thermally dissipated via ΔpH- and zeaxanthin-dependent energy quenching (ΦNPQ) and constitutive non-photochemical energy losses (Φf,D) was performed in control and cold-stressed maize (Zea mays L.) leaves. The estimated energy partitioning of absorbed light to various pathways indicated that the fraction of ΦPSII was twofold lower, whereas the proportion of thermally dissipated energy through ΦNPQ was only 30% higher, in cold-stressed plants compared with control plants. In contrast, Φf,D, the fraction of absorbed light energy dissipated by additional quenching mechanism(s), was twofold higher in cold-stressed leaves. Thermoluminescence measurements revealed that the changes in energy partitioning were accompanied by narrowing of the temperature gap (ΔTM) between S2/3QB− and S2QA− charge recombinations in cold-stressed leaves to 8°C compared with 14.4°C in control maize plants. These observations suggest an increased probability for an alternative non-radiative P680+QA− radical pair recombination pathway for energy dissipation within the reaction centre of PSII in cold-stressed maize plants. This additional quenching mechanism might play an important role in thermal energy dissipation and photoprotection when the capacity for the primary, photochemical (ΦPSII) and zeaxanthin-dependent non-photochemical quenching (ΦNPQ) pathways are thermodynamically restricted in maize leaves exposed to cold temperatures.

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18

Ogunsipe, Abimbola y Tebello Nyokong. "Effects of central metal on the photophysical and photochemical properties of non-transition metal sulfophthalocyanine". Journal of Porphyrins and Phthalocyanines 09, n.º 02 (febrero de 2005): 121–29. http://dx.doi.org/10.1142/s1088424605000186.

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The photophysical and photochemical properties and quenching (by 1,4-benzoquinone) of metallophthalocyanine sulfonates of aluminium ( AlPcSmix), zinc ( ZnPcSmix), silicon ( SiPcSmix), germanium ( GePcSmix) and tin ( SnPcSmix) are presented. The quantum yield values of fluorescence (ΦF), triplet state (ΦT), singlet oxygen (ΦΔ) and photodegradation (Φd) were determined and the observed trends in their variation among the complexes discussed in terms of aggregation and the heavy atom effect. 1,4-benzoquinone effectively quenched the fluorescence of the complexes. Quenching analyses gave positive deviations from Stern-Volmer behavior, suggesting the existence of static quenching in addition to dynamic quenching. The static and dynamic components of the quenching were separated using a modified Stern-Volmer equation and the “sphere of action quenching model”. The quenching constant was found to be a function of the radius of the central metal ion.

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19

Dreuw, A., G. R. Fleming y M. Head-Gordon. "Role of electron-transfer quenching of chlorophyll fluorescence by carotenoids in non-photochemical quenching of green plants". Biochemical Society Transactions 33, n.º 4 (1 de agosto de 2005): 858–62. http://dx.doi.org/10.1042/bst0330858.

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NPQ (non-photochemical quenching) is a fundamental photosynthetic mechanism by which plants protect themselves against excess excitation energy and the resulting photodamage. A discussed molecular mechanism of the so-called feedback de-excitation component (qE) of NPQ involves the formation of a quenching complex. Recently, we have studied the influence of formation of a zeaxanthin–chlorophyll complex on the excited states of the pigments using high-level quantum chemical methodology. In the case of complex formation, electron-transfer quenching of chlorophyll-excited states by carotenoids is a relevant quenching mechanism. Furthermore, additionally occurring charge-transfer excited states can be exploited experimentally to prove the existence of the quenching complex during NPQ.

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Vastag, Erna, Claudia Cocozza, Saša Orlović, Lazar Kesić, Milena Kresoja y Srdjan Stojnić. "Half-Sib Lines of Pedunculate Oak (Quercus robur L.) Respond Differently to Drought Through Biometrical, Anatomical and Physiological Traits". Forests 11, n.º 2 (30 de enero de 2020): 153. http://dx.doi.org/10.3390/f11020153.

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Quercus robur L. is one of the most valued tree species of deciduous temperate forests. However, in the last decade, serious oak declines and loss of adaptation plasticity have been reported throughout Europe as a consequence of drought. Therefore, the aim of the present study was to define the adaptation potential of five Q. robur half-sib lines from the UNESCO Biosphere Reserve Mura-Drava-Danube to drought, using physiological, anatomical and biometrical traits. Half-sib lines that exhibited drought tolerance had particular suites of trait expression regarding biometrical traits (seedling height, root length, root to shoot ratio of dry mass and specific leaf area), leaf stomatal traits (stomatal density per mm2, stomata guard cell length and width, stomatal aperture length and width) and leaf structural traits (adaxial epidermis thickness, palisade parenchyma thickness, spongy parenchyma thickness, lamina thickness). All of the observed parameters of chlorophyll a fluorescence were shown to be good indicators of short-term and severe drought. For the selection of drought-tolerant half-sib lines, all studied chlorophyll a fluorescence parameters associated with the heat dissipation of light energy (coefficient of non-photochemical quenching, quantum yield of regulated energy dissipation, Stern-Volmer type non-photochemical fluorescence quenching) and one parameter related to photochemical dissipation of light energy (effective quantum yield (efficiency) of PS II photochemistry) were proven to be suitable. On the other hand, the coefficient of photochemical quenching, coefficient of photochemical fluorescence quenching assuming interconnected photosystem II antennae and electron transport rate were not suitable for distinguishing the different responses of the studied half-sib lines under drought. The importance of results of the present study is in the selection of drought-tolerant Q. robur half-sib lines for future reforestation programs, particularly in protected areas with sensitive forest management and restricted activities for mitigation of the adverse effects of climate changes.

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Gurova, T. A. y N. E. Chesnochenko. "Chlorophyll fluorescence of wheat leaves when infected with <i>Bipolaris sorokiniana</i>, chloride salinity and seed hyperthermia". Siberian Herald of Agricultural Science 52, n.º 6 (14 de enero de 2023): 12–28. http://dx.doi.org/10.26898/0370-8799-2022-6-2.

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Results of chlorophyll fluorescence parameters (ChlF) informativity measurement and comparison of 10-d-old spring wheat seedlings under laboratory conditions under separate and combined stressors action are presented. It was found that separate and combined action of chloride salinity (1,3%), infection with cereal root rot pathogen Bipolaris sorokiniana Shoem. (5000 conidia per grain) suppressed light and dark reactions of photosynthesis. The effective quantum yield Y(II), photochemical quenching qP and electron transport ETR decreased significantly in both cultivars, most significantly in the co-activated version (up to 62,7%). The maximum photochemical quantum yield of FS II Fv / Fm was less informative, no significant changes in the parameter were found. Inhibition of light-dependent reactions was accompanied by a significant increase in the values of the parameters of non-photochemical quenching ChlF - coefficient qN and quantum yield of regulated non-photochemical quenching ChlF Y (NPQ) from 24.1 to 72.1% in both varieties, most pronounced in the variety Sibirskaya 12. The parameter Y(NO), the quantum yield of unregulated non-photochemical quenching of ChlF, changed insignificantly relative to the control in both varieties. The positive effect of seed pre-heating (43 °C) on the functional activity of photosynthetic apparatus of seedlings - the reliable (p ≤ 0,05) increase of the parameter Y(II), qP, ETR (by 18,0-59,0%) and decrease of the parameter Y(NPQ), Y(NO) and qN (by 18,8-35,1%) at further infection and chloride salinization in both sorts, mainly in the variety Omskaya 18 was revealed. The informativeness of the parameters ChlF for assessment of varieties stress tolerance was established. Significant intervariety differences (from 1.2-6.2 times) were revealed for almost all parameters (except for Fv / Fm, Y(NO), Fv) for all variants of experiment. The varietal specificity was established - the least changes in ChlF parameters relative to the control were in the stable variety Omskaya 18 in all variants of the experiment. The proposed approach will make it possible to develop a noninvasive method for early diagnosis of stress tolerance (phenotyping) of new wheat genotypes to biotic and abiotic stressors.

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22

Zhai, Peng-Wang, Emmanuel Boss, Bryan Franz, P. Werdell y Yongxiang Hu. "Radiative Transfer Modeling of Phytoplankton Fluorescence Quenching Processes". Remote Sensing 10, n.º 8 (20 de agosto de 2018): 1309. http://dx.doi.org/10.3390/rs10081309.

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We report the first radiative transfer model that is able to simulate phytoplankton fluorescence with both photochemical and non-photochemical quenching included. The fluorescence source term in the inelastic radiative transfer equation is proportional to both the quantum yield and scalar irradiance at excitation wavelengths. The photochemical and nonphotochemical quenching processes change the quantum yield based on the photosynthetic active radiation. A sensitivity study was performed to demonstrate the dependence of the fluorescence signal on chlorophyll a concentration, aerosol optical depths and solar zenith angles. This work enables us to better model the phytoplankton fluorescence, which can be used in the design of new space-based sensors that can provide sufficient sensitivity to detect the phytoplankton fluorescence signal. It could also lead to more accurate remote sensing algorithms for the study of phytoplankton physiology.

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23

Georgieva, Katia y Ivan Yordanov. "Temperature Dependence of Photochemical and Non-Photochemical Fluorescence Quenching in Intact Pea Leaves". Journal of Plant Physiology 144, n.º 6 (noviembre de 1994): 754–59. http://dx.doi.org/10.1016/s0176-1617(11)80673-5.

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24

Crepin, Aurélie, Edel Cunill-Semanat, Eliška Kuthanová Trsková, Erica Belgio y Radek Kaňa. "Antenna Protein Clustering In Vitro Unveiled by Fluorescence Correlation Spectroscopy". International Journal of Molecular Sciences 22, n.º 6 (15 de marzo de 2021): 2969. http://dx.doi.org/10.3390/ijms22062969.

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Antenna protein aggregation is one of the principal mechanisms considered effective in protecting phototrophs against high light damage. Commonly, it is induced, in vitro, by decreasing detergent concentration and pH of a solution of purified antennas; the resulting reduction in fluorescence emission is considered to be representative of non-photochemical quenching in vivo. However, little is known about the actual size and organization of antenna particles formed by this means, and hence the physiological relevance of this experimental approach is questionable. Here, a quasi-single molecule method, fluorescence correlation spectroscopy (FCS), was applied during in vitro quenching of LHCII trimers from higher plants for a parallel estimation of particle size, fluorescence, and antenna cluster homogeneity in a single measurement. FCS revealed that, below detergent critical micelle concentration, low pH promoted the formation of large protein oligomers of sizes up to micrometers, and therefore is apparently incompatible with thylakoid membranes. In contrast, LHCII clusters formed at high pH were smaller and homogenous, and yet still capable of efficient quenching. The results altogether set the physiological validity limits of in vitro quenching experiments. Our data also support the idea that the small, moderately quenching LHCII oligomers found at high pH could be relevant with respect to non-photochemical quenching in vivo.

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25

Mohanty, N. y HY Yamamoto. "Mechanism of Non-Photochemical Chlorophyll Fluorescence Quenching. I. The Role of De-Epoxidised Xanthophylls and Sequestered Thylakoid Membrane Protons as Probed by Dibucaine". Functional Plant Biology 22, n.º 2 (1995): 231. http://dx.doi.org/10.1071/pp9950231.

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Dibucaine reportedly inhibits the light-induced transthylakoid proton gradient of chloroplasts without inhibiting energy-dependent non-photochemical chlorophyll fluorescence quenching (Laasch, H. and Weis, E. (1989). Photosynthesis Research 22, 137-146). We show that dibucaine can inhibit fluorescence quenching, depending on the de-epoxidation state of the xanthophyll cycle. Whereas dibucaine (20-40 μM) had little effect on fluorescence quenching in pre-illuminated-type thylakoids (loaded with zeaxanthin and antheraxanthin), it strongly inhibited quenching in dark-adapted-type thylakoids (no preinduction of de-epoxidation). Dibucaine inhibited lumen acidification similarly in both types of thylakoids and also the induction of violaxanthin de-epoxidation in dark-adapted thylakoids. Thus dark-adapted and pre-illuminated thylakoids differed in de-epoxidation states and their suspectibility to dibucaine inhibition of fluorescence quenching corresponded to this difference. The mechanism of inhibition of de-epoxidation by dibucaine is unclear. It could be due to the inhibition of lumen acidification but an inhibition of the violaxanthin available for de-epoxidation is not excluded. High dibucaine concentrations inhibited de-epoxidase activity directly. Dibucaine inhibition of fluorescence quenching, however, is not limited to the inhibition of de-epoxidation. Small but clear effects on fluorescence quenching were present in thylakoids even with de-epoxidation preinduced. Moreover, thylakoids with preinduced de-epoxidation were more resistant to dibucaine inhibition of fluorescene quenching when poised by salt treatments for proton partitioning into membrane-sequestered domains than when poised for proton partitioning into delocalised domains. We conclude that non-photochemical quenching of chlorophyll fluorescence depends on both de-epoxidised xanthophylls and sequestered proton domains in the thylakoid membranes

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26

Naranjo, Belen, Jan-Ferdinand Penzler, Thilo Rühle y Dario Leister. "NTRC Effects on Non-Photochemical Quenching Depends on PGR5". Antioxidants 10, n.º 6 (3 de junio de 2021): 900. http://dx.doi.org/10.3390/antiox10060900.

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Non-photochemical quenching (NPQ) protects plants from the detrimental effects of excess light. NPQ is rapidly induced by the trans-thylakoid proton gradient during photosynthesis, which in turn requires PGR5/PGRL1-dependent cyclic electron flow (CEF). Thus, Arabidopsis thaliana plants lacking either protein cannot induce transient NPQ and die under fluctuating light conditions. Conversely, the NADPH-dependent thioredoxin reductase C (NTRC) is required for efficient energy utilization and plant growth, and in its absence, transient and steady-state NPQ is drastically increased. How NTRC influences NPQ and functionally interacts with CEF is unclear. Therefore, we generated the A. thaliana line pgr5 ntrc, and found that the inactivation of PGR5 suppresses the high transient and steady-state NPQ and impaired growth phenotypes observed in the ntrc mutant under short-day conditions. This implies that NTRC negatively influences PGR5 activity and, accordingly, the lack of NTRC is associated with decreased levels of PGR5, possibly pointing to a mechanism to restrict upregulation of PGR5 activity in the absence of NTRC. When exposed to high light intensities, pgr5 ntrc plants display extremely impaired photosynthesis and growth, indicating additive effects of lack of both proteins. Taken together, these findings suggest that the interplay between NTRC and PGR5 is relevant for photoprotection and that NTRC might regulate PGR5 activity.

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27

Müller, Patricia, Xiao-Ping Li y Krishna K. Niyogi. "Non-Photochemical Quenching. A Response to Excess Light Energy". Plant Physiology 125, n.º 4 (1 de abril de 2001): 1558–66. http://dx.doi.org/10.1104/pp.125.4.1558.

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28

Cogdell, Richard J. "The structural basis of non-photochemical quenching is revealed?" Trends in Plant Science 11, n.º 2 (febrero de 2006): 59–60. http://dx.doi.org/10.1016/j.tplants.2005.12.002.

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29

Johnson, Giles N., Andrew J. Young y Peter Horton. "Activation of non-photochemical quenching in thylakoids and leaves". Planta 194, n.º 4 (diciembre de 1994): 550–56. http://dx.doi.org/10.1007/bf00714469.

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30

Chen, Zhong y Daniel R. Gallie. "Dehydroascorbate Reductase Affects Non-photochemical Quenching and Photosynthetic Performance". Journal of Biological Chemistry 283, n.º 31 (6 de junio de 2008): 21347–61. http://dx.doi.org/10.1074/jbc.m802601200.

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31

Gorbunov, Maxim Y., Fedor I. Kuzminov, Victor V. Fadeev, John Dongun Kim y Paul G. Falkowski. "A kinetic model of non-photochemical quenching in cyanobacteria". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1807, n.º 12 (diciembre de 2011): 1591–99. http://dx.doi.org/10.1016/j.bbabio.2011.08.009.

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32

Očenášová, Petra, Miloš Barták y Josef Hájek. "Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. II. Analysis of non-photochemical quenching mechanisms activated by low to medium light doses". Czech Polar Reports 4, n.º 1 (1 de enero de 2014): 90–99. http://dx.doi.org/10.5817/cpr2014-1-10.

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The paper focus sensitivity of an Antarctic lichen Usnea antarctica to photoinhibition studied under controlled laboratory conditions. Main emphasis was given to the analysis of quenching mechanisms, i.e. deexcitation pathways of absorbed light energy exploited in non-photochemical processes. Thalli of U. antarctica were collected at the James Ross Island, Antarctica (57°52´57´´ W, 63°48´02´´ S) and transferred in dry state to the Czech Republic. After rewetting in a laboratory, they were exposed to medium light intensities (300, 600 and 1000 mmol m-2 s-1 of photosynthetically active radiation) for 6 h. Before and during photoinhibitory treatments, chlorophyll fluorescence parameters, photoinhibitory (qI), state 1-2 transition (qT), and energy-dependent quenching (qE) in particular were measured to evaluate dose- and time-dependent changes in these parameters. The results showed that among the components forming non-photochemical quenching (qN), qI contributes to the largest extent to qN, while qE and qT contribute less. This finding differs from our earlier studies made in a short term-, and high light-treated U. antarctica that found qE together with qI is the most important part of non-photochemical quenching. Possible explanation is that photoinhibition in PS II in U. ant-arctica, when induced by low to medium light, activates qE to only limited extend and for a relatively short time (tens of minutes). With prolonged high light treatment lasting several hours, qE tends to be reduced to the values close to zero and qI then forms a major part of qN.

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33

Fox, Kieran F., Vytautas Balevičius, Jevgenij Chmeliov, Leonas Valkunas, Alexander V. Ruban y Christopher D. P. Duffy. "The carotenoid pathway: what is important for excitation quenching in plant antenna complexes?" Physical Chemistry Chemical Physics 19, n.º 34 (2017): 22957–68. http://dx.doi.org/10.1039/c7cp03535g.

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Plant light-harvesting is regulated by the Non-Photochemical Quenching (NPQ) mechanism involving the slow trapping of excitation energy by carotenoids in the Photosystem II (PSII) antenna in response to high light.

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34

Bilger, W., U. Heber y U. Schreiber. "Kinetic Relationship between Energy-Dependent Fluorescence Quenching, Light Scattering, Chlorophyll Luminescence and Proton Pumping in Intact Leaves". Zeitschrift für Naturforschung C 43, n.º 11-12 (1 de diciembre de 1988): 877–87. http://dx.doi.org/10.1515/znc-1988-11-1214.

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Abstract A measuring system was designed for simultaneous recording of modulated chlorophyll fluorescence and light scattering changes. The kinetic relationship was investigated between lightinduced changes in non-photochemical fluorescence quenching, as determined by the saturation pulse method, and in light scattering, as measured via the apparent absorbance change at 543 nm. Very similar, but not identical kinetics were observed, reflecting a close non-linear relationship between these two indicators of thylakoid membrane energization. Fluorescence was found more sensitive at low levels of energization, while scattering continued indicating further increases in energization when quenching already was saturated. A general relationship between quenching and scattering is demonstrated which holds irrespective of whether energization is varied during induction or via changes in light intensity or CO2 concentration. In the light-off responses, only part of fluorescence quenching was found to relax with the same kinetics as scattering. It is suggested that at high levels of energization slowly reversible membrane changes may be induced which have the potential of non-photochemical quenching at a low level of energization, and which are not accompanied by scattering changes. Neither quenching nor scattering changes displayed kinetics sufficiently fast to be taken as a direct expression of internal thylakoid acidificati on in intact leaves. This conclusion is drawn from comparative measurements of proton-uptake, as reflected by CO2-solubilization upon light-induced stroma alkalization, and of chlorophyll luminescence. Both, the initial CO2 - gulp and the pH-dependent luminescence rise were found to clearly precede the development of energy-dependent quenching.

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35

Ruban, AV y P. Horton. "Regulation of Non-Photochemical Quenching of Chlorophyll Fluorescence in Plants". Functional Plant Biology 22, n.º 2 (1995): 221. http://dx.doi.org/10.1071/pp9950221.

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Non-photochemical quenching of chlorophyll fluorescence indicates the de-excitation of light-generated excited states in the chlorophyll associated with photosystem II (PSII). The principle process contributing to this quenching is dependent on the formation of the thylakoid proton gradient and is an important mechanism for protecting PSII from photodamage. Evidence points to the importance of the light-harvesting chlorophyll proteins as the site of dissipation of energy, and suggests that the structure and function of these proteins are regulated by protonation and the ratio of zeaxanthin to violaxanthin. The minor light-harvesting proteins may have a particularly important role as the primary sites of proton binding and because of their enrichment in xanthophyll cycle carotenoids. The dynamic nature of the light-harvesting system is an important part of the process by which plants are able to adapt to different light environments.

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36

Price, GD, JW Yu, SV Caemmerer, JR Evans, WS Chow, JM Anderson, V. Hurry y MR Badger. "Chloroplast Cytochrome b6/f and ATP Synthase Complexes in Tobacco: Transformation With Antisense RNA Against Nuclear-Encoded Transcripts for the Rieske FeS and ATPδ Polypeptides". Functional Plant Biology 22, n.º 2 (1995): 285. http://dx.doi.org/10.1071/pp9950285.

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Tobacco plants with reduced amounts and activities of both the chloroplast cytochrome b6/f and ATP synthase complexes have been produced using antisense RNA techniques. Antisense constructs were generated from tobacco cDNA clones coding for the Rieske FeS protein and the δ subunit of the b6/f and ATP synthase complexes respectively. Transformants with altered activities were selected using pulse-modulated fluorescence measurements. The b6/ftransformants showed high levels of steady-state fluorescence and reduced levels of both photochemical and non-photochemical quenching. In striking contrast, the ATP synthase transformants showed low levels of steady-state fluorescence and greatly increased levels of non-photochemical quenching. Transformants with a range of suppression were isolated for both constructs, in some cases with photosynthesis reduced to less than 10% of wild-type values. The most severely affected transformants showed extremely slow growth and in some cases they were unable to grow and produce seed. Progeny from the R1 seed from several cytochrome b6/f transformants have been analysed and show segregation of phenotypes ranging from intermediate to severe in repression. Intermediate and severe phenotype plants showed a reduction in Rieske FeS mRNA of more than 90% while FeS polypeptide was reduced to 60 and 86% of wild type. There was a strong correlation between photosynthesis at air and Rieske FeS polypeptide content in the antisense plants suggesting that the cytochrome b6/f complex was a major determinant of photosynthetic rate under these conditions. Photoinhibition studies of FeS antisense plants showed that there was a reduced activity of the xanthophyll cycle in the most severe plants, consistent with a reduction in the transthylakoid pH gradient and a lowered non-photochemical quenching. Preliminary studies of the ATPδ antisense plants showed that they also had reduced levels of mRNA and ATPδ polypeptide.

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37

Lu, Congming, Jianhua Zhang y Avigad Vonshak. "Inhibition of quantum yield of PS II electron transport in Spirulina platensis by osmotic stress may be explained mainly by an increase in the proportion of the QB-non-reducing PS II reaction centres". Functional Plant Biology 25, n.º 6 (1998): 689. http://dx.doi.org/10.1071/pp98043.

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Modulated chlorophyll fluorescence and fluorescence induction kinetics were used to evaluate the PS II photochemistry in Spirulina platensis exposed to osmotic stress (0–0.8 M mannitol). Osmotic stress decreased the efficiency of excitation energy capture by open PS II reaction centres (Fv′/Fm′) and more significantly, decreased photochemical quenching (qP). Osmotic stress also decreased the maximal efficiency of PS II photochemistry (Fv/Fm). There was no significant change in non-photochemical quenching (qN), indicating that the decreased Fv′/Fm′ was not due to an increase in qN. Analyses of the fast fluorescence induction kinetics indicated that osmotic stress caused a significant increase in the proportion of the QB-non-reducing PS II reaction centres. Based on the results in this study, we suggest that a substantial increase in the proportion of the QB-non-reducing PS II reaction centres may be responsible for the decrease in qP and Fv′/Fm′, of which both resulted in the decrease in the quantum yield of PS II electron transport (ΦPSII ).

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38

Schreiber, Ulrich, Heinz Reising y Christian Neubauer. "Contrasting pH-Optima of Light-Driven O2-and H2O2-Reduction in Spinach Chloroplasts as Measured via Chlorophyll Fluorescence Quenching". Zeitschrift für Naturforschung C 46, n.º 7-8 (1 de agosto de 1991): 635–43. http://dx.doi.org/10.1515/znc-1991-7-821.

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Abstract Quenching analysis of chlorophyll fluorescence by the saturation pulse method is used to investigate the pH-dependency of O2-dependent electron flow in intact spinach chloroplasts with high ascorbate peroxidase activity. When carboxylase/oxygenase activity is blocked, photochemical and non-photochemical quenching are initially low and increase with illumination time. Quenching shows a pH-optimum around pH 6.5, but only when ΔpH-formation is al lowed. It is suggested that overall O2-dependent electron flow involves two major components, namely O2-reduction (Mehlerreaction) and reduction of the H2O2 formed in the Mehlerreaction, involving enzymic activity of ascorbate peroxidase and monodehydroascorbate reductase. The separated pH-dependencies of light driven O2-reduction (presence of KCN) and of H2O2-reduction (anaerobic conditions) reveal contrasting pH-optima around pH 5 and 8.5, respectively. Energy-dependent, dark relaxable non-photochemical quenching is not observed with O2-reduction but with H2O2-reduction, and only at pH-values above 6.5. The relevance of these findings with respect to regulation of photosynthetic electron flow is discussed. It is suggested that upon limitation of assimilatory electron flow O2-dependent non-assimilatory flow is responsible for ΔpH-formation, by which it is autocatalytically stimulated. It is proposed that this autocatalytical reaction sequence is the basis of the so-called “Kautsky effect” of chlorophyll fluorescence induction.

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39

Lu, Dandan, Yi Zhang, Aihong Zhang y Congming Lu. "Non-Photochemical Quenching: From Light Perception to Photoprotective Gene Expression". International Journal of Molecular Sciences 23, n.º 2 (8 de enero de 2022): 687. http://dx.doi.org/10.3390/ijms23020687.

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Light is essential for photosynthesis but light levels that exceed an organism’s assimilation capacity can cause serious damage or even cell death. Plants and microalgae have developed photoprotective mechanisms collectively referred to as non-photochemical quenching to minimize such potential damage. One such mechanism is energy-dependent quenching (qE), which dissipates excess light energy as heat. Over the last 30 years, much has been learned about the molecular mechanism of qE in green algae and plants. However, the steps between light perception and qE represented a gap in our knowledge until the recent identification of light-signaling pathways that function in these processes in the green alga Chlamydomonas reinhardtii. In this review, we summarize the high light and UV-mediated signaling pathways for qE in Chlamydomonas. We discuss key questions remaining about the pathway from light perception to photoprotective gene expression in Chlamydomonas. We detail possible differences between green algae and plants in light-signaling mechanisms for qE and emphasize the importance of research on light-signaling mechanisms for qE in plants.

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40

Kulheim, Carsten y Stefan Jansson. "What leads to reduced fitness in non-photochemical quenching mutants?" Physiologia Plantarum 125, n.º 2 (octubre de 2005): 202–11. http://dx.doi.org/10.1111/j.1399-3054.2005.00547.x.

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41

Johansson Jänkänpää, Hanna, Martin Frenkel, Ismayil Zulfugarov, Michael Reichelt, Anja Krieger-Liszkay, Yogesh Mishra, Jonathan Gershenzon, Jon Moen, Choon-Hwan Lee y Stefan Jansson. "Non-Photochemical Quenching Capacity in Arabidopsis thaliana Affects Herbivore Behaviour". PLoS ONE 8, n.º 1 (2 de enero de 2013): e53232. http://dx.doi.org/10.1371/journal.pone.0053232.

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42

Nicol, Lauren, Wojciech J. Nawrocki y Roberta Croce. "Disentangling the sites of non-photochemical quenching in vascular plants". Nature Plants 5, n.º 11 (28 de octubre de 2019): 1177–83. http://dx.doi.org/10.1038/s41477-019-0526-5.

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43

Niyogi, K. K. "Is PsbS the site of non-photochemical quenching in photosynthesis?" Journal of Experimental Botany 56, n.º 411 (29 de noviembre de 2004): 375–82. http://dx.doi.org/10.1093/jxb/eri056.

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44

Pospisil, P. "Mechanisms of non-photochemical chlorophyll fluorescence quenching in higher plants". Photosynthetica 34, n.º 3 (1 de septiembre de 1998): 343–55. http://dx.doi.org/10.1023/a:1006803832366.

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45

Hodges, M., G. Comic y J. M. Briantais. "Chlorophyll fluorescence from spinach leaves: Resolution of non-photochemical quenching". Biochimica et Biophysica Acta (BBA) - Bioenergetics 974, n.º 3 (mayo de 1989): 289–93. http://dx.doi.org/10.1016/s0005-2728(89)80246-4.

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46

Sylak-Glassman, Emily J., Julia Zaks, Kapil Amarnath, Michelle Leuenberger y Graham R. Fleming. "Characterizing non-photochemical quenching in leaves through fluorescence lifetime snapshots". Photosynthesis Research 127, n.º 1 (12 de marzo de 2015): 69–76. http://dx.doi.org/10.1007/s11120-015-0104-2.

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47

Holzwarth, Alfred R., Dagmar Lenk y Peter Jahns. "On the analysis of non-photochemical chlorophyll fluorescence quenching curves". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1827, n.º 6 (junio de 2013): 786–92. http://dx.doi.org/10.1016/j.bbabio.2013.02.011.

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48

Sonani, Ravi R., Alastair Gardiner, Rajesh P. Rastogi, Richard Cogdell, Bruno Robert y Datta Madamwar. "Site, trigger, quenching mechanism and recovery of non-photochemical quenching in cyanobacteria: recent updates". Photosynthesis Research 137, n.º 2 (24 de marzo de 2018): 171–80. http://dx.doi.org/10.1007/s11120-018-0498-8.

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49

Jacob, J. "Phosphate Deficiency Increases the Rate Constant of Thermal Dissipation of Excitation Energy by Photosystem II in Intact Leaves of Sunflower and Maize." Functional Plant Biology 22, n.º 3 (1995): 417. http://dx.doi.org/10.1071/pp9950417.

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Sunflower (Helianthus annuus L.) and maize (Zea mays L.) plants were grown in controlled environment chambers either with adequate supply or no external supply of inorganic phosphate. On the third fully-expanded leaves, chlorophyll fluorescence from photosystem II (PSII) was measured using a modulated fluorescence measuring system at various photon flux densities at room temperature. Phosphate deficiency resulted in an increase in the coefficient of non-photochemical quenching and a decrease in the coefficient of photochemical quenching of variable fluorescence. The efficiency of excitation energy capture by open PSII reaction centres and quantum yield of PSII photochemistry were decreased with phosphate deficiency. There was a significant effect of phosphate deficiency on in vivo PSII photochemistry which was independent of changes in thylakoid membrane energisation induced by the actinic light. An increase in the non-photochemical quenching of variable fluorescence with phosphate deficiency was due to an increased rate constant of thermal dissipation of excitation energy by PSII. Analyses of fluorescence signals suggest that phosphate deficiency decreased the rate constant of PSII photochemistry as well as the probability of excitation energy transfer from PSII antenna to PSII reaction centre. These effects were more apparent at low photon flux densities than at high photon flux densities. Regulation of energy transduction in the thylakoid and in vivo PSII activity in response to the physical environment of the plant are important aspects of environmental regulation of photosynthesis.

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50

Greer, Dennis H. "Short-term temperature dependency of the photosynthetic and PSII photochemical responses to photon flux density of leaves of Vitis vinifera cv. Shiraz vines grown in field conditions with and without fruit". Functional Plant Biology 46, n.º 7 (2019): 634. http://dx.doi.org/10.1071/fp18324.

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Shiraz vines grown outdoors with and without a crop load were used to determine photosynthetic and chlorophyll fluorescence responses to light across a range of leaf temperatures to evaluate the impact of presence/absence of a sink on these responses. Results indicate maximum rates of photosynthesis and light saturation in fruiting vines were biased towards higher temperatures whereas these processes in vegetative vines were biased towards lower temperatures. The maximum efficiency of PSII photochemistry was similarly biased, with higher efficiency for the vegetative vines below 30°C and a higher efficiency for the fruiting vines above. The quantum efficiency of PSII electron transport was generally higher across all temperatures in the fruiting compared with vegetative vines. Photochemical quenching was not sensitive to temperature in fruiting vines but strongly so in vegetative vines, with an optimum at 30°C and marked increases in photochemical quenching at other temperatures. Non-photochemical quenching was not strongly temperature dependent, but there were marked increases in both treatments at 45°C, consistent with marked decreases in assimilation. These results suggest demand for assimilates in fruiting vines induced an acclimation response to high summer temperatures to enhance assimilate supply and this was underpinned by comparable shifts in PSII photochemistry.

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