scholarly journals A mathematical model of non-photochemical quenching to study short-term light memory in plants

2016 ◽  
Author(s):  
Anna Matuszyńska ◽  
Somayyeh Heidari ◽  
Peter Jahns ◽  
Oliver Ebenhöh
Keyword(s):  
Mathematical Model ◽  
Light Exposure ◽  
Slow Component ◽  
Fluorescence Emission ◽  
Basic Mechanism ◽  
Photochemical Quenching ◽  
Short Term ◽  
Epipremnum Aureum ◽  
Quenching Efficiency ◽  
Non Photochemical Quenching

Plants are permanently exposed to rapidly changing environments, therefore it is evident that they had to evolve mechanisms enabling them to dynamically adapt to such fluctuations. Here we study how plants can be trained to enhance their photoprotection and elaborate on the concept of the short-term illumination memory in Arabidopsis thaliana. By monitoring fluorescence emission dynamics we systematically observe the extent of non-photochemical quenching (NPQ) after previous light exposure to recognise and quantify the memory effect. We propose a simplified mathematical model of photosynthesis that includes the key components required for NPQ activation, which allows us to quantify the contribution to photoprotection by those components. Due to its reduced complexity, our model can be easily applied to study similar behavioural changes in other species, which we demonstrate by adapting it to the shadow-tolerant plant Epipremnum aureum. Our results indicate that a basic mechanism of short-term light memory is preserved. The slow component, accumulation of zeaxanthin, accounts for the amount of memory remaining after relaxation in darkness, while the fast one, antenna protonation, increases quenching efficiency. With our combined theoretical and experimental approach we provide a unifying framework describing common principles of key photoprotective mechanisms across species in general, mathematical terms.

scholarly journals A mathematical model of non-photochemical quenching to study short-term light memory in plants

2016 ◽  
Vol 1857 (12) ◽  
pp. 1860-1869 ◽  
Author(s):  
Anna Matuszyńska ◽  
Somayyeh Heidari ◽  
Peter Jahns ◽  
Oliver Ebenhöh
Keyword(s):  
Mathematical Model ◽  
Photochemical Quenching ◽  
Short Term ◽  
Non Photochemical Quenching

scholarly journals An alternative method for correcting fluorescence quenching

Ocean Science ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 83-91 ◽  
Author(s):  
L. Biermann ◽  
C. Guinet ◽  
M. Bester ◽  
A. Brierley ◽  
L. Boehme
Keyword(s):  
Mixed Layer ◽  
Mixed Layer Depth ◽  
Fluorescence Emission ◽  
Euphotic Zone ◽  
Light Level ◽  
High Light Intensity ◽  
Photochemical Quenching ◽  
Layer Depth ◽  
Southern Elephant Seals ◽  
Non Photochemical Quenching

Abstract. Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Southern Ocean, collected over five austral summers by 19 southern elephant seals tagged with fluorometers. Conventionally, fluorescence data collected during the day (quenched) were corrected using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, distinct deep fluorescence maxima were measured in approximately 30% of the night (unquenched) data. To account for the evidence that chlorophyll is not uniformly mixed in the upper layer, we propose correcting from the limit of the euphotic zone, defined as the depth at which photosynthetically available radiation is ~ 1% of the surface value. Mixed layer depth exceeded euphotic depth over 80% of the time. Under these conditions, quenching was corrected from the depth of the remotely derived euphotic zone Zeu, and compared with fluorescence corrected from the depth of the density-derived mixed layer. Deep fluorescence maxima were evident in only 10% of the day data when correcting from mixed layer depth. This was doubled to 21% when correcting from Zeu, more closely matching the unquenched (night) data. Furthermore, correcting from Zeu served to conserve non-uniform chlorophyll features found between the 1% light level and mixed layer depth.

scholarly journals Short-term acclimation of the photosynthetic electron transfer chain to changing light: a mathematical model

2014 ◽  
Vol 369 (1640) ◽  
pp. 20130223 ◽  
Author(s):  
Oliver Ebenhöh ◽  
Geoffrey Fucile ◽  
Giovanni Finazzi ◽  
Jean-David Rochaix ◽  
Michel Goldschmidt-Clermont
Keyword(s):  
Mathematical Model ◽  
Molecular Mechanisms ◽  
Photosynthetic Apparatus ◽  
Light Acclimation ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Short Term ◽  
Dynamic Regulation ◽  
Relative Contribution ◽  
Photosynthetic Eukaryotes

Photosynthetic eukaryotes house two photosystems with distinct light absorption spectra. Natural fluctuations in light quality and quantity can lead to unbalanced or excess excitation, compromising photosynthetic efficiency and causing photodamage. Consequently, these organisms have acquired several distinct adaptive mechanisms, collectively referred to as non-photochemical quenching (NPQ) of chlorophyll fluorescence, which modulates the organization and function of the photosynthetic apparatus. The ability to monitor NPQ processes fluorometrically has led to substantial progress in elucidating the underlying molecular mechanisms. However, the relative contribution of distinct NPQ mechanisms to variable light conditions in different photosynthetic eukaryotes remains unclear. Here, we present a mathematical model of the dynamic regulation of eukaryotic photosynthesis using ordinary differential equations. We demonstrate that, for Chlamydomonas , our model recapitulates the basic fluorescence features of short-term light acclimation known as state transitions and discuss how the model can be iteratively refined by comparison with physiological experiments to further our understanding of light acclimation in different species.

scholarly journals An optimised method for correcting quenched fluorescence yield

2014 ◽  
Vol 11 (3) ◽  
pp. 1243-1264 ◽  
Author(s):  
L. Biermann ◽  
C. Guinet ◽  
M. Bester ◽  
A. Brierley ◽  
L. Boehme
Keyword(s):  
Light Intensity ◽  
Southern Ocean ◽  
Fluorescence Emission ◽  
Euphotic Zone ◽  
Fluorescence Yield ◽  
High Light Intensity ◽  
High Light ◽  
Photochemical Quenching ◽  
Non Photochemical Quenching

Abstract. Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. Previously, this has been done using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, the assumption of homogeneity is not robust in oceanic regimes that support deep chlorophyll maxima. To account for these features, we correct from the limit of the euphotic zone, defined as the depth at which light is at ~1% of the surface value. This method was applied to fluorescence data collected by eleven animal-borne fluorometers deployed in the Southern Ocean over four austral summers. Six tags returned data showing evidence of deep chlorophyll features. Using the depth of the euphotic layer, quenching was corrected without masking subsurface fluorescence signals.

scholarly journals Antenna Protein Clustering In Vitro Unveiled by Fluorescence Correlation Spectroscopy

2021 ◽  
Vol 22 (6) ◽  
pp. 2969
Author(s):  
Aurélie Crepin ◽  
Edel Cunill-Semanat ◽  
Eliška Kuthanová Trsková ◽  
Erica Belgio ◽  
Radek Kaňa
Keyword(s):  
Fluorescence Correlation Spectroscopy ◽  
Higher Plants ◽  
Fluorescence Emission ◽  
Correlation Spectroscopy ◽  
Photochemical Quenching ◽  
High Ph ◽  
Fluorescence Correlation ◽  
Non Photochemical Quenching

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.

Effects of short-term low temperature stress on chlorophyll fluorescence transients in Antarctic lichen species

2016 ◽  
Vol 6 (1) ◽  
pp. 54-65 ◽  
Author(s):  
Michaela Marečková ◽  
Miloš Barták
Keyword(s):  
Chlorophyll Fluorescence ◽  
Low Temperature ◽  
Temperature Effects ◽  
Photochemical Quenching ◽  
Short Term ◽  
Ps Ii ◽  
Species Specific ◽  
Non Photochemical Quenching ◽  
Fluorescence Transients ◽  
Chlorophyll Fluorescence Transients

Chlorophyll fluorescence is an effective tool for investigating characteristics of any photosynthesizing organisms and its responses due to different stressors. Here, we have studied a short-term temperature response on two Antarctic green algal lichen species: Umbilicaria antarctica, and Physconia muscigena. We measured slow chlorophyll fluorescence transients in the species during slow a cooling of thallus temperature from 20°C to 5°C with a 10 min. acclimation at each temperature in dark. The measurements were supplemented with saturation pulses for the analysis of chlorophyll fluorescence parameters: maximum yield of PS II photochemistry (FV/FM), effective quantum yield of PS II photochemistry (FPSII) and non-photochemical quenching (NPQ). In response to decreasing thallus temperature, we observed species-specific changes in chlorophyll fluorescence levels P, S, M, T reached during chlorophyll fluorescence transient as well as in the shape of the chlorophyll fluorescence transients. With a decrease in temperature, the time at which M and T chlorophyll fluorescence levels were reached, increased. These changes were attributed to redox state of plastoquinon pool, changes in Calvin-Benson cycle activity, non-photochemical quenching components, state transition in particular. In this study, we present some chlorophyll fluorescence ratios (P/M, M/T, P/T) and chlorophyll fluorescence increase rates (FR1, i.e. O to P, and FR2 - i.e. S to M) as the parameters reflecting direct temperature effects on chloroplastic apparatus of lichen alga sensitively. We proposed that species-specific changes in the slow phase of chlorophyll fluorescence transients could be potentially used as indicators of low temperature effects in photosynthetic apparatus of lichen algal photobionts. Interspecific differences in response to low temperature might be evaluated using the approach as well.

scholarly journals Chlamydomonas reinhardtii LHCSR1 and LHCSR3 proteins involved in photoprotective non-photochemical quenching have different quenching efficiency and different carotenoid affinity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Federico Perozeni ◽  
Giorgia Beghini ◽  
Stefano Cazzaniga ◽  
Matteo Ballottari
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Functional Properties ◽  
Carbon Fixation ◽  
Thermal Dissipation ◽  
Photochemical Quenching ◽  
High Sequence Identity ◽  
Pigment Analysis ◽  
Quenching Efficiency ◽  
Non Photochemical Quenching

AbstractMicroalgae are unicellular photosynthetic organisms considered as potential alternative sources for biomass, biofuels or high value products. However, their limited biomass productivity represents a bottleneck that needs to be overcome to meet the applicative potential of these organisms. One of the domestication targets for improving their productivity is the proper balance between photoprotection and light conversion for carbon fixation. In the model organism for green algae, Chlamydomonas reinhardtii, a photoprotective mechanism inducing thermal dissipation of absorbed light energy, called Non-photochemical quenching (NPQ), is activated even at relatively low irradiances, resulting in reduced photosynthetic efficiency. Two pigment binding proteins, LHCSR1 and LHCSR3, were previously reported as the main actors during NPQ induction in C. reinhardtii. While previous work characterized in detail the functional properties of LHCSR3, few information is available for the LHCSR1 subunit. Here, we investigated in vitro the functional properties of LHCSR1 and LHCSR3 subunits: despite high sequence identity, the latter resulted as a stronger quencher compared to the former, explaining its predominant role observed in vivo. Pigment analysis, deconvolution of absorption spectra and structural models of LHCSR1 and LHCR3 suggest that different quenching efficiency is related to a different occupancy of L2 carotenoid binding site.

scholarly journals Short-term effects of heavy metal and temperature stresses on the photophysiology of Symbiodinium isolated from the coral Fungia repanda

Ocean Life ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 11-20 ◽  
Author(s):  
MANJULA D. GHOORA ◽  
SIVAJYODEE S. PILLY ◽  
PRAMOD KUMAR CHUMUN ◽  
SHOBHA JAWAHEER ◽  
RANJEET BHAGOOLI
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Photosynthetic Capacity ◽  
Pulse Amplitude ◽  
Photochemical Quenching ◽  
Short Term ◽  
Temperature Stresses ◽  
Clade C ◽  
Non Photochemical Quenching ◽  
Short Term Effects

Ghoora MD, Pilly SS, Chumun PK, Jawaheer S, Bhagooli R. 2017. Short-term effects of heavy metal and temperature stresses on the photo-physiology of Symbiodinium isolated from the coral Fungia repanda. Ocean Life 1: 11-20. This study aimed to investigate the effects of the heavy metals, copper, zinc and lead, on the photo-physiology of the symbiotic dinoflagellate Symbiodinium isolated from the coral Fungia repanda. Freshly isolated Symbiodinium found to belong to clade C were exposed to different concentrations of the three heavy metals for 3-hour and 18-hour treatments at 28°C and 32°C. The Pulse Amplitude Modulated (PAM) fluorometry technique was used to determine the maximum quantum yield (Fv/Fm), relative maximum electron transport rate (rETRmax) and maximum non-photochemical quenching (NPQmax) of the photosystem II (PSII). An increase in non-photochemical quenching accompanied by a decrease in photosynthetic capacity was noted for copper at a concentration of 50 µg/L for both temperatures. The Fv/Fm was not significantly affected by the Zn treatments. However, at 28 °C, isolates treated with 100 µg/L Zn for 18 hours showed an increase in non-photochemical quenching accompanied by a decrease in photosynthetic capacity. Pb had the most profound effect on all of the isolates. The Fv/Fm significantly decreased and an increase in NPQmax was noted. The decrease of rETRmax and increase in NPQmax for the heavy metal bioassays under 32 °C were more significant than at 28 °C. This study suggests that Cu (≥50 µg/L), Zn (≥ 100 µg/L) and Pb decrease the photosynthetic capacity of the Symbiodinium isolates from F. repanda especially more so with increasing temperatures.

scholarly journals Change in H+ Transport across Thylakoid Membrane as Potential Mechanism of 14.3 Hz Magnetic Field Impact on Photosynthetic Light Reactions in Seedlings of Wheat (Triticum aestivum L.)

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2207
Author(s):  
Ekaterina Sukhova ◽  
Ekaterina Gromova ◽  
Lyubov Yudina ◽  
Anastasiia Kior ◽  
Yana Vetrova ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photosystem Ii ◽  
Thylakoid Membrane ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Terrestrial Plants ◽  
Short Term ◽  
Low Frequencies ◽  
Resonance Frequencies ◽  
Non Photochemical Quenching

Natural and artificial extremely low-frequency magnetic fields (ELFMFs) are important factors influencing physiological processes in living organisms including terrestrial plants. Earlier, it was experimentally shown that short-term and long-term treatments by ELFMFs with Schumann resonance frequencies (7.8, 14.3, and 20.8 Hz) influenced parameters of photosynthetic light reactions in wheat leaves. The current work is devoted to an analysis of potential ways of this ELFMF influence on the light reactions. Only a short-term wheat treatment by 14.3 Hz ELFMF was used in the analysis. First, it was experimentally shown that ELFMF-induced changes (an increase in the effective quantum yield of photosystem II, a decrease in the non-photochemical quenching of chlorophyll fluorescence, a decrease in time of changes in these parameters, etc.) were observed under the action of ELFMF with widely ranging magnitudes (from 3 to 180 µT). In contrast, the potential quantum yield of photosystem II and time of relaxation of the energy-dependent component of the non-photochemical quenching were not significantly influenced by ELFMF. Second, it was shown that the ELFMF treatment decreased the proton gradient across the thylakoid membrane. In contrast, the H+ conductivity increased under this treatment. Third, an analysis of the simplest mathematical model of an H+ transport across the thylakoid membrane, which was developed in this work, showed that changes in H+ fluxes related to activities of the photosynthetic electron transport chain and the H+-ATP synthase were not likely a mechanism of the ELFMF influence. In contrast, changes induced by an increase in an additional H+ flux (probably, through the proton leakage and/or through the H+/Ca2+ antiporter activity in the thylakoid membrane) were in good accordance with experimental results. Thus, we hypothesized that this increase is the mechanism of the 14.3 Hz ELFMF influence (and, maybe, influences of other low frequencies) on photosynthetic light reactions in wheat.

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