Characterisation of Three Components of Non-photochemical Fluorescence Quenching and Their Response to Photoinhibition

1988 ◽  
Vol 15 (2) ◽  
pp. 163 ◽  
Author(s):  
B Demmig ◽  
K Winter
Keyword(s):  
Fluorescence Quenching ◽  
Heat Dissipation ◽  
Photosynthetic Electron Transport ◽  
Co2 Assimilation ◽  
Nerium Oleander ◽  
Photochemical Quenching ◽  
Ps Ii ◽  
Fluorescence Characteristics ◽  
Non Photochemical Quenching ◽  
Three Components

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.

Effects of water stress on photosynthesis, chlorophyll fluorescence and photoinhibition in wheat plants

1998 ◽  
Vol 25 (8) ◽  
pp. 883 ◽  
Author(s):  
Congming Lu ◽  
Jianhua Zhang
Keyword(s):  
Water Stress ◽  
Co2 Assimilation ◽  
Photochemical Quenching ◽  
Reaction Centre ◽  
Ps Ii ◽  
Energy Capture ◽  
Stress Effects ◽  
Reaction Centres ◽  
Net Co2 Assimilation ◽  
Non Photochemical Quenching

Effects of water stress on photosynthesis, PS II photochemistry and photoinhibition were investigated in wheat plants (Tritium aestivum L.). To separate water stress effects from photoinhibition, water stress was imposed at low irradiance (180 µmol m-2 s-1). When water stress developed gradually, net CO2 assimilation rate and leaf stomatal conductance decreased significantly. However, water stress had no effects on the PS II photochemistry in dark-adapted leaves. There were no significant changes in the maximal efficiency of PS II photochemistry and no apparent damages in PS II reaction centre, its oxidising and acceptor sides, or its antennae system. However, PS II photochemistry in light-adapted leaves was modified in water-stressed plants. This was shown by the decrease in the efficiency of excitation energy capture by open PS II reaction centres and the quantum yield of PS II electron transport and a significant increase in non-photochemical quenching. In addition, water stress increased the susceptibility to photoinhibition. The extent of photoinhibition became more pronounced as water stress increased. It was found that water-stressed plants exhibited a much greater accumulation of the QB-non-reducing PS II reaction centres and a smaller increase in non- photochemical quenching during photoinhibition. Such changes might be responsible for the increased susceptibility to photoinhibition.

Light use in relation to carbon gain in the mangrove, Avicennia marina, under hypersaline conditions

1999 ◽  
Vol 26 (3) ◽  
pp. 245 ◽  
Author(s):  
M. A. Sobrado ◽  
M. C. Ball
Keyword(s):  
Electron Transport ◽  
Avicennia Marina ◽  
Co2 Assimilation ◽  
Photochemical Quenching ◽  
Carbon Gain ◽  
Co2 Concentrations ◽  
Fluorescence Characteristics ◽  
Electron Transport Rates ◽  
Non Photochemical Quenching ◽  
Intercellular Co2

Photosynthesis was studied in relation to light use in the mangrove, Avicennia marina (Forsk.) Vierh. var. australasica (Walp.) Moldenke, growing under soil salinities equivalent to one and two times seawater (i.e. 35 and 60‰). Midday CO2 assimilation rates averaged 7.6 0.7 and 4.3 0.3 µmol m–2 s–1 at the seawater and hypersaline sites, respectively. Despite this difference, xanthophyll pool sizes per Chl and epoxidation states were similar at both sites. Non-photochemical quenching also indicated comparable energy dissipation from pigment beds. Electron transport rates calculated from fluorescence characteristics were also similar and exceeded the requirements to sustain measured assimilation rates. However, cell wall conductance was low in seawater plants (75 mmol m2 s–1 ) and declined to 40 mmol m–2 s–1 in hypersaline plants. This would cause CO2 concentrations in chloroplasts (Cc ) to be lower than expected from measurements of intercellular CO2 concentrations (Ci ). In seawater plants, Cc was estimated to be 144 µmol mol–1 when Ci was 245 mmol mol–1, while values for Cc and Ci in hypersaline plants were 78 and 212 mmol mol–1, respectively. Reductions in Cc would enhance rates of photorespiration relative to assimilation, with the higher photorespiratory rates being sufficient to account for apparent excess electron transport rates.

scholarly journals Linking remote sensing parameters to CO2 assimilation rates at a leaf scale

2021 ◽  
Author(s):  
Kouki Hikosaka ◽  
Katsuto Tsujimoto
Keyword(s):  
Remote Sensing ◽  
Chlorophyll Fluorescence ◽  
Heat Dissipation ◽  
Spatial Scales ◽  
Photochemical Efficiency ◽  
Co2 Assimilation ◽  
Photochemical Quenching ◽  
Future Prediction ◽  
Environmental Responses ◽  
Non Photochemical Quenching

AbstractSolar-induced chlorophyll fluorescence (SIF) and photochemical reflectance index (PRI) are expected to be useful for remote sensing of photosynthetic activity at various spatial scales. This review discusses how chlorophyll fluorescence and PRI are related to the CO2 assimilation rate at a leaf scale. Light energy absorbed by photosystem II chlorophylls is allocated to photochemistry, fluorescence, and heat dissipation evaluated as non-photochemical quenching (NPQ). PRI is correlated with NPQ because it reflects the composition of xanthophylls, which are involved in heat dissipation. Assuming that NPQ is uniquely related to the photochemical efficiency (quantum yield of photochemistry), photochemical efficiencies can be assessed from either chlorophyll fluorescence or PRI. However, this assumption may not be held under some conditions such as low temperatures and photoinhibitory environments. Even in such cases, photosynthesis may be estimated more accurately if both chlorophyll fluorescence and PRI are determined simultaneously. To convert from photochemical efficiency to CO2 assimilation, environmental responses in stomatal conductance also need to be considered. Models linking chlorophyll fluorescence and PRI with CO2 assimilation rates will contribute to understanding and future prediction of the global carbon cycle.

scholarly journals Chilling tolerance in Zizania latifólia

2016 ◽  
Vol 34 (1) ◽  
pp. 39-45
Author(s):  
Zihong Ye ◽  
Haifeng Cui ◽  
Xinxin An ◽  
Xiaoping Yu
Keyword(s):  
Cold Stress ◽  
Heat Dissipation ◽  
Chilling Tolerance ◽  
Photochemical Quenching ◽  
Electric Transport ◽  
Zizania Latifolia ◽  
Critical Pathways ◽  
Photosynthesis Inhibition ◽  
Non Photochemical Quenching ◽  
Latent Activity

ABSTRACT: The tumescent stems of Zizania latifolia are consumed as vegetable in southern and eastern Asia. This study aimed to compare photosynthesis and chilling tolerance parameters between two well-known Zizania latifolia cultivars: Longjiao 2 and Zhejiao 911, which are chilling tolerant and sensitive, respectively. We found that severe cold stress induced photosynthesis inhibition (5°C) resulted from non-stomatal factors. However, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of the cultivar Longjiao 2 were higher than that of Zhejiao 911 with more gradual variations. Six parameters of chlorophyll fluorescence including latent activity of PSII (Fv/F0), efficiency of primary photochemistry (Fv/Fm), photochemical quenching coefficient (qP), non-photochemical quenching coefficient (qN), quantum yield of electric transport (Yield) and the ratio of electric transport at PSII (ETR) were analyzed in the two cultivars. We found that Longjiao 2 had significantly higher Fv/Fm and qN than Zhejiao 911 while qP values were only slightly different for the two lines at severe cold stress. In our experiments, Yield and ETR changed in a similar way in both Longjiao 2 and Zhejiao 911. In addition, the ability of heat dissipation of Longjiao 2 was statistically higher than that found in Zhejiao 911 when treated at 5°C for one day. These data suggest that cultivar Longjiao 2 induces chilling tolerance by modulating critical pathways including photosynthesis and energy dissipation.

scholarly journals Photosynthesis sensitivity to NH4+-N change with nitrogen fertilizer type

2014 ◽  
Vol 60 (No. 6) ◽  
pp. 274-279 ◽  
Author(s):  
A. Nasraoui-Hajaji ◽  
H. Gouia
Keyword(s):  
Net Photosynthesis ◽  
Dry Weight ◽  
N Fertilization ◽  
Photochemical Quenching ◽  
Negative Effects ◽  
Ps Ii ◽  
Chl A ◽  
Inhibitory Site ◽  
Tomato Growth ◽  
Non Photochemical Quenching

N-fertilization type affected differently tomato growth. In the field experiment, hydroponic cultures were conducted using NO<sub>3</sub>-N (5 mmol); mixture of KNO<sub>3</sub>-N (3 mmol) and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-N (2 mmol); NH<sub>4</sub><sup>+</sup>-N (5 mmol) or urea&nbsp;(5 mmol) as nitrogen source. Compared to nitrate, ammonium and urea had negative effects on morphology and dry matter production. Effects of the different nitrogen forms were investigated by measuring several photosynthesis parameters and chl a fluorescence. Two different significant types of reaction were found. When nitrogen was added as ammonium or urea, dry weight, chlorophyll tenor, transpiration rate, stomatal conductance and photosynthetic activity were inhibited. Supply of ammonium or urea, reduced the ratio (F<sub>v</sub>/F<sub>m</sub>), photochemical quenching and enhanced the non photochemical quenching. These data suggest that the adverse decrease in tomato growth under ammonium or urea supply may be related principally to inhibition of net photosynthesis activity. The high non photochemical quenching shown in tomato fed with ammonium or urea indicated that PS II was the inhibitory site of NH<sub>4</sub><sup>+</sup>-N which was directly uptaken by roots, or librated via urea hydrolysis cycle.

Salt stress resilience potential of a fungal inoculant isolated from tea cultivation area in maize

Biologia ◽  
2017 ◽  
Vol 72 (6) ◽  
Author(s):  
Nuran Durmus ◽  
Abdullah Muhammed Yesilyurt ◽  
Necla Pehlivan ◽  
Sengul Alpay Karaoglu
Keyword(s):  
Salt Stress ◽  
Water Status ◽  
Cost Effective ◽  
Nacl Stress ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Stress Resilience ◽  
Ps Ii ◽  
Tea Plants ◽  
Non Photochemical Quenching

AbstractAgriculture needs to be sustained by organic processes in current era as population explosion energy and the number of individuals undernourished are raising public concerns. Global warming poses additional threat by lifting the damage of salt stress especially in agro-economically vital crops like maize whose cultivation dates back to Mayans. To that end, cost-effective and organic fungal agents may be great candidates in stress resilience. We isolated the fungal strain from the soil of tea plants and characterized that via 5.8 S rDNA gene with internal transcribed spacer ITS-1 and ITS-2 regions, then named the target strain as TA. Reduced maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (ΦPS2), electron transport rate (ETR), photochemical quenching (qP) and increased non-photochemical quenching (NPQ) were detected in maize plants stressed with dose dependent salt. Enhanced Fv/Fm, ΦPS2, ETR, qP and decreased NPQ was observed in TA primed plus NaCl treated plants. TA biopriming significantly increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation. Maize seedlings bioprimed with TA had less MDA and higher soluble protein, proline, total chlorophyll, carotenoid and RWC under NaCl. Furthermore, SOD, GPX and GR activities were much more increased in root and leaves of TA primed seedlings, however CAT activity did not significantly change. This is the first report to our knowledge that TA reverses the damage of NaCl stress on maize growth through improving water status, antioxidant machinery and especially photosynthetic capacity.

scholarly journals RETRACTED ARTICLE: Increased biomass productivity in green algae by tuning non-photochemical quenching

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Silvia Berteotti ◽  
Matteo Ballottari ◽  
Roberto Bassi
Keyword(s):  
Heat Dissipation ◽  
Biomass Productivity ◽  
Growth Conditions ◽  
Complex Stress ◽  
Biofuel Production ◽  
Photochemical Quenching ◽  
Protein Accumulation ◽  
Potential Productivity ◽  
Wide Range ◽  
Non Photochemical Quenching

Abstract Photosynthetic microalgae have a high potential for the production of biofuels and highly valued metabolites. However, their current industrial exploitation is limited by a productivity in photobioreactors that is low compared to potential productivity. The high cell density and pigment content of the surface layers of photosynthetic microalgae result in absorption of excess photons and energy dissipation through non-photochemical quenching (NPQ). NPQ prevents photoinhibition, but its activation reduces the efficiency of photosynthetic energy conversion. In Chlamydomonas reinhardtii, NPQ is catalyzed by protein subunits encoded by three lhcsr (light harvesting complex stress related) genes. Here, we show that heat dissipation and biomass productivity depends on LHCSR protein accumulation. Indeed, algal strains lacking two lhcsr genes can grow in a wide range of light growth conditions without suffering from photoinhibition and are more productive than wild-type. Thus, the down-regulation of NPQ appears to be a suitable strategy for improving light use efficiency for biomass and biofuel production in microalgae.

Greenhouse and field cucumber genotypes use different mechanisms to protect against dark chilling

2004 ◽  
Vol 31 (12) ◽  
pp. 1215 ◽  
Author(s):  
Yan-Hong Zhou ◽  
Li-Feng Huang ◽  
Yao-Shun Du ◽  
Jing-Quan Yu
Keyword(s):  
Calvin Cycle ◽  
Photosynthetic Electron Transport ◽  
Co2 Assimilation ◽  
Photochemical Quenching ◽  
Genotypic Differences ◽  
Diurnal Changes ◽  
Cucumis Sativus L ◽  
Photosynthetic Gas Exchange ◽  
Protection Mechanism ◽  
Psii Photochemistry

Diurnal changes in photosynthetic gas exchange and chlorophyll fluorescence were measured after two consecutive night chills to reveal the photosynthetic characteristics and the mechanism of photoprotection in a greenhouse genotype Jinyou No. 3 (GH), and in a field genotype Jinyan No. 4 (OF) of cucumber (Cucumis sativus L.). Both genotypes showed inhibition of CO2 assimilation immediately after the dark chill, with OF exhibiting a greater reduction. Dark chilling had little effect on stomatal limitation (l) and RuBP regeneration (Jmax) but significantly decreased maximum carboxylation velocity of Rubisco (Vcmax). The reduced capacity for CO2 fixation in the Calvin cycle induced a downstream regulation of PSII photochemistry, a mechanism that regulates the photosynthetic electron transport to match the lower demand for ATP and NADPH in the stroma of chloroplasts. The reduced quantum efficiency of PSII photochemistry was mainly due to reductions both in the photochemical quenching coefficient (qP) and in the efficiency of excitation energy capture by open PSII reaction centres (Fv′ / Fm′) for OF, but only to the latter for GH. Night chills resulted in an enhanced photorespiration proportion in GH and an O2-dependent alternative electron flux in OF, which served as protective mechanisms for the two varieties. These results showed that there are genotypic differences in the limitation factor for CO2 assimilation and in photo-protection mechanism to night chill in cucumber.

scholarly journals Allosteric regulation of the light-harvesting system of photosystem II

2000 ◽  
Vol 355 (1402) ◽  
pp. 1361-1370 ◽  
Author(s):  
Peter Horton ◽  
Alexander V. Ruban ◽  
Mark Wentworth
Keyword(s):  
Photosystem Ii ◽  
Xanthophyll Cycle ◽  
Light Harvesting ◽  
Allosteric Regulation ◽  
Photochemical Quenching ◽  
Protein Subunit ◽  
Ps Ii ◽  
Non Photochemical Quenching

Non–photochemical quenching of chlorophyll fluorescence (NPQ) is symptomatic of the regulation of energy dissipation by the light–harvesting antenna of photosystem II (PS II). The kinetics of NPQ in both leaves and isolated chloroplasts are determined by the transthylakoid ΔpH and the de–epoxidation state of the xanthophyll cycle. In order to understand the mechanism and regulation of NPQ we have adopted the approaches commonly used in the study of enzyme–catalysed reactions. Steady–state measurements suggest allosteric regulation of NPQ, involving control by the xanthophyll cycle carotenoids of a protonationdependent conformational change that transforms the PS II antenna from an unquenched to a quenched state. The features of this model were confirmed using isolated light–harvesting proteins. Analysis of the rate of induction of quenching both in vitro and in vivo indicated a bimolecular second–order reaction; it is suggested that quenching arises from the reaction between two fluorescent domains, possibly within a single protein subunit. A universal model for this transition is presented based on simple thermodynamic principles governing reaction kinetics.

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