The roles of photochemical and non-photochemical quenching in regulating photosynthesis depend on the phases of fluctuating light conditions

Abstract The induction and relaxation of photochemistry and non-photochemical quenching (NPQ) are not instantaneous and require time to respond to fluctuating environments. There is a lack of integrated understanding on how photochemistry and NPQ influence photosynthesis in fluctuating environments. We measured the induction and relaxation of chlorophyll a fluorescence and gas exchange in poplar and cotton at varying temperatures under saturating and fluctuating lights. When the light shifted from dark to high, the fraction of open reaction centers in photosystem II (qL) gradually increased while NPQ increased suddenly and then remained stable. Temperature significantly changed the response of qL but not that of NPQ during the dark to high light transition. Increased qL led to higher photosynthesis but their precise relationship was affected by NPQ and temperature. qL was significantly related to biochemical capacity. Thus, qL appears to be a strong indicator of the activation of carboxylase, leading to the similar dynamics between qL and photosynthesis. When the light shifted from high to low intensity, NPQ is still engaged at a high level, causing a stronger decline in photosynthesis. Our finding suggests that the dynamic effects of photochemistry and NPQ on photosynthesis depend on the phases of environmental fluctuations and interactive effects of light and temperature. Across the full spectra of light fluctuation, the slow induction of qL is a more important limiting factor than the slow relaxation of NPQ for photosynthesis in typical ranges of temperature for photosynthesis. The findings provided a new perspective to improve photosynthetic productivity with molecular biology under natural fluctuating environments.

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Role of electron-transfer quenching of chlorophyll fluorescence by carotenoids in non-photochemical quenching of green plants

Biochemical Society Transactions ◽

10.1042/bst0330858 ◽

2005 ◽

Vol 33 (4) ◽

pp. 858-862 ◽

Cited By ~ 40

Author(s):

A. Dreuw ◽

G.R. Fleming ◽

M. Head-Gordon

Keyword(s):

Electron Transfer ◽

Chlorophyll Fluorescence ◽

Charge Transfer ◽

Excited States ◽

Quantum Chemical ◽

Photochemical Quenching ◽

Quenching Mechanism ◽

High Level ◽

Non Photochemical Quenching

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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Exogenous putrescine alleviates photoinhibition caused by salt stress through increasing cyclic electron flow in cucumber

10.1101/301762 ◽

2018 ◽

Author(s):

Xinyi Wu ◽

Sheng Shu ◽

Yu Wang ◽

Ruonan Yuan ◽

Shirong Guo

Keyword(s):

Salt Stress ◽

Electron Flow ◽

Critical Role ◽

Photochemical Efficiency ◽

Cyclic Electron Flow ◽

Photochemical Quenching ◽

Photochemical Efficiency Of Psii ◽

High Level ◽

Non Photochemical Quenching ◽

Related Proteins

AbstractWhen plants suffer from abiotic stresses, cyclic electron flow (CEF) is induced for photoprotection. Putrescine (Put), a main polyamine in chloroplasts, plays a critical role in stress tolerance. To elucidate the mechanism of Put regulating CEF for salt-tolerance in cucumber leaves, we measured chlorophyll fluorescence, P700 redox state, ATP and NADPH accumulation and so on. The maximum photochemical efficiency of PSII (Fv/Fm) was not influenced by NaCl and/or Put, but the activity of PSI reaction center (P700) was seriously inhibited by NaCl. Salt stress induced high level of CEF, moreover, NaCl and Put treated plants exhibited much higher CEF activity and ATP accumulation than single salt-treated plants to provide adequate ATP/NADPH ratio for plants growth. Furthermore, Put decreased the trans-membrane proton gradient (ΔpH), accompanied by reducing the pH-dependent non-photochemical quenching (qE) and increasing efficient quantum yield of PSII (Y(II)). The ratio of NADP+/NADPH in salt stressed leaves was significantly increased by Put, indicating that Put relieved over-reduction pressure at PSI accepter side. Taken together, our results suggest that exogenous Put enhances CEF to supply extra ATP for PSI recovery and CO2 assimilation, decreases ΔpH for electron transport related proteins staying active, and enable the non-photochemical quenching transformed into photochemical quenching.

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Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure

International Journal of Molecular Sciences ◽

10.3390/ijms22010041 ◽

2020 ◽

Vol 22 (1) ◽

pp. 41

Author(s):

Ioannis-Dimosthenis S. Adamakis ◽

Ilektra Sperdouli ◽

Anetta Hanć ◽

Anelia Dobrikova ◽

Emilia Apostolova ◽

...

Keyword(s):

Photosystem Ii ◽

Control Plant ◽

Chloroplast Ultrastructure ◽

Optimal Growth ◽

Defense Responses ◽

Photochemical Quenching ◽

Short Period ◽

High Level ◽

Non Photochemical Quenching ◽

Cd Exposure

Five-day exposure of clary sage (Salvia sclarea L.) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (ΦNO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (1O2) formation. A basal ROS level was detected in control plant leaves for optimal growth, while a low increased level of ROS under 5 days Cd exposure seemed to be beneficial for triggering defense responses, and a high level of ROS out of the boundaries (8 days Cd exposure), was harmful to plants. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered. However, exposure to a combination of Cd and high light or to Cd alone (8 days) resulted in an inhibition of PSII functionality, indicating Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposure and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of “adaptive response” and “toxicity”, respectively.

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Light Absorption and Partitioning in Response to Nitrogen in Apple Leaves

HortScience ◽

10.21273/hortsci.33.3.541a ◽

1998 ◽

Vol 33 (3) ◽

pp. 541a-541

Author(s):

Lailiang Cheng ◽

Leslie H. Fuchigami ◽

Patrick J. Breen

Keyword(s):

High Light ◽

Thermal Dissipation ◽

Photochemical Quenching ◽

Light Conditions ◽

Psii Efficiency ◽

Fluorescence Measurements ◽

Free Radical Formation ◽

Highly Correlated ◽

Non Photochemical Quenching ◽

Leaf N

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.

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Gradual Response of Cyanobacterial Thylakoids to Acute High-Light Stress—Importance of Carotenoid Accumulation

Cells ◽

10.3390/cells10081916 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1916

Author(s):

Myriam Canonico ◽

Grzegorz Konert ◽

Aurélie Crepin ◽

Barbora Šedivá ◽

Radek Kaňa

Keyword(s):

Single Cell ◽

Thylakoid Membrane ◽

Intermediate Phase ◽

Light Stress ◽

Fast Response ◽

High Light ◽

Photochemical Quenching ◽

Second Phase ◽

Ros Scavenging ◽

Non Photochemical Quenching

Light plays an essential role in photosynthesis; however, its excess can cause damage to cellular components. Photosynthetic organisms thus developed a set of photoprotective mechanisms (e.g., non-photochemical quenching, photoinhibition) that can be studied by a classic biochemical and biophysical methods in cell suspension. Here, we combined these bulk methods with single-cell identification of microdomains in thylakoid membrane during high-light (HL) stress. We used Synechocystis sp. PCC 6803 cells with YFP tagged photosystem I. The single-cell data pointed to a three-phase response of cells to acute HL stress. We defined: (1) fast response phase (0–30 min), (2) intermediate phase (30–120 min), and (3) slow acclimation phase (120–360 min). During the first phase, cyanobacterial cells activated photoprotective mechanisms such as photoinhibition and non-photochemical quenching. Later on (during the second phase), we temporarily observed functional decoupling of phycobilisomes and sustained monomerization of photosystem II dimer. Simultaneously, cells also initiated accumulation of carotenoids, especially ɣ–carotene, the main precursor of all carotenoids. In the last phase, in addition to ɣ-carotene, we also observed accumulation of myxoxanthophyll and more even spatial distribution of photosystems and phycobilisomes between microdomains. We suggest that the overall carotenoid increase during HL stress could be involved either in the direct photoprotection (e.g., in ROS scavenging) and/or could play an additional role in maintaining optimal distribution of photosystems in thylakoid membrane to attain efficient photoprotection.

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The Role of Acidic Residues in the C Terminal Tail of the LHCSR3 Protein of Chlamydomonas reinhardtii in Non-Photochemical Quenching

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.1c01382 ◽

2021 ◽

pp. 6895-6900

Author(s):

Franco V. A. Camargo ◽

Federico Perozeni ◽

Gabriel de la Cruz Valbuena ◽

Luca Zuliani ◽

Samim Sardar ◽

...

Keyword(s):

Chlamydomonas Reinhardtii ◽

Photochemical Quenching ◽

Acidic Residues ◽

Non Photochemical Quenching

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Effects of iron limitation on carbon balance and photophysiology of the Antarctic diatom Chaetoceros cf. simplex

Polar Biology ◽

10.1007/s00300-020-02785-1 ◽

2021 ◽

Author(s):

Deborah Bozzato ◽

Torsten Jakob ◽

Christian Wilhelm ◽

Scarlett Trimborn

Keyword(s):

Oxygen Evolution ◽

Photochemical Quenching ◽

Gross Photosynthesis ◽

Manganese Zinc ◽

C Cycle ◽

Uptake Rates ◽

Carbon Pump ◽

Non Photochemical Quenching ◽

The Antarctic ◽

Biological Carbon Pump

AbstractIn the Southern Ocean (SO), iron (Fe) limitation strongly inhibits phytoplankton growth and generally decreases their primary productivity. Diatoms are a key component in the carbon (C) cycle, by taking up large amounts of anthropogenic CO2 through the biological carbon pump. In this study, we investigated the effects of Fe availability (no Fe and 4 nM FeCl3 addition) on the physiology of Chaetoceros cf. simplex, an ecologically relevant SO diatom. Our results are the first combining oxygen evolution and uptake rates with particulate organic carbon (POC) build up, pigments, photophysiological parameters and intracellular trace metal (TM) quotas in an Fe-deficient Antarctic diatom. Decreases in both oxygen evolution (through photosynthesis, P) and uptake (respiration, R) coincided with a lowered growth rate of Fe-deficient cells. In addition, cells displayed reduced electron transport rates (ETR) and chlorophyll a (Chla) content, resulting in reduced cellular POC formation. Interestingly, no differences were observed in non-photochemical quenching (NPQ) or in the ratio of gross photosynthesis to respiration (GP:R). Furthermore, TM quotas were measured, which represent an important and rarely quantified parameter in previous studies. Cellular quotas of manganese, zinc, cobalt and copper remained unchanged while Fe quotas of Fe-deficient cells were reduced by 60% compared with High Fe cells. Based on our data, Fe-deficient Chaetoceros cf. simplex cells were able to efficiently acclimate to low Fe conditions, reducing their intracellular Fe concentrations, the number of functional reaction centers of photosystem II (RCII) and photosynthetic rates, thus avoiding light absorption rather than dissipating the energy through NPQ. Our results demonstrate how Chaetoceros cf. simplex can adapt their physiology to lowered assimilatory metabolism by decreasing respiratory losses.

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167 Effects of L-lys Hcl and Distillers Dried Grains Inclusion Rate on Growth Performance of Finishing Pigs

Journal of Animal Science ◽

10.1093/jas/skab054.096 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 57-57

Author(s):

Henrique S Cemin ◽

Luke A Swalla ◽

Jamie L Pietig ◽

Sharlie A Hansen ◽

Ernie L Hansen

Keyword(s):

Growth Performance ◽

Soybean Meal ◽

Interactive Effects ◽

Finishing Pigs ◽

Distillers Dried Grains ◽

White Grease ◽

Inclusion Rate ◽

Quadratic Response ◽

High Level ◽

Crystalline Amino Acids

Abstract An experiment was conducted to determine the effects of L-Lys HCl inclusion in diets with or without distillers dried grains with solubles (DDGS) on growth performance of finishing pigs. A total of 2,414 pigs (initial BW = 92.7 kg) were used in a 34-d trial. Treatments were arranged as a 2 × 3 factorial treatment structure with two levels of DDGS (0 or 10%) and three levels of L-Lys HCl (0.2, 0.3, or 0.4%). Diets were corn and soybean meal-based and were formulated to be isocaloric (NE = 2,668 kcal/kg) and isolysinic (0.75% SID Lys) by adjusting the inclusion of soybean meal, crystalline amino acids, and choice white grease. All other nutrient levels met or exceeded the NRC (2012) requirement estimates. There were 16 replicates per treatment. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, and G:F. Data was analyzed with SAS MIXED procedure. There was no evidence (P > 0.10) for interactive effects between L-Lys HCl and DDGS inclusion rate. Pigs fed diets with 10% DDGS had improved (P = 0.002) G:F, but there was no evidence (P > 0.10) for differences in ADG or ADFI. Pigs fed increasing levels of L-Lys HCl had higher (linear, P = 0.026) ADFI, decreased (quadratic, P = 0.013) G:F, and a tendency for quadratic response (P = 0.063) in ADG, overall with the poorest performance observed for pigs fed the diet with 0.4% L-Lys HCl. In conclusion, pigs fed 0 or 10% DDGS presented similar performance; however, pigs fed the high level of L-Lys HCl presented decreased performance.

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