Photochemistry of Photosystems II and I in Rice Plants Grown Under Different N Levels at Normal and High Temperature

Abstract Although N levels affect leaf photosynthetic capacity, the effects of N levels on the photochemistry of photosystems II and I (PSII and PSI, respectively) are not well-understood. In the present study, we examined this aspect in rice (Oryza sativa L. ‘Hitomebore’) plants grown under three different N levels at normal or high temperature that can occur during rice culture and does not severely suppress photosynthesis. At both growth temperatures, the quantum efficiency of PSII [Y(II)] and the fraction of the primary quinone electron acceptor in its oxidized state were positively correlated with the amount of total leaf-N, whereas the quantum yields of non-photochemical quenching and donor-side limitation of PSI [Y(ND)] were negatively correlated with the amount of total leaf-N. These changes in PSII and PSI parameters were strongly correlated with each other. Growth temperatures scarcely affected these relationships. These results suggest that the photochemistry of PSII and PSI is coordinately regulated primarily depending on the amount of total leaf-N. When excess light energy occurs in low-N acclimated plants, oxidation of the reaction center chlorophyll of PSI is thought to be stimulated to protect PSI from excess light energy. It is also suggested that PSII and PSI normally operate at high temperature used in the present study. In addition, as the relationships between Y(II) and Y(ND) were found to be almost identical to those observed in osmotically stressed rice plants, common regulation is thought to be operative when excess light energy occurs due to different causes.

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Non-Photochemical Quenching. A Response to Excess Light Energy

PLANT PHYSIOLOGY ◽

10.1104/pp.125.4.1558 ◽

2001 ◽

Vol 125 (4) ◽

pp. 1558-1566 ◽

Cited By ~ 1538

Author(s):

Patricia Müller ◽

Xiao-Ping Li ◽

Krishna K. Niyogi

Keyword(s):

Light Energy ◽

Photochemical Quenching ◽

Excess Light ◽

Non Photochemical Quenching

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Photosynthesis, light energy partitioning, and photoprotection in the shade-demanding species Panax notoginseng under high and low level of growth irradiance

Functional Plant Biology ◽

10.1071/fp15283 ◽

2016 ◽

Vol 43 (6) ◽

pp. 479 ◽

Cited By ~ 11

Author(s):

Jun-Wen Chen ◽

Shuang-Bian Kuang ◽

Guang-Qiang Long ◽

Sheng-Chao Yang ◽

Zhen-Gui Meng ◽

...

Keyword(s):

Panax Notoginseng ◽

High Light ◽

Light Energy ◽

Quantum Yields ◽

Photochemical Quenching ◽

Light Illumination ◽

Low Light ◽

Psii Photochemistry ◽

Growth Irradiance ◽

Non Photochemical Quenching

Partitioning of light energy into several pathways and its relation to photosynthesis were examined in a shade-demanding species Panax notoginseng (Burkill) F.H.Chen ex C.Y.Wu & K.M.Feng grown along a light gradient. In fully light-induced leaves, the actual efficiency of PSII photochemistry (ΔF/Fmʹ), electron transport rate (ETR), non-photochemical quenching (NPQ) and photochemical quenching (qP) were lower in low-light-grown plants; this was also the case in fully dark-adapted leaves under a simulated sunfleck. In response to varied light intensity, high-light-grown plants showed greater quantum yields of light-dependent non-photochemical quenching (ΦNPQ) and PSII photochemistry (ΦPSII) and smaller quantum yields of fluorescence and constitutive thermal dissipation (Φf,d). Under the simulated sunfleck, high-light-grown plants showed greater ΦPSII and smaller Φf,d. There were positive relationships between net photosynthesis (Anet) and ΦNPQ+f,d and negative relationships between Anet and ΦPSII in fully light-induced leaves; negative correlations of Anet with ΦNPQ+f,d and positive correlations of Anet with ΦPSII were observed in fully dark-adapted leaves. In addition, more nitrogen was partitioned to light-harvesting components in low-light-grown plants, whereas leaf morphology and anatomy facilitate reducing light capture in high-light-grown plants. The pool of xanthophyll pigments and the de-epoxidation state was greater in high-light-grown plants. Antioxidant defence was elevated by increased growth irradiance. Overall, the evidences from P. notoginseng suggest that in high-light-grown shade-demanding plants irradiated by high light more electrons were consumed by non-net carboxylative processes that activate the component of NPQ, that low-light-grown plants correspondingly protect the photosynthetic apparatus against photodamage by reducing the efficiency of PSII photochemistry under high light illumination, and that during the photosynthetic induction, the ΔpH-dependent (qE) component of NPQ might dominate photoprotection, but the NPQ also depresses the enhancement of photosynthesis via competition for light energy.

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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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Different strategies of acclimation of photosynthesis, electron transport and antioxidative activity in leaves of two cotton species to water deficit

Functional Plant Biology ◽

10.1071/fp15247 ◽

2016 ◽

Vol 43 (5) ◽

pp. 448 ◽

Cited By ~ 9

Author(s):

Xiao-Ping Yi ◽

Ya-Li Zhang ◽

He-Sheng Yao ◽

Hong-Hai Luo ◽

Ling Gou ◽

...

Keyword(s):

Electron Transport ◽

Water Deficit ◽

Heat Dissipation ◽

Photosynthetic Apparatus ◽

Light Energy ◽

Photochemical Quenching ◽

Antioxidant Systems ◽

Mehler Reaction ◽

Cotton Species ◽

Excess Light

To better understand the adaptation mechanisms of the photosynthetic apparatus of cotton plants to water deficit conditions, the influence of water deficit on photosynthesis, chlorophyll a fluorescence and the activities of antioxidant systems were determined simultaneously in Gossypium hirsutum L. cv. Xinluzao 45 (upland cotton) and Gossypium barbadense L. cv. Xinhai 21 (pima cotton). Water deficit decreased photosynthesis in both cotton species, but did not decrease chlorophyll content or induce any sustained photoinhibition in either cotton species. Water deficit increased ETR/4 − AG, where ETR/4 estimates the linear photosynthetic electron flux and AG is the gross rate of carbon assimilation. The increase in ETR/4 − AG, which represents an increase in photorespiration and alternative electron fluxes, was particularly pronounced in Xinluzao 45. In Xinluzao 45, water deficit increased the activities of antioxidative enzymes, as well as the contents of reactive oxygen species (ROS), which are related to the Mehler reaction. In contrast, moderate water deficit particularly increased non-photochemical quenching (NPQ) in Xinhai 21. Our results suggest that Xinluzao 45 relied on enhanced electron transport such as photorespiration and the Mehler reaction to dissipate excess light energy under mild and moderate water deficit. Xinhai 21 used enhanced photorespiration for light energy utilisation under mild water deficit but, when subjected to moderate water deficit, possessed a high capacity for dissipating excess light energy via heat dissipation.

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Responses of Rainforest Understorey Plants to Excess Light during Sunflecks

Functional Plant Biology ◽

10.1071/pp96074 ◽

1997 ◽

Vol 24 (1) ◽

pp. 17 ◽

Cited By ~ 32

Author(s):

Jenny R. Watling ◽

Sharon A. Robinson ◽

Ian E. Woodrow ◽

C. Barry Osmond

Keyword(s):

Tropical Rainforest ◽

Photon Flux ◽

Photochemical Quenching ◽

Photon Flux Density ◽

Leaf Angle ◽

Low Light ◽

Fourth Species ◽

Excess Light ◽

Understorey Plants ◽

Non Photochemical Quenching

Responses of Alocasia macrorrhiza (L.) G. Don, Castanospora alphandii (F. Muell.) F. Muell. and Alpinia hylandii R. Smith, growing in a tropical rainforest understorey, to excess light during sunflecks were investigated using chlorophyll fluorescence techniques and by analysing xanthophyll cycle activity. A fourth species, the pioneerOmalanthus novo-guineensis (Warb.) Schum., growing in a small gap, was also studied. In all three understorey species there were large and rapid decreases in the proportion of open Photosystem II (PSII) centres, as indicated by qP, on illumination with saturating light and a concurrent increase in non-photochemical quenching. qP remained low (< 0.4) throughout the period of illumination (~15 min), although it did increase gradually, probably reflecting photosynthetic induction. Sustained declines (up to 120 min) in quantum yield, indicated by Fv/Fm, occurred in all three understorey species following exposure to saturating Photon flux density (PFD) during sunflecks. When ?PSII was monitored during sunflecks it was found to be very sensitive to changes in PFD, declining rapidly with even modest rises in the latter. There was rapid and continuing net conversion of violaxanthin (V) to antheraxanthin plus zeaxanthin (A+Z) on exposure of A. macrorrhiza and C. alphandii to saturating sunflecks. On returning to low light A. macrorrhiza retained its high levels of A+Z for up to 60 min, while C. alphandii rapidly converted back to V. O. novo- guineensis responded to high light by changing its leaf angle to reduce interception and showed no indication of photoinhibition during or after exposure.

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Photosynthetic light reactions in Oryza sativa L. under Cd stress: Influence of iron, calcium, and zinc supplements

The EuroBiotech Journal ◽

10.2478/ebtj-2019-0021 ◽

2019 ◽

Vol 3 (4) ◽

pp. 175-181

Author(s):

Abin Sebastian ◽

M. N. V. Prasad

Keyword(s):

Oryza Sativa L ◽

Cadmium Stress ◽

Photochemical Quenching ◽

Linear Electron ◽

Cd Stress ◽

Cd Accumulation ◽

Ca Ions ◽

Zinc Supplements ◽

Non Photochemical Quenching ◽

Stress Influence

Abstract Some mineral nutrients may help to alleviate cadmium stress in plants. Therefore, influence of Fe, Ca, and Zn supplements on photosynthesis light reactions under Cd stress studied in two Indian rice cultivars namely, MO-16 and MTU-7029 respectively. Exogenous application of both Fe and Ca ions helped to uphold quantum efficiency and linear electron transport during Cd stress. Also, recovery of biomass noticed during Cd treatment with Fe and Ca supplements. It was found that accumulation of carotenoids as well as non photochemical quenching enhances with Fe, Ca, and Zn supplements. Chlorophyll a/b ratio increased with Cd accumulation as a strategy to increase light harvest. Lipid peroxidation level was ascertained the highest during Cd plus Zn treatments. Above results point that both Fe and Ca ions supplements help to alleviate Cd stress on photosynthesis light reactions of rice plants.

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Non-photochemical Quenching Plays a Key Role in Light Acclimation of Rice Plants Differing in Leaf Color

Frontiers in Plant Science ◽

10.3389/fpls.2016.01968 ◽

2017 ◽

Vol 7 ◽

Cited By ~ 19

Author(s):

Xia Zhao ◽

Tingting Chen ◽

Baohua Feng ◽

Caixia Zhang ◽

Shaobing Peng ◽

...

Keyword(s):

Light Acclimation ◽

Photochemical Quenching ◽

Leaf Color ◽

Rice Plants ◽

Non Photochemical Quenching

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DAY-LENGTH-DEPENDENT DELAYED-GREENING1, the Arabidopsis Homolog of the Cyanobacterial H+-Extrusion Protein, Is Essential for Chloroplast pH Regulation and Optimization of Non-Photochemical Quenching

Plant and Cell Physiology ◽

10.1093/pcp/pcz203 ◽

2019 ◽

Vol 60 (12) ◽

pp. 2660-2671 ◽

Cited By ~ 3

Author(s):

Kyohei Harada ◽

Takatoshi Arizono ◽

Ryoichi Sato ◽

Mai Duy Luu Trinh ◽

Akira Hashimoto ◽

...

Keyword(s):

Ph Regulation ◽

Regulatory Protein ◽

Protein A ◽

Continuous Light ◽

Membrane Vesicles ◽

Light Energy ◽

Day Length ◽

Chloroplast Envelope ◽

Photochemical Quenching ◽

Non Photochemical Quenching

Abstract Plants convert solar energy into chemical energy through photosynthesis, which supports almost all life activities on earth. Because the intensity and quality of sunlight can change dramatically throughout the day, various regulatory mechanisms help plants adjust their photosynthetic output accordingly, including the regulation of light energy accumulation to prevent the generation of damaging reactive oxygen species. Non-photochemical quenching (NPQ) is a regulatory mechanism that dissipates excess light energy, but how it is regulated is not fully elucidated. In this study, we report a new NPQ-regulatory protein named Day-Length-dependent Delayed-Greening1 (DLDG1). The Arabidopsis DLDG1 associates with the chloroplast envelope membrane, and the dldg1 mutant had a large NPQ value compared with wild type. The mutant also had a pale-green phenotype in developing leaves but only under continuous light; this phenotype was not observed when dldg1 was cultured in the dark for ≥8 h/d. DLDG1 is a homolog of the plasma membrane-localizing cyanobacterial proton-extrusion-protein A that is required for light-induced H+ extrusion and also shows similarity in its amino-acid sequence to that of Ycf10 encoded in the plastid genome. Arabidopsis DLDG1 enhances the growth-retardation phenotype of the Escherichia coli K+/H+ antiporter mutant, and the everted membrane vesicles of the E. coli expressing DLDG1 show the K+/H+ antiport activity. Our findings suggest that DLDG1 functionally interacts with Ycf10 to control H+ homeostasis in chloroplasts, which is important for the light-acclimation response, by optimizing the extent of NPQ.

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Shade lichens are characterized by rapid relaxation of non-photochemical quenching on transition to darkness

The Lichenologist ◽

10.1017/s0024282921000323 ◽

2021 ◽

Vol 53 (5) ◽

pp. 409-414

Author(s):

Richard P. Beckett ◽

Farida V. Minibayeva ◽

Kwanele W. G. Mkhize

Keyword(s):

Chlorophyll Fluorescence ◽

Quantum Yield ◽

Light Energy ◽

Photochemical Quenching ◽

Photosynthetic Organisms ◽

Light Levels ◽

Lower Light ◽

Optimal Productivity ◽

Sun And Shade ◽

Non Photochemical Quenching

AbstractNon-photochemical quenching (NPQ) plays an important role in protecting photosynthetic organisms from photoinhibition by dissipating excess light energy as heat. However, excess NPQ can greatly reduce the quantum yield of photosynthesis at lower light levels. Recently, there has been considerable interest in understanding how plants balance NPQ to ensure optimal productivity in environments in which light levels are rapidly changing. In the present study, chlorophyll fluorescence was used to study the induction and relaxation of non-photochemical quenching (NPQ) in the dark and the induction of photosynthesis in ten species of lichens, five sampled from exposed and five sampled from shaded habitats. Here we show that the main difference between sun and shade lichens is the rate at which NPQ relaxes in the dark, rather than the speed that photosynthesis starts upon illumination. During the first two minutes in the dark, NPQ values in the five sun species declined only by an average of 2%, while by contrast, in shade species the average decline was 40%. For lichens growing in microhabitats where light levels are rapidly changing, rapid relaxation of NPQ may enable their photobionts to use the available light most efficiently.

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