The role of photochemical quenching and antioxidants in photoprotection of Deschampsia antarctica

2004 ◽  
Vol 31 (7) ◽  
pp. 731 ◽  
Author(s):  
Eduardo Pérez-Torres ◽  
Andrea García ◽  
Jorge Dinamarca ◽  
Miren Alberdi ◽  
Ana Gutiérrez ◽  
...  
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Active Oxygen Species ◽  
Photochemical Efficiency ◽  
High Light ◽  
Photochemical Quenching ◽  
Deschampsia Antarctica ◽  
Oxygen Species ◽  
Excitation Light ◽  
Photochemical Efficiency Of Psii

Deschampsia antarctica Desv. (Poaceae) is the only grass that grows in the maritime Antarctic. Constant low temperatures and episodes of high light are typical conditions during the growing season at this latitude. These factors enhance the formation of active oxygen species and may cause photoinhibition. Therefore, an efficient mechanism of energy dissipation and / or scavenging of reactive oxygen species (ROS) would contribute to survival in this harsh environment. In this paper, non-acclimated and cold-acclimated D. antarctica were subjected to high light and / or low temperature for 24 h. The contribution of non-photochemical dissipation of excitation light energy and the activities of detoxifying enzymes in the development of resistance to chilling induced photoinhibition were studied by monitoring PSII fluorescence, total soluble antioxidants, and pigments contents and measuring variations in activity of superoxide dismutase (SOD; EC 1.15.1.1), ascorbate peroxidase (APX; EC 1.11.1.11), and glutathione reductase (GR; EC 1.6.4.2). The photochemical efficiency of PSII, measured as Fv / F m, and the yield of PSII electron transport (ΦPSII) both decreased under high light and low temperatures. In contrast, photochemical quenching (qP) in both non-acclimated and cold-acclimated plants remained relatively constant (approximately 0.8) in high-light-treated plants. Unexpectedly, qP was lower (0.55) in cold-acclimated plants exposed to 4°C and low light intensity. Activity of SOD in cold-acclimated plants treated with high light at low temperature showed a sharp peak 2–4 h after the beginning of the experiment. In cold-acclimated plants APX remained high with all treatments. Activity of GR decreased in cold-acclimated plants. Compared with other plants, D. antarctica exhibited high levels of SOD and APX activity. Pigment analyses show that the xanthophyll cycle is operative in this plant. We propose that photochemical quenching and particularly the high level of antioxidants help D. antarctica to resist photoinhibitory conditions. The relatively high antioxidant capacity of D. antarctica may be a determinant for its survival in the harsh Antarctic environment.

scholarly journals Correction: Activity enhancement of Pt/MnOx catalyst by novel β-MnO2 for low-temperature CO oxidation: study of the CO–O2 competitive adsorption and active oxygen species

2020 ◽  
Vol 10 (20) ◽  
pp. 7067-7067
Author(s):  
Ningqiang Zhang ◽  
Lingcong Li ◽  
Rui Wu ◽  
Liyun Song ◽  
Lirong Zheng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Co Oxidation ◽  
Competitive Adsorption ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Oxidation Study ◽  
Low Temperature Co Oxidation ◽  
Activity Enhancement

Correction for ‘Activity enhancement of Pt/MnOx catalyst by novel β-MnO2 for low-temperature CO oxidation: study of the CO–O2 competitive adsorption and active oxygen species’ by Ningqiang Zhang et al., Catal. Sci. Technol., 2019, 9, 347–354, DOI: 10.1039/C8CY01879K.

Engineering the Nucleophilic Active Oxygen Species in CuTiOx for Efficient Low-Temperature Propene Combustion

2020 ◽  
Vol 54 (23) ◽  
pp. 15476-15488
Author(s):  
Yarong Fang ◽  
Li Li ◽  
Ji Yang ◽  
Son Hoang ◽  
Liming Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species

scholarly journals Ascorbate biosynthesis and function in photoprotection

2000 ◽  
Vol 355 (1402) ◽  
pp. 1455-1464 ◽  
Author(s):  
Nicholas Smirnoff
Keyword(s):  
Active Oxygen Species ◽  
Electron Flow ◽  
High Light Intensity ◽  
High Light ◽  
Pool Size ◽  
Ultraviolet B ◽  
Photochemical Quenching ◽  
Inner Mitochondrial Membrane ◽  
Oxidative Stresses ◽  
High Concentrations

Ascorbate (vitamin C) can reach very high concentrations in chloroplasts (20–300 mM).The pool size in leaves and chloroplasts increases during acclimation to high light intensity and the highest concentrations recorded are in high alpine plants. Multiple functions for ascorbate in photosynthesis have been proposed, including scavenging of active oxygen species generated by oxygen photoreduction and photorespiration, regeneration of α–tocopherol from α–tocopheryl radicals, cofactor for violaxanthin de–epoxidase and donation of electrons to photosystem II. Hydrogen peroxide scavenging is catalysed by ascorbate peroxidase (Mehler peroxidase reaction) and the subsequent regeneration of ascorbate by reductant derived from photosystem I allows electron flow in addition to that used for CO 2 assimilation. Ascorbate is synthesized from guanosine diphosphate–mannose via L–galactose and L–galactono–1,4–lactone. The last step, catalysed by L–galactono–1,4–lactone dehydrogenase, is located on the inner mitochondrial membrane and uses cytochrome c as electron acceptor. L–galactono–1,4–lactone oxidation to ascorbate by intact leaves is faster in high–light acclimated leaves and is also enhanced by high light, suggesting that this step contributes to the control of pool size by light. Ascorbate–deficient Arabidopsis thaliana vtc mutants are hypersensitive to a number of oxidative stresses including ozone and ultraviolet B radiation. Further investigation of these mutants shows that they have reduced zeaxanthin–dependent non–photochemical quenching, confirming that ascorbate is the cofactor for violaxanthin de–epoxidase and that availability of thylakoid lumen ascorbate could limit this reaction. The vtc mutants are also more sensitive to photooxidation imposed by combined high light and salt treatments.

scholarly journals Roles of OsSOQ1 in photoprotection and fatty acid metabolism of rice

2021 ◽  
Author(s):  
Zhen-Hui Kang ◽  
Yang Gou ◽  
Qi-Rui Deng ◽  
Zi-yu Hu ◽  
Guan-Rong Li
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Function Analysis ◽  
Photochemical Efficiency ◽  
High Light Intensity ◽  
High Light ◽  
Redox Activity ◽  
Photochemical Quenching

Abstract Presented here is the function analysis of a homolog of Arabidopsis SOQ1, OsSOQ1 in rice. Homozygous mutants (ossoq1) were obtained by CRISPR/Cas9 to knockout OsSOQ1. The mutants showed significant lower plant height, tiller number, panicle length, effective panicle, and grain number per panicle compared to the wild-type (WT). Western blot analysis showed that OsSOQ1 is a thylakoid membrane protein, with the thioredoxin-like (Trx-like) domain facing the lumen. Loss of OsSOQ1 did not significantly affect the protein level of photosystem II (PSII) subunits, but down-regulated the content of a non-photochemical quenching (NPQ) player PsbS, resulting in a low NPQ under high light intensity in the mutant. UPLC-MS/MS experiments showed that OsSOQ1 is involved in the fatty acid biosynthesis pathway of rice. The Trx-like domain possessed redox activity in vitro as shown by insulin assay; and in the yeast two-hybrid experiment, it was found that the Trx-like domain interacted with the chloroplast lipocalin OsLCNP, which usually binds lipid molecules. These findings revealed that the role of OsSOQ1 is to maintain the photochemical efficiency of PSII under high light intensity and regulate fatty acid metabolism in rice.

scholarly journals Effects of Smoke-water on Photosynthetic Characteristics of Isatis indigotica Seedlings

2012 ◽  
Vol 2 (2) ◽  
pp. 24 ◽  
Author(s):  
Jie Zhou ◽  
Lei Fang ◽  
Xiao Wang ◽  
Lanping Guo ◽  
Luqi Huang
Keyword(s):  
Water Treatment ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Photochemical Efficiency ◽  
Photosynthetic Characteristics ◽  
Photochemical Quenching ◽  
Isatis Indigotica ◽  
Photochemical Efficiency Of Psii ◽  
Non Photochemical Quenching ◽  
Smoke Water

<p>Smoke-water (SW) had been reported to improve the growth of <em>Isatis indigotica</em>, a Chinese medicinal plant. However, there were very few reports on the mechanism of smoke-water improving plant growth. In this study the effects of smoke-water on the photosynthetic characteristics of <em>I.</em><em> indigotica</em> seedlings were investigated for the purpose of understanding the mechanism behind this improved plant growth. The results showed that net photosynthetic rate (<em>P<sub>n</sub></em>) was increased by smoke-water, reaching a maximum on 15, 5 and 15 d after treatment with smoke-water at dilutions of 1:500, 1:1000 and 1:2000 respectively. Transpiration rate (<em>T<sub>r</sub></em>) and stomatal conductance (<em>G<sub>s</sub></em>) both showed similar trends to<sub> </sub><em>P<sub>n</sub></em>, however, intercellular CO<sub>2</sub> concentration<em> </em>(<em>C<sub>i</sub></em>) was decreased with smoke-water treatment. The F<sub>v</sub>/F<sub>m</sub> was not significantly influenced by smoke-water treatment. The ?PSII was markedly promoted with the application of smoke-water (1:1000) compared with the control and the coefficient of photochemical quenching (qP) showed a similar trend to ?PSII. However the coefficient of non-photochemical quenching of chlorophyll (NPQ) was decreased with treatment of smoke-water. These findings indicate that smoke-water treatment induce an increase in photosynthesis and suggest the main factors leading to this might be the improved stomatal conductance and the enhanced level of the photochemical efficiency of PSII in leaves.</p>

scholarly journals The non-photochemical quenching protein LHCSR3 prevents oxygen-dependent photoinhibition in Chlamydomonas reinhardtii

2020 ◽  
Vol 71 (9) ◽  
pp. 2650-2660 ◽  
Author(s):  
Thomas Roach ◽  
Chae Sun Na ◽  
Wolfgang Stöggl ◽  
Anja Krieger-Liszkay
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Colony Growth ◽  
High Light ◽  
Photochemical Quenching ◽  
Oxygen Species ◽  
Wild Type ◽  
Psii Activity ◽  
High O2 ◽  
Non Photochemical Quenching ◽  
Repair Cycle

Abstract Non-photochemical quenching (NPQ) helps dissipate surplus light energy, preventing formation of reactive oxygen species (ROS). In Chlamydomonas reinhardtii, the thylakoid membrane protein LHCSR3 is involved in pH-dependent (qE-type) NPQ, lacking in the npq4 mutant. Preventing PSII repair revealed that npq4 lost PSII activity faster than the wild type (WT) in elevated O2, while no difference between strains was observed in O2-depleted conditions. Low Fv/Fm values remained 1.5 h after moving cells out of high light, and this qH-type quenching was independent of LHCSR3 and not accompanied by losses of maximum PSII activity. Culturing cells in historic O2 atmospheres (30–35%) increased the qE of cells, due to increased LHCSR1 and PsbS levels, and LHCSR3 in the WT, showing that atmospheric O2 tensions regulate qE capacity. Colony growth of npq4 was severely restricted at elevated O2, and npq4 accumulated more reactive electrophile species (RES) than the WT, which could damage PSI. Levels of PsaA (PSI) were lower in npq4 grown at 35% O2, while PsbA (PSII) levels remained stable. We conclude that even at high O2 concentrations, the PSII repair cycle is sufficient to maintain net levels of PSII. However, LHCSR3 has an important function in protecting PSI against O2-mediated damage, such as via RES.

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

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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