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Davis GA, Rutherford AW, Kramer DM. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δ ψ and ΔpH. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0381. [PMID: 28808100 DOI: 10.1098/rstb.2016.0381] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching (qE), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δψ) induce photosystem II recombination reactions that produce damaging singlet oxygen (1O2). Both qE and FRIP are directly linked to the thylakoid proton motive force (pmf), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δψ and formation of ΔpH. This would result in increased rates for the formation and decay of qE while resulting in a more rapid decline in the amplitudes of Δψ-spikes and decreasing 1O2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo, while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis researchers to further explore and test specific hypotheses.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | | | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA .,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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152
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Niewiadomska E, Brückner K, Mulisch M, Kruk J, Orzechowska A, Pilarska M, Luchowski R, Gruszecki WI, Krupinska K. Lack of tocopherols influences the PSII antenna and the functioning of photosystems under low light. JOURNAL OF PLANT PHYSIOLOGY 2018; 223:57-64. [PMID: 29499454 DOI: 10.1016/j.jplph.2018.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 02/02/2018] [Accepted: 02/04/2018] [Indexed: 06/08/2023]
Abstract
As tocopherols are expected to protect PSII against toxic singlet oxygen it is surprising that the null tocopherol mutant vte1 has been reported to show only a weak enhancement of photosystem II photoinhibition under high irradiance. Based on the view that singlet oxygen is formed also in unstressed conditions, such as low light (LL), we hypothesized that some defense strategies are activated in vte1 in these light conditions. In support for that we noted several symptoms of stress at PSII in the mutant under LL, by means of parameters of fast and slow kinetics of chlorophyll fluorescence and of changes in the relative contribution of PSII antenna in comparison to those of PSI. This was associated with a lower extent of phosphorylation of PSII core proteins (D1 and CP43). PSII RCs do not totally recover from stress in vte1 even after the nocturnal phase. As a clear compensation for the impeded performance of PSII in the vte1 we noted an increased quantum efficiency of PSI. A pronounced changes between WT and the vte1 mutant were also related to conformation of LHCII at the beginning of photoperiod, suggesting the absence of LHCII trimers in the mutant. The thylakoids thickness was similar in WT and vte1 under LL, but a pronounced unstacking of thylakoids was evoked by HL only in vte1. In conclusion, we postulate that action of 1O2 on PSII in vte1 leads to some permanent damage at PSII core and at LHCII already under LL.
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Affiliation(s)
- Ewa Niewiadomska
- The F. Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland
| | - Kathleen Brückner
- Leibniz Institute of Plant Biochemistry, Department of Cell and Metabolic Biology, Weinberg 3, 06120 Halle, Germany.
| | - Maria Mulisch
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr, 40, 24098 Kiel, Germany.
| | - Jerzy Kruk
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland.
| | - Aleksandra Orzechowska
- Department of Medical Physics and Biophysics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Reymonta 19, 30-059 Krakow, Poland.
| | - Maria Pilarska
- The F. Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Rafał Luchowski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
| | - Wiesław I Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr, 40, 24098 Kiel, Germany.
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153
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Inhibition of Cyanobacterial Growth on a Municipal Wastewater Sidestream Is Impacted by Temperature. mSphere 2018; 3:mSphere00538-17. [PMID: 29507895 PMCID: PMC5830474 DOI: 10.1128/msphere.00538-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/07/2018] [Indexed: 01/21/2023] Open
Abstract
Cyanobacteria are viewed as promising platforms to produce fuels and/or high-value chemicals as part of so-called “biorefineries.” Their integration into wastewater treatment systems is particularly interesting because removal of the nitrogen and phosphorus in many wastewater streams is an expensive but necessary part of wastewater treatment. In this study, we evaluated strategies for cultivating Synechococcus sp. strain PCC 7002 on media comprised of two wastewater streams, i.e., treated secondary effluent supplemented with the liquid fraction extracted from sludge following anaerobic digestion. This strain is commonly used for metabolic engineering to produce a variety of valuable chemical products and product precursors (e.g., lactate). However, initial attempts to grow PCC 7002 under otherwise-standard conditions of light and temperature failed. We thus systematically evaluated alternative cultivation conditions and then used multiple methods to dissect the apparent toxicity of the media under standard cultivation conditions. Sidestreams in wastewater treatment plants can serve as concentrated sources of nutrients (i.e., nitrogen and phosphorus) to support the growth of photosynthetic organisms that ultimately serve as feedstock for production of fuels and chemicals. However, other chemical characteristics of these streams may inhibit growth in unanticipated ways. Here, we evaluated the use of liquid recovered from municipal anaerobic digesters via gravity belt filtration as a nutrient source for growing the cyanobacterium Synechococcus sp. strain PCC 7002. The gravity belt filtrate (GBF) contained high levels of complex dissolved organic matter (DOM), which seemed to negatively influence cells. We investigated the impact of GBF on physiological parameters such as growth rate, membrane integrity, membrane composition, photosystem composition, and oxygen evolution from photosystem II. At 37°C, we observed an inverse correlation between GBF concentration and membrane integrity. Radical production was also detected upon exposure to GBF at 37°C. However, the dose-dependent relationship between the GBF concentration and the lack of membrane integrity was abolished at 27°C. Immediate resuspension of strains in high levels of GBF showed markedly reduced oxygen evolution rates relative to those seen with the control. Taken together, the data indicate that one mechanism responsible for GBF toxicity to Synechococcus is the interruption of photosynthetic electron flow and subsequent phenomena. We hypothesize that this is likely due to the presence of phenolic compounds within the DOM. IMPORTANCE Cyanobacteria are viewed as promising platforms to produce fuels and/or high-value chemicals as part of so-called “biorefineries.” Their integration into wastewater treatment systems is particularly interesting because removal of the nitrogen and phosphorus in many wastewater streams is an expensive but necessary part of wastewater treatment. In this study, we evaluated strategies for cultivating Synechococcus sp. strain PCC 7002 on media comprised of two wastewater streams, i.e., treated secondary effluent supplemented with the liquid fraction extracted from sludge following anaerobic digestion. This strain is commonly used for metabolic engineering to produce a variety of valuable chemical products and product precursors (e.g., lactate). However, initial attempts to grow PCC 7002 under otherwise-standard conditions of light and temperature failed. We thus systematically evaluated alternative cultivation conditions and then used multiple methods to dissect the apparent toxicity of the media under standard cultivation conditions.
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154
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Murata N, Nishiyama Y. ATP is a driving force in the repair of photosystem II during photoinhibition. PLANT, CELL & ENVIRONMENT 2018; 41:285-299. [PMID: 29210214 DOI: 10.1111/pce.13108] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 05/15/2023]
Abstract
Repair of photosystem II (PSII) during photoinhibition involves replacement of photodamaged D1 protein by newly synthesized D1 protein. In this review, we summarize evidence for the indispensability of ATP in the degradation and synthesis of D1 during the repair of PSII. Synthesis of one molecule of the D1 protein consumes more than 1,300 molecules of ATP equivalents. The degradation of photodamaged D1 by FtsH protease also consumes approximately 240 molecules of ATP. In addition, ATP is required for several other aspects of the repair of PSII, such as transcription of psbA genes. These requirements for ATP during the repair of PSII have been demonstrated by experiments showing that the synthesis of D1 and the repair of PSII are interrupted by inhibitors of ATP synthase and uncouplers of ATP synthesis, as well as by mutation of components of ATP synthase. We discuss the contribution of cyclic electron transport around photosystem I to the repair of PSII. Furthermore, we introduce new terms relevant to the regulation of the PSII repair, namely, "ATP-dependent regulation" and "redox-dependent regulation," and we discuss the possible contribution of the ATP-dependent regulation of PSII repair under environmental stress.
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Affiliation(s)
- Norio Murata
- National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
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155
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Fritsche S, Wang X, Jung C. Recent Advances in our Understanding of Tocopherol Biosynthesis in Plants: An Overview of Key Genes, Functions, and Breeding of Vitamin E Improved Crops. Antioxidants (Basel) 2017; 6:E99. [PMID: 29194404 PMCID: PMC5745509 DOI: 10.3390/antiox6040099] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 12/17/2022] Open
Abstract
Tocopherols, together with tocotrienols and plastochromanols belong to a group of lipophilic compounds also called tocochromanols or vitamin E. Considered to be one of the most powerful antioxidants, tocochromanols are solely synthesized by photosynthetic organisms including plants, algae, and cyanobacteria and, therefore, are an essential component in the human diet. Tocochromanols potent antioxidative properties are due to their ability to interact with polyunsaturated acyl groups and scavenge lipid peroxyl radicals and quench reactive oxygen species (ROS), thus protecting fatty acids from lipid peroxidation. In the plant model species Arabidopsis thaliana, the required genes for tocopherol biosynthesis and functional roles of tocopherols were elucidated in mutant and transgenic plants. Recent research efforts have led to new outcomes for the vitamin E biosynthetic and related pathways, and new possible alternatives for the biofortification of important crops have been suggested. Here, we review 30 years of research on tocopherols in model and crop species, with emphasis on the improvement of vitamin E content using transgenic approaches and classical breeding. We will discuss future prospects to further improve the nutritional value of our food.
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Affiliation(s)
- Steffi Fritsche
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany.
| | - Xingxing Wang
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany.
- Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang 455000, China.
| | - Christian Jung
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany.
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156
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Discovery of carotenoid red-shift in endolithic cyanobacteria from the Atacama Desert. Sci Rep 2017; 7:11116. [PMID: 28894222 PMCID: PMC5593868 DOI: 10.1038/s41598-017-11581-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 08/22/2017] [Indexed: 11/18/2022] Open
Abstract
The biochemical responses of rock-inhabiting cyanobacteria towards native environmental stresses were observed in vivo in one of the Earth’s most challenging extreme climatic environments. The cryptoendolithic cyanobacterial colonization, dominated by Chroococcidiopsis sp., was studied in an ignimbrite at a high altitude volcanic area in the Atacama Desert, Chile. Change in the carotenoid composition (red-shift) within a transect through the cyanobacteria dominant microbial community (average thickness ~1 mm) was unambiguously revealed in their natural endolithic microhabitat. The amount of red shifted carotenoid, observed for the first time in a natural microbial ecosystem, is depth dependent, and increased with increasing proximity to the rock surface, as proven by resonance Raman imaging and point resonance Raman profiling. It is attributed to a light-dependent change in carotenoid conjugation, associated with the light-adaptation strategy of cyanobacteria. A hypothesis is proposed for the possible role of an orange carotenoid protein (OCP) mediated non-photochemical quenching (NPQ) mechanism that influences the observed spectral behavior. Simultaneously, information about the distribution of scytonemin and phycobiliproteins was obtained. Scytonemin was detected in the uppermost cyanobacteria aggregates. A reverse signal intensity gradient of phycobiliproteins was registered, increasing with deeper positions as a response of the cyanobacterial light harvesting complex to low-light conditions.
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157
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Rozentsvet O, Kosobryukhov A, Zakhozhiy I, Tabalenkova G, Nesterov V, Bogdanova E. Photosynthetic parameters and redox homeostasis of Artemisia santonica L. under conditions of Elton region. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 118:385-393. [PMID: 28710946 DOI: 10.1016/j.plaphy.2017.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Structural and functional parameters and redox homeostasis in leaves of Artemisia santonica L. under environment conditions of Elton lake (the southeast region of the European part of Russia) were measured. The highest photosynthetic apparatus (PA) activity in A. santonica leaves on CO2 gas exchange as well as the highest content of green pigments was observed in the morning. Maximum share of violaxanthin cycle key pigments - zeaxanthin (Zx) and antheraxanthin (Ax) was observed in the afternoon and decreased in the evening. Lipids/chlorophyll (Chl) ratio increased in the evening due to the decrease in Chl concentration, and content of linolenic acid (С18:3n3) was decreased in the middle of the day. The content of TBA-reacting products increased 1.4-fold in the middle of the day, and decreased approximately 2-fold in the evening. The decrease of the activity was observed in diurnal dynamics of superoxide dismutase (SOD) and polyphenol oxidase (PPO). Increased accumulation of phenols and flavonoids, as well as free amino acids (FAA) in A. santonica leaves was observed in the middle of the day. Thus, the ability of A. santonica plants to resist the soil salinization, high levels of solar illumination and temperature consists of a number of protectively-adaptive reactions of metabolic and photosynthetic control.
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Affiliation(s)
- Olga Rozentsvet
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia.
| | - Anatoly Kosobryukhov
- Institute of Basic Biological Problems, Russian Academy of Sciences, 2 Institutskaya St., 142290 Pushchino, Moscow region, Russia
| | - Ilya Zakhozhiy
- Institute of Biology of the Komi Science Centre of the Ural Division, Russian Academy of Sciences, 8 Kommunisticheskaya St., 167982 Syktyvkar, Komi Republic, Russia
| | - Galina Tabalenkova
- Institute of Biology of the Komi Science Centre of the Ural Division, Russian Academy of Sciences, 8 Kommunisticheskaya St., 167982 Syktyvkar, Komi Republic, Russia
| | - Viktor Nesterov
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia
| | - Elena Bogdanova
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia
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158
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Cantrell M, Peers G. A mutant of Chlamydomonas without LHCSR maintains high rates of photosynthesis, but has reduced cell division rates in sinusoidal light conditions. PLoS One 2017. [PMID: 28644828 PMCID: PMC5482440 DOI: 10.1371/journal.pone.0179395] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment. We found that a mutant of Chlamydomonas reinhardtii lacking LHCSR, npq4lhcsr1, displays minimal photoinhibition of photosystem II and minimal inhibition of short term oxygen evolution when grown in constant excess light compared to a wild type strain. We also investigated the impact of no LHCSR during growth in a sinusoidal light regime, which mimics daily changes in photosynthetically active radiation. The absence of LHCSR correlated with a slight reduction in the quantum efficiency of photosystem II and a stimulation of the maximal rates of photosynthesis compared to wild type. However, there was no reduction in carbon accumulation during the day. Another novel finding was that npq4lhcsr1 cultures underwent fewer divisions at night, reducing the overall growth rate compared to the wild type. Our results show that the rapid regulation of light harvesting mediated by LHCSR is required for high growth rates, but it is not required for efficient carbon accumulation during the day in a sinusoidal light environment. This finding has direct implications for engineering strategies directed at increasing photosynthetic productivity in mass cultures.
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Affiliation(s)
- Michael Cantrell
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
- * E-mail:
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159
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Gu J, Zhou Z, Li Z, Chen Y, Wang Z, Zhang H, Yang J. Photosynthetic Properties and Potentials for Improvement of Photosynthesis in Pale Green Leaf Rice under High Light Conditions. FRONTIERS IN PLANT SCIENCE 2017; 8:1082. [PMID: 28676818 PMCID: PMC5476740 DOI: 10.3389/fpls.2017.01082] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 06/06/2017] [Indexed: 05/24/2023]
Abstract
Light is the driving force of plant growth, providing the energy required for photosynthesis. However, photosynthesis is also vulnerable to light-induced damage caused by the production of reactive oxygen species (ROS). Plants have therefore evolved various protective mechanisms such as non-photochemical quenching (NPQ) to dissipate excessively absorbed solar energy as heat; however, photoinhibition and NPQ represent a significant loss in solar energy and photosynthetic efficiency, which lowers the yield potential in crops. To estimate light capture and light energy conversion in rice, a genotype with pale green leaves (pgl) and a normally pigmented control (Z802) were subjected to high (HL) and low light (LL). Chlorophyll content, light absorption, chloroplast micrographs, abundance of light-harvesting complex (LHC) binding proteins, electron transport rates (ETR), photochemical and non-photochemical quenching, and generation of ROS were subsequently examined. Pgl had a smaller size of light-harvesting chlorophyll antenna and absorbed less photons than Z802. NPQ and the generation of ROS were also low, while photosystem II efficiency and ETR were high, resulting in improved photosynthesis and less photoinhibition in pgl than Z802. Chlorophyll synthesis and solar conversion efficiency were higher in pgl under HL compared to LL treatment, while Z802 showed an opposite trend due to the high level of photoinhibition under HL. In Z802, excessive absorption of solar energy not only increased the generation of ROS and NPQ, but also exacerbated the effects of increases in temperature, causing midday depression in photosynthesis. These results suggest that photosynthesis and yield potential in rice could be enhanced by truncated light-harvesting chlorophyll antenna size.
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Affiliation(s)
- Junfei Gu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Zhenxiang Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Zhikang Li
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Ying Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Zhiqin Wang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Hao Zhang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
| | - Jianchang Yang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou UniversityYangzhou, China
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Moejes FW, Matuszynska A, Adhikari K, Bassi R, Cariti F, Cogne G, Dikaios I, Falciatore A, Finazzi G, Flori S, Goldschmidt-Clermont M, Magni S, Maguire J, Le Monnier A, Müller K, Poolman M, Singh D, Spelberg S, Stella GR, Succurro A, Taddei L, Urbain B, Villanova V, Zabke C, Ebenhöh O. A systems-wide understanding of photosynthetic acclimation in algae and higher plants. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2667-2681. [PMID: 28830099 DOI: 10.1093/jxb/erx137] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/28/2017] [Indexed: 05/27/2023]
Abstract
The ability of phototrophs to colonise different environments relies on robust protection against oxidative stress, a critical requirement for the successful evolutionary transition from water to land. Photosynthetic organisms have developed numerous strategies to adapt their photosynthetic apparatus to changing light conditions in order to optimise their photosynthetic yield, which is crucial for life on Earth to exist. Photosynthetic acclimation is an excellent example of the complexity of biological systems, where highly diverse processes, ranging from electron excitation over protein protonation to enzymatic processes coupling ion gradients with biosynthetic activity, interact on drastically different timescales from picoseconds to hours. Efficient functioning of the photosynthetic apparatus and its protection is paramount for efficient downstream processes, including metabolism and growth. Modern experimental techniques can be successfully integrated with theoretical and mathematical models to promote our understanding of underlying mechanisms and principles. This review aims to provide a retrospective analysis of multidisciplinary photosynthetic acclimation research carried out by members of the Marie Curie Initial Training Project, AccliPhot, placing the results in a wider context. The review also highlights the applicability of photosynthetic organisms for industry, particularly with regards to the cultivation of microalgae. It intends to demonstrate how theoretical concepts can successfully complement experimental studies broadening our knowledge of common principles in acclimation processes in photosynthetic organisms, as well as in the field of applied microalgal biotechnology.
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Affiliation(s)
- Fiona Wanjiku Moejes
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Anna Matuszynska
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Kailash Adhikari
- Department of Biological and Medical Sciences, Oxford Brookes University, United Kingdom
| | - Roberto Bassi
- University of Verona, Department of Biotechnology, Italy
| | - Federica Cariti
- Department of Botany and Plant Biology, University of Geneva, Switzerland
| | | | | | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologie de Grenoble (BIG), Université Grenoble Alpes (UGA), Grenoble 38100, France
| | - Serena Flori
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologie de Grenoble (BIG), Université Grenoble Alpes (UGA), Grenoble 38100, France
| | | | - Stefano Magni
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Julie Maguire
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | | | - Kathrin Müller
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Mark Poolman
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Dipali Singh
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Stephanie Spelberg
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Giulio Rocco Stella
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Antonella Succurro
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Lucilla Taddei
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Brieuc Urbain
- LUNAM, University of Nantes, GEPEA, UMR-CNRS 6144, France
| | | | | | - Oliver Ebenhöh
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
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Kalaji HM, Schansker G, Brestic M, Bussotti F, Calatayud A, Ferroni L, Goltsev V, Guidi L, Jajoo A, Li P, Losciale P, Mishra VK, Misra AN, Nebauer SG, Pancaldi S, Penella C, Pollastrini M, Suresh K, Tambussi E, Yanniccari M, Zivcak M, Cetner MD, Samborska IA, Stirbet A, Olsovska K, Kunderlikova K, Shelonzek H, Rusinowski S, Bąba W. Frequently asked questions about chlorophyll fluorescence, the sequel. PHOTOSYNTHESIS RESEARCH 2017; 132:13-66. [PMID: 27815801 PMCID: PMC5357263 DOI: 10.1007/s11120-016-0318-y] [Citation(s) in RCA: 221] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/17/2016] [Indexed: 05/20/2023]
Abstract
Using chlorophyll (Chl) a fluorescence many aspects of the photosynthetic apparatus can be studied, both in vitro and, noninvasively, in vivo. Complementary techniques can help to interpret changes in the Chl a fluorescence kinetics. Kalaji et al. (Photosynth Res 122:121-158, 2014a) addressed several questions about instruments, methods and applications based on Chl a fluorescence. Here, additional Chl a fluorescence-related topics are discussed again in a question and answer format. Examples are the effect of connectivity on photochemical quenching, the correction of F V /F M values for PSI fluorescence, the energy partitioning concept, the interpretation of the complementary area, probing the donor side of PSII, the assignment of bands of 77 K fluorescence emission spectra to fluorescence emitters, the relationship between prompt and delayed fluorescence, potential problems when sampling tree canopies, the use of fluorescence parameters in QTL studies, the use of Chl a fluorescence in biosensor applications and the application of neural network approaches for the analysis of fluorescence measurements. The answers draw on knowledge from different Chl a fluorescence analysis domains, yielding in several cases new insights.
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Affiliation(s)
- Hazem M. Kalaji
- Department of Plant Physiology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland
| | | | - Marian Brestic
- Department of Plant Physiology, Slovak Agricultural University, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
| | - Filippo Bussotti
- Department of Agricultural, Food and Environmental Sciences, University of Florence, Piazzale delle Cascine 28, 50144 Florence, Italy
| | - Angeles Calatayud
- Departamento de Horticultura, Instituto Valenciano de Investigaciones Agrarias, Ctra. Moncada-Náquera Km 4.5., 46113 Moncada, Valencia Spain
| | - Lorenzo Ferroni
- Department of Life Sciences and Biotechnology, University of Ferrara, Corso Ercole I d’Este, 32, 44121 Ferrara, Italy
| | - Vasilij Goltsev
- Department of Biophysics and Radiobiology, Faculty of Biology, St. Kliment Ohridski University of Sofia, 8 Dr.Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Lucia Guidi
- Department of Agriculture, Food and Environment, Via del Borghetto, 80, 56124 Pisa, Italy
| | - Anjana Jajoo
- School of Life Sciences, Devi Ahilya University, Indore, M.P. 452 001 India
| | - Pengmin Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Pasquale Losciale
- Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria [Research Unit for Agriculture in Dry Environments], 70125 Bari, Italy
| | - Vinod K. Mishra
- Department of Biotechnology, Doon (P.G.) College of Agriculture Science, Dehradun, Uttarakhand 248001 India
| | - Amarendra N. Misra
- Centre for Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Ranchi, 835205 India
| | - Sergio G. Nebauer
- Departamento de Producción vegetal, Universitat Politècnica de València, Camino de Vera sn., 46022 Valencia, Spain
| | - Simonetta Pancaldi
- Department of Life Sciences and Biotechnology, University of Ferrara, Corso Ercole I d’Este, 32, 44121 Ferrara, Italy
| | - Consuelo Penella
- Departamento de Horticultura, Instituto Valenciano de Investigaciones Agrarias, Ctra. Moncada-Náquera Km 4.5., 46113 Moncada, Valencia Spain
| | - Martina Pollastrini
- Department of Agricultural, Food and Environmental Sciences, University of Florence, Piazzale delle Cascine 28, 50144 Florence, Italy
| | - Kancherla Suresh
- ICAR – Indian Institute of Oil Palm Research, Pedavegi, West Godavari Dt., Andhra Pradesh 534 450 India
| | - Eduardo Tambussi
- Institute of Plant Physiology, INFIVE (Universidad Nacional de La Plata — Consejo Nacional de Investigaciones Científicas y Técnicas), Diagonal 113 N°495, CC 327, La Plata, Argentina
| | - Marcos Yanniccari
- Institute of Plant Physiology, INFIVE (Universidad Nacional de La Plata — Consejo Nacional de Investigaciones Científicas y Técnicas), Diagonal 113 N°495, CC 327, La Plata, Argentina
| | - Marek Zivcak
- Department of Plant Physiology, Slovak Agricultural University, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
| | - Magdalena D. Cetner
- Department of Plant Physiology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Izabela A. Samborska
- Department of Plant Physiology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland
| | | | - Katarina Olsovska
- Department of Plant Physiology, Slovak University of Agriculture, A. Hlinku 2, 94976 Nitra, Slovak Republic
| | - Kristyna Kunderlikova
- Department of Plant Physiology, Slovak University of Agriculture, A. Hlinku 2, 94976 Nitra, Slovak Republic
| | - Henry Shelonzek
- Department of Plant Anatomy and Cytology, Faculty of Biology and Environmental Protection, University of Silesia, ul. Jagiellońska 28, 40-032 Katowice, Poland
| | - Szymon Rusinowski
- Institute for Ecology of Industrial Areas, Kossutha 6, 40-844 Katowice, Poland
| | - Wojciech Bąba
- Department of Plant Ecology, Institute of Botany, Jagiellonian University, Lubicz 46, 31-512 Kraków, Poland
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162
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Arabidopsis thaliana dehydroascorbate reductase 2: Conformational flexibility during catalysis. Sci Rep 2017; 7:42494. [PMID: 28195196 PMCID: PMC5307357 DOI: 10.1038/srep42494] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/11/2017] [Indexed: 02/05/2023] Open
Abstract
Dehydroascorbate reductase (DHAR) catalyzes the glutathione (GSH)-dependent reduction of dehydroascorbate and plays a direct role in regenerating ascorbic acid, an essential plant antioxidant vital for defense against oxidative stress. DHAR enzymes bear close structural homology to the glutathione transferase (GST) superfamily of enzymes and contain the same active site motif, but most GSTs do not exhibit DHAR activity. The presence of a cysteine at the active site is essential for the catalytic functioning of DHAR, as mutation of this cysteine abolishes the activity. Here we present the crystal structure of DHAR2 from Arabidopsis thaliana with GSH bound to the catalytic cysteine. This structure reveals localized conformational differences around the active site which distinguishes the GSH-bound DHAR2 structure from that of DHAR1. We also unraveled the enzymatic step in which DHAR releases oxidized glutathione (GSSG). To consolidate our structural and kinetic findings, we investigated potential conformational flexibility in DHAR2 by normal mode analysis and found that subdomain mobility could be linked to GSH binding or GSSG release.
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163
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Murphy CD, Roodvoets MS, Austen EJ, Dolan A, Barnett A, Campbell DA. Photoinactivation of Photosystem II in Prochlorococcus and Synechococcus. PLoS One 2017; 12:e0168991. [PMID: 28129341 PMCID: PMC5271679 DOI: 10.1371/journal.pone.0168991] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/10/2016] [Indexed: 01/15/2023] Open
Abstract
The marine picocyanobacteria Synechococcus and Prochlorococcus numerically dominate open ocean phytoplankton. Although evolutionarily related they are ecologically distinct, with different strategies to harvest, manage and exploit light. We grew representative strains of Synechococcus and Prochlorococcus and tracked their susceptibility to photoinactivation of Photosystem II under a range of light levels. As expected blue light provoked more rapid photoinactivation than did an equivalent level of red light. The previous growth light level altered the susceptibility of Synechococcus, but not Prochlorococcus, to this photoinactivation. We resolved a simple linear pattern when we expressed the yield of photoinactivation on the basis of photons delivered to Photosystem II photochemistry, plotted versus excitation pressure upon Photosystem II, the balance between excitation and downstream metabolism. A high excitation pressure increases the generation of reactive oxygen species, and thus increases the yield of photoinactivation of Photosystem II. Blue photons, however, retained a higher baseline photoinactivation across a wide range of excitation pressures. Our experiments thus uncovered the relative influences of the direct photoinactivation of Photosystem II by blue photons which dominates under low to moderate blue light, and photoinactivation as a side effect of reactive oxygen species which dominates under higher excitation pressure. Synechococcus enjoyed a positive metabolic return upon the repair or the synthesis of a Photosystem II, across the range of light levels we tested. In contrast Prochlorococcus only enjoyed a positive return upon synthesis of a Photosystem II up to 400 μmol photons m-2 s-1. These differential cost-benefits probably underlie the distinct photoacclimation strategies of the species.
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Affiliation(s)
- Cole D. Murphy
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Mitchell S. Roodvoets
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Emily J. Austen
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Allison Dolan
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Audrey Barnett
- Michigan Technological University, Houghton, Michigan, United States of America
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164
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Kirilovsky D, Kerfeld CA. Cyanobacterial photoprotection by the orange carotenoid protein. NATURE PLANTS 2016; 2:16180. [PMID: 27909300 DOI: 10.1038/nplants.2016.180] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/20/2016] [Indexed: 05/18/2023]
Abstract
In photosynthetic organisms, the production of dangerous oxygen species is stimulated under high irradiance. To cope with this stress, these organisms have evolved photoprotective mechanisms. One type of mechanism functions to decrease the energy arriving at the photochemical centres by increasing thermal dissipation at the level of antennae. In cyanobacteria, the trigger for this mechanism is the photoactivation of a soluble carotenoid protein, the orange carotenoid protein (OCP), which is a structurally and functionally modular protein. The inactive orange form (OCPo) is compact and globular, with the carotenoid spanning the effector and the regulatory domains. In the active red form (OCPr), the two domains are completely separated and the carotenoid has translocated entirely into the effector domain. The activated OCPr interacts with the phycobilisome (PBS), the cyanobacterial antenna, and induces excitation-energy quenching. A second protein, the fluorescence recovery protein (FRP), dislodges the active OCPr from the PBSs and accelerates its conversion to the inactive OCP.
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Affiliation(s)
- Diana Kirilovsky
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
- Institut de Biologie et Technologies de Saclay (iBiTec-S), Commissariat à l'Energie Atomique (CEA), 91191 Gif-sur-Yvette, France
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Berkeley Synthetic Biology Institute, Berkeley, California 94720, USA
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165
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Stamatakis K, Papageorgiou GC. Effects of exogenous β-carotene, a chemical scavenger of singlet oxygen, on the millisecond rise of chlorophyll a fluorescence of cyanobacterium Synechococcus sp. PCC 7942. PHOTOSYNTHESIS RESEARCH 2016; 130:317-324. [PMID: 27034066 DOI: 10.1007/s11120-016-0255-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/23/2016] [Indexed: 06/05/2023]
Abstract
Singlet-excited oxygen (1O 2* ) has been recognized as the most destructive member of the reactive oxygen species (ROS) which are formed during oxygenic photosynthesis by plants, algae, and cyanobacteria. ROS and 1O 2* are known to damage protein and phospholipid structures and to impair photosynthetic electron transport and de novo protein synthesis. Partial protection is afforded to photosynthetic organism by the β-carotene (β-Car) molecules which accompany chlorophyll (Chl) a in the pigment-protein complexes of Photosystem II (PS II). In this paper, we studied the effects of exogenously added β-Car on the initial kinetic rise of Chl a fluorescence (10-1000 μs, the OJ segment) from the unicellular cyanobacterium Synechococcus sp. PCC7942. We show that the added β-Car enhances Chl a fluorescence when it is excited at an intensity of 3000 μmol photons m-2 s-1 but not when excited at 1000 μmol photons m-2 s-1. Since β-Car is an efficient scavenger of 1O 2* , as well as a quencher of 3Chl a * (precursor of 1O 2* ), both of which are more abundant at higher excitations, we assume that the higher Chl a fluorescence in its presence signifies a protective effect against photo-oxidative damages of Chl proteins. The protective effect of added β-Car is not observed in O2-depleted cell suspensions. Lastly, in contrast to β-Car, a water-insoluble molecule, a water-soluble scavenger of 1O 2* , histidine, provides no protection to Chl proteins during the same time period (10-1000 μs).
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, National Center of Scientific Research "Demokritos", 15310, Athens, Greece
| | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center of Scientific Research "Demokritos", 15310, Athens, Greece.
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166
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Kato Y, Ishii R, Noguchi T. Comparative Analysis of the Interaction of the Primary Quinone QA in Intact and Mn-Depleted Photosystem II Membranes Using Light-Induced ATR-FTIR Spectroscopy. Biochemistry 2016; 55:6355-6358. [DOI: 10.1021/acs.biochem.6b01052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuki Kato
- Division of Material
Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Rina Ishii
- Division of Material
Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material
Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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167
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016. [PMID: 27697149 DOI: 10.7554/elife.16921.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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168
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Davis GA, Kanazawa A, Schöttler MA, Kohzuma K, Froehlich JE, Rutherford AW, Satoh-Cruz M, Minhas D, Tietz S, Dhingra A, Kramer DM. Limitations to photosynthesis by proton motive force-induced photosystem II photodamage. eLife 2016; 5. [PMID: 27697149 PMCID: PMC5050024 DOI: 10.7554/elife.16921] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/08/2016] [Indexed: 12/20/2022] Open
Abstract
The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field. DOI:http://dx.doi.org/10.7554/eLife.16921.001
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Graduate Program of Cell and Molecular Biology, Michigan State University, East Lansing, United States
| | - Atsuko Kanazawa
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Chemistry, Michigan State University, East Lansing, United States
| | | | - Kaori Kohzuma
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - John E Froehlich
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | | | - Mio Satoh-Cruz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Deepika Minhas
- Department of Horticulture, Washington State University, Pullman, United States
| | - Stefanie Tietz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Amit Dhingra
- Department of Horticulture, Washington State University, Pullman, United States
| | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, United States
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169
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Rehman AU, Szabó M, Deák Z, Sass L, Larkum A, Ralph P, Vass I. Symbiodinium sp. cells produce light-induced intra- and extracellular singlet oxygen, which mediates photodamage of the photosynthetic apparatus and has the potential to interact with the animal host in coral symbiosis. THE NEW PHYTOLOGIST 2016; 212:472-484. [PMID: 27321415 DOI: 10.1111/nph.14056] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/08/2016] [Indexed: 06/06/2023]
Abstract
Coral bleaching is an important environmental phenomenon, whose mechanism has not yet been clarified. The involvement of reactive oxygen species (ROS) has been implicated, but direct evidence of what species are involved, their location and their mechanisms of production remains unknown. Histidine-mediated chemical trapping and singlet oxygen sensor green (SOSG) were used to detect intra- and extracellular singlet oxygen ((1) O2 ) in Symbiodinium cultures. Inhibition of the Calvin-Benson cycle by thermal stress or high light promotes intracellular (1) O2 formation. Histidine addition, which decreases the amount of intracellular (1) O2 , provides partial protection against photosystem II photoinactivation and chlorophyll (Chl) bleaching. (1) O2 production also occurs in cell-free medium of Symbiodinium cultures, an effect that is enhanced under heat and light stress and can be attributed to the excretion of (1) O2 -sensitizing metabolites from the cells. Confocal microscopy imaging using SOSG showed most extracellular (1) O2 around the cell surface, but it is also produced across the medium distant from the cells. We demonstrate, for the first time, both intra- and extracellular (1) O2 production in Symbiodinium cultures. Intracellular (1) O2 is associated with photosystem II photodamage and pigment bleaching, whereas extracellular (1) O2 has the potential to mediate the breakdown of symbiotic interaction between zooxanthellae and their animal host during coral bleaching.
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Affiliation(s)
- Ateeq Ur Rehman
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, PO Box 521, H-6701, Szeged, Hungary
| | - Milán Szabó
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
- Division of Plant Sciences, Research School of Biology, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia
| | - Zsuzsanna Deák
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, PO Box 521, H-6701, Szeged, Hungary
| | - László Sass
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, PO Box 521, H-6701, Szeged, Hungary
| | - Anthony Larkum
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Peter Ralph
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Imre Vass
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, PO Box 521, H-6701, Szeged, Hungary.
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170
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Carmody M, Waszczak C, Idänheimo N, Saarinen T, Kangasjärvi J. ROS signalling in a destabilised world: A molecular understanding of climate change. JOURNAL OF PLANT PHYSIOLOGY 2016; 203:69-83. [PMID: 27364884 DOI: 10.1016/j.jplph.2016.06.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 05/29/2023]
Abstract
Climate change results in increased intensity and frequency of extreme abiotic and biotic stress events. In plants, reactive oxygen species (ROS) accumulate in proportion to the level of stress and are major signalling and regulatory metabolites coordinating growth, defence, acclimation and cell death. Our knowledge of ROS homeostasis, sensing, and signalling is therefore key to understanding the impacts of climate change at the molecular level. Current research is uncovering new insights into temporal-spatial, cell-to-cell and systemic ROS signalling pathways, particularly how these affect plant growth, defence, and more recently acclimation mechanisms behind stress priming and long term stress memory. Understanding the stabilising and destabilising factors of ROS homeostasis and signalling in plants exposed to extreme and fluctuating stress will concomitantly reveal how to address future climate change challenges in global food security and biodiversity management.
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Affiliation(s)
- Melanie Carmody
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
| | - Cezary Waszczak
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
| | - Niina Idänheimo
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
| | - Timo Saarinen
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland.
| | - Jaakko Kangasjärvi
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland; Distinguished Scientist Fellowship Program, College of Science, King Saud University, Riyadh, Saudi Arabia.
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171
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Jallet D, Caballero MA, Gallina AA, Youngblood M, Peers G. Photosynthetic physiology and biomass partitioning in the model diatom Phaeodactylum tricornutum grown in a sinusoidal light regime. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.05.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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172
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Xu W, Lv H, Zhao M, Li Y, Qi Y, Peng Z, Xia G, Wang M. Proteomic comparison reveals the contribution of chloroplast to salt tolerance of a wheat introgression line. Sci Rep 2016; 6:32384. [PMID: 27562633 PMCID: PMC4999883 DOI: 10.1038/srep32384] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/08/2016] [Indexed: 12/15/2022] Open
Abstract
We previously bred a salt tolerant wheat cv. SR3 with bread wheat cv. JN177 as the parent via asymmetric somatic hybridization, and found that the tolerance is partially attributed to the superior photosynthesis capacity. Here, we compared the proteomes of two cultivars to unravel the basis of superior photosynthesis capacity. In the maps of two dimensional difference gel electrophoresis (2D-DIGE), there were 26 differentially expressed proteins (DEPs), including 18 cultivar-based and 8 stress-responsive ones. 21 of 26 DEPs were identified and classified into four categories, including photosynthesis, photosynthesis system stability, linolenic acid metabolism, and protein synthesis in chloroplast. The chloroplast localization of some DEPs confirmed that the identified DEPs function in the chloroplast. The overexpression of a DEP enhanced salt tolerance in Arabidopsis thaliana. In line with these data, it is concluded that the contribution of chloroplast to high salinity tolerance of wheat cv. SR3 appears to include higher photosynthesis efficiency by promoting system protection and ROS clearance, stronger production of phytohormone JA by enhancing metabolism activity, and modulating the in chloroplast synthesis of proteins.
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Affiliation(s)
- Wenjing Xu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Hongjun Lv
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Mingming Zhao
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Yongchao Li
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Yueying Qi
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Zhenying Peng
- Bio-Tech Research Center, Shandong Academy of Agricultural Science, Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crop, Jinan, 250100, China
| | - Guangmin Xia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
| | - Mengcheng Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100, China
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173
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Johnson GN, Stepien P. Plastid Terminal Oxidase as a Route to Improving Plant Stress Tolerance: Known Knowns and Known Unknowns. PLANT & CELL PHYSIOLOGY 2016; 57:1387-1396. [PMID: 26936791 DOI: 10.1093/pcp/pcw042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/21/2016] [Indexed: 05/24/2023]
Abstract
A plastid-localized terminal oxidase, PTox, was first described due to its role in chloroplast development, with plants lacking PTox producing white sectors on their leaves. This phenotype is explained as being due to PTox playing a role in carotenoid biosynthesis, as a cofactor of phytoene desaturase. Co-occurrence of PTox with a chloroplast-localized NADPH dehydrogenase (NDH) has suggested the possibility of a functional respiratory pathway in plastids. Evidence has also been found that, in certain stress-tolerant plant species, PTox can act as an electron acceptor from PSII, making it a candidate for engineering stress-tolerant crops. However, attempts to induce such a pathway via overexpression of the PTox protein have failed to date. Here we review the current understanding of PTox function in higher plants and discuss possible barriers to inducing PTox activity to improve stress tolerance.
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Affiliation(s)
- Giles N Johnson
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Piotr Stepien
- Department of Plant Nutrition, Wroclaw University of Environmental and Life Sciences, ul. Grunwaldzka 53, 50-357 Wroclaw, Poland
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174
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Raanan H, Oren N, Treves H, Keren N, Ohad I, Berkowicz SM, Hagemann M, Koch M, Shotland Y, Kaplan A. Towards clarifying what distinguishes cyanobacteria able to resurrect after desiccation from those that cannot: The photosynthetic aspect. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:715-22. [DOI: 10.1016/j.bbabio.2016.02.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/26/2016] [Accepted: 02/13/2016] [Indexed: 11/24/2022]
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175
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Mignolet-Spruyt L, Xu E, Idänheimo N, Hoeberichts FA, Mühlenbock P, Brosché M, Van Breusegem F, Kangasjärvi J. Spreading the news: subcellular and organellar reactive oxygen species production and signalling. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3831-44. [PMID: 26976816 DOI: 10.1093/jxb/erw080] [Citation(s) in RCA: 231] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
As plants are sessile organisms that have to attune their physiology and morphology continuously to varying environmental challenges in order to survive and reproduce, they have evolved complex and integrated environment-cell, cell-cell, and cell-organelle signalling circuits that regulate and trigger the required adjustments (such as alteration of gene expression). Although reactive oxygen species (ROS) are essential components of this network, their pathways are not yet completely unravelled. In addition to the intrinsic chemical properties that define the array of interaction partners, mobility, and stability, ROS signalling specificity is obtained via the spatiotemporal control of production and scavenging at different organellar and subcellular locations (e.g. chloroplasts, mitochondria, peroxisomes, and apoplast). Furthermore, these cellular compartments may crosstalk to relay and further fine-tune the ROS message. Hence, plant cells might locally and systemically react upon environmental or developmental challenges by generating spatiotemporally controlled dosages of certain ROS types, each with specific chemical properties and interaction targets, that are influenced by interorganellar communication and by the subcellular location and distribution of the involved organelles, to trigger the suitable acclimation responses in association with other well-established cellular signalling components (e.g. reactive nitrogen species, phytohormones, and calcium ions). Further characterization of this comprehensive ROS signalling matrix may result in the identification of new targets and key regulators of ROS signalling, which might be excellent candidates for engineering or breeding stress-tolerant plants.
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Affiliation(s)
- Lorin Mignolet-Spruyt
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Enjun Xu
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, 00014 University of Helsinki, Finland
| | - Niina Idänheimo
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, 00014 University of Helsinki, Finland
| | - Frank A Hoeberichts
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Per Mühlenbock
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Mikael Brosché
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, 00014 University of Helsinki, Finland
| | - Frank Van Breusegem
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Jaakko Kangasjärvi
- Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, 00014 University of Helsinki, Finland Distinguished Scientist Fellowship Program, College of Science, King Saud University, Riyadh, Saudi Arabia
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176
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Naranjo B, Mignée C, Krieger-Liszkay A, Hornero-Méndez D, Gallardo-Guerrero L, Cejudo FJ, Lindahl M. The chloroplast NADPH thioredoxin reductase C, NTRC, controls non-photochemical quenching of light energy and photosynthetic electron transport in Arabidopsis. PLANT, CELL & ENVIRONMENT 2016; 39:804-22. [PMID: 26476233 DOI: 10.1111/pce.12652] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 05/19/2023]
Abstract
High irradiances may lead to photooxidative stress in plants, and non-photochemical quenching (NPQ) contributes to protection against excess excitation. One of the NPQ mechanisms, qE, involves thermal dissipation of the light energy captured. Importantly, plants need to tune down qE under light-limiting conditions for efficient utilization of the available quanta. Considering the possible redox control of responses to excess light implying enzymes, such as thioredoxins, we have studied the role of the NADPH thioredoxin reductase C (NTRC). Whereas Arabidopsis thaliana plants lacking NTRC tolerate high light intensities, these plants display drastically elevated qE, have larger trans-thylakoid ΔpH and have 10-fold higher zeaxanthin levels under low and medium light intensities, leading to extremely low linear electron transport rates. To test the impact of the high qE on plant growth, we generated an ntrc-psbs double-knockout mutant, which is devoid of qE. This double mutant grows faster than the ntrc mutant and has a higher chlorophyll content. The photosystem II activity is partially restored in the ntrc-psbs mutant, and linear electron transport rates under low and medium light intensities are twice as high as compared with plants lacking ntrc alone. These data uncover a new role for NTRC in the control of photosynthetic yield.
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Affiliation(s)
- Belén Naranjo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Sevilla, 410 92, Seville, Spain
| | - Clara Mignée
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA) Saclay, Institut de Biologie et de Technologie de Saclay, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, 91191, Gif-sur-Yvette Cedex, France
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA) Saclay, Institut de Biologie et de Technologie de Saclay, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, 91191, Gif-sur-Yvette Cedex, France
| | - Dámaso Hornero-Méndez
- Departamento de Fitoquímica de los Alimentos, Instituto de la Grasa, CSIC, 41013, Seville, Spain
| | | | - Francisco Javier Cejudo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Sevilla, 410 92, Seville, Spain
| | - Marika Lindahl
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Sevilla, 410 92, Seville, Spain
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177
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Järvi S, Isojärvi J, Kangasjärvi S, Salojärvi J, Mamedov F, Suorsa M, Aro EM. Photosystem II Repair and Plant Immunity: Lessons Learned from Arabidopsis Mutant Lacking the THYLAKOID LUMEN PROTEIN 18.3. FRONTIERS IN PLANT SCIENCE 2016; 7:405. [PMID: 27064270 PMCID: PMC4814454 DOI: 10.3389/fpls.2016.00405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/16/2016] [Indexed: 05/29/2023]
Abstract
Chloroplasts play an important role in the cellular sensing of abiotic and biotic stress. Signals originating from photosynthetic light reactions, in the form of redox and pH changes, accumulation of reactive oxygen and electrophile species or stromal metabolites are of key importance in chloroplast retrograde signaling. These signals initiate plant acclimation responses to both abiotic and biotic stresses. To reveal the molecular responses activated by rapid fluctuations in growth light intensity, gene expression analysis was performed with Arabidopsis thaliana wild type and the tlp18.3 mutant plants, the latter showing a stunted growth phenotype under fluctuating light conditions (Biochem. J, 406, 415-425). Expression pattern of genes encoding components of the photosynthetic electron transfer chain did not differ between fluctuating and constant light conditions, neither in wild type nor in tlp18.3 plants, and the composition of the thylakoid membrane protein complexes likewise remained unchanged. Nevertheless, the fluctuating light conditions repressed in wild-type plants a broad spectrum of genes involved in immune responses, which likely resulted from shade-avoidance responses and their intermixing with hormonal signaling. On the contrary, in the tlp18.3 mutant plants there was an imperfect repression of defense-related transcripts upon growth under fluctuating light, possibly by signals originating from minor malfunction of the photosystem II (PSII) repair cycle, which directly or indirectly modulated the transcript abundances of genes related to light perception via phytochromes. Consequently, a strong allocation of resources to defense reactions in the tlp18.3 mutant plants presumably results in the stunted growth phenotype under fluctuating light.
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Affiliation(s)
- Sari Järvi
- Molecular Plant Biology, Department of Biochemistry, University of TurkuTurku, Finland
| | - Janne Isojärvi
- Molecular Plant Biology, Department of Biochemistry, University of TurkuTurku, Finland
| | | | - Jarkko Salojärvi
- Plant Biology, Department of Biosciences, University of HelsinkiHelsinki, Finland
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry—Ångström Laboratory, Uppsala UniversityUppsala, Sweden
| | - Marjaana Suorsa
- Molecular Plant Biology, Department of Biochemistry, University of TurkuTurku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of TurkuTurku, Finland
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178
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Dahro B, Wang F, Peng T, Liu JH. PtrA/NINV, an alkaline/neutral invertase gene of Poncirus trifoliata, confers enhanced tolerance to multiple abiotic stresses by modulating ROS levels and maintaining photosynthetic efficiency. BMC PLANT BIOLOGY 2016. [PMID: 27025596 DOI: 10.1016/j.envexpbot.2018.12.009] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND Alkaline/neutral invertase (A/N-INV), an enzyme that hydrolyzes sucrose irreversibly into glucose and fructose, is essential for normal plant growth,development, and stress tolerance. However, the physiological and/or molecular mechanism underpinning the role of A/N-INV in abiotic stress tolerance is poorly understood. RESULTS In this report, an A/N-INV gene (PtrA/NINV) was isolated from Poncirus trifoliata, a cold-hardy relative of citrus, and functionally characterized. PtrA/NINV expression levels were induced by cold, salt, dehydration, sucrose, and ABA, but decreased by glucose. PtrA/NINV was found to localize in both chloroplasts and mitochondria. Overexpression of PtrA/NINV conferred enhanced tolerance to multiple stresses, including cold, high salinity, and drought, as supported by lower levels of reactive oxygen species (ROS), reduced oxidative damages, decreased water loss rate, and increased photosynthesis efficiency, relative to wild-type (WT). The transgenic plants exhibited higher A/N-INV activity and greater reducing sugar content under normal and stress conditions. CONCLUSIONS PtrA/NINV is an important gene implicated in sucrose decomposition, and plays a positive role in abiotic stress tolerance by promoting osmotic adjustment, ROS detoxification and photosynthesis efficiency. Thus, PtrA/NINV has great potential to be used in transgenic breeding for improvement of stress tolerance.
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Affiliation(s)
- Bachar Dahro
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China
- Department of Horticulture, Faculty of Agriculture, Tishreen University, Lattakia, Syria
| | - Fei Wang
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ting Peng
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ji-Hong Liu
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
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179
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Pottosin I, Shabala S. Transport Across Chloroplast Membranes: Optimizing Photosynthesis for Adverse Environmental Conditions. MOLECULAR PLANT 2016; 9:356-370. [PMID: 26597501 DOI: 10.1016/j.molp.2015.10.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/17/2015] [Accepted: 10/19/2015] [Indexed: 05/18/2023]
Abstract
Chloroplasts are central to solar light harvesting and photosynthesis. Optimal chloroplast functioning is vitally dependent on a very intensive traffic of metabolites and ions between the cytosol and stroma, and should be attuned for adverse environmental conditions. This is achieved by an orchestrated regulation of a variety of transport systems located at chloroplast membranes such as porines, solute channels, ion-specific cation and anion channels, and various primary and secondary active transport systems. In this review we describe the molecular nature and functional properties of the inner and outer envelope and thylakoid membrane channels and transporters. We then discuss how their orchestrated regulation affects thylakoid structure, electron transport and excitation energy transfer, proton-motive force partition, ion homeostasis, stromal pH regulation, and volume regulation. We link the activity of key cation and anion transport systems with stress-specific signaling processes in chloroplasts, and discuss how these signals interact with the signals generated in other organelles to optimize the cell performance, with a special emphasis on Ca(2+) and reactive oxygen species signaling.
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Affiliation(s)
- Igor Pottosin
- Biomedical Centre, University of Colima, Colima, Colima 28045, Mexico; School of Land and Food, University of Tasmania, Hobart, TAS 7001, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, TAS 7001, Australia.
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180
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Fréchette E, Chang CYY, Ensminger I. Photoperiod and temperature constraints on the relationship between the photochemical reflectance index and the light use efficiency of photosynthesis in Pinus strobus. TREE PHYSIOLOGY 2016; 36:311-24. [PMID: 26846980 PMCID: PMC4885948 DOI: 10.1093/treephys/tpv143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 12/16/2015] [Indexed: 05/14/2023]
Abstract
The photochemical reflectance index (PRI) is a proxy for the activity of the photoprotective xanthophyll cycle and photosynthetic light use efficiency (LUE) in plants. Evergreen conifers downregulate photosynthesis in autumn in response to low temperature and shorter photoperiod, and the dynamic xanthophyll cycle-mediated non-photochemical quenching (NPQ) is replaced by sustained NPQ. We hypothesized that this shift in xanthophyll cycle-dependent energy partitioning during the autumn is the cause for variations in the PRI-LUE relationship. In order to test our hypothesis, we characterized energy partitioning and pigment composition during a simulated summer-autumn transition in a conifer and assessed the effects of temperature and photoperiod on the PRI-LUE relationship. We measured gas exchange, chlorophyll fluorescence and leaf reflectance during the photosynthetic downregulation in Pinus strobus L. seedlings exposed to low temperature/short photoperiod or elevated temperature/short photoperiod conditions. Shifts in energy partitioning during simulated autumn were observed when the pools of chlorophylls decreased and pools of photoprotective carotenoids increased. On a seasonal timescale, PRI was controlled by carotenoid pool sizes rather than xanthophyll cycle dynamics. Photochemical reflectance index variation under cold autumn conditions mainly reflected long-term pigment pool adjustments associated with sustained NPQ, which impaired the PRI-LUE relationship. Exposure to warm autumn conditions prevented the induction of sustained NPQ but still impaired the PRI-LUE relationship. We therefore conclude that alternative zeaxanthin-independent NPQ mechanisms, which remain undetected by the PRI, are present under both cold and warm autumn conditions, contributing to the discrepancy in the PRI-LUE relationship during autumn.
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Affiliation(s)
- Emmanuelle Fréchette
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON, Canada L5L 1C6 Graduate Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 1A1
| | - Christine Yao-Yun Chang
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON, Canada L5L 1C6 Graduate Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 1A1
| | - Ingo Ensminger
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON, Canada L5L 1C6 Graduate Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada M5S 1A1 Graduate Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada M5S 3B2
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181
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Kuzminov FI, Gorbunov MY. Energy dissipation pathways in Photosystem 2 of the diatom, Phaeodactylum tricornutum, under high-light conditions. PHOTOSYNTHESIS RESEARCH 2016; 127:219-235. [PMID: 26220363 DOI: 10.1007/s11120-015-0180-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/17/2015] [Indexed: 05/24/2023]
Abstract
To prevent photooxidative damage under supraoptimal light, photosynthetic organisms evolved mechanisms to thermally dissipate excess absorbed energy, known as non-photochemical quenching (NPQ). Here we quantify NPQ-induced alterations in light-harvesting processes and photochemical reactions in Photosystem 2 (PS2) in the pennate diatom Phaeodactylum tricornutum. Using a combination of picosecond lifetime analysis and variable fluorescence technique, we examined the dynamics of NPQ activation upon transition from dark to high light. Our analysis revealed that NPQ activation starts with a 2-3-fold increase in the rate constant of non-radiative charge recombination in the reaction center (RC); however, this increase is compensated with a proportional increase in the rate constant of back reactions. The resulting alterations in photochemical processes in PS2 RC do not contribute directly to quenching of antenna excitons by the RC, but favor non-radiative dissipation pathways within the RC, reducing the yields of spin conversion of the RC chlorophyll to the triplet state. The NPQ-induced changes in the RC are followed by a gradual ~ 2.5-fold increase in the yields of thermal dissipation in light-harvesting complexes. Our data suggest that thermal dissipation in light-harvesting complexes is the major sink for NPQ; RCs are not directly involved in the NPQ process, but could contribute to photoprotection via reduction in the probability of (3)Chl formation.
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Affiliation(s)
- Fedor I Kuzminov
- Environmental Biophysics and Molecular Biology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA.
- International Laser Center, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia.
| | - Maxim Y Gorbunov
- Environmental Biophysics and Molecular Biology Program, Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
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182
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Yamamoto Y. Quality Control of Photosystem II: The Mechanisms for Avoidance and Tolerance of Light and Heat Stresses are Closely Linked to Membrane Fluidity of the Thylakoids. FRONTIERS IN PLANT SCIENCE 2016; 7:1136. [PMID: 27532009 PMCID: PMC4969305 DOI: 10.3389/fpls.2016.01136] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/18/2016] [Indexed: 05/22/2023]
Abstract
When oxygenic photosynthetic organisms are exposed to excessive light and/or heat, Photosystem II is damaged and electron transport is blocked. In these events, reactive oxygen species, endogenous radicals and lipid peroxidation products generated by photochemical reaction and/or heat cause the damage. Regarding light stress, plants first dissipate excessive light energy captured by light-harvesting chlorophyll protein complexes as heat to avoid the hazards, but once light stress is unavoidable, they tolerate the stress by concentrating damage in a particular protein in photosystem II, i.e., the reaction-center binding D1 protein of Photosystem II. The damaged D1 is removed by specific proteases and replaced with a new copy produced through de novo synthesis (reversible photoinhibition). When light intensity becomes extremely high, irreversible aggregation of D1 occurs and thereby D1 turnover is prevented. Once the aggregated products accumulate in Photosystem II complexes, removal of them by proteases is difficult, and irreversible inhibition of Photosystem II takes place (irreversible photoinhibition). Important is that various aspects of both the reversible and irreversible photoinhibition are highly dependent on the membrane fluidity of the thylakoids. Heat stress-induced inactivation of photosystem II is an irreversible process, which may be also affected by the fluidity of the thylakoid membranes. Here I describe why the membrane fluidity is a key to regulate the avoidance and tolerance of Photosystem II on environmental stresses.
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183
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Redox potential of the terminal quinone electron acceptor QB in photosystem II reveals the mechanism of electron transfer regulation. Proc Natl Acad Sci U S A 2015; 113:620-5. [PMID: 26715751 DOI: 10.1073/pnas.1520211113] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Photosystem II (PSII) extracts electrons from water at a Mn4CaO5 cluster using light energy and then transfers them to two plastoquinones, the primary quinone electron acceptor QA and the secondary quinone electron acceptor QB. This forward electron transfer is an essential process in light energy conversion. Meanwhile, backward electron transfer is also significant in photoprotection of PSII proteins. Modulation of the redox potential (Em) gap of QA and QB mainly regulates the forward and backward electron transfers in PSII. However, the full scheme of electron transfer regulation remains unresolved due to the unknown Em value of QB. Here, for the first time (to our knowledge), the Em value of QB reduction was measured directly using spectroelectrochemistry in combination with light-induced Fourier transform infrared difference spectroscopy. The Em(QB (-)/QB) was determined to be approximately +90 mV and was virtually unaffected by depletion of the Mn4CaO5 cluster. This insensitivity of Em(QB (-)/QB), in combination with the known large upshift of Em(QA (-)/QA), explains the mechanism of PSII photoprotection with an impaired Mn4CaO5 cluster, in which a large decrease in the Em gap between QA and QB promotes rapid charge recombination via QA (-).
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184
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Liu H, Weisz DA, Pakrasi HB. Multiple copies of the PsbQ protein in a cyanobacterial photosystem II assembly intermediate complex. PHOTOSYNTHESIS RESEARCH 2015; 126:375-83. [PMID: 25800517 DOI: 10.1007/s11120-015-0123-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/15/2015] [Indexed: 05/03/2023]
Abstract
Photosystem II (PSII) undergoes frequent damage owing to the demanding electron transfer chemistry it performs. To sustain photosynthetic activity, damaged PSII undergoes a complex repair cycle consisting of many transient intermediate complexes. By purifying PSII from the cyanobacterium Synechocystis sp. PCC 6803 using a histidine-tag on the PsbQ protein, a lumenal extrinsic subunit, a novel PSII assembly intermediate was isolated in addition to the mature PSII complex. This new complex, which we refer to as PSII-Q4, contained four copies of the PsbQ protein per PSII monomer, instead of the expected one copy. In addition, PSII-Q4 lacked two other lumenal extrinsic proteins, PsbU and PsbV, which are present in the mature PSII complex. We suggest that PSII-Q4 is a late PSII assembly intermediate that is formed just before the binding of PsbU and PsbV, and we incorporate these results into an updated model of PSII assembly.
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Affiliation(s)
- Haijun Liu
- Department of Biology, CB1137, Washington University, 1 Brookings Drive, St. Louis, MO, 63130, USA
| | - Daniel A Weisz
- Department of Biology, CB1137, Washington University, 1 Brookings Drive, St. Louis, MO, 63130, USA
- Department of Chemistry, Washington University, St. Louis, MO, 63130, USA
| | - Himadri B Pakrasi
- Department of Biology, CB1137, Washington University, 1 Brookings Drive, St. Louis, MO, 63130, USA.
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185
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Kerchev P, De Smet B, Waszczak C, Messens J, Van Breusegem F. Redox Strategies for Crop Improvement. Antioxid Redox Signal 2015; 23:1186-205. [PMID: 26062101 DOI: 10.1089/ars.2014.6033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Recently, the agro-biotech industry has been driven by overcoming the limitations imposed by fluctuating environmental stress conditions on crop productivity. A common theme among (a)biotic stresses is the perturbation of the redox homeostasis. RECENT ADVANCES As a strategy to engineer stress-tolerant crops, many approaches have been centered on restricting the negative impact of reactive oxygen species (ROS) accumulation. CRITICAL ISSUES In this study, we discuss the scientific background of the existing redox-based strategies to improve crop performance and quality. In this respect, a special focus goes to summarizing the current patent landscape because this aspect is very often ignored, despite constituting the forefront of applied research. FUTURE DIRECTIONS The current increased understanding of ROS acting as signaling molecules has opened new avenues to exploit redox biology for crop improvement required for sustainable food security.
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Affiliation(s)
- Pavel Kerchev
- 1 Department of Plant Systems Biology , VIB, Ghent, Belgium .,2 Department of Plant Biotechnology and Bioinformatics, Ghent University , Ghent, Belgium
| | - Barbara De Smet
- 1 Department of Plant Systems Biology , VIB, Ghent, Belgium .,2 Department of Plant Biotechnology and Bioinformatics, Ghent University , Ghent, Belgium .,3 Structural Biology Research Center , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussel, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussel, Belgium
| | - Cezary Waszczak
- 1 Department of Plant Systems Biology , VIB, Ghent, Belgium .,2 Department of Plant Biotechnology and Bioinformatics, Ghent University , Ghent, Belgium .,3 Structural Biology Research Center , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussel, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussel, Belgium
| | - Joris Messens
- 3 Structural Biology Research Center , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussel, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussel, Belgium
| | - Frank Van Breusegem
- 1 Department of Plant Systems Biology , VIB, Ghent, Belgium .,2 Department of Plant Biotechnology and Bioinformatics, Ghent University , Ghent, Belgium
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186
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Zhou Y, Jiang J, Gao Y, Ma J, Pang SY, Li J, Lu XT, Yuan LP. Activation of Peroxymonosulfate by Benzoquinone: A Novel Nonradical Oxidation Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12941-12950. [PMID: 26452059 DOI: 10.1021/acs.est.5b03595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The reactions between peroxymonosulfate (PMS) and quinones were investigated for the first time in this work, where benzoquinone (BQ) was selected as a model quinone. It was demonstrated that BQ could efficiently activate PMS for the degradation of sulfamethoxazole (SMX; a frequently detected antibiotic in the environments), and the degradation rate increased with solution pH from 7 to 10. Interestingly, quenching studies suggested that neither hydroxyl radical (•OH) nor sulfate radical (SO4•-) was produced therein. Instead, the generation of singlet oxygen (1O2) was proved by using two chemical probes (i.e., 2,2,6,6-tetramethyl-4-piperidinol and 9,10-diphenylanthracene) with the appearance of 1O2 indicative products detected by electron paramagnetic resonance spectrometry and liquid chromatography mass spectrometry, respectively. A catalytic mechanism was proposed involving the formation of a dioxirane intermediate between PMS and BQ and the subsequent decomposition of this intermediate into 1O2. Accordingly, a kinetic model was developed, and it well described the experimental observation that the pH-dependent decomposition rate of PMS was first-order with respect to BQ. These findings have important implications for the development of novel nonradical oxidation processes based on PMS, because 1O2 as a moderately reactive electrophile may suffer less interference from background organic matters compared with nonselective •OH and SO4•-.
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Affiliation(s)
- Yang Zhou
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China
| | - Jin Jiang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China
| | - Yuan Gao
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China
| | - Su-Yan Pang
- Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China
| | - Juan Li
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China
| | - Xue-Ting Lu
- Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China
| | - Li-Peng Yuan
- Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin, Heilongjiang 150040, China
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187
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Wang J, Leister D, Bolle C. Photosynthetic lesions can trigger accelerated senescence in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6891-903. [PMID: 26272903 PMCID: PMC4623695 DOI: 10.1093/jxb/erv393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Senescence is a highly regulated process characterized by the active breakdown of cells, which ultimately leads to the death of plant organs or whole plants. In annual plants such as Arabidopsis thaliana senescence can be observed in each individual leaf. Whether deficiencies in photosynthesis promote the induction of senescence was investigated by monitoring chlorophyll degradation, photosynthetic parameters, and reactive oxygen species accumulation in photosynthetic mutants. Several mutations affecting components of the photosynthetic apparatus, including psal-2, psan-2, and psbs, were found to lead to premature or faster senescence, as did simultaneous inactivation of the STN7 and STN8 kinases. Premature senescence is apparently not directly linked to an overall reduction in photosynthesis but to perturbations in specific aspects of the process. Dark-induced senescence is accelerated in mutants affected in linear electron flow, especially psad2-1, psan-2, and pete2-1, as well as in stn7 and stn8 mutants and STN7 and STN8 overexpressor lines. Interestingly, no direct link with ROS production could be observed.
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Affiliation(s)
- Jing Wang
- Ludwig-Maximilians-Universität München (LMU), Department Biologie I, Botanik, Großhaderner Str. 2-4, D-82152 Planegg-Martinsried, Germany
| | - Dario Leister
- Ludwig-Maximilians-Universität München (LMU), Department Biologie I, Botanik, Großhaderner Str. 2-4, D-82152 Planegg-Martinsried, Germany
| | - Cordelia Bolle
- Ludwig-Maximilians-Universität München (LMU), Department Biologie I, Botanik, Großhaderner Str. 2-4, D-82152 Planegg-Martinsried, Germany
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188
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Korkaric M, Xiao M, Behra R, Eggen RIL. Acclimation of Chlamydomonas reinhardtii to ultraviolet radiation and its impact on chemical toxicity. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 167:209-219. [PMID: 26349947 DOI: 10.1016/j.aquatox.2015.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
The toxicity of chemical pollutants can be modulated under stressful environmental conditions, such as increased temperature, salinity or ultraviolet radiation (UVR), due to the interaction of effects during simultaneous stressor exposure. However, organisms may acclimate to such conditions by activation of physiological and biochemical defence mechanisms. In sequential exposures, organisms acclimated to environmental stressors may display an increased sensitivity or co-tolerance towards chemical pollutants. It has been suggested that co-tolerance might be expected for similarly acting stressors due to common defence mechanisms. To test this for combinations of UVR and chemical stressors, we first acclimatized the model green alga Chlamydomonas reinhardtii to UVR and subsequently compared the sensitivity of UVR pre-exposed and control algae towards chemicals. Selected chemicals all act on photosynthesis and thus share a common physiological target, but display distinct toxicity mechanisms. Results showed that UVR pre-exposure for four days partially inhibited algal growth and photosynthesis, but also increased algal tolerance to higher UVR levels, confirming UVR acclimation. HPLC analysis of algal pigments indicated that UVR acclimation might in part be explained by the protective function of lutein while the contribution of UVR absorbing compounds was less clear. Challenge exposure to chemicals in the absence of UVR showed that acclimated algae were co-tolerant to the photosensitizer rose bengal, but not to the herbicides paraquat and diuron, suggesting that the fast physiological and biochemical defence mechanisms that conferred tolerance of algae towards higher UVR levels were related to singlet oxygen defence. The presented study suggests that knowledge of the molecular toxicity mechanisms of chemicals, rather than their general physiological target, is needed in order to predict co-tolerance between environmental and chemical stressors.
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Affiliation(s)
- Muris Korkaric
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Mao Xiao
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Renata Behra
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland
| | - Rik I L Eggen
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland.
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189
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Strategies to optimize photosensitizers for photodynamic inactivation of bacteria. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 150:2-10. [DOI: 10.1016/j.jphotobiol.2015.05.010] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 01/06/2023]
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190
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Zavafer A, Chow WS, Cheah MH. The action spectrum of Photosystem II photoinactivation in visible light. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:247-60. [PMID: 26298696 DOI: 10.1016/j.jphotobiol.2015.08.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/23/2015] [Accepted: 08/10/2015] [Indexed: 12/25/2022]
Abstract
Photosynthesis is always accompanied by light induced damage to the Photosystem II (PSII) which is compensated by its subsequent repair. Photoinhibition of PSII is a complex process, balancing between photoinactivation, protective and repair mechanisms. Current understanding of photoinactivation is limited with competing hypotheses where the photosensitiser is either photosynthetic pigments or the Mn4CaO5 cluster itself, with little consensus on the mechanisms and consequences of PSII photoinactivation. The mechanism of photoinactivation should be reflected in the action spectrum of PSII photoinactivation, but there is a great diversity of the action spectra reported thus far. The only consensus is that PSII photoinactivation is greatest in the UV region of the electromagnetic spectrum. In this review, the authors revisit the methods, technical constraints and the different action spectra of PSII photoinactivation reported to date and compare them against the diverse mechanisms proposed. Upon critical examination of the reported action spectra, a hybrid mechanism of photoinactivation, sensitised by both photosynthetic pigments and the Mn4CaO5 appears to be the most plausible rationalisation.
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Affiliation(s)
- Alonso Zavafer
- Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 2601, Australia
| | - Wah Soon Chow
- Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 2601, Australia
| | - Mun Hon Cheah
- Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 2601, Australia.
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191
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Sano Y, Endo K, Tomo T, Noguchi T. Modified molecular interactions of the pheophytin and plastoquinone electron acceptors in photosystem II of chlorophyll D-containing Acaryochloris marina as revealed by FTIR spectroscopy. PHOTOSYNTHESIS RESEARCH 2015; 125:105-114. [PMID: 25560630 DOI: 10.1007/s11120-014-0073-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/20/2014] [Indexed: 06/04/2023]
Abstract
Acaryochloris marina is a unique cyanobacterium that contains chlorophyll (Chl) d as a major pigment. Because Chl d has smaller excitation energy than Chl a used in ordinary photosynthetic organisms, the energetics of the photosystems of A. marina have been the subject of interest. It was previously shown that the redox potentials (E m's) of the redox-active pheophytin a (Pheo) and the primary plastoquinone electron acceptor (QA) in photosystem II (PSII) of A. marina are higher than those in Chl a-containing PSII, to compensate for the smaller excitation energy of Chl d (Allakhverdiev et al., Proc Natl Acad Sci USA 107: 3924-3929, 2010; ibid. 108: 8054-8058, 2011). To clarify the mechanisms of these E m increases, in this study, we have investigated the molecular interactions of Pheo and QA in PSII core complexes from A. marina using Fourier transform infrared (FTIR) spectroscopy. Light-induced FTIR difference spectra upon single reduction of Pheo and QA showed that spectral features in the regions of the keto and ester C=O stretches and the chlorin ring vibrations of Pheo and in the CO/CC stretching region of the Q A (-) semiquinone anion in A. marina are significantly different from those of the corresponding spectra in Chl a-containing cyanobacteria. These observations indicate that the molecular interactions, including the hydrogen bond interactions at the C=O groups, of these cofactors are modified in their binding sites of PSII proteins. From these results, along with the sequence information of the D1 and D2 proteins, it is suggested that A. marina tunes the E m's of Pheo and QA by altering nearby hydrogen bond networks to modify the structures of the binding pockets of these cofactors.
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Affiliation(s)
- Yuko Sano
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
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192
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Griesbeck AG, Kleczka M, de Kiff A, Vollmer M, Eske A, Sillner S. Singlet oxygen and natural substrates: functional polyunsaturated models for the photooxidative degradation of carotenoids. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2015-0209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe primary chemical reactions of singlet molecular oxygen with polyunsaturated carotenoids are the focus of this research report. Model compounds that exhibit electronic properties and substituent pattern similar to natural carotenes, xanthophylls or apocarotenoids, respectively, were investigated with regard to photooxygenation reactivity. For dienes and trienes as substrates, high tandem reactivity was observed and hydroperoxy-endoperoxides were isolated as the secondary products of singlet oxygen reaction. The electronic gem-effect on the regioselectivity of the ene reaction is conserved also in vinylogous positions and thus appears to originate from a radical-stabilizing effect. In an attempt to combine different peroxide groups derived from natural products as a tool for new pharmaceutically active products, a dyade synthesis of an artemisinine-safranol with subsequent singlet oxygen addition was realized.
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Affiliation(s)
- Axel G. Griesbeck
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
| | - Margarethe Kleczka
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
| | - Alan de Kiff
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
| | - Moritz Vollmer
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
| | - Angelika Eske
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
| | - Sarah Sillner
- 1Department of Chemistry, University of Cologne, Greinstr. 4, 50939 Cologne, Germany
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193
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Maisch T. Resistance in antimicrobial photodynamic inactivation of bacteria. Photochem Photobiol Sci 2015; 14:1518-26. [PMID: 26098395 DOI: 10.1039/c5pp00037h] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antibiotics have increasingly lost their impact to kill bacteria efficiently during the last 10 years. The emergence and dissemination of superbugs with resistance to multiple antibiotic classes have occurred among Gram-positive and Gram-negative strains including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter strains. These six superbugs can "escape" more or less any single kind of antibiotic treatment. That means bacteria are very good at developing resistance against antibiotics in a short time. One new approach is called photodynamic antimicrobial chemotherapy (PACT) which already has demonstrated an efficient antimicrobial efficacy among multi-resistant bacteria. Until now it has been questionable if bacteria can develop resistance against PACT. This perspective summarises the current knowledge about the susceptibility of bacteria towards oxidative stress and sheds some light on possible strategies of the development of photodynamic inactivation of bacteria (PACT)-induced oxidative stress resistance by bacteria.
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Affiliation(s)
- Tim Maisch
- Department of Dermatology, Antimicrobial Photodynamic and Cold Plasma Research Unit, University Hospital Regensburg, Regensburg, Germany.
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194
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Chen Y, Chang SKC. Macronutrients, Phytochemicals, and Antioxidant Activity of Soybean Sprout Germinated with or without Light Exposure. J Food Sci 2015; 80:S1391-8. [PMID: 25916398 DOI: 10.1111/1750-3841.12868] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/05/2015] [Indexed: 01/08/2023]
Abstract
This study examined the macronutrients, phytochemicals, and antioxidant activities of yellow soybean sprout (YSS) and green soybean sprout (GSS) with different germination days. YSS and GSS were obtained by sprouting soybean in darkness or with light exposure at 21 °C. Lipid, protein, carbohydrate, and ash contents were analyzed before and after soybean germination. Phytochemicals (total phenolic compounds, saponin, and isoflavone) were also determined. DPPH, ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) were determined to examine the antioxidant activities of soybean sprout. Results showed YSS had a higher yield than GSS. Based on dry mass composition, 7-d germination of GSS decreased 14% protein, 37% lipid, 22% carbohydrate, and 16% ash, whereas 7-d germination of YSS decreased 6% protein and 47% lipid. Carbohydrate did not change and ash significantly increased for the 7-d germinated YSS. Lipid was greatly metabolized in germination, which explained why the protein relative percentage in dried soybean sprout was higher than that in the corresponding soybean. Total phenolic compounds and saponin (mg/g soybean sprout, dry basis) had the same accumulation trend in soybean sprout with the increases in germination days. Aglycone isoflavones (genistein, glycitein, and daidzein) and daidzin showed an increased trend, whereas malonylgenistin and malonylglycitin showed a decreased trend with germination days for both GSS and YSS. The change in other isoflavones did not show definite trends. GSS had 20% more antioxidant activities than YSS (7-d germinated soybean sprout). The increases in ORAC antioxidant activity suggest eating GSS may be more beneficial than GSS for promoting human health.
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Affiliation(s)
- Yeming Chen
- School of Food Science and Technology, Jiangnan Univ, Wuxi, Jiangsu, 214122, People's Republic of China
| | - Sam K C Chang
- Dept. of Food Science, Nutrition and Health Promotion, Mississippi State Univ, Box 9805, MS State, Miss., 39762-9805, U.S.A
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195
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Uberegui E, Hall M, Lorenzo Ó, Schröder WP, Balsera M. An Arabidopsis soluble chloroplast proteomic analysis reveals the participation of the Executer pathway in response to increased light conditions. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2067-77. [PMID: 25740923 PMCID: PMC4378640 DOI: 10.1093/jxb/erv018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/11/2014] [Accepted: 12/19/2014] [Indexed: 05/18/2023]
Abstract
The Executer1 and Executer2 proteins have a fundamental role in the signalling pathway mediated by singlet oxygen in chloroplast; nonetheless, not much is known yet about their specific activity and features. Herein, we have followed a differential-expression proteomics approach to analyse the impact of Executer on the soluble chloroplast protein abundance in Arabidopsis. Because singlet oxygen plays a significant role in signalling the oxidative response of plants to light, our analysis also included the soluble chloroplast proteome of plants exposed to a moderate light intensity in the time frame of hours. A number of light- and genotype-responsive proteins were detected, and mass-spectrometry identification showed changes in abundance of several photosynthesis- and carbon metabolism-related proteins as well as proteins involved in plastid mRNA processing. Our results support the participation of the Executer proteins in signalling and control of chloroplast metabolism, and in the regulation of plant response to environmental changes.
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Affiliation(s)
- Estefanía Uberegui
- Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas (IRNASA-CSIC), 37008-Salamanca, Spain Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Michael Hall
- Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Óscar Lorenzo
- Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, 37185 Salamanca, Spain
| | | | - Mónica Balsera
- Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas (IRNASA-CSIC), 37008-Salamanca, Spain
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196
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Simultaneous measurements of photocurrents and H2O2 evolution from solvent exposed photosystem 2 complexes. Biointerphases 2015; 11:019001. [PMID: 26700470 DOI: 10.1116/1.4938090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In plants, algae, and cyanobacteria, photosystem 2 (PS2) catalyzes the light driven oxidation of water. The main products of this reaction are protons and molecular oxygen. In vitro, however, it was demonstrated that reactive oxygen species like hydrogen peroxide are obtained as partially reduced side products. The transition from oxygen to hydrogen peroxide evolution might be induced by light triggered degradation of PS2's active center. Herein, the authors propose an analytical approach to investigate light induced bioelectrocatalytic processes such as PS2 catalyzed water splitting. By combining chronoamperometry and fluorescence microscopy, the authors can simultaneously monitor the photocurrent and the hydrogen peroxide evolution of light activated, solvent exposed PS2 complexes, which have been immobilized on a functionalized gold electrode. The authors show that under limited electron mediation PS2 displays a lower photostability that correlates with an enhanced H2O2 generation as a side product of the light induced water oxidation.
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197
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Turan S, Tripathy BC. Salt-stress induced modulation of chlorophyll biosynthesis during de-etiolation of rice seedlings. PHYSIOLOGIA PLANTARUM 2015; 153:477-91. [PMID: 25132047 DOI: 10.1111/ppl.12250] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 05/19/2014] [Indexed: 05/08/2023]
Abstract
Chlorophyll biosynthesis in plants is subjected to modulation by various environmental factors. To understand the modulation of the chlorophyll (Chl) biosynthesis during greening process by salt, 100-200 mM NaCl was applied to the roots of etiolated rice seedlings 12 h prior to the transfer to light. Application of 200 mM NaCl to rice seedlings that were grown in light for further 72 h resulted in reduced dry matter production (-58%) and Chl accumulation (-66%). Ionic imbalance due to salinity stress resulted in additional downregulation (41-45%) of seedling dry weight, Chl and carotenoid contents over and above that of similar osmotic stress induced by polyethylene glycol. Downregulation of Chl biosynthesis may be attributed to decreased activities of Chl biosynthetic pathway enzymes, i.e. 5-aminolevulinic acid (ALA) dehydratase (EC-2.4.1.24), porphobilinogen deaminase (EC-4.3.1.8), coproporphyrinogen III oxidase (EC-1.3.3.3), protoporphyrinogen IX oxidase (EC-1.3.3.4), Mg-protoporphyrin IX chelatase (EC-6.6.1.1) and protochlorophyllide oxidoreductase (EC-1.3.33.1). Reduced enzymatic activities were due to downregulation of their protein abundance and/or gene expression in salt-stressed seedlings. The extent of downregulation of ALA biosynthesis nearly matched with that of protochlorophyllide and Chl to prevent the accumulation of highly photosensitive photodynamic tetrapyrroles that generates singlet oxygen under stress conditions. Although, ALA synthesis decreased, the gene/protein expression of glutamyl-tRNA reductase (EC-1.2.1.70) increased suggesting it may play a role in acclimation to salt stress. The similar downregulation of both early and late Chl biosynthesis intermediates in salt-stressed seedlings suggests a regulatory network of genes involved in tetrapyrrole biosynthesis.
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Affiliation(s)
- Satpal Turan
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
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198
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Khorobrykh SA, Karonen M, Tyystjärvi E. Experimental evidence suggesting that H2O2 is produced within the thylakoid membrane in a reaction between plastoquinol and singlet oxygen. FEBS Lett 2015; 589:779-86. [PMID: 25701589 DOI: 10.1016/j.febslet.2015.02.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/30/2015] [Accepted: 02/10/2015] [Indexed: 10/24/2022]
Abstract
Plastoquinol (PQH2-9) and plastoquinone (PQ-9) mediate photosynthetic electron transfer. We isolated PQH2-9 from thylakoid membranes, purified it with HPLC, subjected the purified PQH2-9 to singlet oxygen ((1)O2) and analyzed the products. The main reaction of (1)O2 with PQH2-9 in methanol was found to result in formation of PQ-9 and H2O2, and the amount of H2O2 produced was essentially the same as the amount of oxidized PQH2-9. Formation of H2O2 in the reaction between (1)O2 and PQH2-9 may be an important source of H2O2 within the lipophilic thylakoid membrane.
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Affiliation(s)
- Sergey A Khorobrykh
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Maarit Karonen
- Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, FI-20014 Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland.
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199
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Biogenesis of light harvesting proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:861-71. [PMID: 25687893 DOI: 10.1016/j.bbabio.2015.02.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/04/2015] [Accepted: 02/07/2015] [Indexed: 11/20/2022]
Abstract
The LHC family includes nuclear-encoded, integral thylakoid membrane proteins, most of which coordinate chlorophyll and xanthophyll chromophores. By assembling with the core complexes of both photosystems, LHCs form a flexible peripheral moiety for enhancing light-harvesting cross-section, regulating its efficiency and providing protection against photo-oxidative stress. Upon its first appearance, LHC proteins underwent evolutionary diversification into a large protein family with a complex genetic redundancy. Such differentiation appears as a crucial event in the adaptation of photosynthetic organisms to changing environmental conditions and land colonization. The structure of photosystems, including nuclear- and chloroplast-encoded subunits, presented the cell with a number of challenges for the control of the light harvesting function. Indeed, LHC-encoding messages are translated in the cytosol, and pre-proteins imported into the chloroplast, processed to their mature size and targeted to the thylakoids where are assembled with chromophores. Thus, a tight coordination between nuclear and plastid gene expression, in response to environmental stimuli, is required to adjust LHC composition during photoacclimation. In recent years, remarkable progress has been achieved in elucidating structure, function and regulatory pathways involving LHCs; however, a number of molecular details still await elucidation. In this review, we will provide an overview on the current knowledge on LHC biogenesis, ranging from organization of pigment-protein complexes to the modulation of gene expression, import and targeting to the photosynthetic membranes, and regulation of LHC assembly and turnover. Genes controlling these events are potential candidate for biotechnological applications aimed at optimizing light use efficiency of photosynthetic organisms. This article is part of a Special Issue entitled: Chloroplast biogenesis.
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Laloi C, Havaux M. Key players of singlet oxygen-induced cell death in plants. FRONTIERS IN PLANT SCIENCE 2015; 6:39. [PMID: 25699067 PMCID: PMC4316694 DOI: 10.3389/fpls.2015.00039] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/15/2015] [Indexed: 05/03/2023]
Abstract
The production of reactive oxygen species (ROS) is an unavoidable consequence of oxygenic photosynthesis. Singlet oxygen ((1)O2) is a highly reactive species to which has been attributed a major destructive role during the execution of ROS-induced cell death in photosynthetic tissues exposed to excess light. The study of the specific biological activity of (1)O2 in plants has been hindered by its high reactivity and short lifetime, the concurrent production of other ROS under photooxidative stress, and limited in vivo detection methods. However, during the last 15 years, the isolation and characterization of two (1)O2-overproducing mutants in Arabidopsis thaliana, flu and ch1, has allowed the identification of genetically controlled (1)O2 cell death pathways and a (1)O2 acclimation pathway that are triggered at sub-cytotoxic concentrations of (1)O2. The study of flu has revealed the control of cell death by the plastid proteins EXECUTER (EX)1 and EX2. In ch1, oxidized derivatives of β-carotene, such as β-cyclocitral and dihydroactinidiolide, have been identified as important upstream messengers in the (1)O2 signaling pathway that leads to stress acclimation. In both the flu and ch1 mutants, phytohormones act as important promoters or inhibitors of cell death. In particular, jasmonate has emerged as a key player in the decision between acclimation and cell death in response to (1)O2. Although the flu and ch1 mutants show many similarities, especially regarding their gene expression profiles, key differences, such as EXECUTER-independent cell death in ch1, have also been observed and will need further investigation to be fully understood.
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Affiliation(s)
- Christophe Laloi
- Laboratoire de Génétique et Biophysique des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux Énergies AlternativesMarseille, France
- CNRS, UMR 7265 Biologie Végétale et Microbiologie EnvironnementalesMarseille, France
- Aix Marseille UniversitéMarseille, France
- *Correspondence: Christophe Laloi, Laboratoire de Génétique et Biophysique des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux nergies Alternatives, F -13009 Marseille, France e-mail: ; Michel Havaux, Laboratoire d’Ecophysiologie Moléculaire des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux Énergies Alternatives, F-13108 Saint-Paul-lez-Durance, France e-mail:
| | - Michel Havaux
- CNRS, UMR 7265 Biologie Végétale et Microbiologie EnvironnementalesMarseille, France
- Aix Marseille UniversitéMarseille, France
- Laboratoire d’Ecophysiologie Moléculaire des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux Énergies AlternativesSaint-Paul-lez-Durance, France
- *Correspondence: Christophe Laloi, Laboratoire de Génétique et Biophysique des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux nergies Alternatives, F -13009 Marseille, France e-mail: ; Michel Havaux, Laboratoire d’Ecophysiologie Moléculaire des Plantes, Institut de Biologie Environnementale et Biotechnologie, Commissariat à l’Énergie Atomique et aux Énergies Alternatives, F-13108 Saint-Paul-lez-Durance, France e-mail:
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