Quality control of photosystem II: impact of light and heat stresses

Yamamoto, Yasusi; Aminaka, Ryota; Yoshioka, Miho; Khatoon, Mahbuba; Komayama, Keisuke; Takenaka, Daichi; Yamashita, Amu; Nijo, Nobuyoshi; Inagawa, Kayo; Morita, Noriko; Sasaki, Takayuki; Yamamoto, Yoko

doi:10.1007/s11120-008-9372-4

Cited by 214 publications

(188 citation statements)

References 161 publications

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“…Prolonged illumination induces the formation of aggregates that are so large they do not penetrate into the gel (Fig. S6) (32,33,(35)(36)(37)(38). We assessed the degree of photodamage in the different strains by comparing the disappearance rate of D1 from the 32 kDa region of the SDS/PAGE by immunoblotting.…”

Section: Resultsmentioning

confidence: 99%

Engineering of an alternative electron transfer path in photosystem II

Larom

Salama

Schuster

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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The initial steps of oxygenic photosynthetic electron transfer occur within photosystem II, an intricate pigment/protein transmembrane complex. Light-driven electron transfer occurs within a multistep pathway that is efficiently insulated from competing electron transfer pathways. The heart of the electron transfer system, composed of six linearly coupled redox active cofactors that enable electron transfer from water to the secondary quinone acceptor Q B , is mainly embedded within two proteins called D1 and D2. We have identified a site in silico, poised in the vicinity of the Q A intermediate quinone acceptor, which could serve as a potential binding site for redox active proteins. Here we show that modification of Lysine 238 of the D1 protein to glutamic acid (Glu) in the cyanobacterium Synechocystis sp. PCC 6803, results in a strain that grows photautotrophically. The Glu thylakoid membranes are able to perform light-dependent reduction of exogenous cytochrome c with water as the electron donor. Cytochrome c photoreduction by the Glu mutant was also shown to significantly protect the D1 protein from photodamage when isolated thylakoid membranes were illuminated. We have therefore engineered a novel electron transfer pathway from water to a soluble protein electron carrier without harming the normal function of photosystem II. cyanobacteria | energy conversion | proinhibition | photosynthesis | protein engineering P hotosynthesis is the major source of useful chemical energy in the biosphere. All photosynthetic processes require efficient electron transfer (ET) pathways that are utilized for proton gradient formation (to be used for the production of ATP) and/or accumulation of reducing equivalents (1, 2). Light energy, absorbed by light-harvesting antenna complexes, is transferred to photochemical reaction centers (RC), initiating charge separation in specific chlorophyll molecules bound to the RC proteins. Following charge separation, electrons are transferred sequentially to a series of acceptor molecules, each with a redox potential determined by its immediate environment (3, 4). The source of electron replenishment differs according to the reaction center type. For instance in purple non-sulfur bacteria, electrons are cycled back to the oxidized reaction center by a soluble cytochrome c (cyt c) type protein (5, 6). Oxygenic photosynthetic organisms (cyanobacteria, red and green algae and plants) contain two photosystems: photosystem I (PSI) and photosystem II (PSII) that work linearly (1, 7), and the source of electrons is water. One common facet of all ET pathways is the requirement for insulation of the redox active cofactors from potentially reducing/oxidizing molecules within the RC or in the surrounding media. Insulation provides the system with maximal ET rates and efficiencies and also prevents damage to the RC.PSII has a redox potential of up to 1.2 V (8, 9), required to abstract electrons from water (Fig. 1A). The photoexcited P 680 reaction center chlorophyll a primary donor transfers electron...

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Section: Resultsmentioning

confidence: 99%

Engineering of an alternative electron transfer path in photosystem II

Larom

Salama

Schuster

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…1c). The moderate correlation obtained between clonal electrolytic leakage and photosystem efficiency following artificial freezing was not surprising, as the two methods take into account different parameters and while electrolyte leakage can be considered an estimate of the cellular membrane damage, F v /F m shows the efficiency of photosystem II, which can be impaired even without physical membrane damage (Saibo et al 2009;Yamamoto et al 2008). The two techniques were used to measure cold damage at different freezing temperatures in Arabidopsis (Ehlert and Hincha 2008) and while a general correspondence was found, differences between the two methods were highlighted.…”

Section: Discussionmentioning

confidence: 99%

Cold tolerance in cypress (Cupressus sempervirens L.): a physiological and molecular study

Baldi

Pedron

Hietala³

et al. 2010

Tree Genetics & Genomes

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Twenty cypress accessions were tested for freezing tolerance. After freezing to −15°C, differences among cypress accessions were tested by measuring electrolyte leakage and chlorophyll fluorescence. Based on these data, cypress accessions showing contrasting freezing tolerance were subjected to transcript profiling of candidate genes upon the development of cold hardening, with the ultimate goal of providing a scientific basis for selecting/breeding cypress genotypes with higher tolerance to low temperature. Nine different cypress genes were selected: a heat shock protein, a putative chaperonin, a chlorophyll-binding protein, a serine/threonine protein kinase, a putative exonuclease, a dehydrin, and three senescenceassociated proteins. Transcript levels of these genes were profiled during cold hardening under controlled conditions using real-time reverse-transcription-polymerase chain reaction. While the genes showed regulation patterns common to both cypress accessions, in the case of chaperonin, exonuclease, and some senescence-associated proteins, clonal differences in gene regulation were found. The potential relationship of these differences with cold tolerance is discussed.

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“…In addition, both excess and deficiency of Cu 2+ ions can induce formation of reactive oxygen species (ROS), leading to the formation of hydrogen peroxide in the cell walls, causing loosening of the cell wall (Fry et al, 2002). In addition, EROs damage the structure of the photosynthetic apparatus, causing damage to the lipid membranes, and possible extravasation of the cellular content (Yamamoto et al, 2008). High levels of copper in the cells may lead to the replacement of the Mg 2+ in the center of the chlorophyll molecule, giving rise to the so-called cupric chlorophyll.…”

Section: Introductionmentioning

confidence: 99%

Copper (Cu) stress affects carbon and antioxidant metabolism in Coffea arabica seedlings

Santos¹,

Fária²,

Silva³

et al. 2017

Aust J Crop Sci

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Although copper is a micronutrient essential for the normal development of plants, both insufficient and supra optimal doses can disrupt the functioning of metabolism and the production of biomass. To study the biochemical and physiological impacts of deficiency and excess of copper in coffee, we treated 6-month-old seedlings of Coffea arabica L. Catuaí cultivar to three copper treatments: control (0.03 ppm), excess (0.12 ppm) and deficiency (0 ppm) for 60 days. The changes in levels of photosynthetic pigments, biomass allocation, carbohydrate partitioning, antioxidant system and proline levels were evaluated. Under deficiency and excess of copper coffee seedlings showed lower levels of chlorophyll, reduction on dry weight of shoot, lower sugar levels and higher content of hydrogen peroxide. We also observed increased levels of proline and enzymatic activity of the antioxidant system, providing conditions for the reduction of oxidative stress triggered by nutritional imbalance. In general, the results showed that coffee plants invest in antioxidant defense system as an alternative to maintain redox balance when exposed to deficiency or excess copper. However, it is not effective to prevent an increase in lipid peroxidation. Authors may indicate an optimum range for application of copper in coffee.

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Quality control of photosystem II: impact of light and heat stresses

Cited by 214 publications

References 161 publications

Engineering of an alternative electron transfer path in photosystem II

Engineering of an alternative electron transfer path in photosystem II

Cold tolerance in cypress (Cupressus sempervirens L.): a physiological and molecular study

Copper (Cu) stress affects carbon and antioxidant metabolism in Coffea arabica seedlings

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