Photosynthetic electron flow affects H2O2 signaling by inactivation of catalase in Chlamydomonas reinhardtii

Shao, Ningsheng; Beck, Christoph F.; Lemaire, Stéphane D.; Krieger‐Liszkay, Anja

doi:10.1007/s00425-008-0807-0

Cited by 64 publications

(35 citation statements)

References 57 publications

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“…However, the plant cells contain chloroplasts with an intense electron flow which results in high rates of ROS production (Foyer & Noctor 2005;Shao et al 2008). In chloroplasts, O…”

Section: Discussionmentioning

confidence: 99%

Effects of NaCl and Na2CO3 stresses on photosynthetic ability of Chlamydomonas reinhardtii

et al. 2014

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Chloride and carbonate salts are the main salts causing salinization and widely exist in aquatic environment, so algae may suffer from salinization stress for high water evaporation. In this study, in order to investigate and compare the toxic effects of the two salts on algal photosynthesis, we used NaCl and Na2CO3 to stress Chlamydomonas reinhardtii. Under the two salt stresses, the content of O −.2 and H2O2 in the cells was increased significantly, and it was much higher in Na2CO3 treatment than in NaCl treatment at the same Na + concentration. The absorbance spectra and 4 th derivative spectra of photosynthetic pigments were declined under 300 mM NaCl and 25 mM Na2CO3 stresses, and remarkably changed under 50 mM and 100 mM Na2CO3 stresses. When the cells stressed by the two salts, the maximum quantum yield (Fv/Fm), electron transport rate (ETR) and photochemical quenching (qP) were reduced markedly, but the nonphotochemical dissipation (NPQ) was increased markedly. At the same Na + concentration, Na2CO3 stress had stronger toxic effects on photosynthetic ability than NaCl stress.

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“…However, the plant cells contain chloroplasts with an intense electron flow which results in high rates of ROS production (Foyer & Noctor 2005;Shao et al 2008). In chloroplasts, O…”

Section: Discussionmentioning

confidence: 99%

Effects of NaCl and Na2CO3 stresses on photosynthetic ability of Chlamydomonas reinhardtii

et al. 2014

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“…Active oxygen species may also have a signalling function. For instance, the down-regulation of SOD occurring in the light in C. reinhardtii, was proposed to maintain a certain level of H 2 O 2 required to activate H 2 O 2 -dependent signalling pathways (Shao et al 2008). Recent study in cyanobacteria brought a molecular support to the existence of Mehler-type reactions through the discovery of flavodiiron (Flv) proteins (Zhang et al 2009).…”

Section: Oxygen Photoreduction At Psi Acceptor Side: Role Of Flavodiimentioning

confidence: 97%

Auxiliary electron transport pathways in chloroplasts of microalgae

et al. 2010

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Microalgae are photosynthetic organisms which cover an extraordinary phylogenic diversity and have colonized extremely diverse habitats. Adaptation to contrasted environments in terms of light and nutrient's availabilities has been possible through a high flexibility of the photosynthetic machinery. Indeed, optimal functioning of photosynthesis in changing environments requires a fine tuning between the conversion of light energy by photosystems and its use by metabolic reaction, a particularly important parameter being the balance between phosphorylating (ATP) and reducing (NADPH) power supplies. In addition to the main route of electrons operating during oxygenic photosynthesis, called linear electron flow or Z scheme, auxiliary routes of electron transfer in interaction with the main pathway have been described. These reactions which include non-photochemical reduction of intersystem electron carriers, cyclic electron flow around PSI, oxidation by molecular O(2) of the PQ pool or of the PSI electron acceptors, participate in the flexibility of photosynthesis by avoiding over-reduction of electron carriers and modulating the NADPH/ATP ratio depending on the metabolic demand. Forward or reverse genetic approaches performed in model organisms such as Arabidopsis thaliana for higher plants, Chlamydomonas reinhardtii for green algae and Synechocystis for cyanobacteria allowed identifying molecular components involved in these auxiliary electron transport pathways, including Ndh-1, Ndh-2, PGR5, PGRL1, PTOX and flavodiiron proteins. In this article, we discuss the diversity of auxiliary routes of electron transport in microalgae, with particular focus in the presence of these components in the microalgal genomes recently sequenced. We discuss how these auxiliary mechanisms of electron transport may have contributed to the adaptation of microalgal photosynthesis to diverse and changing environments.

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“…Recent work done with green algae has suggested a possible mechanism explaining this tight relationship. Expression of a nuclearencoded reporter gene coupled to a H 2 O 2 sensitive promoter was shown to respond not only to the levels of exogenously added H 2 O 2 but also to light-induced photosynthetic electron transfer, its transcriptional activation correlating with a lower intracellular H 2 O 2 scavenging activity [36]. This suggests that enhanced H 2 O 2 production in the light should reflect a transient inactivation of the ROS scavenging processes rather than an increased H 2 O 2 production, possibly to trigger specific ROS signalling responses within the cell.…”

Section: Light-induced Reactive Oxygen Species Signals Trigger a Genementioning

confidence: 99%

Signalling crosstalk in light stress and immune reactions in plants

Trotta

Rahikainen

Konert

et al. 2014

Phil. Trans. R. Soc. B

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The evolutionary history of plants is tightly connected with the evolution of microbial pathogens and herbivores, which use photosynthetic end products as a source of life. In these interactions, plants, as the stationary party, have evolved sophisticated mechanisms to sense, signal and respond to the presence of external stress agents. Chloroplasts are metabolically versatile organelles that carry out fundamental functions in determining appropriate immune reactions in plants. Besides photosynthesis, chloroplasts host key steps in the biosynthesis of amino acids, stress hormones and secondary metabolites, which have a great impact on resistance against pathogens and insect herbivores. Changes in chloroplast redox signalling pathways and reactive oxygen species metabolism also mediate local and systemic signals, which modulate plant resistance to light stress and disease. Moreover, interplay among chloroplastic signalling networks and plasma membrane receptor kinases is emerging as a key mechanism that modulates stress responses in plants. This review highlights the central role of chloroplasts in the signalling crosstalk that essentially determines the outcome of plant-pathogen interactions in plants.

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Photosynthetic electron flow affects H2O2 signaling by inactivation of catalase in Chlamydomonas reinhardtii

Abstract: A speciWc signaling role for H 2 O 2 in Chlamydomonas reinhardtii was demonstrated by the deWnition of a promoter that speciWcally responded to this ROS.

Cited by 64 publications

References 57 publications

Effects of NaCl and Na2CO3 stresses on photosynthetic ability of Chlamydomonas reinhardtii

Effects of NaCl and Na2CO3 stresses on photosynthetic ability of Chlamydomonas reinhardtii

Auxiliary electron transport pathways in chloroplasts of microalgae

Signalling crosstalk in light stress and immune reactions in plants

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