Overexpression of plastid terminal oxidase in
            <i>Synechocystis</i>
            sp. PCC 6803 alters cellular redox state

Feilke, Kathleen; Ajlani, Ghada; Krieger‐Liszkay, Anja

doi:10.1098/rstb.2016.0379

Cited by 12 publications

(9 citation statements)

References 55 publications

(85 reference statements)

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“…These authors found that the spectroscopic signature of charge separation in preparations of partially oxidized reaction centres was replaced by that of an energy dissipation process. Krieger-Liszkay and co-workers [10] describe how photosystem (PS) II electron transport capacity in the cyanobacterium Synechocystis sp. PCC 6803 was altered relative to PSI by constitutive expression of the plastid terminal oxidase, which oxidizes plastoquinol and reduces oxygen to water.…”

Section: Enhancing Photosynthesis In Microorganismsmentioning

confidence: 99%

Photosynthesis solutions to enhance productivity

Foyer

Ruban

Nixon

2017

Phil. Trans. R. Soc. B

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The concept that photosynthesis is a highly inefficient process in terms of conversion of light energy into biomass is embedded in the literature. It is only in the past decade that the processes limiting photosynthetic efficiency have been understood to an extent that allows a step change in our ability to manipulate light energy assimilation into carbon gain. We can therefore envisage that future increases in the grain yield potential of our major crops may depend largely on increasing the efficiency of photosynthesis. The papers in this issue provide new insights into the nature of current limitations on photosynthesis and identify new targets that can be used for crop improvement, together with information on the impacts of a changing environment on the productivity of photosynthesis on land and in our oceans. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

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Section: Enhancing Photosynthesis In Microorganismsmentioning

confidence: 99%

Photosynthesis solutions to enhance productivity

Foyer

Ruban

Nixon

2017

Phil. Trans. R. Soc. B

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“…While over-expression of C. reinhardtii PTOX1 in plants makes the mutants more sensitive to HL than WT [38,39] and Arabidopsis PTOX in tobacco promotes oxidative stress [40,41]. Similarly, OsPTOX expression in Synechocystis did not affect growth under standard growth conditions (light intensities between 50 and 150 µmol photons m − 2 s − 1 ) [42]. In other stress treatments, over-expression of PTOX from the salt-tolerant brassica species Eutrema salsugineum show faster induction and a greater final level of PTOX activity once exposed to salt stress [43].…”

Section: Discussionmentioning

confidence: 93%

Plastid terminal oxidases in Chlamydomonas: connections with astaxanthin and bio-hydrogen production

Li¹,

Zheng²,

Xiao³

et al. 2020

Preprint

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Background: as a plasto quinol oxidase involved in plastoquinol oxidation in higher plants and microalgae, the plastid terminal oxidase (PTOX) was first recognized in the tomato mutant GHOST (GH) and Arabidopsis mutant IMMUTANS (IM). Genome sequence analysis revealed that duplication of the PTOX gene occurs in certain eukaryotic microalgae, but not in cyanobacteria and most higher plants. PTOX may also be involved in carotenoid synthesis and play a critical protective role against stress, such as high light, heat shock and hyperosmosis. However, the connections of PTOX with astaxanthin and bio-hydrogen production and their functional relationship between two PTOX genes in the model green microalga Chlamydomonas is unknown. Results: we successfully knocked down two ptoxs through RNAi in Chlamydomonas, respectively. We demonstrated that expression levels of both PTOXs were increased under stress conditions, and interestingly when one PTOX was silenced the other’s transcriptional level was significantly raised. Conclusions: this shows a complementary relationship under high light condition. In addition, the astaxanthin accumulation level was up-regulated in silenced ptox2 strain, compared to the wide type strain. What’s more, significantly increased hydrogen production was observed in silenced ptox1 strain. In conclusion, PTOXs in Chlamydomonas are connected with not only astaxanthin accumulation but also hydrogen production, and their knock-down strains provide new insights in manipulating microalgae for high light stress tolerant strains, carotenoid production and even biofuels.

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“…Such hypothesis is corroborated by the markedly upregulated protein levels of NDC1 in the plants under NH + 4 nutrition ( Figure 6B). Remarkably, PTOX is considered an important component of redox sensing in higher plants in relation to the redoxin system (Kambakam et al, 2016;Feilke et al, 2017; and references therein), which regulates several chloroplast-localized processes including PSI assembly (Zhu et al, 2016) and improves the tolerance of plants to stress (Johnson and Stepien, 2016).…”

Section: The Upregulated Cet/ndc1-ptox Pathways Under Nh + 4 Nutritiomentioning

confidence: 99%

Efficient Photosynthetic Functioning of Arabidopsis thaliana Through Electron Dissipation in Chloroplasts and Electron Export to Mitochondria Under Ammonium Nutrition

et al. 2020

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An improvement in photosynthetic rate promotes the growth of crop plants. The sinkregulation of photosynthesis is crucial in optimizing nitrogen fixation and integrating it with carbon balance. Studies on these processes are essential in understanding growth inhibition in plants with ammonium (NH + 4) syndrome. Hence, we sought to investigate the effects of using nitrogen sources with different states of reduction (during assimilation of NO − 3 versus NH + 4) on the photosynthetic performance of Arabidopsis thaliana. Our results demonstrated that photosynthetic functioning during long-term NH + 4 nutrition was not disturbed and that no indication of photoinhibition of PSII was detected, revealing the robustness of the photosynthetic apparatus during stressful conditions. Based on our findings, we propose multiple strategies to sustain photosynthetic activity during limited reductant utilization for NH + 4 assimilation. One mechanism to prevent chloroplast electron transport chain overreduction during NH + 4 nutrition is for cyclic electron flow together with plastid terminal oxidase activity. Moreover, redox state in chloroplasts was optimized by a dedicated type II NAD(P)H dehydrogenase. In order to reduce the amount of energy that reaches the photosynthetic reaction centers and to facilitate photosynthetic protection during NH + 4 nutrition, non-photochemical quenching (NPQ) and ample xanthophyll cycle pigments efficiently dissipate excess excitation. Additionally, high redox load may be dissipated in other metabolic reactions outside of chloroplasts due to the direct export of nucleotides through the malate/oxaloacetate valve. Mitochondrial alternative pathways can downstream support the overreduction of chloroplasts. This mechanism correlated with the improved growth of A. thaliana with the overexpression of the alternative oxidase 1a (AOX1a) during NH + 4 nutrition. Most remarkably, our findings

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Overexpression of plastid terminal oxidase in Synechocystis sp. PCC 6803 alters cellular redox state

Cited by 12 publications

References 55 publications

Photosynthesis solutions to enhance productivity

Photosynthesis solutions to enhance productivity

Plastid terminal oxidases in Chlamydomonas: connections with astaxanthin and bio-hydrogen production

Efficient Photosynthetic Functioning of Arabidopsis thaliana Through Electron Dissipation in Chloroplasts and Electron Export to Mitochondria Under Ammonium Nutrition

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