Deficiency in flavodiiron protein Flv3 promotes cyclic electron flow and state transition under high light in the cyanobacterium Synechocystis sp. PCC 6803

Elanskaya, I.V.; Булычев, А. А.; Лукашев, Е. П.; Muronets, E. M.

doi:10.1016/j.bbabio.2020.148318

Cited by 7 publications

(5 citation statements)

References 58 publications

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“…Both the ∆flv1A and ∆flv3A mutants showed significantly lower F m D than WT in LC (Figure 1 and Table 1), implying a more pronounced state 2 in the dark. Accordingly, a stronger state 2-to-state 1 transition (qT in Table 1) was observed during illumination in comparison to WT, similarly to the phenotype previously described in the Synechocystis ∆flv3 mutant (Elanskaya et al, 2021). Notably, during the dark-to-light transition, the fluorescence kinetics were differently affected in the two mutants grown under LC conditions.…”

Section: Fluorescence and P700 Oxidoreduction Properties Of ∆Flv1a And ∆Flv3asupporting

confidence: 79%

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Santana‐Sánchez

Nikkanen

Tóth

et al. 2021

Preprint

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The model heterocyst-forming filamentous cyanobacterium, Anabaena sp. PCC 7120 (Anabaena) represents multicellular organisms capable of simultaneously performing oxygenic photosynthesis in vegetative cells and the O2-sensitive N2-fixation inside the heterocysts. The flavodiiron proteins (FDPs) have been shown to participate in photoprotection of photosynthesis by driving excess electrons to O2 (Mehler-like reaction). Here, we addressed the physiological relevance of the vegetative cell-specific Flv1A and Flv3A on the bioenergetic processes occurring in diazotrophic Anabaena under variable CO2. We demonstrate that both Flv1A and Flv3A are required for proper induction of the Mehler-like reaction upon a sudden increase in light intensity, which is likely important for the activation of carbon-concentrating mechanisms (CCM) and CO2 fixation. Under low CO2 diazotrophic conditions, Flv3A is capable of mediating moderate O2 photoreduction, independently of Flv1A, but in coordination with Flv2 and Flv4. Strikingly, the lack of Flv3A resulted in strong downregulation of the heterocyst-specific uptake hydrogenase, which led to enhanced H2 photoproduction under both oxic and micro-oxic conditions. These results reveal a novel regulatory network between the Mehler-like reaction and the H2 metabolism, which is of great interest for future photobiological production of H2 in Anabaena.

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Section: Fluorescence and P700 Oxidoreduction Properties Of ∆Flv1a And ∆Flv3asupporting

confidence: 79%

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Santana‐Sánchez

Nikkanen

Tóth

et al. 2021

Preprint

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“…Photooxidation of cyanobacterial PSI has been reported to be affected when electron consuming pathways peripheral to photosynthesis are disrupted, presumably due to acceptor side limitations in electron transfer at PSI. [4][5][6][7][8] These pathways act as sinks for electrons under certain environmental and physiological conditions, and disruptions to these typically result in electron congestion at the PSI acceptor side. 9 One such pathway comprises avodiiron (Flv) enzymes which catalyze the oxygen reduction reaction (ORR) that contributes to the relief of excess electron ux via the generation of water.…”

Section: Introductionmentioning

confidence: 99%

The influence of electron utilization pathways on photosystem I photochemistry in Synechocystis sp. PCC 6803

et al. 2022

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“…S6d ; Methods S2 ), implying a more pronounced state 2 in the dark. Accordingly, a stronger state‐2‐to‐state‐1 transition (qT, Table 1 ) was observed during illumination in comparison to the WT, similar to the phenotype described previously in the Synechocystis ∆flv3 mutant (Elanskaya et al ., 2021 ). Notably, fluorescence kinetics during dark‐to‐light transitions were affected differently in the two mutants grown under LC conditions.…”

Section: Resultsmentioning

confidence: 99%

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

et al. 2022

View full text Add to dashboard Cite

The model heterocyst-forming filamentous cyanobacterium Anabaena sp. PCC 7120 (Anabaena) is a typical example of a multicellular organism capable of simultaneously performing oxygenic photosynthesis in vegetative cells and O 2 -sensitive N 2 -fixation inside heterocysts. The flavodiiron proteins have been shown to participate in photoprotection of photosynthesis by driving excess electrons to O 2 (a Mehler-like reaction).Here, we performed a phenotypic and biophysical characterization of Anabaena mutants impaired in vegetative-specific Flv1A and Flv3A in order to address their physiological relevance in the bioenergetic processes occurring in diazotrophic Anabaena under variable CO 2 conditions.We demonstrate that both Flv1A and Flv3A are required for proper induction of the Mehler-like reaction upon a sudden increase in light intensity, which is likely important for the activation of carbon-concentrating mechanisms and CO 2 fixation. Under ambient CO 2 diazotrophic conditions, Flv3A is responsible for moderate O 2 photoreduction, independently of Flv1A, but only in the presence of Flv2 and Flv4. Strikingly, the lack of Flv3A resulted in strong downregulation of the heterocyst-specific uptake hydrogenase, which led to enhanced H 2 photoproduction under both oxic and micro-oxic conditions.These results reveal a novel regulatory network between the Mehler-like reaction and the diazotrophic metabolism, which is of great interest for future biotechnological applications.

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Deficiency in flavodiiron protein Flv3 promotes cyclic electron flow and state transition under high light in the cyanobacterium Synechocystis sp. PCC 6803

Cited by 7 publications

References 58 publications

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

The influence of electron utilization pathways on photosystem I photochemistry in Synechocystis sp. PCC 6803

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

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Deficiency in flavodiiron protein Flv3 promotes cyclic electron flow and state transition under high light in the cyanobacterium Synechocystis sp. PCC 6803

Cited by 7 publications

References 58 publications

Flv3A facilitates O2 photoreduction and affects H2 photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Flv3A facilitates O2 photoreduction and affects H2 photoproduction independently of Flv1A in diazotrophic Anabaena filaments

The influence of electron utilization pathways on photosystem I photochemistry in Synechocystis sp. PCC 6803

Flv3A facilitates O2 photoreduction and affects H2 photoproduction independently of Flv1A in diazotrophic Anabaena filaments

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Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments

Flv3A facilitates O₂ photoreduction and affects H₂ photoproduction independently of Flv1A in diazotrophic Anabaena filaments