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Literature summary for 1.97.1.12 extracted from

  • Tongra, T.; Bharti, S.; Jajoo, A.
    Cyclic electron flow around photosystem I is enhanced at low pH (2014), Plant Physiol. Biochem., 83, 194-199 .
    View publication on PubMed

Activating Compound

Activating Compound Comment Organism Structure
additional information positive correlation between non-photochemical quenching (NPQ) and stimulation of CEF-PS I Spinacia oleracea

Localization

Localization Comment Organism GeneOntology No. Textmining
chloroplast
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Spinacia oleracea 9507
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thylakoid membrane
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Spinacia oleracea 42651
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Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
reduced cytochrome b6 + oxidized ferredoxin + hv Spinacia oleracea
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oxidized cytochrome b6 + reduced ferredoxin
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?

Organism

Organism UniProt Comment Textmining
Spinacia oleracea P80470 AND P06512 AND P10098 psaA, psaB, and psaC
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Source Tissue

Source Tissue Comment Organism Textmining
leaf
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Spinacia oleracea
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Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
reduced cytochrome b6 + oxidized ferredoxin + hv
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Spinacia oleracea oxidized cytochrome b6 + reduced ferredoxin
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?

Synonyms

Synonyms Comment Organism
PS I
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Spinacia oleracea

pH Range

pH Minimum pH Maximum Comment Organism
additional information
-
cyclic electron flow around photosystem I is enhanced at low pH of 5.5. The light response curve of PS I is significantly affected by acidification of the thylakoid membranes Spinacia oleracea

Cofactor

Cofactor Comment Organism Structure
plastoquinone
-
Spinacia oleracea

General Information

General Information Comment Organism
metabolism cyclic electron flow (CEF) can be stimulated to provide significant additional protection in plants when they are confronted with acidic pH conditions. But at low pH, the photosynthetic efficiency greatly decreases resulting in excessive excitation pressure in PS II and consequently an increased risk of damage on the donor side of PS II Spinacia oleracea
additional information cyclic electron flow around photosystem I is enhanced at low pH of 5.5. The light response curve of PS I is significantly affected by acidification of the thylakoid membranes Spinacia oleracea
physiological function cyclic electron flow (CEF) PS I is a highly dynamic, regulated and large capacity pathway involving ferredoxin (Fd) and Cytb6f complex. In CEF, the plastoquinone (PQ) pool is reduced by Fd which is photoreduced by PS I. The reduced PQ pool is oxidized by the Cytb6f complex, where DpH is generated across thylakoid membranes through the Q cycle. This DpH drives ATP synthase and produces the ATP required for the net CO2 assimilation and also stimulates NPQ. It has been proposed that there are two physiological functions of CEF in thylakoid membrane. During photosynthesis, cyclic electron flow around PSI can generate a pH gradient across the thylakoid membrane that not only is used to synthesize ATP, but can also induce thermal dissipation and provide protection for the photosynthetic apparatus Spinacia oleracea