EC Number   |
General Information |
Reference |
|---|
    1.97.1.12 | evolution |
it is proposed that PSI evolved stepwise from a trimeric form to tetrameric oligomer en route to becoming monomeric in plants/algae |
746026 |
| 1.97.1.12 | malfunction |
impairment of NDH-dependent cyclic electron flow in rice specifically causes a reduction in the electron transport rate through PS I (ETR I) at low light intensity with a concomitant reduction in CO2 assimilation rate, plant biomass and importantly, grain production, while there is no effect on PS II function at low or high light intensity. Oryza sativa crr6 mutant does not accumulate the NDH complex, CRR6 is specifically required for the assembly of NdhI in subcomplex A of chloroplast NDH, knockout of the crr6 gene in rice also leads to the lack of intact chloroplast NDH, no formation of a NDH-PS I supercomplex in the Crr6 mutant. Phenotype overview |
746439 |
| 1.97.1.12 | malfunction |
photosynthetic performance is affected in WHY1 knockout mutant under different light conditions. Loss of WHIRLY1 decreases chloroplast NAD(P)H dehydrogenase-like complex (NDH) activity and the accumulation of NDH supercomplex. Loss of WHIRLY1 leads to a higher photochemical quantum yield of photosystem I Y(I) and electron transport rate and a lower non-photochemical quenching involved in the thermal dissipation of excitation energy of chlorophyll fluorescence than the wild-type. Several genes encoding the PSI-NDH complexes are also upregulated in kowhy1 and the whirly1whirly3 double mutant (ko1/3) but steady in oepWHY1 plants. Under high light conditions, both kowhy1 and ko1/3 plants show lower electron transport rate than wild-type which are contrary to that under normal light condition. Moreover, the expression of several PSI-NDH encoding genes and ERF109, which is related to jasmonate (JA) response, varies in kowhy1 under different light conditions. Loss of WHY1 seems to increase photosystem I quantum yield but not photosystem II quantum yield, phenotype, overview. Overexpression of WHY1 in both nucleus and plastid improves the transcription level of a number of genes encoding PSI core subunits which are essential to the formation of super complexes of PSI |
-, 745118 |
| 1.97.1.12 | malfunction |
site-directed mutagenesis of residues involved in the respective phylloquinone-binding sites results in a specific alteration of the rates of semiquinone oxidation. Mutation in the PhQA binding pocket (PsaA-F689N) in PSI of Chlamydomonas reinhardtii reduces down PhQA- oxidation kinetics by almost two orders of magnitude. This creates an unprecedented situation in which the reduction of P700+ is faster than the oxidation of the semiquinone, thereby providing the opportunity to initiate a second photochemical event while PhQA- is still present in ETCA, kinetics, overview |
-, 744516 |
| 1.97.1.12 | malfunction |
the PsaA-N604L mutation (near ec2B) results in a 50% reduction in the amount of electron transfer in the cofactor B-branch, while the PsaB-N591L mutation (near ec2A) results in a 70% reduction in the amount of electron transfer in the cofactor A-branch. The PsaB-N591L mutation had a significant effect upon trapping, while the PsaA-N604L mutation does not have a significant effect upon trapping |
744412 |
| 1.97.1.12 | 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 |
746134 |
| 1.97.1.12 | metabolism |
the physiological contribution of NDH-mediated CEF is greater in C4 photosynthesis than in C3 photosynthesis, suggesting that the mechanism of PET in C4 photosynthesis has changed from that in C3 photosynthesis accompanying the changes in the mechanism of CO2 assimilation |
746044 |
| 1.97.1.12 | more |
charge transfer and recombination reactions in intact and PsaC-depleted (FX-core) wild-type PS I complexes and in the menB PS I complexes containing plastoquinone (menB-PQ) and 2,3-dichloro-1,4-naphthoquinone (menB-Cl2NQ), overview. 2,3-Dichlorophenolindophenol reduced by ascorbate serves as an external electron donor for the photooxidized P700, while methylviologen plays a role of external acceptor capturing electrons from the photoreduced terminal FA/FB cluster |
745985 |
| 1.97.1.12 | more |
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 |
746134 |
| 1.97.1.12 | more |
cytochrome c6 in the Phaeodactylum tricornutum alga, as inmost diatoms, is the only electron donor to photosystem I, and thus they lack plastocyanin as an alternative electron carrier |
744392 |
