Effects of DDT on photosynthetic electron flow in Secale species

1985 ◽  
Vol 23 (12) ◽  
pp. 2785-2789
Author(s):  
S Akbar
Keyword(s):  
Electron Flow ◽  
Photosynthetic Electron Flow

Interaction of Photosystem II Herbicides with Bicarbonate and Formate in Their Effects on Photosynthetic Electron Flow

1984 ◽  
Vol 39 (5) ◽  
pp. 374-377 ◽  
Author(s):  
J. J. S. van Rensen
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Hill Reaction ◽  
Amaranthus Hybridus ◽  
Apparent Affinity ◽  
Photosynthetic Electron Flow ◽  
Different Characteristics ◽  
The Hill

The reactivation of the Hill reaction in CO2-depleted broken chloroplasts by various concentrations of bicarbonate was measured in the absence and in the presence of photosystem II herbicides. It appears that these herbicides decrease the apparent affinity of the thylakoid membrane for bicarbonate. Different characteristics of bicarbonate binding were observed in chloroplasts of triazine-resistant Amaranthus hybridus compared to the triazine-sensitive biotype. It is concluded that photosystem II herbicides, bicarbonate and formate interact with each other in their binding to the Qв-protein and their interference with photosynthetic electron transport.

Non-Invasive Monitoring of the Light-Induced Cyclic Photosynthetic Electron Flow during Cold Hardening in Wheat Leaves

2006 ◽  
Vol 61 (9-10) ◽  
pp. 734-740 ◽  
Author(s):  
Simona Apostol ◽  
Gabriella Szalai ◽  
László Sujbert ◽  
Losanka P. Popova ◽  
Tibor Janda
Keyword(s):  
Winter Wheat ◽  
Electron Flow ◽  
Wheat Variety ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Light Conditions ◽  
Non Invasive ◽  
Photosynthetic Electron Flow ◽  
Temperature Hardening ◽  
Wheat Leaves

AbstractThe effect of irradiance during low temperature hardening was studied in a winter wheat variety. Ten-day-old winter wheat plants were cold-hardened at 5 °C for 11 days under light (250 μmol m-2 s-1) or dark (20 μmol m-2 s-1) conditions. The effectiveness of hardening was significantly lower in the dark, in spite of a slight decrease in the Fv/Fm chlorophyll fluorescence induction parameter, indicating the occurrence of photoinhibition during the hardening period in the light. Hardening in the light caused a downshift in the far-red induced AG (afterglow) thermoluminescence band. The faster dark re-reduction of P700+, monitored by 820-nm absorbance, could also be observed in these plants. These results suggest that the induction of cyclic photosynthetic electron flow may also contribute to the advantage of frost hardening under light conditions in wheat plants.

Antibodies to Chlorophyll and their Reactions with Chloroplast Preparations

1971 ◽  
Vol 26 (5) ◽  
pp. 435-446 ◽  
Author(s):  
Alfons Radunz ◽  
Georg H. Schmid ◽  
Wilhelm Menke
Keyword(s):  
Photosystem I ◽  
Electron Flow ◽  
Membrane Surface ◽  
Protein Composition ◽  
Inhibitory Effect ◽  
Hill Reaction ◽  
Protein Layer ◽  
Lamellar System ◽  
Light Reaction ◽  
Photosynthetic Electron Flow

Antibodies to chlorophyll are specifically adsorbed onto the membrane surface of thylakoids. The antibodies inhibit photosynthetic electron flow from water to NADP⊕. This inhibition is presumably caused by adsorption of the antibodies onto the centre chlorophyll of light reaction II. Fragments of the thylakoid membrane, obtained by ultrasonication and subsequent fractioning centrifugation, exhibit only photosystem-I activity. Conversely, the specific adsorption of antibodies to sensitizer chlorophyll has no inhibitory effect on electron transport. The ferricyanide Hill reaction of chloroplast preparations is inhibited by chlorophyll antibodies. From these observations it is concluded that the centre chlorophyll of light reaction II and at least part of the sensitizer chlorophyll is located on the surface of the thylakoids. As agglutination is sterically inhibited by the membrane protein, it is assumed that the chlorophyll is located in gaps or pores of the protein layer.Two fractions of the lamellar system exhibit photosystem I activity of different characteristic electron donor specificity. These fractions can be further distinguished in terms of their circular dichroism and protein composition.

Formate as an Inhibitor of Photosynthetic Electron Flow

1984 ◽  
Vol 39 (5) ◽  
pp. 386-388 ◽  
Author(s):  
Jan F. H. Snel ◽  
Dirk Naber ◽  
Jack J. S. van Rensen
Keyword(s):  
Inhibitory Action ◽  
Electron Flow ◽  
Hill Reaction ◽  
Maximal Inhibition ◽  
Photosynthetic Electron Flow ◽  
The Hill

The effects of formate on the Hill reaction in isolated broken pea chloroplasts were in­vestigated. Addition of formate to chloroplasts has two distinct effects: I. basal electron flow can be stimulated 3-fold; 2. uncoupled electron flow is inhibited. The stimulating effect is due to uncoupling by formate and appears instantaneous. Maximal inhibition by form ate is only observed after prolonged illumination. The inhibitory action of form ate on electron flow can be relieved by bicarbonate *.

scholarly journals The effects of acetaldehyde on nitrogenase, hydrogenase and photosynthesis in the cyanobacterium Anabaena cylindrica

1983 ◽  
Vol 212 (3) ◽  
pp. 755-758 ◽  
Author(s):  
B Slatyer ◽  
A Daday ◽  
G D Smith
Keyword(s):  
Methyl Viologen ◽  
Co2 Fixation ◽  
Electron Flow ◽  
Anabaena Cylindrica ◽  
O2 Uptake ◽  
Irreversible Inhibitor ◽  
Photosynthetic Electron Flow ◽  
Separate Electron ◽  
Cyanobacterium Anabaena ◽  
Flow Through

Acetaldehyde was shown to be an irreversible inhibitor of nitrogenase, hydrogenase, CO2 fixation and growth in the cyanobacterium Anabaena cylindrica, but had no effect on photosynthetic electron flow as measured by Methyl Viologen-dependent O2 uptake. The concentration-dependence of the inhibition of nitrogenase and hydrogenase activities was determined, and it was shown that acetaldehyde inhibition poses problems for anaerobic experiments in which the activities of these enzymes are measured in the presence of the frequently used glucose/glucose oxidase/catalase/ethanol O2 trap. It is suggested that acetaldehyde may find use as an inhibitor in experiments designed to separate electron flow through the photosystems from consequent fixation of CO2 and N2.

Mode of Inhibition of Photosynthetic Electron Transport by Substituted Diphenylethers

1981 ◽  
Vol 36 (9-10) ◽  
pp. 848-852 ◽  
Author(s):  
W. Draber ◽  
H. J. Knops ◽  
A. Trebst
Keyword(s):  
Electron Transport ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Thylakoid Membranes ◽  
Photosynthetic Electron Flow ◽  
Spinach Chloroplasts

Abstract Several substituted diphenylethers were found to be effective inhibitors of photosynthetic electron flow in isolated thylakoid membranes from spinach chloroplasts. T heir site of inhibition was localized with artificial acceptor and donor systems. The phenylether of an alkyl substituted nitrophenol is prim arely inhibiting electron flow after plastoquinone function whereas a dinitro-phenylether of a phenyl substituted nitrophenol is inhibiting before plastoquinone function. Therefore certain diphenylethers interfere with plastoquinone function at the oxidation or reduction site, depending on the substitution.

Interference by Nickel(II) Salts and Their 5-Methylimidazole-4-carboxylate Coordination Compounds on the Chloroplast Redox Chain

1998 ◽  
Vol 53 (11-12) ◽  
pp. 987-994 ◽  
Author(s):  
Beatriz King-Díaz ◽  
Nórah Barba-Behrens ◽  
Josefina Montes-Ayala ◽  
Silvia E. Castillo-Blum ◽  
Concepción Escartín-Guzmán ◽  
...  
Keyword(s):  
Binding Sites ◽  
Coordination Compounds ◽  
Electron Flow ◽  
D1 Protein ◽  
Atp Synthesis ◽  
Fluorescence Yield ◽  
The Other ◽  
Hill Reaction ◽  
Photosynthetic Electron Flow ◽  
Redox Chain

Abstract Nickel(II) salts and their coordination com pounds with ethyl 5-m ethylim idazole-4-carboxylate (emizco), [Ni(emizco)2Cl2], [Ni(emizco)2Br2], [Ni(emizco)2(H2O)2] (NO3)2 H2O · Ni(NO3)2, inhibit photosynthetic electron flow (basal, phosphorylating and uncoupled) and ATP-synthesis, therefore behave as Hill reaction inhibitors. Coordination compounds are more potent inhibitors than the salts. It was found that the target for NiCl2; NiBr2 and Ni(NO3)2 is at the b6f level. On the other hand, the complexes [Ni(Emizco)2Cl2], [Ni(Emizco)2Br2] and [Ni(emizco)2(H2O )2] (NO3)2H2O binding sites are located at QB(D1)-protein and b6f level. Therefore, they have a common inhibition site located at b6f avoiding the PQH2 oxidation. The QB inhibition site was corroborated by variable chlorophyll a fluorescence yield [V(j)]. The emizco ligand has no activity on photosynthetic electron flow.

Sign in / Sign up

Export Citation Format

Share Document