Conjugated Enamino Compounds, a New Molecular Probe for the Mechanism of Photosynthetic Electron Transport

1986 ◽  
Vol 41 (7-8) ◽  
pp. 751-757 ◽  
Author(s):  
Tadao Asami ◽  
Nobutaka Takahashi ◽  
Shigeo Yoshida
Keyword(s):  
Electron Transport ◽  
Binding Site ◽  
Photosynthetic Electron Transport ◽  
Biological Characteristics ◽  
Molecular Probe ◽  
Hill Reaction ◽  
The Hill ◽  
Isolated Chloroplasts ◽  
Good Probe

Abstract A series of 2-(1-alkylamino)vinylidene-1,3-cyclohexanedione was synthesized and assayed as inhibitors of the Hill reaction in isolated chloroplasts. The pI50 value of this series was dramatically changed by modification of the peripheral of its hydrophilic moiety and the maximum pI50 value of this series was almost equal to that of DCMU . The results suggest that this series may be a good probe for searching the environment of inhibitors binding site because of its chemical and biological characteristics and its ease of synthesis.

On a new inhibitor of photosynthetic electron-transport in isolated chloroplasts

1970 ◽  
Vol 25 (10) ◽  
pp. 1157-1159 ◽  
Author(s):  
A. Trebst ◽  
E. Harth ◽  
W. Draber
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Photosynthetic Electron Transport ◽  
Hill Reaction ◽  
High Concentration ◽  
Ferricyanide Reduction ◽  
The Hill ◽  
Photosystem I And Ii ◽  
Isolated Chloroplasts

A halogenated benzoquinone has been found to inhibit the photosynthetic electron transport system in isolated chloroplasts. 2·10-6ᴍ of dibromo-thymoquinone inhibit the Hill- reaction with NADP, methylviologen or anthraquinone to 100%, but do not effect the photoreduction of NADP at the expense of an artificial electron donor. The Hill - reaction with ferricyanide is inhibited even at the high concentration of 2·10-5ᴍ of dibromo-thymoquinone to only 60%. The remaining reduction in the presence of the inhibitor reflects the rate of ferricyanide reduction by photosystem II. It is concluded that the inhibition of electron transport by the quinone occurs between photosystem I and II and close to or at the functional site of plastoquinone.

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.

Photoautotrophic Cultured Plant Cells: A Novel System to Survey New Photosynthetic Electron Transport Inhibitors

1991 ◽  
Vol 46 (7-8) ◽  
pp. 563-568 ◽  
Author(s):  
Fumihiko Sato ◽  
Yasuyuki Yamada ◽  
Sang Soo Kwak ◽  
Katsunori Ichinose ◽  
Mitsuhiro Kishida ◽  
...  
Keyword(s):  
Electron Transport ◽  
Cultured Cells ◽  
Plant Cells ◽  
Photosynthetic Electron Transport ◽  
Herbicidal Activity ◽  
Marchantia Polymorpha ◽  
Hill Reaction ◽  
Transport Inhibitors ◽  
Comparison Of The Results ◽  
The Hill

Abstract The responses of photoautotrophic (PA) cultured cells of tobacco (Nicotiana tabacum cv. Samsun NN) and liverwort (Marchantia polymorpha L.) to thirty-eight cyclohexanedione derivatives were surveyed. Each derivative was also tested for inhibitory activity on photosynthetic electron transport (PET), using isolated thylakoids, and herbicidal activity, using seed­ lings and mature plants. Comparison of the results from the different assays showed that the responses of PA cells to each com pound correlated more closely with the responses of seed­ lings and mature plants than did the results of the Hill reaction assays. Our findings suggest that PA cultured cells would be a suitable screening material for identifying potential herbicides with PET-inhibiting activity.

Counteraction of Paraquat Toxicity at the Chloroplast Level

1987 ◽  
Vol 42 (7-8) ◽  
pp. 824-828 ◽  
Author(s):  
Brad L. Upham ◽  
Kriton K. Hatzios
Keyword(s):  
Electron Transport ◽  
Pisum Sativum ◽  
Photosynthetic Electron Transport ◽  
Heme Iron ◽  
Hill Reaction ◽  
Ion Toxicity ◽  
Plastoquinone Pool ◽  
Pisum Sativum L ◽  
Paraquat Toxicity ◽  
Isolated Chloroplasts

Six pyridyl derivatives [benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4- pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine] and five heme-iron derivatives [hemoglobin, hemin, hematin, ferritin, and ferrocene] were screened for their potential to coun- teract paraquat (1,1′-dimethyl-4.4′-bipyridinium ion) toxicity on pea (Pisum sativum L.) isolated chloroplasts. The H2O -> methylviologen(MV)/O2 and H2O → ferredoxin(Fd)/NADP+ were two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. All pyridyl derivatives examined did not inhibit the reaction H2O → MV/O2. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H2O → MV/O2 without inhibiting the reaction H2O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. They also inhibited H2O → diaminodurene(DAD)ox and durohydro-quinone → MV/O2 Hill reactions but not the dichlorophenol indophenolred → MV/O2 and DADred → MV/O2 Hill reactions. These results suggest that hemin and hematin are inhibiting the photosynthetic electron transport in the plastoquinone-pool region.

Mannich Bases of Glyoxylanilide 2-Oximes and their Effect on Photosynthetic Electron Transport

1972 ◽  
Vol 27 (7) ◽  
pp. 797-799 ◽  
Author(s):  
M. M. Sidky ◽  
F. M. Soliman ◽  
A. A. El-Kateb
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
Mannich Bases ◽  
Secondary Amines ◽  
Biological Assay ◽  
Hill Reaction ◽  
The Hill

Glyoxylanilide 2-oximes (I a—c) condense with formaldehyde and secondary amines to give the corresponding Mannich bases (II a—1). The assigned structure II finds support from chemical and spectral evidences. Representative examples of the Mannich bases are tested as inhibitors for the Hill reaction and the result of the biological assay are discussed.

Über eine p-Hydroxylierung in isolierten Chloroplasten

1963 ◽  
Vol 18 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Achim Trebst ◽  
Herbert Eck
Keyword(s):  
Electron Transport ◽  
Transport System ◽  
Phenyl Ring ◽  
Functional Role ◽  
Electron Transport System ◽  
Hill Reaction ◽  
The Hill ◽  
Isolated Chloroplasts ◽  
Carbonyl Function

Salicylaldoxime at a concentration of 10-2-m. is an inhibitor of the Hill - reaction and therefore also of aerobic photophosphorylation in isolated chloroplasts. This might indicate a functional role for copper in the electron transport system of photosynthesis.At a concentration of 10-3-m. and lower, salicylaldoxime is not an inhibitor, but a cofactor of aerobic photophosphorylation. This is due to its hydroxylation to the p-hydroquinone, which is the actual cofactor. This p-hydroxylation, which is probably catalyzed by a peroxidase, takes place only with salicylaldehyde and its oxime, but not with other phenols, whether they have a carbonyl function attached to the phenyl ring or not. A number of o- and p-hydroquinones with a carbonyl function at the phenyl ring and two naphthohydroquinones, of which the corresponding quinone cannot be prepared by chemical means, are reversibly oxidized and reduced in photosynthetic phosphorylation in chloroplasts. A possible explanation is that these hydroquinones are oxidized only to the semiquinone level and rapidly reduced again.

scholarly journals Effect of herbicides on photosynthetic electron transport and on the growth of the alga Scenedesmus quadricauda

2015 ◽  
Vol 45 (1–2) ◽  
pp. 101-110
Author(s):  
W. Hendrich ◽  
Z> Kubiak ◽  
K. Jurajda ◽  
M. Pawlaczyk-Szpilowa
Keyword(s):  
Electron Transport ◽  
Mechanism Of Action ◽  
Photosynthetic Electron Transport ◽  
Inhibitory Effect ◽  
Scenedesmus Quadricauda ◽  
Hill Reaction ◽  
The Hill ◽  
Alga Scenedesmus Quadricauda

The inhibitory effect of herbicides on the Hill reaction (with 2,6-dichloro-phenol-indophenol as acceptor) and their influence on development of the alga <i>Scenedesmus quadricauda</i> was studied. The following herbicides were tested: 2,4-D, Gramoxone, Afalon, Kresamone, CIPC and Simazine. The results are discussed in terms of the mechanism of action of the investigated herbicides.

Synthesis and Use of Radiolabelled Cyanoacrylate Probes of the Photosystem II Herbicide Binding Site

1990 ◽  
Vol 45 (3-4) ◽  
pp. 196-202 ◽  
Author(s):  
Helen G. McFadden ◽  
John N. Phillips
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Binding Site ◽  
Active Site ◽  
Photosynthetic Electron Transport ◽  
Inhibitor Binding ◽  
Similar System ◽  
Weak Binding ◽  
Herbicide Binding ◽  
The Hill

Abstract Cyanoacrylates are potent inhibitors of photosynthetic electron transport (PET) and are potentially useful probes of the photosystem II herbicide binding site. A series of cyanoacrylates was synthesized and the Hill inhibition activities evaluated in order to select compounds suita­ble for radioactive synthesis. A cyanoacrylate, 2-(2-nitrophenoxy)ethyl 3-benzylamino-2-cyano-2-pentenoate, was found to displace diuron from the photosystem II herbicide binding site. For this compound the dissociation constant of the inhibitor/binding site complex was found to be 2 × 10-8 M with an active site concentration of 2 nmol/mg chlorophyll. In a similar system the corresponding figures for diuron were 1.2 × 10-8 m and 1.3 nmol/mg chlorophyll. Photoaffinity labelling of 1% II thylakoid proteins with 2-(2-azidophenoxy)ethyl 3-[7-14C]-benzylamino-2-cyano-2-pentenoate showed weak binding in the 32 and 28 kD mass regions, consistent with binding to the D, peptide.

Reactions of Antisera to Lutein and Plastoquinone with Chloroplast Preparations and their Effects on Photosynthetic Electron Transport

1973 ◽  
Vol 28 (1-2) ◽  
pp. 36-44 ◽  
Author(s):  
Alfons Radunz ◽  
Georg H. Schmid
Keyword(s):  
Electron Transport ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Potassium Ferricyanide ◽  
Electron Donors ◽  
Hill Reaction ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain ◽  
Pass Through ◽  
The Hill

An antiserum to lutein inhibits photosynthetic electron transport between water and potassium ferricyanide in diloroplasts from green Nicotiana tabacum var. John William’s Breadleaf. However, electron transport between diphenylcarbazide and potassium ferricyanide is not impaired. From this it is concluded that the photochemically active carotenoid should feed its electrons into the photosynthetic electron transport chain before the site from which diphenyl-carbazide donates electrons. The inhibition of the ferricyanide Hill reaction in diloroplasts by antibodies to lutein depends on the accessibility of the carotenoid antigen in the thylakoid membrane. In fresh preparations the accessibility is greater in diloroplasts in which photo- synthetic electron transport is coupled to photophosphorylation. Concomitantly the antiserum to lutein agglutinates only such chloroplast preparations in which the Hill reaction is impaired by the antiserum. An antiserum to plastoquinone inhibits ferricyanide photoreduction of diloroplasts regardless whether driven by water or diphenylcarbazide as the electron donors. Typical photosystem-I-reactions are not influenced by the antiserum. In a certain type of chloroplast preparations the antiserum does not inhibit PMS-mediated photophosphorylation inferring that plastoquinone, eventually involved in this reaction, is either not accessible to antibodies, or that this cyclic electron flow does not necessarily pass through plastoquinone.

Comparative Triazine Effects Upon System II Photochemistry in Chloroplasts of Two Common Lambsquarters(Chenopodium album)Biotypes

Weed Science ◽  
1978 ◽  
Vol 26 (4) ◽  
pp. 318-322 ◽  
Author(s):  
V. Souza Machado ◽  
C. J. Arntzen ◽  
J. D. Bandeen ◽  
G. R. Stephenson
Keyword(s):  
Electron Transport ◽  
Chenopodium Album ◽  
Chloroplast Envelope ◽  
Hill Reaction ◽  
Ps Ii ◽  
Common Lambsquarters ◽  
Relative Tolerance ◽  
The Hill ◽  
Ps Ii Activity ◽  
Isolated Chloroplasts

Biotypes of several annual broadleaved weeds tolerant to 2-chloro-s-triazines have been recorded, including common lambsquarters(Chenopodium albumL.). The mechanism of resistance in common lambsquarter was based on the differential inhibition of the Hill reaction in chloroplasts by atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine]. Chlorophyll fluorescence and electron transport assays were used with isolated chloroplasts of atrazine-tolerant and susceptible biotypes, to determine the effect of atrazine and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] on photosystem II (PS II) activity, differential atrazine penetration of the chloroplast envelope, and relative tolerance to chloro, methoxy, and methylthio triazines. Atrazine and diuron inhibited electron transport on the reducing side of PS II in susceptible biotype chloroplasts. In tolerant biotype chloroplasts only diuron inhibited electron transport whereas atrazine had only slight effects. There were no differences in the chloroplast membrane permeability to atrazine in the two biotypes. Chloroplasts of the atrazine-tolerant biotype of common lambsquarters were also tolerant to the other classes of triazines tested.

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