Inhibition of the Photosynthetic Electron Transport by Pyrethroid Insecticides in Cell Cultures and Thylakoid Suspensions from Higher Plants

Synthetic pyrethroid insecticides with different molecular structures have been investigated with respect to their effect on photosynthetic electron transport reactions in chloroplast suspensions and cell cultures from higher plants. The fluorescence induction curves of tobacco (Nicotiana tabacum) leaves and tomato cells were substantially affected by permethrin and cypermethrin resulting in a strong increase of the maximum fluorescence. Application of different concentrations (0.3-1.2 mᴍ ) of the respective chemical abolishes virtually any kinetics of the normal Kautsky effect. Oxygen evolution from cell cultures from tomato (Lycopersicon peruvianum) was completely inhibited by cypermethrin. Analysis of partial reactions of the photosynthetic electron transport showed that both a methylviologen-mediated Mehler reaction and a ferricyanide-driven Hill reaction were quantitatively inhibited by e.g. fenvalerate. On the other hand, neither a silicomolybdate-driven Hill reaction nor a methylviologen- driven Mehler reaction using dichlorophenol indophenol/ascorbate as electron donors could be inhibited by the pyrethroid. The analyses suggest that pyrethroid insecticides interfere with the photosynthetic electron transport at the same site as urea-type herbicides do. Depending on the molecular structure and on the halogen compound in the molecule, however, different pyrethroids are more or less phytotoxic to the investigated photosynthetic membranes - cypermethrin with two Cl-substituents requires much higher concentrations to be applied for significant inhibition of the electron transport reactions than the Br-derivative deltamethrin does. Moreover, qualitative differences have to be taken into account. In the case of fenvalerate the effect seems to exist in a type of all-or-nothing reaction when the reaction centres are inhibited by the pyrethroid. None of the S-states nor the transition probabilities are specifically influenced by increasing concentrations of fenvalerate. In the case of deltamethrin, however, it was found that the overreduced state S-1 is significantly increased at the expense of both S1 and S0. Moreover, the miss parameter a is increased in the case of deltamethrin addition. The results and the significance of different substituents for the investigated pyrethroids are discussed

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

Zeitschrift für Naturforschung C ◽

10.1515/znc-1984-0512 ◽

1984 ◽

Vol 39 (5) ◽

pp. 374-377 ◽

Cited By ~ 2

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.

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X-Ray Structure Analysis of a Cyanoacrylate Inhibitor of Photosystem II Electron Transport

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-1-215 ◽

1991 ◽

Vol 46 (1-2) ◽

pp. 93-98 ◽

Cited By ~ 8

Author(s):

Helen G. McFadden ◽

Donald C. Craig ◽

John L. Huppatz ◽

John N. Phillips

Keyword(s):

Electron Transport ◽

Photosystem Ii ◽

Chlorophyll Concentration ◽

Photosynthetic Electron Transport ◽

Hill Reaction ◽

Ps Ii ◽

X Ray ◽

High Affinity ◽

Modelling Studies ◽

Intramolecular Hydrogen

Abstract X-ray crystallographic data for the highly potent cyanoacrylate photosynthetic electron transport inhibitor, (Z)-ethoxyethyl 3-(4-chlorobenzylamino)-2-cyano-4-methylpent-2-enoate, are presented. This compound has a particularly high affinity for the photosystem II (PS II) herbicide receptor with a p I50 value of 9.5 (in the Hill reaction under uncoupled conditions with a chlorophyll concentration of 0.1 μg/ml). Data regarding the structure of small ligands, such as this potent cyanoacrylate, which bind to the site with high affinity may be used to provide the basis for modelling studies of PS II/herbicide complexes. The X-ray data presented confirm the Z-stereochemistry of active cyanoacrylates and demonstrate the presence of a planar core stabilized by an intramolecular hydrogen bond between the ester carbonyl oxygen and a benzylamino hydrogen atom. In order to assess the importance of the benzylamino -NH -group in this type of cyanoacrylate, analogues containing a methylene group in its place were synthesized and found to be 100-and 1000-fold less active as Hill inhibitors.

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Plastocyanin is the long-range electron carrier between photosystem II and photosystem I in plants

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2005832117 ◽

2020 ◽

Vol 117 (26) ◽

pp. 15354-15362 ◽

Cited By ~ 2

Author(s):

Ricarda Höhner ◽

Mathias Pribil ◽

Miroslava Herbstová ◽

Laura Susanna Lopez ◽

Hans-Henning Kunz ◽

...

Keyword(s):

Electron Transport ◽

Photosystem Ii ◽

Long Range ◽

Narrow Range ◽

Higher Plants ◽

Regulatory Element ◽

Photosynthetic Electron Transport ◽

Electron Carrier ◽

Mobile Electron ◽

Electron Carriers

In photosynthetic electron transport, large multiprotein complexes are connected by small diffusible electron carriers, the mobility of which is challenged by macromolecular crowding. For thylakoid membranes of higher plants, a long-standing question has been which of the two mobile electron carriers, plastoquinone or plastocyanin, mediates electron transport from stacked grana thylakoids where photosystem II (PSII) is localized to distant unstacked regions of the thylakoids that harbor PSI. Here, we confirm that plastocyanin is the long-range electron carrier by employing mutants with different grana diameters. Furthermore, our results explain why higher plants have a narrow range of grana diameters since a larger diffusion distance for plastocyanin would jeopardize the efficiency of electron transport. In the light of recent findings that the lumen of thylakoids, which forms the diffusion space of plastocyanin, undergoes dynamic swelling/shrinkage, this study demonstrates that plastocyanin diffusion is a crucial regulatory element of plant photosynthetic electron transport.

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

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-7-810 ◽

1991 ◽

Vol 46 (7-8) ◽

pp. 563-568 ◽

Cited By ~ 4

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.

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Counteraction of Paraquat Toxicity at the Chloroplast Level

Zeitschrift für Naturforschung C ◽

10.1515/znc-1987-7-814 ◽

1987 ◽

Vol 42 (7-8) ◽

pp. 824-828 ◽

Cited By ~ 2

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.

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Regulation of photosystem II by metabolic and environmental factors

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1989.0009 ◽

1989 ◽

Vol 323 (1216) ◽

pp. 269-279 ◽

Cited By ~ 8

Keyword(s):

Electron Transport ◽

Higher Plants ◽

Photosynthetic Electron Transport ◽

Thylakoid Membranes ◽

Internal Factors ◽

Regulatory Processes ◽

Quenching Analysis ◽

Intact Chloroplasts ◽

Rate Of Dissipation

The thylakoid membranes of higher plants possess several mechanisms that control both the distribution and rate of dissipation of absorbed light. These mechanisms, which allow regulation of photosynthetic electron transport in response to alteration in external and internal factors, can be observed as the various processes that quench chlorophyll fluorescence. By using the 'light-doubling techniques’, together with analysis of quenching relaxation, it is possible to assess quantitatively the extents of these regulatory processes and to allow their interrelations to be studied. These techniques can be applied to in vitro systems or to leaves, and can be particularly useful when applied with electron-transport measurements and when models are used to aid interpretation. Results of quenching analysis at different light intensities in isolated thylakoids, intact chloroplasts, protoplasts, algae and leaves of a variety of species are presented.

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Diethyldithiocarbamate, a New Photosystem I Electron Donor of Mehler-Type Hill Reactions

Zeitschrift für Naturforschung C ◽

10.1515/znc-1986-9-1011 ◽

1986 ◽

Vol 41 (9-10) ◽

pp. 861-866 ◽

Cited By ~ 1

Author(s):

Brad L. Upham ◽

Kriton K. Hatzios

Keyword(s):

Superoxide Dismutase ◽

Electron Transport ◽

Electron Donor ◽

Photosystem I ◽

Photosynthetic Electron Transport ◽

Mehler Reaction ◽

Plastoquinone Pool ◽

Electron Donation

Abstract Diethyldithiocarbamate (DEDTC) does not accept electrons from the photosynthetic electron transport (PET) but can donate electrons to a photosystem I (PSI) Mehler reaction in the presence of the following PET inhibitors: DCMU. DBMIB, and bathophenanthroline. It cannot photoreduce PSI in the presence of cyanide, a PET inhibitor. These data indicate that the site of electron donation is after the plastoquinone pool. Ascorbate is not required for the ability of DEDTC to donate electrons to PSI. There is no photoreductant activity by DEDTC inferredoxin/NADP Hill reactions. Superoxide dismutase inhibits DEDTC/DCMU or bathophenanthroline→methylviologen/O2 Mehler reaction. Catalase does not recover the consumed O2 from a DEDTC/DCMU→methylviologen/O2 Mehler reaction, indicating O2- has not been dismutating into H2O2. These results indicate that superoxide is required for DEDTC ability to donate electrons, therefore DEDTC is limited only to Mehler-type reactions.

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Inhibitory Effects of the Insecticides Allethrin, Lindane, and Jacutin-Fogetten Sublimate on Photosynthetic Electron Transport

Zeitschrift für Naturforschung C ◽

10.1515/znc-1979-1139 ◽

1979 ◽

Vol 34 (11) ◽

pp. 1070-1071

Author(s):

Aloysius Wild

Keyword(s):

Electron Transport ◽

Photosynthetic Electron Transport ◽

Hill Reaction ◽

Inhibitory Effects

Abstract The inhibitory effects of the insecticides Allethrin, Lindane, and Jacutin-Fogetten sublimate on photosynthetic electron transport of broken chloroplasts were tested. 50 μmol l-1 Allethrin caused an inhibition of 80% of the benzoquinone and ferricyanide Hill-reactions. 39 μmol l-1 Lindane inhibited the basal, coupled and uncoupled electron transport to ferricyanide up to 35%. The precipitate formed by the sublimation of Jauctin-Fogetten containing Lindane depressed electron transport much more than pure Lindane. 50 μg ml-1 of the sublimate led to an 80% inhibition of ferricyanide Hill-reaction.

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

Zeitschrift für Naturforschung B ◽

10.1515/znb-1970-1018 ◽

1970 ◽

Vol 25 (10) ◽

pp. 1157-1159 ◽

Cited By ~ 233

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.

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