Plant Response to Combinations of Mesotrione and Photosystem II Inhibitors

2006 ◽  
Vol 20 (1) ◽  
pp. 267-274 ◽  
Author(s):  
Julie A. Abendroth ◽  
Alex R. Martin ◽  
Fred W. Roeth
Keyword(s):  
Photosystem Ii ◽  
Joint Action ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Carotenoid Biosynthesis ◽  
Ps Ii ◽  
Whole Plant ◽  
Transport Chain ◽  
Leaf Necrosis ◽  
Plant Level

Photosystem II (PS II) inhibitors halt electron flow within the photosynthetic electron transport chain, thereby leading to increased oxidative stress. As a result, their addition to mesotrione, which inhibits carotenoid biosynthesis by inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), is complementary. Field and greenhouse experiments were conducted in 2002 and 2003 to investigate the joint action of POST mesotrione plus PS II inhibitor herbicide combinations. The joint action of mesotrione plus PS II inhibitors was investigated across five plant species, three PS II inhibitors, and two moisture environments to determine their influence on the joint action response. Rates of mesotrione evaluated ranged from 4.4 to 87.6 g ai/ha alone and in combination with reduced rates of atrazine, bromoxynil, and metribuzin. In the field, all combinations of mesotrione at 8.8, 17.5, and 35.0 g/ha plus atrazine, bromoxynil, or metribuzin were synergistic for necrosis 6 d after treatment (DAT) on sunflower. Addition of atrazine at 280 g/ha to mesotrione at 8.8 g/ha increased velvetleaf leaf necrosis by 18 to 47%. In the greenhouse, the addition of bromoxynil at 70 g/ha to mesotrione at 17.5 g/ha increased leaf necrosis by 23 to 34% and biomass reduction by 38 to 47%. Synergism on Palmer amaranth occurred similarly under both normal and dry moisture environments at application. Plant height at application was found to influence detection of synergism on the whole-plant level.

Inhibition by Tetranitromethane of Photosynthetic Electron Transport from Water to Photosystem II in Chloroplasts

1980 ◽  
Vol 35 (3-4) ◽  
pp. 293-297 ◽  
Author(s):  
P. V. Sane ◽  
Udo Johanningmeier
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Flow ◽  
Ph Dependence ◽  
Photosynthetic Electron Transport ◽  
Donor Side ◽  
Ps Ii ◽  
Diphenyl Carbazide ◽  
Low Concentrations ◽  
Sh Group

Abstract Low concentrations (10 µM) of tetranitromethane inhibit noncyclic electron transport in spinach chloroplasts. A study of different partial electron transport reactions shows that tetranitromethane primarily interferes with the electron flow from water to PS II. At higher concentrations the oxidation of plastohydroquinone is also inhibited. Because diphenyl carbazide but not Mn2+ ions can donate electrons efficiently to PS II in the presence of tetranitromethane it is suggested that it blocks the donor side of PS II prior to donation of electrons by diphenyl carbazide. The pH dependence of the inhibition by this protein modifying reagent may indicate that a functional-SH group is essential for a protein, which mediates electron transport between the water splitting complex and the reaction center of PS II.

scholarly journals The Role of Selected Wavelengths of Light in the Activity of Photosystem II in Gloeobacter violaceus

2021 ◽  
Vol 22 (8) ◽  
pp. 4021
Author(s):  
Monika Kula-Maximenko ◽  
Kamil Jan Zieliński ◽  
Ireneusz Ślesak
Keyword(s):  
Photosystem Ii ◽  
Spectral Composition ◽  
Photosynthetic Electron Transport ◽  
Metabolic Energy ◽  
Light Conditions ◽  
Gloeobacter Violaceus ◽  
Transport Chain ◽  
Cyanobacterial Culture ◽  
Photosynthetic Antennas

Gloeobacter violaceus is a cyanobacteria species with a lack of thylakoids, while photosynthetic antennas, i.e., phycobilisomes (PBSs), photosystem II (PSII), and I (PSI), are located in the cytoplasmic membrane. We verified the hypothesis that blue–red (BR) light supplemented with a far-red (FR), ultraviolet A (UVA), and green (G) light can affect the photosynthetic electron transport chain in PSII and explain the differences in the growth of the G. violaceus culture. The cyanobacteria were cultured under different light conditions. The largest increase in G. violaceus biomass was observed only under BR + FR and BR + G light. Moreover, the shape of the G. violaceus cells was modified by the spectrum with the addition of G light. Furthermore, it was found that both the spectral composition of light and age of the cyanobacterial culture affect the different content of phycobiliproteins in the photosynthetic antennas (PBS). Most likely, in cells grown under light conditions with the addition of FR and G light, the average antenna size increased due to the inactivation of some reaction centers in PSII. Moreover, the role of PSI and gloeorhodopsin as supplementary sources of metabolic energy in the G. violaceus growth is discussed.

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.

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

1991 ◽  
Vol 46 (1-2) ◽  
pp. 93-98 ◽  
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.

Rewiring photosynthesis: a photosystem I-hydrogenase chimera that makes H2in vivo

2020 ◽  
Vol 13 (9) ◽  
pp. 2903-2914 ◽  
Author(s):  
Andrey Kanygin ◽  
Yuval Milrad ◽  
Chandrasekhar Thummala ◽  
Kiera Reifschneider ◽  
Patricia Baker ◽  
...  
Keyword(s):  
Electron Transport ◽  
Hydrogen Production ◽  
Photosystem I ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

Photosystem I-hydrogenase chimera intercepts electron flow directly from the photosynthetic electron transport chain and directs it to hydrogen production.

Involvement of the Xanthophyll Cycle in Regulation of Cyclic Electron Flow around Photosystem II

1996 ◽  
Vol 51 (1-2) ◽  
pp. 47-52 ◽  
Author(s):  
W. I. Gruszecki ◽  
K. Strzałk ◽  
K.P. Bader ◽  
A. Radunz ◽  
G.H. Schmid
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Oxygen Evolution ◽  
Xanthophyll Cycle ◽  
Electron Flow ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Oxygen Evolution ◽  
Cyclic Electron Transport ◽  
Ps Ii ◽  
Low Levels

Abstract In our previous study (Gruszecki et al., 1995) we have postulated that the mechanism of cyclic electron transport around photosystem II, active under overexcitation of the photosynthetic apparatus by light is under control of the xanthophyll cycle. The combination of dif­ferent light quality and thylakoids having various levels of xanthophyll cycle pigments were applied to support this hypothesis. In the present work photosynthetic oxygen evolution from isolated tobacco chloroplasts was measured by means of mass spectrometry under conditions of high or low levels of violaxanthin, being transformed to zeaxanthin during dark incubation in an ascorbate containing buffer at pH 5.7. Analysis of oxygen evolution and of light-induced oxygen uptake indicate that the de-epoxidation of violaxanthin to zeaxanthin results in an increased cyclic electron transport around PS II, thus dimishing the vectorial electron flow from water. An effect similar to de-epoxidation was observed after incubation of thylakoid membranes with specific antibodies against violaxanthin.

Negative Cross Resistance; a Possible Key to Atrazine Resistance Management: A Call for Whole Plant Data

1990 ◽  
Vol 45 (5) ◽  
pp. 470-473 ◽  
Author(s):  
Jonathan Gressel ◽  
Lee A. Segel
Keyword(s):  
Resistance Management ◽  
Cross Resistance ◽  
Response Curves ◽  
Maize Crop ◽  
Ps Ii ◽  
Atrazine Resistance ◽  
Whole Plant ◽  
Herbicide Mixtures ◽  
Plant Data ◽  
Plant Level

Many photosystem II inhibiting herbicides still inhibit this process in triazine-resistant plants; i.e. they have no cross resistance with atrazine. Five- to twenty-fold lower concentrations of phenolic type herbicidcs and 5-fold less of the active ingredient of pyridate and half as much ioxynil are required to inhibit thylakoid PS II in atrazine-resistant biotypes than in sensitive biotypes; i.e., they even show “negative cross resistance”. Negative cross resistance may be the major reason that atrazine resistance did not evolve where herbicide mixtures were used, when the mixed herbicide (usually a non-PS II inhibiting acetanilide) also controlled triazine-sensitivc weeds. Mathematical modeling in principle allows quantification of the very low field levels of herbicides possessing negative cross resistance that could be mixed with atrazine that would stop or delay the evolution of resistant populations without affecting the maize crop. There are few available actual dose response curves of atrazine-resistant vs. susceptible weeds at the whole plant level for herbicidcs exerting negative cross resistance. Thus, “real situation” modeling cannot be done. Data acquisition is called for so that the model can be extrapolated from the thylakoid to the field.

scholarly journals Herbicides as Probes in Plant Biology

Weed Science ◽  
2010 ◽  
Vol 58 (3) ◽  
pp. 340-350 ◽  
Author(s):  
Franck E. Dayan ◽  
Stephen O. Duke ◽  
Klaus Grossmann
Keyword(s):  
Protein Targeting ◽  
Critical Role ◽  
Photosynthetic Electron Transport ◽  
Molecular Probes ◽  
Ps Ii ◽  
Physiological Processes ◽  
Nonmevalonate Pathway ◽  
Transport Chain ◽  
Target Sites ◽  
Acetyl Coenzyme A Carboxylase

Herbicides are small molecules that inhibit specific molecular target sites within plant biochemical pathways and/or physiological processes. Inhibition of these sites often has catastrophic consequences that are lethal to plants. The affinity of these compounds for their respective target sites makes them useful tools to study and dissect the intricacies of plant biochemical and physiological processes. For instance, elucidation of the photosynthetic electron transport chain was achieved in part by the use of herbicides, such as terbutryn and paraquat, which act on photosystem II and I, respectively, as physiological probes. Work stemming from the discovery of the binding site of PS II–inhibiting herbicides was ultimately awarded the Nobel Prize in 1988. Although not as prestigious as the seminal work on photosynthesis, our knowledge of many other plant processes expanded significantly through the ingenious use of inhibitors as molecular probes. Examples highlight the critical role played by herbicides in expanding our understanding of the fundamental aspects of the synthesis of porphyrins and the nonmevalonate pathway, the evolution of acetyl-coenzyme A carboxylase, cell wall physiology, the functions of microtubules and the cell cycle, the role of auxin and cyanide, the importance of subcellular protein targeting, and the development of selectable markers.

The Inhibition of Photosynthetic Light Reactions by Halogenated Naphthoquinones

1981 ◽  
Vol 36 (7-8) ◽  
pp. 645-655 ◽  
Author(s):  
Klaus Pfister ◽  
Hartmut K. Lichtenthaler ◽  
Günther Burger ◽  
Hans Musso ◽  
Manuel Zahn
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Binding Site ◽  
Chlorophyll A ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Ps Ii ◽  
Photosynthetic Electron Flow ◽  
A Site ◽  
Fluorescence Transients

Abstract Halogenated naphthoquinones act as inhibitors of photosynthetic electron flow. I50 concentra­ tion for inhibition of methylviologen reduction were found to range between 2 × 10-5 m to 2 × 10-6 M. Comparing their effects on several partial reactions of electron flow, the inhibition site of the naphthoquinones was found to be at the reducing site of PS II. Studies of fluorescence transients in presence of halogenated naphthoquinones give further evidence for a site action similar to that of diuron and different to that of DBMIB. All naphthoquinones act as quenchers of chlorophyll fluorescence with pure chlorophyll a, and with much higher efficiency in green algae and chloroplasts. It is concluded, that the halogenated naphthoquinones act similar to PS II-inhibitors like diuron, but do not share a common binding site at the PS II-complex. Implications of a possible involvement of phylloquinone K 1 in photosynthetic electron transport are discussed. The synthesis of 2-chloro-as well as 2-bromo-3-isopropyl-1,4-naphthoquinone is described.

Photosynthetic components and activities of nitrogen-fixing isolated heterocysts of Anabaena cylindrica

1977 ◽  
Vol 198 (1130) ◽  
pp. 61-86 ◽  
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Cytochrome B ◽  
Nitrogenase Activity ◽  
Photosynthetic Electron Transport ◽  
Central Component ◽  
Reaction Centre ◽  
Anabaena Cylindrica ◽  
Higher Plant ◽  
Transport Chain

Isolated heterocysts of the N 2 -fixing Anabaena cylindrica , prepared by a combination of lysozyme and Yeda press treatments, are metabolically active with over 90% of the measurable nitrogenase activity being located in the heterocyst preparations after disruption of the intact filaments. The photosynthetic activities of such isolated heterocysts are characterized by an inability to carry out the photolysis of water or to fix CO 2 . The lack of O 2 evolution appears to be due in part to the deple­tion during heterocyst differentiation of Mn, a central component of the photosystem II reaction centre in O 2 -evolving algae. There is evidence that components of the photosynthetic electron transport chain on the reducing side of the photosystem II reaction centre are present and functional in heterocysts. These include cytochrome c 554 , plastocyanin, plastoquinone, cytochrome b 559 , P700, cytochrome b 563 , and iron-sulphur proteins which appear to correspond to centre A and centre B of higher plant chloroplasts. Soluble, or loosely bound ferredoxin is also present and involved in electron transport from ferredoxin to NADP. Isolated heterocysts photoreduce methylviologen when reduced 2,6-dichlorophenolindophenol and diphenylcarbazide serve as electron donors. They show P700 photo-oxidation and photoreduction, photosyn­thetic electron transport which is inhibited by 2,5-dibromo-3-methyl-6-isopropyl- p -benzoquinone an antagonist of plastoquinone, photophos­phorylation, oxidative phosphorylation and ferredoxin-NADP oxido-reductase mediated reactions. The photosynthetic modifications of the heterocyst are such that electron transport and the generation of ATP for nitrogenase can occur without concomitant O 2 evolution and with­out nitrogenase having to compete with CO 2 fixation for ATP and reductant.

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