Einfluß von Röntgenstrahlen auf HILL-Reaktion und Photosynthesephosphorylierung bei verschiedener Erhaltung isolierter und fragmentierter Chloroplasten

1965 ◽  
Vol 20 (11) ◽  
pp. 1077-1085 ◽  
Author(s):  
E. Perner ◽  
S. von Falck ◽  
G. Jacobi
Keyword(s):  
Oxygen Evolution ◽  
Structural State ◽  
Dose Effect ◽  
Hill Reaction ◽  
X Rays ◽  
Membrane Systems ◽  
Low Salinity ◽  
Hill Activity ◽  
Free Membrane ◽  
The Hill

Isolated chloroplasts and chloroplast-fragments of different structural state characterized by electron microscopy were irradiated with X-rays. The resistance of Hill- activity and phosphorylation coupled with ferricyanide is strongly dependent on the structural state of chloroplasts and thylakoids influenced by isolation media or by treatment with hypotonic media or digitonin. Whole chloroplasts are more resistant than free membrane systems without stroma and envelop. If free membrane systems were suspended in media of low salinity (broken chloroplasts) the rate of oxygen evolution and of phosphorylation decreases with a factor of 3.8 or 3.0 respectively after irradiation. Hill- reaction and phosphorylation are suppressed successively by washing the particles in hypotonic media or by treatment with digitonin. However, the sensitivity of oxygen evolution against X-rays remains constant in the washed particles whereas the rate of ATP-formation further decreases. As demonstrated by dose effect curves low intensities of X-rays activated the Hill- activity for all fractions. The results are discussed in relation to the integrity of chloroplasts and the state of membrane (thylakoids) as carrier for the systems of Hill - reaction and phosphorylation.

Die Wirkung von Simazin auf die Bildung der plastidären Prenyllipide in Keimlingen von Hordeum vulgare L./Effect of Simazine on Formation of Chloroplasts Prenyllipids in Seedlings of H ordeum vulgare L.

1979 ◽  
Vol 34 (1-2) ◽  
pp. 110-113 ◽  
Author(s):  
H. K. Kleudgen
Keyword(s):  
Chlorophyll A ◽  
Photosynthetic Activity ◽  
Red Light ◽  
Hill Reaction ◽  
Common Site ◽  
Hordeum Vulgare L ◽  
Hill Activity ◽  
Multiple Process ◽  
The Hill ◽  
Β Carotene

Abstract Barley seedlings were grown for 7, 10 or 13 days under continuous white light (Fluora lamps) on a nutrient solution containing simazine (2-chloro-4,6-bis-(ethylamino)-s-triazine, 10, 100 μᴍ) . Accumulation of chlorophylls and in part of carotenoids was increasingly enhanced depending on age and concentrations applied. The ratio chlorophyll a/b decreased on this line in 10 and 13 day old plants, the ratio xanthophylls/β-carotene and the ratio chlorophyll a/prenylquinones (plasto-quinone-90X. + red. , α-tocopherol, α-tocoquinone) increased. The way how these prenyllipid ratios are changed in 10 and 13 day old plants is characteristic of a shade type adaptation, as it was shown earlier for other herbicides inhibiting photosystem II.In 7 day old plants the ratio chlorophyll a/prenylquinones decreased. Photosynthetic activity (Hill-reaction) was enhanced in the simazine plants. The ratio chlorophyll a/b was higher, the ratio xanthophylls/β-carotene was lower than in the older seedlings.Similar changes of prenyllipid ratios like in 7 day seedlings and a higher Hill activity were also found in plants grown under blue light (sun type adaptation) as compared to red light (shade type adaptation). This points to similar metabolic changes in the chloroplasts which could be related to a common site of regulation, perhaps the endogenuous cytokinins. The Hill activity, increasing with age in the 10 and 13 day plants, indicates that the mode of action of simazine may be a multiple process resulting to a parallel formation of shade type and sun type characteristics.

Cyanoacrylate Inhibitors as Probes for the Nature of the Photosystem II Herbicide Binding Site

1990 ◽  
Vol 45 (5) ◽  
pp. 336-342 ◽  
Author(s):  
John L. Huppatz ◽  
Helen G. McFadden ◽  
Leslie F. McCaffery
Keyword(s):  
Binding Site ◽  
Hydrophobic Effect ◽  
Phenyl Group ◽  
Hill Reaction ◽  
Structure Activity ◽  
Herbicide Binding ◽  
Hill Activity ◽  
Quantitative Structure Activity Relationships ◽  
The Hill ◽  
Different Parts

Three series of phenyl-substituted 2-cyanoacrylates were evaluated using simple quantitative structure activity relationships (QSAR) in an attempt to elucidate the nature of the regions of the binding site occupied by different parts of the molecules. Inhibition of the Hill reaction by substituted 3-phenylamino-2-cyanoacrylates correlated well with the lipophilicity of the substituent. The hydrophobic effect was also dominant when the Hill activity of a series of 3-benzylamino-2-cyanoacrylates was analyzed, although potency was considerably higher in the latter series. Lipophilicity and the electronic nature of the substituents were not major determinants in the Hill inhibitory activity of a series of substituted phcnoxycthyl 2-cyanoacrylic esters. In this case, a significant correlation was found with the molar rcfractivity (MR) of meta substituents, a parameter reflecting substituent size. The results indicate that the phenyl moiety of substituted 3-phenylamino- and 3-bcnzyl- amino-2-cyanoacrylates interacts with an essentially lipophilic binding domain, though it is likely that the two series are oriented differently with the 3-bcnzylamino series able to bind with greater affinity. In the phcnoxycthyl ester series, the substituted phenyl group interacts with a different environment, wherein ortho- and we7tf-substitution is tolerated, dependent on the bulk of the substituent, but /wra-substitution is detrimental to affinity for this region of the site.

Entkopplung der Photophosphorylierung durch 2-Alkylbenzimidazole

1966 ◽  
Vol 21 (7) ◽  
pp. 667-672 ◽  
Author(s):  
A. Trebst ◽  
E. Pistorius ◽  
K. H. Büchel
Keyword(s):  
Oxygen Evolution ◽  
Saturated Hydrocarbon ◽  
Short Chain ◽  
Side Chain ◽  
Hill Reaction ◽  
Cyclic Photophosphorylation ◽  
Photosynthetic Reactions ◽  
And Shifts ◽  
The Hill ◽  
Long Chain

The influence of benzimidazoles with saturated hydrocarbon side chains at C-2 on photosynthetic reactions of isolated spinach chloroplasts was investigated. They show little or no inhibition of the Hill- reaction, but are effective uncouplers depending on the length of the side chain. 2-Alkylbenzimidazoles with a side chain of at least eight and not more than fourteen carbon atoms uncouple non-cyclic and cyclic photophosphorylation at a concentration of less than 10~5-m., 2-decyl-benzimidazole being the most potent uncoupler. Alkyl-benzimidazoles with less than seven or more than fourteen carbon atoms in the side chain do not uncouple photophosphorylation at 10~5-m. N-Methyl-2-undecyl-benzimidazole is less effective as uncoupler than 2-undecyl-benzimidazole but is an inhibitor of oxygen evolution.2-Undecyl-benzimidazole stimulates the Hill - reaction in the absence of the phosphorylation system and shifts the pH-optimum to a lower value, as expected from an uncoupler.Long chain alkylamines (C10-C14) are uncouplers at lower concentrations (5 ·10-5-m.) than short chain amines.

Cyanoacrylate Inhibitors of the Hill Reaction V. The Effect of Chirality on Inhibitor Binding

1987 ◽  
Vol 42 (6) ◽  
pp. 684-689 ◽  
Author(s):  
John L. Huppatz ◽  
John N. Phillips
Keyword(s):  
Phenyl Ring ◽  
Alkyl Substituent ◽  
Receptor Site ◽  
Optically Active ◽  
Hill Reaction ◽  
Inhibitor Binding ◽  
Level Of Activity ◽  
The Difference ◽  
The Hill

Optically active α-methylbenzylamino 2-cyanoacrylic esters were synthesized and assayed as inhibitors of the Hill reaction in isolated pea chloroplast fragments. The 5-isomers were more potent inhibitors than the S-isomers with discriminations of from ten to greater than 100-fold being observed. A β-alkyl substituent in the cyanoacrylate molecule affected both the level of activity and the difference in activity between the isomers. An α,α-dimethylbenzylamino derivative was also active at about the same level as the corresponding α-methylbenzylamino racemate. This result could be explained in terms of the orientation of the phenyl ring in the receptor site. Replacement of the α-methylbenzylamino group by other α-alkyl and α-phenyl substituents had little effect on activity. However, an α-benzyl group was beneficial.

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.

Metabolism of a Pyrrolidine Urea Herbicide in Corn and Weeds

Weed Science ◽  
1974 ◽  
Vol 22 (1) ◽  
pp. 10-14 ◽  
Author(s):  
R. E. Holm ◽  
D. E. Stallard
Keyword(s):  
Adventitious Roots ◽  
Parent Compound ◽  
Soil Surface ◽  
Abutilon Theophrasti ◽  
Water Soluble ◽  
Hill Reaction ◽  
Panicum Miliaceum ◽  
Proso Millet ◽  
Ipomoea Purpurea ◽  
The Hill

Five 2,5-dimethyl-1-pyrrolidinecarboxanilides were effective inhibitors of the Hill reaction. However, only thecisisomers were active; thetransisomers were totally inactive. Experiments were conducted using14C-5328 (cis-2,5-dimethyl-1-pyrrolidinecarboxanilide). A correlation existed between resistance of various plants to 5328 and their ability to metabolize it to water soluble metabolites. Velvetleaf (Abutilon theophrastiMedic.) and proso millet (Panicum miliaceumL.) seedlings were very susceptible to 5328 and were unable to metabolize it. Tall morningglory [Ipomoea purpurea(L.) Roth] seedlings were highly tolerant to 5328 and converted it completely to its metabolites. Corn (Zea maysL. ‘DeKalb variety XL-45′) seedlings which were slightly susceptible to 5328 injury were able to metabolize up to 90% of the parent compound. Corn foliage uptake of14C-5328 applied to the soil surface occurred through the adventitious roots.

scholarly journals Studies on the Second Emerson Effect in the Hill Reaction in Algal Cells

1961 ◽  
Vol 1 (5) ◽  
pp. 377-388 ◽  
Author(s):  
Rajni Govindjee ◽  
Eugene Rabinowitch
Keyword(s):  
Hill Reaction ◽  
The Hill

The mechanism of cyclic phosphorylation by illuminated chloroplasts

1963 ◽  
Vol 157 (968) ◽  
pp. 332-345 ◽  
Keyword(s):  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reducing Power ◽  
Catalytic Amount ◽  
Adenosine Diphosphate ◽  
Hill Reaction ◽  
Hydrogen Transport ◽  
Hydrogen Acceptor ◽  
Light Reaction ◽  
The Hill ◽  
Evolution Of Oxygen

In the reaction discovered by Hill (1937, 1939), chloroplasts isolated from the cell were shown to be capable, upon illumination, of reducing an artificial hydrogen acceptor with the concurrent evolution of oxygen. The ‘Hill reaction’ was regarded as a partial model of the light reaction in photosynthesis where limited reducing power and molecular oxygen arose from the photolysis of water. Attempts to relate this reaction to the photochemical events preceding the dark reduction of carbon dioxide in photosynthesis received their first direct support from the finding of San Pietro & Lang (1958) that nicotinamide adenine dinucleotide phosphate ( NADP )can serve as an effective acceptor of hydrogen in the photochemical reaction when the system is supplemented with a catalytic amount of a soluble protein extracted from leaves. Added significance was given to this finding by the further observation of Amon, Whatley & Allen (1959), that hydrogen transport in the reaction could be coupled to the phosphorylation of adenosine diphosphate { ADP ) to yield adenosine triphosphate { ATP ) concurrently with the reduction of NADP and the production of oxygen in the stoicheiometric proportions: l NADP LL 2 jl ATP /^0 2 . They had previously demonstrated a similar coupling of phosphorylation to hydrogen transport when the artificial reagent, ferricyanide, served as hydrogen acceptor (Arnon, Whatley & Allen 1958). In this work, Amon et al. made the further important observation that hydrogen transport in the ferricyanide reaction is strongly stimulated when phosphorylation occurs concurrently.

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