scholarly journals Studies on The Greening of Dark-Grown Bean Plants II. Development of Photochemical Activity

1964 ◽  
Vol 17 (1) ◽  
pp. 93 ◽  
Author(s):  
Jan M Anderson ◽  
NK Boardman
Keyword(s):  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Photochemical Activity ◽  
Hill Reaction ◽  
Ferricyanide Reduction ◽  
Etiolated Leaves ◽  
Maximum Value ◽  
Bean Plants ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
The Hill ◽  
Bean Leaves

A study of the photochemical activity of plastids isolated from etiolated bean leaves which had been illuminated for increasing periods was undertaken. Proplastids isolated from etiolated leaves were inactive in the Hill reaction. Photochemical ferricyanide reduction was obtained with plastids isolated from etiolated leaves which had been illuminated for 6 hr. The reduction increased to a maximum value of 400 p.lloles ferricyanide/mg chlorophyll/hr after 10 hr of illumina� tion and thereafter decreased to 300,umoles ferricyanidejmg chlorophylljhr for mature bean chloroplasts. Plastids isolated from etiolated leaves illuminated for 16 hr reduced nicotinamide adenine dinucleotide phosphate (NADP) at a rate less than half that of mature chloroplasts, while B�hr plastids showed no NADP reduction.

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.

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.

SOME EFFECTS OF MALEIC HYDRAZIDE ON LIGHT REACTIONS OF PHOTOSYNTHESIS IN ISOLATED CHLOROPLASTS FROM PHASEOLUS VULGARIS PLANTS

1975 ◽  
Vol 55 (1) ◽  
pp. 145-149 ◽  
Author(s):  
T. J. KOSKE ◽  
L. V. SVEC
Keyword(s):  
Phaseolus Vulgaris ◽  
Maleic Hydrazide ◽  
Cytochrome F ◽  
Morphological Alteration ◽  
Hill Reaction ◽  
Ferricyanide Reduction ◽  
Ps Ii ◽  
Reduction Activity ◽  
Dye Reduction ◽  
The Hill

The light reactions in leaf chloroplasts extracted from maleic hydrazide (MH)-treated and untreated snapbean plants (Phaseolus vulgaris L. ’Tendercrop’) were studied using three dye reduction tests. The intact plants were treated with a level of MH which caused little or no morphological alteration. The Hill reaction and dichlorophenol indophenol (DCPIP) reduction by pigment system II (PS II) were significantly decreased by the MH treatment. Ferricyanide reduction activity was significantly accelerated by the MH treatment. The Hill reaction and DCPIP reduction results suggest that there is not an uncoupling of photophosphorylation. The point of action for MH in photosynthesis appears not to be in PS II but between cytochrome f and plastocyanin.

scholarly journals Isolation of chloroplasts in the Karwinskia species and determination of their photochemical activity under in vitro conditions

2011 ◽  
Vol 50 (No. 4) ◽  
pp. 149-156 ◽  
Author(s):  
M. Henselová ◽  
M. Regecová ◽  
A. Sováková
Keyword(s):  
Chlorophyll A ◽  
Photochemical Activity ◽  
Hill Reaction ◽  
Reaction Conditions ◽  
Significant Difference ◽  
The Hill ◽  
Isolated Chloroplasts ◽  
Photochemical Activity Of Chloroplasts

Reaction conditions for evaluation of the photochemical activity of isolated chloroplasts in the Hill reaction of Karwinskia humboldtiana (Roem &amp; Schut) Zucc. and Karwinskia parvifolia Rose species were determined. Hill&rsquo;s reaction activity was measured spectrophotometrically at 630 nm as the amount of DCPIP reduction by the chloroplast suspension at an irradiance of 400 &micro;mol/m<sup>2</sup>/sPAR. A significant difference was observed between the activity of chloroplasts isolated at 2&deg;C and 25&deg;C amounting to 27% in Karwinskia humboldtiana and 18.5% in K. parvifolia. After 24 hours of storage of chloroplasts at a suspension of 2&deg;C, a significant decrease of chloroplasts activity was noted in both species, e.g. 38% in Karwinskia humboldtiana and 45% in K. parvifolia. The photochemical activity of chloroplasts increased also with the length of irradiation of the reaction mixture and the content of chlorophyll (a + b) in chloroplast suspension. The activity of chloroplasts was found to be significantly higher in the species K. humboldtiana than in K. parvifolia and it proved higher in both when these were grown under field conditions rather than in a greenhouse.

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.

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