Effects of adenosine triphosphate and inorganic pyrophosphate on carbon dioxide fixation by isolated spinach chloroplasts

Vose, John R.; Spencer, Margaret Beale

doi:10.1139/o69-069

Cited by 11 publications

(2 citation statements)

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“…Restoration by ATP of 02 evolution in phosphate-depleted media may be due to external hydrolysis of ATP and entry of Pi rather than any direct uptake of ATP. Thus, the stimulatory effect of ATP and of PPi reported by Vose and Spencer (24) (19) suggested that additional ATP from cyclic phosphorylation was required for CO2 fixation and that exogenous ATP could meet this need in the absence of cyclic phosphorylation. However, the rates of CO2 fixation were low and the stimulation by ATP could be explained on the basis of the slow rate of ATP uptake via the adenine nucleotide transporter (9).…”

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confidence: 92%

Stimulation of Carbon Dioxide Fixation in Isolated Pea Chloroplasts by Catalytic Amounts of Adenine Nucleotides

Robinson¹,

Wiskich²

1976

Plant Physiol.

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Carbon dioxide-dependent 02 evolution by isolated pea (Pisum sativum var. Massey Gem) chloroplasts was increased two to 12 times by the addition of ATP. 02 evolution was also stimulated by ADP and to a lesser extent by AMP. The ATP effects were not due to broken chloroplasts present in the preparations nor was ATP acting as a phosphate source. We concluded that the adenine nucleotides were acting catalytically. The concentration of ATP required for half-maximum rate of 02 evolution was 16 to 25 FAM. The degree to which ATP stimulated 02 evolution depended on the age of pea plants from which the chloroplasts were isolated. Spinach (Spinacia oleracea var. True Hybrid 102) chloroplasts did not show a consistent stimulation of 02 evolution by adenine nucleotides.The adenine nucleotide content of pea chloroplasts was not lower than that of spinach chloroplasts, but pea chloroplasts which showed a large stimulation of 02 evolution by ATP contained an ATP-hydrolyzing reaction with rates of 10 to 50 iLmol ATP hydrolyzed mg chlorophyll-' hour-'. The rate of the ATP-consuming reaction was much lower in spinach chloroplasts and in chloroplasts from older pea plants which did not show large stimulation of 02 evolution by ATP. We propose that the ATP-consuming reaction, with a high affinity for ATP, decreased the effective size of the ATP pool available for CO2 frixation. Added adenine nucleotides could be transported into the chloroplasts increasing the concentration of internal nucleotides. Calculations showed that the adenine nucleotide transporter on the outer chloroplast membranes could operate at a sufficient rate to produce such an effect. Adelaide 5001, Australia tion of 02 evolution by uncoupling agents. These reports suggest that adenine nucleotides penetrate intact chloroplasts to some extent. Jensen and Bassham (11) showed that ATP stimulated CO2 fixation to a small extent in intact chloroplasts, and that in the dark, ATP increased the level of ribulose-1,5-diphosphate. Studies of diffusion of compounds from isolated chloroplasts suggested that ATP and ADP diffuse out of chloroplasts but can re-enter and be used metabolically (2). Heldt (9) reported the presence of an adenine nucleotide transporter on the chloroplast outer membrane which apparently operates primarily to move ATP into the chloroplast, although the rates of transfer were low (5 ,umol mg Chl-' hr-'). The experiments of Heber and Santarius (8) similarly suggested low rates of adenine nucleotide transport into chloroplasts. Stokes and Walker (22) suggested that the failure of ATP to reverse uncoupler inhibition of P-glyceratedependent 02 evolution indicated impermeability of the chloroplast outer membrane to adenine nucleotides. It should be noted, however, that the adenine nucleotide transporter is inhibited by uncouplers (9), and that reversal of uncoupler inhibition requires the accumulation of substrate quantities of ATP.Stimulation of C02-dependent 02 evolution by ATP does not necessarily imply entry of ATP into chloroplasts. The ATP coul...

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confidence: 92%

Stimulation of Carbon Dioxide Fixation in Isolated Pea Chloroplasts by Catalytic Amounts of Adenine Nucleotides

Robinson¹,

Wiskich²

1976

Plant Physiol.

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“…Tlie photosynthetic rate of several trees and seedlings was highest at 20-30 C (Kramer and Kozlowski, 1960). Vose and Spencer (1969) and Zelawski and Kinelska (1967) reported that temperature in closed photoassimilation chambers usually is maintained within a range of 20 to 27 C.…”

Section: Dr W Zelawski (Personal Communication) Suggested Evolution Ofmentioning

confidence: 99%

Enzyme activity as an index of growth superiority of pinus clausa var. clausa on two soils /

Burns¹

1971

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Tliis study attempted to 1) identify the metabolic pathways and enzymes involved in the photos>mthetic fixation of carbon and to determine 2) if metabolic intermediates were altered by changes in the supply of nitrogen and phosphorus; 3) if activity level of specific enzymes differed in tissue of superior and nonsuperior trees and their half-sibling seedling progeny; 4) if the activity was altered by the soils in which seedlings grew. Distribution of photoassimilated^^U02 measured in ethanolsoluble fractions of green tissue from 3-month-old Ocala sand pines grown from seed in sand culture and complete nutrient solutions containing two levels each of nitrogen and phosphorus. Portions of the metabolic pathways involved in carbon fixation were determined. Tlie activity and electrophoretic migration rate of malate dehydrogenase isoenz\nres, glucose-6-phosphate dehydrogenase isoenzymes, and proteins were compared in green tissue from saw log-size superior viii and neighboring, nonsuperior sand pine trees and their half-sibling progeny grown in pots on Lakeland coarse sand and Paola sand. Sugars contained 75%, organic acids 19%, and amino acids 6% of the radioactive carbon in the ethanol-soluble fraction from green tissue. Radioactivity was highest in fructose, glucose, and galactose. Nitrogen directly affected chlorophyll formation, seedling growth, and photosynthetic incorporation of 14c. Phosphorus appeared to be the principal rate-limiting element in the incorporation of carbon in sugars and in some organic acid precursors of amino acids. Results indicated that enzymes of glycolysis, the Calvin cycle, and the tricarboxylic acid cycle were principally involved in fixation of carbon in sand pine seedlings allowed to photoassimilate^^C 02 for 10 minutes in a controlled environment. Measurements of activity and migration of isoenzymes did not provide an index of growth superiority in parent trees or in halfsibling seedling progeny. Superior parent trees, but not their progeny, lacked one or more protein bands found in nonsuperior trees indicating that a genetic marker exists. However, no relationship was found between the location of malate dehydrogenase and glucose-6-phophate dehydrogenase isoenzymes and protein bands. Activity and Rf values of some malate dehydrogenase isoenzyme and protein bands were altered by the soil in which seedlings grew as well as by genetic factors. Both the isoenzyme and protein bands and factors influencing them were identifiable.

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Intracellular location of nitrate reductase and nitrite reductase in spinach and sunflower leaves

Grant

Atkins

Canvin

1970

Planta

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Chloroplasts have been isolated from spinach and from sunflower which retain their outer membrane and their stroma protein as determined both by ability to fix CO2 and evolve O2 at high rates, and by appearance under the phase contrast microscope. Such chloroplasts contain both nitrate and nitrite reductase activity. However, calculations on the distribution of these enzymes, when compared with the distribution of pyruvate kinase and cytochrome c oxidase activity, demonstrate that the larger part of both nitrate and nitrite reductase is located outside of the chloroplast.

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Effects of adenosine triphosphate and inorganic pyrophosphate on carbon dioxide fixation by isolated spinach chloroplasts

Cited by 11 publications

References 2 publications

Stimulation of Carbon Dioxide Fixation in Isolated Pea Chloroplasts by Catalytic Amounts of Adenine Nucleotides

Stimulation of Carbon Dioxide Fixation in Isolated Pea Chloroplasts by Catalytic Amounts of Adenine Nucleotides

Enzyme activity as an index of growth superiority of pinus clausa var. clausa on two soils /

Intracellular location of nitrate reductase and nitrite reductase in spinach and sunflower leaves

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