The Effect of Light on the Tricarboxylic Acid Cycle in Green Leaves

Chapman, E. A.; Osmond, C. B.

doi:10.1104/pp.53.6.893

Cited by 23 publications

(6 citation statements)

References 20 publications

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“…While complex traits are typically dissected by measuring the quantitative variation across a polymorphic population, this approach is not promising for C 4 photosynthesis, due to lack of known plasticity in "C 4 -ness" (Sage and McKown, 2006). Historical crosses between C 3 and C 4 plants (Chapman and Osmond, 1974) are no longer available and would have to be reconstructed before they can be analyzed with molecular tools.…”

Section: Introductionmentioning

confidence: 99%

Comparative Transcriptome Atlases Reveal Altered Gene Expression Modules between Two Cleomaceae C3 and C4 Plant Species

et al. 2014

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C4 photosynthesis outperforms the ancestral C3 state in a wide range of natural and agro-ecosystems by affording higher water-use and nitrogen-use efficiencies. It therefore represents a prime target for engineering novel, high-yielding crops by introducing the trait into C3 backgrounds. However, the genetic architecture of C4 photosynthesis remains largely unknown. To define the divergence in gene expression modules between C3 and C4 photosynthesis during leaf ontogeny, we generated comprehensive transcriptome atlases of two Cleomaceae species, Gynandropsis gynandra (C4) and Tarenaya hassleriana (C3), by RNA sequencing. Overall, the gene expression profiles appear remarkably similar between the C3 and C4 species. We found that known C4 genes were recruited to photosynthesis from different expression domains in C3, including typical housekeeping gene expression patterns in various tissues as well as individual heterotrophic tissues. Furthermore, we identified a structure-related module recruited from the C3 root. Comparison of gene expression patterns with anatomy during leaf ontogeny provided insight into genetic features of Kranz anatomy. Altered expression of developmental factors and cell cycle genes is associated with a higher degree of endoreduplication in enlarged C4 bundle sheath cells. A delay in mesophyll differentiation apparent both in the leaf anatomy and the transcriptome allows for extended vein formation in the C4 leaf.

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Section: Introductionmentioning

confidence: 99%

Comparative Transcriptome Atlases Reveal Altered Gene Expression Modules between Two Cleomaceae C3 and C4 Plant Species

et al. 2014

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“…Also, the activity of PEP carboxylase found in this investigation ranged from 20-to over a 100-fold greater than that reported by Hawker (14). Differences in the method of enzyme extraction and the use of fresh 6 (Fig. 5).…”

Section: Methodsmentioning

confidence: 99%

“…They synthesized malic acid-2,3-"C by administering fumaric acid-2, 3-"C to grape berries for a relatively short period of time, thus minimizing randomization of the label and subsequent interference of 'CO,-refixation, which may occur when malic acid is labeled in carbon 1 or 4 position. The "C-labeling pattern in the glucose molecule derived from fumaric acid-2,3-"C coincided with that of gluconeogenetic transformation in C4 plants (6).…”

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confidence: 97%

Phosphoenolpyruvate Carboxykinase Activity in Grape Berries

Ruffner

Kliewer²

1975

Plant Physiol.

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Phosphoenolpyruvate (PEP) carboxykinase activity was found in crude extracts of 'Pinot noir' grape berries. The enzyme required ATP, Mn'+ plus Mg, a pH of 6.6, and a temperature of 40 C for maximum activity. The range in concentration of oxaloacetic acid needed for maximum phosphoenolpyruvate carboxykinase activity was 5 to 10 mM, and the Km for HC03-in the exchange of 1CO2 into oxaloacetic acid was 26.8 mM.Changes in the activity of PEP carboxykinase and PEP carboxylase in berries were studied at weekly intervals throughout fruit development. PEP carboxykinase had maximum activity 4 weeks after flowering, and during the following 11 weeks remained relatively constant. The activity of PEP carboxylase was 2-to 4-fold higher than PEP carboxykinase throughout fruit development, and changed little except for a sharp reduction at the onset of ripening.

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“…Therefore, in order to achieve maximal uptake of "C and distribution to active metabolic pools, a standard time of 2 hr was used for the feeding of labeled substrates. Uptake of "C-substrates varied with each leaf sample and accordingly, to enable comparisons to be made, data are generally expressed in this and the subsequent papers (12,13) as percentages of the "C in the total ethanol-soluble fraction.…”

Section: Methodsmentioning

confidence: 99%

“…In order that the complex data resulting from light-induced changes in intermediary metabolites may be interpreted in terms of control points, recourse will be made in the following paper (12) to the use of the Chance crossover theorem (11 (13).…”

Section: Methodsmentioning

confidence: 99%

The Effect of Light on the Tricarboxylic Acid Cycle in Green Leaves

Chapman

Graham²

1974

Plant Physiol.

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Excised green leaves of mung bean (Phaseolus aureus L. var. Mungo) were used to determine the effect of light on the rate of endogenous respiration via the tricarboxylic acid cycle. ILlumination with white light at an intensity of 0.043 gram calories cm'minn (approximately 8600 lux) of visible radiation (400-700 nm) gave a rate of apparent photosynthesis, measured as net C02 uptake, of 21 mg CO2 dm-2hr-' which was about 11-fold greater than the rate of dark respiration. The feeding of '4CO2 or 14C-labeled acids of the tricarboxylic acid cycle in the dark for 2 hours was established as a suitable method for labeling mitochondrial pools of cycle intermediates.At a concentration of 0.1 mM 3-(3,4-dichlorophenyl)-1,1-dimethylurea, apparent photosynthesis was inhibited 82%, and the refixation of 14CO2 derived internally from endogenous respiration was largely prevented. In the presence of this inhibitor endogenous respiration, measured as "CO2 evolution, continued in the light at a rate comparable to that in the dark. Consequently, under these conditions light-induced nonphotosynthetic processes have no significant effect on endogenous dark respiration. Inhibitors of the tricarboxylic acid cycle, malonate and fluoroacetate, were used to determine the relative rates of carbon flux through the cycle in the dark and in the light by measuring the rate of accumulation of 4(C in either succinate or citrate. Results were interpreted to indicate that the tricarboxylic acid cycle functions in the light at a rate similar to that in the dark except for a brief initial inhibition on transition from dark to light. Evidence was obtained that succinate dehydrogenase as well as aconitase, was inhibited in the presence of fluoroacetate.Controversy has surrounded the question of the effect of light on endogenous aerobic respiration via glycolysis and the tricarboxylic acid cycle in algae and green leaves of higher plants. Reports have included stimulation, inhibition, or no effect of light on respiration. For example, physiological studies, using the mass spectrometer to measure respiratory and photosynthetic gas exchange simultaneously, showed that relatively low light intensities had little or no effect on rate of respiratory oxygen uptake in barley leaves or in suspensions of the alga Chiorella (8). With the green alga Ankistrodesmus braunii (9) or the algal flagellate Ochromonas malhamensis (52) it was found that respiratory CO2 evolution was almost independent of light intensity, and that respiratory oxygen consumption was not affected by low light although it was enhanced at high light intensities. Hoch et al. (24) concluded from their results obtained with the mass spectrometer that low light intensities inhibited endogenous respiration in Anacystis, a blue-green alga, but not in Scenedesmus, a green alga, whereas higher light intensities promoted oxygen uptake in both organisms. The total oxygen consumption or CO2 evolution cannot be separated, however, into dark endogenous respiratory and light-induced photorespirator...

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The Effect of Light on the Tricarboxylic Acid Cycle in Green Leaves

Abstract: The chlorophyll-based specific activity of

Cited by 23 publications

References 20 publications

Comparative Transcriptome Atlases Reveal Altered Gene Expression Modules between Two Cleomaceae C3 and C4 Plant Species

Comparative Transcriptome Atlases Reveal Altered Gene Expression Modules between Two Cleomaceae C3 and C4 Plant Species

Phosphoenolpyruvate Carboxykinase Activity in Grape Berries

The Effect of Light on the Tricarboxylic Acid Cycle in Green Leaves

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