Influence of light and ambient carbon dioxide concentration on nitrate assimilation by intact barley seedlings.
TLDR
It appeared that recently fixed photosynthate could supply all of the energy required for nitrate reduction in carbohydrate-deficient tissue, and when sufficient metabolites were present in the green tissue, light was not obligatory for the reduction of nitrate and nitrite.Abstract:
The influence of light, dark, and ambient CO 2 on nitrate assimilation in 8- to 9-day-old barley seedlings was studied. To develop the photosynthetic apparatus fully, the seedlings were grown in nitrogen-free Hoagland solution for 5 days in darkness followed by 3 days in continuous light. The seedlings reduced nitrate and nitrite in both light and dark, although more slowly in darkness. The slower nitrate reduction in darkness was not due to decreased uptake, since the steady-state internal concentration of nitrate was doubled. The faster nitrate reduction in light was attributed to recent products of photosynthetic CO 2 fixation supplying reducing energy, possibly by shuttle reactions between chloroplasts and cytoplasm. In carbohydrate-deficient tissue, it appeared that recently fixed photosynthate could supply all of the energy required for nitrate reduction. When sufficient metabolites were present in the green tissue, light was not obligatory for the reduction of nitrate and nitrite.read more
Citations
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Journal ArticleDOI
Nitrogen and plant production
R. Novoa,R. S. Loomis +1 more
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Integration of Carbon and Nitrogen Metabolism in Plant and Algal Cells
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The CO 2 Dependence of Photosynthesis, Plant Growth Responses to Elevated Atmospheric CO 2 Concentrations and Their Interaction with Soil Nutrient Status. I. General Principles and Forest Ecosystems
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Evolved strategies in nitrogen acquisition by plants
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Nitrogen Metabolism in Roots
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References
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Journal ArticleDOI
Generation of reduced nicotinamide adenine dinucleotide for nitrate reduction in green leaves.
TL;DR: It was concluded that sugars that migrate from the chloroplast to the cytoplasm were the prime source of energy and that the oxidation of glyceraldehyde 3-phosphate was ultimately the in vivo source of NADH for nitrate reduction.
Journal ArticleDOI
Effect of light and glucose on the induction of nitrate reductase and on the distribution of nitrate in etiolated barley leaves.
TL;DR: The results suggest two mechanisms for regulating the metabolic NO(3) (-) pool: (a) a transfer from the storage pool which requires light; and (b) aTransfer from the external medium which requires either glucose or light.
Journal ArticleDOI
In Vivo Nitrate Reduction in Relation to Nitrate Uptake, Nitrate Content, and in Vitro Nitrate Reductase Activity in Intact Barley Seedlings
TL;DR: The results suggest that the rates of in vivo reduction of nitrate in barley seedlings may be regulated by the rate of uptake at the ambient concentrations of nitrates employed in the study.
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Generation of reduced nicotinamide adenine dinucleotide for nitrate reduction in green leaves.
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