Plant physiology (Bethesda), 2005-09, Vol.139 (1), p.64-78
2005
Details
- Autor(en) / Beteiligte
- Titel
- Mitochondria-Driven Changes in Leaf NAD Status Exert a Crucial Influence on the Control of Nitrate Assimilation and the Integration of Carbon and Nitrogen Metabolism
- Ist Teil von
- Plant physiology (Bethesda), 2005-09, Vol.139 (1), p.64-78
- Ort / Verlag
- Rockville, MD: American Society of Plant Biologists
- Erscheinungsjahr
- 2005
- Link zum Volltext
- Quelle
- Free E-Journal (出版社公開部分のみ）
- Beschreibungen/Notizen
- The Nicotiana sylvestris mutant, CMS, lacks the mitochondrial gene nad7 and functional complex I, and respires using low-affinity NADH (alternative) mitochondrial dehydrogenases. Here, we show that this adjustment of respiratory pathways is associated with a profound modification of foliar carbon-nitrogen balance. CMS leaves are characterized by abundant amino acids compared to either wild-type plants or CMS in which complex I function has been restored by nuclear transformation with the nad7 cDNA. The metabolite profile of CMS leaves is enriched in amino acids with low carbon/nitrogen and depleted in starch and 2-oxoglutarate. Deficiency in 2-oxoglutarate occurred despite increased citrate and malate and higher capacity of key anaplerotic enzymes, notably the mitochondrial NAD-dependent isocitrate dehydrogenase. The accumulation of nitrogen-rich amino acids was not accompanied by increased expression of enzymes involved in nitrogen assimilation. Partitioning of ¹⁵N-nitrate into soluble amines was enhanced in CMS leaf discs compared to wild-type discs, especially in the dark. Analysis of pyridine nucleotides showed that both NAD and NADH were increased by 2-fold in CMS leaves. The growth retardation of CMS relative to the wild type was highly dependent on photoperiod, but at all photoperiod regimes the link between high contents of amino acids and NADH was observed. Together, the data provide strong evidence that (1) NADH availability is a critical factor in influencing the rate of nitrate assimilation and that (2) NAD status plays a crucial role in coordinating ammonia assimilation with the anaplerotic production of carbon skeletons.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0032-0889eISSN: 1532-2548DOI: 10.1104/pp.105.066399Titel-ID: cdi_proquest_miscellaneous_68588505
- Format
- –
- Schlagworte
- ADP-glucose pyrophosphorylase, amides, Amides - metabolism, Amines, Amines - metabolism, Amino acid metabolism, Amino acids, Ammonia, assimilation (physiology), Biochemical Processes and Macromolecular Structures, Biological and medical sciences, carbohydrate metabolism, carbon, Carbon - metabolism, carbon nitrogen ratio, Cell Respiration, Dehydrogenases, electron transport chain, Enzymes, Fundamental and applied biological sciences. Psychology, Gene Expression Profiling, Gene Expression Regulation, Enzymologic, Gene Expression Regulation, Plant, Genetic aspects, glutamate-ammonia ligase, isocitrate dehydrogenase, Leaves, Metabolism, metabolites, mitochondria, Mitochondria - metabolism, Mitochondrial Proteins - genetics, Mitochondrial Proteins - metabolism, molecular sequence data, Mutation, NAD (coenzyme), NAD - metabolism, NADH dehydrogenase (ubiquinone), Nicotiana - genetics, Nicotiana - metabolism, Nicotiana sylvestris, Nitrates, Nitrates - metabolism, Nitrogen, Nitrogen metabolism, nucleotide sequences, nucleotidyltransferases, Oxidation-Reduction, oxoglutarate, plant biochemistry, plant genetics, Plant Leaves - genetics, Plant Leaves - metabolism, Plant mitochondria, Plant physiology, Plant physiology and development, plant proteins, Plant Proteins - genetics, Plant Proteins - metabolism, Plants, pyridine nucleotides, Pyrimidine Nucleotides - metabolism, Respiration, tobacco