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Requirement for the plastidial oxidative pentose phosphate pathway for nitrate assimilation in Arabidopsis.
- Source :
-
The Plant journal : for cell and molecular biology [Plant J] 2013 Aug; Vol. 75 (4), pp. 578-91. Date of Electronic Publication: 2013 May 30. - Publication Year :
- 2013
-
Abstract
- Sugar metabolism and the oxidative pentose phosphate pathway (OPPP) are strongly implicated in N assimilation, although the relationship between them and the roles of the plastidial and cytosolic OPPP have not been established genetically. We studied a knock-down mutant of the plastid-localized OPPP enzyme 6-phosphogluconolactonase 3 (PGL3). pgl3-1 plants exhibited relatively greater resource allocation to roots but were smaller than the wild type. They had a lower content of amino acids and free NO3 - in leaves than the wild type, despite exhibiting comparable photosynthetic rates and efficiency, and normal levels of many other primary metabolites. When N-deprived plants were fed via the roots with 15NO3 -, pgl3-1 exhibited normal induction of OPPP and nitrate assimilation genes in roots, and amino acids in roots and shoots were labeled with (15) N at least as rapidly as in the wild type. However, when N-replete plants were fed via the roots with sucrose, expression of specific OPPP and N assimilation genes in roots increased in the wild type but not in pgl3-1. Thus, sugar-dependent expression of N assimilation genes requires OPPP activity and the specificity of the effect of the pgl3-1 mutation on N assimilation genes establishes that it is not the result of general energy deficiency or accumulation of toxic intermediates. We conclude that expression of specific nitrate assimilation genes in the nucleus of root cells is positively regulated by a signal emanating from OPPP activity in the plastid.<br /> (© 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.)
- Subjects :
- Amino Acid Sequence
Antibodies
Arabidopsis cytology
Arabidopsis drug effects
Arabidopsis genetics
Arabidopsis Proteins metabolism
Carboxylic Ester Hydrolases genetics
Cell Nucleus genetics
Gene Expression Regulation, Plant
Metabolome
Mutagenesis, Insertional
Nitrates pharmacology
Nitrogen Isotopes analysis
Phenotype
Photosynthesis
Plant Leaves
Plant Roots cytology
Plant Roots drug effects
Plant Roots genetics
Plant Roots metabolism
Plant Shoots cytology
Plant Shoots drug effects
Plant Shoots genetics
Plant Shoots metabolism
Sucrose pharmacology
Arabidopsis physiology
Arabidopsis Proteins genetics
Carboxylic Ester Hydrolases metabolism
Nitrates metabolism
Pentose Phosphate Pathway physiology
Plastids metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1365-313X
- Volume :
- 75
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The Plant journal : for cell and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 23621281
- Full Text :
- https://doi.org/10.1111/tpj.12222