Expression of root glutamate dehydrogenase genes in tobacco plants subjected to boron deprivation
Autor: | Wolfram Weckwerth, M. Teresa Navarro-Gochicoa, Juan J. Camacho-Cristóbal, Jesús Rexach, Stefan Kempa, Agustín González-Fontes, M. Begoña Herrera-Rodríguez, Víctor Manuel Beato |
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Rok vydání: | 2011 |
Předmět: |
DNA
Complementary Time Factors Physiology Nicotiana tabacum Asparagine synthetase Carbohydrates Carboxylic Acids Plant Science Biology Models Biological Plant Roots Gene Expression Regulation Enzymologic chemistry.chemical_compound Glutamate Dehydrogenase Phenols Gene Expression Regulation Plant Gene expression Ammonium Compounds Tobacco Genetics Metabolomics Ammonium Asparagine Amino Acids Boron Plant Proteins chemistry.chemical_classification Nitrates Glutamate dehydrogenase Fructose biology.organism_classification Plants Genetically Modified Amino acid chemistry Biochemistry RNA Plant |
Zdroj: | Plant physiology and biochemistry : PPB. 49(11) |
ISSN: | 1873-2690 |
Popis: | Recently it has been reported that boron (B) deficiency increases the expression of Nicotiana tabacum asparagine synthetase (AS) gene in roots, and that AS might play a main role as a detoxifying mechanism to convert ammonium into asparagine. Interestingly, glutamate dehydrogenase (GDH) genes, Ntgdh-NAD;A1 and Ntgdh-NAD;B2, were up-regulated when tobacco roots were subjected to B deprivation for 8 and 24 h. In addition, aminating and deaminating GDH (EC 1.4.1.2) activities were higher in B-deficient than in B-sufficient plants after 24 h of B deficiency. Ammonium concentrations were kept sufficiently low and with similar values in B-deficient roots when compared to control. Glucose and fructose contents decreased after 24 h of B deprivation. This drop in hexoses, which was corroborated by metabolomic analysis, correlated with higher GDH gene expression. Furthermore, metabolomic profiling showed that concentrations of several organic acids, phenolics, and amino acids increased after 24 h of B deficiency. Our results suggest that GDH enzyme plays an important role in metabolic acclimation of tobacco roots to B deprivation. A putative model to explain these results is proposed and discussed. |
Databáze: | OpenAIRE |
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