A large decrease of cytosolic triosephosphate isomerase in transgenic potato roots affects the distribution of carbon in primary metabolism
| Autor: | Enrique Martinez Force, Jean Rivoal, Julie Jeukens, Joaquín J. Salas, Andrea A. Haner, R. David Law, Audrey Clendenning, Sonia Dorion, Nanhi Parveen |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Population
Carbohydrates Carboxylic Acids Plant Science Biology Pentose phosphate pathway Plant Roots Triosephosphate isomerase chemistry.chemical_compound Cytosol Glyceraldehyde parasitic diseases Genetics Aromatic amino acids RNA Antisense Carbon Radioisotopes Amino Acids education Solanum tuberosum chemistry.chemical_classification education.field_of_study Catabolism Nucleotides Fructose Biological Transport Lipid Metabolism Plants Genetically Modified Molecular biology Lipids Carbon Amino acid Isoenzymes Oxygen chemistry Biochemistry RNA Plant Carbohydrate Metabolism Glycolysis Triose-Phosphate Isomerase |
| Zdroj: | Planta. 236(4) |
| ISSN: | 1432-2048 |
| Popis: | Triosephosphate isomerase (TPI, EC 5.3.1.1) catalyzes the interconversion of dihydroxyacetone-P and glyceraldehyde 3-P in the glycolytic pathway. A constitutively expressed antisense construct for cytosolic TPI was introduced into potato (Solanum tuberosum) using Agrobacterium rhizogenes to examine the metabolic effects of a reduction in cytosolic TPI in roots. We obtained a population of transgenic root clones displaying ~36 to 100 % of the TPI activity found in control clones carrying an empty binary vector. Ion exchange chromatography and immunoblot analysis showed that the antisense strategy significantly decreased the cytosolic TPI isoform, while levels of plastidial TPI activity remained apparently unaffected. Transgenic roots were characterized with respect to the activity of glycolytic enzymes, their metabolite contents and carbon fluxes. Metabolite profiling of sugars, organic acids, amino acids and lipids showed elevated levels of sucrose, glucose, fructose, fumarate, isocitrate, 4-aminobutyrate, alanine, glycine, aromatic amino acids and saturated long chain fatty acids in roots containing the lowest TPI activity. Labelings with (14)C-glucose, (14)C-sucrose and (14)C-acetate indicated that a reduction of cytosolic TPI activity in roots increased carbon metabolism through the pentose phosphate pathway, O(2) uptake and catabolism of sucrose to CO(2), and capacity for lipid synthesis. These results demonstrate that a large reduction of cytosolic TPI alters the distribution of carbon in plant primary metabolism. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink