Roessner-Tunali, U., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Hegemann, B., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Lytovchenko, A., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Carrari, F., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Bruedigam, C., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Granot, D., Institute for Field and Garden Crops, Agricultural Research Organization, Volcani Centre, Bet Dagan 50250, Israel Fernie, A.R., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany
We have conducted a comprehensive metabolic profiling on tomato (Lycopersicon esculentum) leaf and developing fruit tissue using a recently established gas chromatography-mass spectrometry profiling protocol alongside conventional spectrophotometric and liquid chromatographic methodologies. Applying a combination of these techniques, we were able to identify in excess of 70 small-Mr metabolites and to catalogue the metabolite composition of developing tomato fruit. In addition to comparing differences in metabolite content between source and sink tissues of the tomato plant and after the change in metabolite pool sizes through fruit development, we have assessed the influence of hexose phosphorylation through fruit development by analyzing transgenic plants constitutively overexpressing Arabidopsis hexokinase AtHXK1. Analysis of the total hexokinase activity in developing fruits revealed that both wild-type and transgenic fruits exhibit decreasing hexokinase activity with development but that the relative activity of the transgenic lines with respect to wild type increases with development. Conversely, both point-by-point and principal component analyses suggest that the metabolic phenotype of these lines becomes less distinct from wild type during development. In summary, the data presented in this paper demonstrate that the influence of hexose phosphorylation diminishes during fruit development and highlights the importance of greater temporal resolution of metabolism.
Metabolic profiling of transgenic tomato plants overexpressing hexokinase reveals that the influence of hexose phosphorylation diminishes during fruit development
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Roessner-Tunali, U., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Hegemann, B., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Lytovchenko, A., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Carrari, F., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Bruedigam, C., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany Granot, D., Institute for Field and Garden Crops, Agricultural Research Organization, Volcani Centre, Bet Dagan 50250, Israel Fernie, A.R., Department of Lothar Willmitzer, Max-Planck-Inst. Molec. P., Am Mühlenberg 1, 14476 Golm, Germany
Metabolic profiling of transgenic tomato plants overexpressing hexokinase reveals that the influence of hexose phosphorylation diminishes during fruit development
We have conducted a comprehensive metabolic profiling on tomato (Lycopersicon esculentum) leaf and developing fruit tissue using a recently established gas chromatography-mass spectrometry profiling protocol alongside conventional spectrophotometric and liquid chromatographic methodologies. Applying a combination of these techniques, we were able to identify in excess of 70 small-Mr metabolites and to catalogue the metabolite composition of developing tomato fruit. In addition to comparing differences in metabolite content between source and sink tissues of the tomato plant and after the change in metabolite pool sizes through fruit development, we have assessed the influence of hexose phosphorylation through fruit development by analyzing transgenic plants constitutively overexpressing Arabidopsis hexokinase AtHXK1. Analysis of the total hexokinase activity in developing fruits revealed that both wild-type and transgenic fruits exhibit decreasing hexokinase activity with development but that the relative activity of the transgenic lines with respect to wild type increases with development. Conversely, both point-by-point and principal component analyses suggest that the metabolic phenotype of these lines becomes less distinct from wild type during development. In summary, the data presented in this paper demonstrate that the influence of hexose phosphorylation diminishes during fruit development and highlights the importance of greater temporal resolution of metabolism.