Marina Camara Mattos Martins, Mahdi Hejazi, Jörg Fettke, Martin Steup, Regina Feil, Ursula Krause, Stephanie Arrivault, Daniel Vosloh, Carlos Maria Figueroa, Alexander Ivakov, Umesh Prasad Yadav, Maria Piques, Daniela Metzner, Mark Stitt, John Edward Lunn
- Many plants accumulate substantial starch reserves in their leaves during the day and remobilize them at night to provide carbon and energy for maintenance and growth. In this paper, we explore the role of a sugar-signaling metabolite, trehalose-6-phosphate (Tre6P), in regulating the accumulation and turnover of transitory starch in Arabidopsis (Arabidopsis thaliana) leaves. Ethanol-induced overexpression of trehalose-phosphate synthase during the day increased Tre6P levels up to 11-fold. There was a transient increase in the rate of starch accumulation in the middle of the day, but this was not linked to reductive activation of ADP-glucose pyrophosphorylase. A 2- to 3-fold increase in Tre6P during the night led to significant inhibition of starch degradation. Maltose and maltotriose did not accumulate, suggesting that Tre6P affects an early step in the pathway of starch degradation in the chloroplasts. Starch granules isolated from induced plants had a higher orthophosphate content than granules from noninduced control plants,Many plants accumulate substantial starch reserves in their leaves during the day and remobilize them at night to provide carbon and energy for maintenance and growth. In this paper, we explore the role of a sugar-signaling metabolite, trehalose-6-phosphate (Tre6P), in regulating the accumulation and turnover of transitory starch in Arabidopsis (Arabidopsis thaliana) leaves. Ethanol-induced overexpression of trehalose-phosphate synthase during the day increased Tre6P levels up to 11-fold. There was a transient increase in the rate of starch accumulation in the middle of the day, but this was not linked to reductive activation of ADP-glucose pyrophosphorylase. A 2- to 3-fold increase in Tre6P during the night led to significant inhibition of starch degradation. Maltose and maltotriose did not accumulate, suggesting that Tre6P affects an early step in the pathway of starch degradation in the chloroplasts. Starch granules isolated from induced plants had a higher orthophosphate content than granules from noninduced control plants, consistent either with disruption of the phosphorylation-dephosphorylation cycle that is essential for efficient starch breakdown or with inhibition of starch hydrolysis by beta-amylase. Nonaqueous fractionation of leaves showed that Tre6P is predominantly located in the cytosol, with estimated in vivo Tre6P concentrations of 4 to 7 mu M in the cytosol, 0.2 to 0.5 mu M in the chloroplasts, and 0.05 mu M in the vacuole. It is proposed that Tre6P is a component in a signaling pathway that mediates the feedback regulation of starch breakdown by sucrose, potentially linking starch turnover to demand for sucrose by growing sink organs at night.…
MetadatenVerfasserangaben: | Marina Camara Mattos Martins, Mahdi Hejazi, Jörg FettkeORCiDGND, Martin SteupORCiDGND, Regina FeilORCiD, Ursula Krause, Stephanie Arrivault, Daniel Vosloh, Carlos Maria Figueroa, Alexander Ivakov, Umesh Prasad Yadav, Maria Piques, Daniela Metzner, Mark StittORCiDGND, John Edward LunnORCiD |
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DOI: | https://doi.org/10.1104/pp.113.226787 |
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ISSN: | 0032-0889 |
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ISSN: | 1532-2548 |
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Titel des übergeordneten Werks (Englisch): | Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants |
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Verlag: | American Society of Plant Physiologists |
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Verlagsort: | Rockville |
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Publikationstyp: | Wissenschaftlicher Artikel |
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Sprache: | Englisch |
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Jahr der Erstveröffentlichung: | 2013 |
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Erscheinungsjahr: | 2013 |
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Datum der Freischaltung: | 26.03.2017 |
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Band: | 163 |
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Ausgabe: | 3 |
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Seitenanzahl: | 22 |
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Erste Seite: | 1142 |
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Letzte Seite: | 1163 |
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Fördernde Institution: | Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior Brazil
[BEX2762/07-2]; Deutscher Akademischer Austauschdienst [A/07/70615];
Deutsche Forschungsgemeinschaft [SFB 429]; European Commission [245142];
Max Planck Society |
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Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
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Peer Review: | Referiert |
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