Sink regulation of photosynthesis
The concept that photosynthetic flux is influenced by the accumulation of photo-assimilate persisted for 100 years before receiving any strong experimental support. Precise analysis of the mechanisms of photosynthetic responses to sink activity required the development of a battery of appropriate mo...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 52(2001), 360 vom: 16. Juli, Seite 1383-400 |
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| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2001
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Review Carbon Dioxide 142M471B3J Nitrogen N762921K75 |
| Zusammenfassung: | The concept that photosynthetic flux is influenced by the accumulation of photo-assimilate persisted for 100 years before receiving any strong experimental support. Precise analysis of the mechanisms of photosynthetic responses to sink activity required the development of a battery of appropriate molecular techniques and has benefited from contemporary interest in the effects of elevated CO2 on photosynthesis. Photosynthesis is one of the most highly integrated and regulated metabolic processes to maximize the use of available light, to minimize the damaging effects of excess light and to optimize the use of limiting carbon and nitrogen resources. Hypotheses of feedback regulation must take account of this integration. In the short term, departure from homeostasis can lead to redox signals, which cause rapid changes in the transcription of genes encoding photosystems I and II. End-product synthesis can exert short-term metabolic feedback control through Pi recycling. Beyond this, carbohydrate accumulation in leaves when there is an imbalance between source and sink at the whole plant level can lead to decreased expression of photosynthetic genes and accelerated leaf senescence. In a high CO2 world this may become a more prevalent feature of photosynthetic regulation. However, sink regulation of photosynthesis is highly dependent on the physiology of the rest of the plant. This physiological state regulates photosynthesis through signal transduction pathways that co-ordinate the plant carbon : nitrogen balance, which match photosynthetic capacity to growth and storage capacity and underpin and can override the direct short-term controls of photosynthesis by light and CO2. Photosynthate supply and phytohormones, particularly cytokinins, interact with nitrogen supply to control the expression of photosynthesis genes, the development of leaves and the whole plant nitrogen distribution, which provides the dominant basis for sink regulation of photosynthesis |
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| Beschreibung: | Date Completed 04.10.2001 Date Revised 09.04.2022 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |