Sink-source transition in tobacco leaves visualized using chlorophyll fluorescence imaging
• The sink-source transition of developing Nicotiana tabacum (tobacco) leaves was studied here using chlorophyll fluorescence imaging. • In accordance with leaf development, the quantum efficiency of PSII, showed a steep gradient across the leaf with increasing values towards the tip. • The linea...
| Veröffentlicht in: | The New phytologist. - 1979. - 151(2001), 3 vom: 28. Sept., Seite 585-595 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2001
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article 14C-translocation Nicotiana tabacum (tobacco) chlorophyll a fluorescence electron transport rate (ETR) imaging leaf development quantum efficiency of photosystem II sink-source transition |
| Zusammenfassung: | • The sink-source transition of developing Nicotiana tabacum (tobacco) leaves was studied here using chlorophyll fluorescence imaging. • In accordance with leaf development, the quantum efficiency of PSII, showed a steep gradient across the leaf with increasing values towards the tip. • The linear electron transport rate (ETR) saturated at higher CO2 concentrations in the younger, than in the mature, part of the leaf, probably due to a lower Rubisco activity or a higher CO2 diffusion resistance. • The induction of ETR at CO2 concentrations near the compensation point after long-term dark adaptation of the young leaf, showed distinct responses; ETR rose rapidly in the basal but more slowly in the apical regions. There was a correlation between fast induction and carbohydrate import, as measured by 14 C-translocation. In the basal regions, larger pools of metabolic intermediates are expected due to imported carbohydrates. These might be used in the Calvin cycle directly after dark-light transition providing the electron acceptors for the faster induction of ETR. Additionally, a higher mitochondrial respiration can provide CO2 for the Calvin cycle in these regions |
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| Beschreibung: | Date Revised 15.04.2021 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1046/j.0028-646x.2001.00224.x |