Sink-source transition in tobacco leaves visualized using chlorophyll fluorescence imaging.
Sink-source transition in tobacco leaves visualized using chlorophyll fluorescence imaging.
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DOI：
10.1046/j.0028-646x.2001.00224.x
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发表时间：
2001-09
期刊：
影响因子：
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通讯作者：
Q. Meng;K. Siebke;P. Lippert;B. Baur;U. Mukherjee;E. Weis
中科院分区：
文献类型：
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作者：
Q. Meng;K. Siebke;P. Lippert;B. Baur;U. Mukherjee;E. Weis
• 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.
