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Carbon dioxide signalling in plant leaves
1Institute of Botany, Department of Biology, Technical University Darmstadt, Schnittspahnstrasse 3-5, 64287 Darmstadt, Germany. luettge@bio.tu-darmstadt.de
Comptes Rendus Biologies
|May 29, 2007
Summary
Carbon dioxide (CO2) acts as a crucial signal in plant biochemical networks. Its transport and concentration mechanisms, like C4 photosynthesis and CAM, are vital for photosynthesis and intercellular CO2 signaling.
Area of Science:
- Plant Physiology
- Biochemistry
- Photosynthesis Research
Background:
- Carbon dioxide (CO2) and bicarbonate (HCO3-) transport are fundamental to cellular signaling in plants.
- While a specific CO2 sensor remains elusive, reactions utilizing CO2/HCO3- as substrates are potential candidates for sensing mechanisms.
- Carbon concentrating mechanisms, such as C4 photosynthesis and Crassulacean Acid Metabolism (CAM), elevate internal CO2 levels, influencing both photosynthesis and CO2-based signaling.
Purpose of the Study:
- To explore the signaling role of carbon dioxide (CO2) within plant biochemical regulation networks.
- To survey the transport mechanisms of CO2 and HCO3- as prerequisites for CO2-based signaling.
- To investigate how carbon concentrating mechanisms influence CO2 signaling and photosynthetic synchronization.
Main Methods:
- Review of CO2 and HCO3- transport mechanisms in plants.
- Analysis of carbon concentrating mechanisms (C4 photosynthesis, CAM) in relation to CO2 signaling.
- Utilizing chlorophyll fluorescence imaging to observe spatiotemporal dynamics of photosynthetic activity.
- Examining patchiness in stomatal opening/closing and its link to lateral CO2 diffusion in heterobaric leaves.
Main Results:
- CO2 and HCO3- transport mechanisms are essential for CO2 signaling pathways.
- High internal CO2 concentrations generated by C4 and CAM pathways support both photosynthesis and CO2 diffusion-based signaling.
- Chlorophyll fluorescence imaging reveals spatiotemporal dynamics of photosynthetic desynchronization/synchronization.
- Anatomical constraints on lateral CO2 diffusion contribute to photosynthetic desynchronization in heterobaric leaves.
Conclusions:
- CO2 functions as a significant signaling molecule in plant biochemical networks.
- Understanding CO2 transport and concentration is key to deciphering its signaling roles.
- CAM plants provide a model system to study the impact of lateral CO2 diffusion on photosynthetic synchronization across leaves.
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