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Analysis of Arabidopsis thaliana Growth Behavior in Different Light Qualities
Published on: February 2, 2018
Lateral CO2 diffusion inside dicotyledonous leaves can be substantial: quantification in different light intensities
James I L Morison1, Tracy Lawson, Gabriel Cornic
1Department of Biological Sciences, University of Essex, Colchester, United Kingdom. morisj@essex.ac.uk
Plant Physiology
|October 2, 2007
Summary
Carbon dioxide (CO2) can move sideways within dicot leaves, supplying photosynthesis even when stomata are blocked. This lateral CO2 diffusion is significant, especially under moderate light conditions.
Area of Science:
- Plant Physiology
- Photosynthesis Research
- Leaf Gas Exchange
Background:
- Stomatal pores are the primary pathway for CO2 entry into leaves.
- Understanding CO2 diffusion within leaf tissues is crucial for photosynthesis efficiency.
Purpose of the Study:
- To quantify lateral CO2 diffusion rates in dicotyledonous and monocotyledonous plants.
- To investigate the influence of photosynthetic photon flux density (PPFD) on lateral CO2 diffusion.
- To determine the impact of blocked stomata on CO2 supply for photosynthesis.
Main Methods:
- Gas exchange measurements
- Chlorophyll a fluorescence imaging
- Two-dimensional diffusion modeling
- Stomatal blockage using grease patches
Main Results:
- Substantial lateral CO2 diffusion observed in five dicot species, but minimal in monocot maize.
- Lateral CO2 diffusion increased with moderate PPFD, reaching 15-24% of normal CO2 assimilation.
- Smaller blockage areas and higher ambient CO2 concentrations enhanced lateral diffusion.
Conclusions:
- Lateral CO2 diffusion within dicot leaves is a significant factor in photosynthesis, particularly when stomata are occluded.
- This internal CO2 supply can compensate for blocked stomata over distances up to 1 mm.
- Plant species and environmental conditions influence the importance of lateral CO2 diffusion.
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