Desiccation of the leaf mesophyll and its implications for CO2 diffusion and light processing
Mina Momayyezi1, Aleca M Borsuk2, Craig R Brodersen2
1Department of Viticulture and Enology, University of California, Davis, California, USA.
Plant, Cell & Environment
|February 10, 2022
Summary
Leaf structure significantly impacts photosynthesis and gas exchange in walnut species. Contrasting anatomies reveal how leaf traits influence crop performance under drought, affecting water transport and carbon dioxide uptake.
Area of Science:
- Plant biology
- Photosynthesis research
- Crop physiology
Background:
- Leaves are vital for CO2 absorption, radiative balance, and water transport to maximize photosynthesis.
- Comparing species with different leaf anatomies offers insights into crop structure-function relationships under stress.
Purpose of the Study:
- To investigate how contrasting walnut leaf anatomies affect gas exchange, hydraulic conductance, and light absorption under normal and drought conditions.
- To understand the links between inherent leaf structure and drought-induced changes in photosynthetic capacity.
Main Methods:
- Utilized light microscopy and X-ray microCT for detailed leaf anatomy analysis.
- Measured gas exchange, hydraulic conductance, and chlorophyll distribution profiles.
- Compared two walnut species (Juglans regia and Juglans microcarpa) under non-stressed and drought conditions.
Main Results:
- Juglans regia showed higher gas-phase diffusion (gIAS), stomatal and mesophyll (gm) conductances, and carboxylation capacity due to thicker palisade mesophyll and greater porosity.
- Juglans microcarpa exhibited higher fluorescence associated with densely packed cells and bundle sheath extensions (BSEs).
- Drought reduced mesophyll cell volume in both species, but increased porosity and gIAS were offset by decreased biochemical activity (gm).
Conclusions:
- Inherent leaf anatomical differences between walnut species correlate with variations in gas exchange, light absorption, and photosynthetic capacity.
- Drought stress impacts leaf performance by imposing species-specific limitations on light absorption, gas exchange, and hydraulics.
- Leaf structure plays a critical role in determining crop adaptability and performance under environmental stress.
Keywords:
3D leaf complexityX-ray microcomputed tomographydrought stressleaf carbon-water exchangeleaf structure and functionlight absorption profilesmesophyll conductanceMore Related Videos
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