Relationship between ultrasonic properties and structural changes in the mesophyll during leaf dehydration
Domingo Sancho-Knapik1, Tomás Gómez Alvarez-Arenas, José Javier Peguero-Pina
1Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, E-50059, Zaragoza, Spain.
Journal of Experimental Botany
|March 19, 2011
Summary
Ultrasonic spectroscopy reveals how leaf structure changes during dehydration. Changes in cell wall elasticity and mesophyll cell shrinkage explain acoustic property shifts, aiding in understanding plant water status.
Area of Science:
- Plant Physiology
- Biophysics
- Materials Science
Background:
- Broad-band ultrasonic spectroscopy can determine relative water content (RWC) in leaves.
- The standardized frequency (f/f(o)) correlates with RWC, showing two phases around the turgor loss point.
Purpose of the Study:
- Investigate structural changes in *Quercus muehlenbergii* leaves during dehydration.
- Understand the relationship between RWC and f/f(o) through ultrasonic and structural analysis.
Main Methods:
- Ultrasound measurements
- Cell wall elasticity assessment
- Leaf thickness and density measurements
- Microscopic leaf structure analysis
Main Results:
- Before turgor loss, decreasing f/f(o) is linked to changes in the leaf's elastic constant (c(33)) due to cell wall elasticity (ε).
- After turgor loss, mesophyll cell shrinkage/stretching and increased intercellular spaces alter acoustic properties.
- Ultrasound attenuation increases beyond the turgor loss point due to irregular acoustic pathways.
Conclusions:
- Ultrasonic spectroscopy provides insights into leaf biomechanical properties beyond traditional pressure-volume analysis.
- Understanding these structural and acoustic changes enhances knowledge of plant water relations and drought response.
Related Concept Videos
01:57Adaptations that Reduce Water Loss
Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
02:41Responses to Drought and Flooding
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
02:03Xylem and Transpiration-driven Transport of Resources
The xylem of vascular plants distributes water and dissolved minerals that are taken up by the roots to the rest of the plant. The cells that transport xylem sap are dead upon maturity, and the movement of xylem sap is a passive process.
02:45Responses to Heat and Cold Stress
Every organism has an optimum temperature range within which healthy growth and physiological functioning can occur. At the ends of this range, there will be a minimum and maximum temperature that interrupt biological processes.
02:04Regulation of Transpiration by Stomata
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
02:16Light Acquisition
In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.