Water permeability differs between growing and non-growing barley leaf tissues.
Vadim Volkov1, Charles Hachez, Menachem Moshelion
1Division of Biological Sciences, University of Paisley, Paisley, PA1 2BE, Scotland, UK.
Journal of Experimental Botany
|November 24, 2006
Summary
Growing barley leaf tissues exhibit significantly higher water transport properties, including hydraulic conductivity and water permeability, compared to non-growing tissues. These differences are crucial for understanding plant water movement during growth.
Area of Science:
- Plant Physiology
- Biophysics
- Cell Biology
Background:
- Water transport is vital for plant growth and development.
- Understanding cell-specific water permeability is key to plant physiology.
Purpose of the Study:
- To compare water transport properties in growing versus non-growing barley leaf tissues.
- To investigate cell-type specific differences in water permeability.
Main Methods:
- Utilized pressure probe technique for in planta epidermal cell analysis.
- Employed osmotic swelling assay for mesophyll protoplast analysis.
- Assessed the impact of aquaporin inhibitors on water transport.
Main Results:
- Epidermal cells in the growing leaf elongation zone showed 31% higher hydraulic conductivity (Lp) and water permeability (Pf).
- Mesophyll protoplasts from the elongation zone had 55% higher Pf than those from the emerged zone.
- A subpopulation of larger protoplasts from the elongation zone exhibited three-fold higher Pf.
Conclusions:
- Growing barley tissues possess enhanced water transport capabilities.
- Significant cell-type and growth-stage specific variations in water transport exist.
- Aquaporin inhibitor phloretin partially affected water permeability, with variable responses.
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.
02:03Xylem 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.
02:04Regulation 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.
00:53Tonicity in Plants
Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity delimits the magnitude and direction of osmosis and results in three possible scenarios that alter the volume of a cell: hypertonicity, hypotonicity, and isotonicity. Due to differences in structure and physiology, tonicity of plant cells is different from that of animal cells in some scenarios.Plants and Hypotonic EnvironmentsUnlike animal cells,...
01:20Tonicity in Plants
Plant cells maintain appropriate osmotic balance in extreme conditions. For instance, plants in dry environments store water in vacuoles, limit the opening of their stoma, and have thick, waxy cuticles to prevent unnecessary water loss. Some species of plants that live in salty environments store salt in their roots. As a result, water osmosis occurs in the root from the surrounding soil.
Tonicity
Tonicity describes the capacity of a cell to lose or gain water depending on the solute...
Tonicity
Tonicity describes the capacity of a cell to lose or gain water depending on the solute...
02:34Water and Mineral Acquisition
Specialized tissues in plant roots have evolved to capture water, minerals, and some ions from the soil. Roots exhibit a variety of branching patterns that facilitate this process. The outermost root cells have specialized structures called root hairs that increase the root surface, thus increasing soil contact. Water can passively cross into roots, as the concentration of water in the soil is higher than that of the root tissue. Minerals, in contrast, are actively transported into root cells.