Application: Understanding the osmotic potential properties of solutes common in the soil-plant solution continuum.
The absorption of soil solution by plant roots is undoubtedly due to osmosis. Flow from roots to leaves via the plant xylem tissue is generally considered as a cohesion-tension mechanism that is speeded up by evapotranspiration at the stomata organs of leaves (Sperry et al., 2003). From the leaves to roots and other non-green tissues, mass-flow along the phloem vessels has long been accredited to osmosis (Crafts and Crisp, 1971). There is no doubt that osmosis plays a key role in solution flow through the soil-plant continuum. The purpose of this paper was to record the preliminary quantification of the osmotic potential characteristics of a series of both inorganic and organic solutes common in the soil-planr solution continuum, and to discuss the significance of the findings in relation to solution flow from soils to plants and throughout plants:
- Reviews the calculations of the several components of osmotic pressure for a series of organic and inorganic solute particles (molecules and, or ions), common to plant solutions and soil solutions respectively.
- Illustrates and provides a record of how different solutes found in the soil-plant solution continuum affect the osmotic potential of solutions differently, and
- Discusses the significance of the findings with reference to understand solution flow through the soil-plant continuum.
Some minor but significant improvements to the new osmotic potential equation published in 1994 were presented in this paper, along with its testing and application to further help elucidate the properties of inorganic and organic solutes common in the soil-plant continuum
Application: To study plant stomatal guard cell solutes associated with stomata aperture osmoregulation; differences in the way potassiun chloride and sucrose solutions effect modulation.
The objective of the following paper was to report on the osmotic potential properties and size characteristics of the guard cell solutes that predominate during the different phases of the opening and closing of stomatal apertures, specifically K+ and Cl– ions and sucrose. It is considered that this may provide an insight into the way they affect the osmotic potentials of the solutions in the guard cell, and possibly their ease of flow and modulation in and out of the complex ion channel networks of the latter.
Additional research and calculations related to the vital role of potassium in the osmotic mechanism of plant stomata aperture modulation is presented in the following paper. Potassium deficiency in older plant leaves appears to be a “signal” trigger for potassium to flow to younger leaves to support stomata modulation.