This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (38) Citing Articles via Google Scholar Google Scholar Articles by Fiscus, E. L. Articles by Kaufmann, M. R. Search for Related Content PubMed PubMed Citation Articles by Fiscus, E. L. Articles by Kaufmann, M. R. Agricola Articles by Fiscus, E. L. Articles by Kaufmann, M. R.

Articles

An Interpretation of Some Whole Plant Water Transport Phenomena

United States Department of Agriculture-Agricultural Research Service, Crops Research Laboratory, Colorado State University, Fort Collins, Colorado 80523, United States Department of Agriculture-Agricultural Research Service, Agronomy Department, Colorado State University, Fort Collins, Colorado 80523, United States Department of Agriculture—Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado 80526

A treatment of water flow into and through plants to the evaporating surface of the leaves is presented. The model is driven by evaporation from the cell wall matrix of the leaves. The adsorptive and pressure components of the cell wall matric potential are analyzed and the continuity between the pressure component and the liquid tension in the xylem established. Continuity of these potential components allows linking of a root transport function, driven by the tension in the xylem, to the leaf water potential. The root component of the overall model allows for the solvent-solute interactions characteristic of a membrane-bound system and discussion of the interactions of environmental variables such as root temperature and soil water potentials. A partition function is developed from data in the literature which describes how water absorbed by the plant might be divided between transpiration and leaf growth over a range of leaf water potentials.

Relationships between the overall system conductance and the conductance coefficients of the various plant parts (roots, xylem, leaf matrix) are established and the influence of each of these discussed.

The whole plant flow model coupled to the partition function is used to simulate several possible relationships between leaf water potential and transpiration rate. The effects of changing some of the partition function coefficients, as well as the root medium water potential on these simulations is illustrated.

In addition to the general usefulness of the model and its ability to describe a wide range of situations, we conclude that the relationships used, dealing with bulk fluid flow, diffusion, and solute transport, are adequate to describe the system and that analogically based theoretical systems, such as the Ohm's law analogy, probably ought to be abandoned for this purpose.

This article has been cited by other articles:

				V. Gloser, M. A. Zwieniecki, C. M. Orians, and N. M. Holbrook Dynamic changes in root hydraulic properties in response to nitrate availability J. Exp. Bot., July 1, 2007; 58(10): 2409 - 2415. [Abstract] [Full Text] [PDF]

				M. Tsuda and M. T. Tyree Plant hydraulic conductance measured by the high pressure flow meter in crop plants J. Exp. Bot., April 1, 2000; 51(345): 823 - 828. [Abstract] [Full Text] [PDF]