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 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 Google Scholar Google Scholar Articles by Lockhart, J. A. Search for Related Content PubMed PubMed Citation Articles by Lockhart, J. A. Agricola Articles by Lockhart, J. A.

Articles

Physical Nature of Irreversible Deformation of Plant Cells ¹

Department of Botany, University of Massachusetts, Amherst, Massachusetts 01002

Etiolated mung bean hypocotyl segments were incubated in 0.25 M mannitol solutions with indoleacetic acid. They were then deformed mechanically with a longitudinal tensile force at a constant strain rate. The magnitudes of the mechanical forces were comparable to those of the hydrostatic forces existing in normally growing tissues. Each segment was repeatedly deformed and returned to zero force. The total deformation was increased at each cycle.

The irreversible and elastic changes in length and diameter were measured for each deformation and the changes in surface area and volume calculated. In addition the applied stress and the work of irreversible and of elastic deformation were determined as functions of deformation.

It was found that irreversible elongation, irreversible change in surface area and total change in surface area all were linear functions of total imposed elongation. However, very little change in volume occurred during the deformations.

The work of irreversible deformation was found to be independent of temperature between 8° and 25°. It was also virtually independent of rate of deformation measured over a 5-fold range of deformation rates.

From these results it is concluded that the irreversible deformation of mung bean hypocotyl tissue occurs by plastic deformation rather than by viscous flow. Thus, the irreversible deformation occurred as a result of breaking cross-links of a cross-linked polymer system.

This article has been cited by other articles:

				P. Schopfer Biomechanics of plant growth Am. J. Botany, October 1, 2006; 93(10): 1415 - 1425. [Abstract] [Full Text] [PDF]

				T. E. Proseus, G.-L. Zhu, and J. S. Boyer Turgor, temperature and the growth of plant cells: using Chara corallina as a model system J. Exp. Bot., September 1, 2000; 51(350): 1481 - 1494. [Abstract] [Full Text] [PDF]

				T. E. Proseus, J. K.E. Ortega, and J. S. Boyer Separating Growth from Elastic Deformation during Cell Enlargement Plant Physiology, February 1, 1999; 119(2): 775 - 784. [Abstract] [Full Text]