© 1995 Oxford University Press
RESEARCH-ARTICLE |
Tissue 8
Botanisches Institut, Universitüt Bonn Venusbergweg 22, D-53115 Bonn, Germany
1To whom correspondence should be addressed: Fax: +49 228 732677.
The longitudinal and transverse forces involved in tissue stresses (TSs) and the stresses themselves, were determined for the hypocotyl of Helianthus annuus L. using Poisson ratios and data from measurements of (i) the forces necessary to restretch the strips of outer tissue (OT) to their initial length in situ; (ii) the external compressive force and (iii) the external osmotic pressure required to prevent the extension of isolated inner tissue (IT) immersed in water or mannitol solutions. These three independent measurements gave a similar magnitude for the longitudinal forces (tensile in the OT, compressive in the IT), 0.37 N in the apical region. More than 80% of the tensile force is transmitted by the epidermis, resulting in a longitudinal TS three times higher than that due to turgor pressure in this layer. The longitudinal compressive TS in the IT amounts to approximately one-third of turgor pressure in this tissue. Transverse TSs in the OT and in the IT were calculated from the longitudinal forces. In the OT, the tensile, circumferential TS is one-fifth to one-sixth of that in the longitudinal direction. In the IT the compressive TS in the transverse direction amounts to nearly half of that in the longitudinal direction.
Key words: Tissue stresses, sunflower hypocotyl, epidermis
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
F. Guillon, S. Philippe, B. Bouchet, M.-F. Devaux, P. Frasse, B. Jones, M. Bouzayen, and M. Lahaye Down-regulation of an Auxin Response Factor in the tomato induces modification of fine pectin structure and tissue architecture J. Exp. Bot., February 10, 2008; (2008) erm323v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Schopfer Biomechanics of plant growth Am. J. Botany, October 1, 2006; 93(10): 1415 - 1425. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.S. Thompson Extensiometric determination of the rheological properties of the epidermis of growing tomato fruit J. Exp. Bot., June 1, 2001; 52(359): 1291 - 1301. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. S. Peters and A. D. Tomos The Mechanic State of "Inner Tissue" in the Growing Zone of Sunflower Hypocotyls and the Regulation of Its Growth Rate Following Excision Plant Physiology, June 1, 2000; 123(2): 605 - 612. [Abstract] [Full Text] |
||||


