caa a22 4500 397521162 CHVBK 20180308164633.0 cr unu---uuuuu 161202e199508 xx s 000 0 eng 10.1093/jxb/46.8.1035 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.8.1035 Tissue 8 [Elektronische Daten] [Zygmunt Hejnowicz, Andreas Sievers] Tissue stress (TS) is defined as the stress which acts on a tissue layer in an organ in excess of the turgor-induced tensile stress which also acts on the layer when it is isolated from the organ. The tensile TS in one layer of an organ is always accompanied by com-pressive TS in another layer. To calculate TS from data obtained for isolated tissue, one needs to know the Poisson ratios VIKcontraction in the k-direction/extension in the i-direction for the tensile force applied in the i-direction for that tissue. Poisson ratios apply in the relationships between (i) tissue extensions caused by uniaxial stress (due to applied force) and multiaxial stress (due to turgor pressure); (ii) extensions of tissues subjected to lateral constraint, and (iii) TSs in different directions. The ratios VIW and VWI, for the stress applied either longitudinally (I) or in the direction of width (W), respectively, were determined for the outer tissue (OT) of sunflower hypocotyls, tulip leaves and tulip stems. The two ratios for a particular OT differed considerably. The ratios depended on the applied extension (strain). Knowing them, the tensile force (F1) generating TS in the OT of an intact organ could be calculated from the longitudinal force (FI(s)) which when applied to the isolated (unconstrained laterally) OT restored its original length. In the case of the sunflower hypocotyls, FI(s)<F1<1.3 ×FI(s). The ratio VIr (r denotes the radial direction), which was determined for segments of inner tissue, from sunflower hypocotyls and tulip stems, did not depend on the applied stress (extension). This ratio allowed us to calculate the relationship between the strain changes caused by equal changes of uniaxial and multiaxial stresses: the uniaxial stress was approximately 3-fold more efficient than the multiaxial stress. © Oxford University Press Research Papers nationallicence Elastic strains nationallicence Poisson ratios nationallicence tissue stresses nationallicence tissue elasticity nationallicence uni- and multiaxial stresses nationallicence Hejnowicz Zygmunt Botanisches Institut, Universität Bonn, Venusbergweg 22, D-53115 Bonn, Germany aut Sievers Andreas Botanisches Institut, Universität Bonn, Venusbergweg 22, D-53115 Bonn, Germany aut Journal of Experimental Botany Oxford University Press 46/8(1995-08), 1035-1043 0022-0957 46:8<1035 1995 46 exbotj https://doi.org/10.1093/jxb/46.8.1035 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.8.1035 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hejnowicz Zygmunt Botanisches Institut, Universität Bonn, Venusbergweg 22, D-53115 Bonn, Germany aut NATIONALLICENCE 700 1- Sievers Andreas Botanisches Institut, Universität Bonn, Venusbergweg 22, D-53115 Bonn, Germany aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/8(1995-08), 1035-1043 0022-0957 46:8<1035 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence SWISSBIB 397521162 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford