Measurements of the volumetric and transverse elastic extensibilities of Chara corallina internodes by combining the external force and pressure probe techniques

The transverse and volumetric elastic extensibilities of Chara corallina internodal cell wall tubes were studied by simultaneous application of the external force and pressure probe measuring techniques. It was found that there is a deformation of the cell wall resulting from the concentrated force exerted by the external force, which dominates the transverse extensibility at low turgor pressures, and which can be important at high turgor pressure. The implications of the effect for the use of the external force technique on higher plant tissue are discussed.