WATER TRANSPORT-SYSTEM AND ITS COMPONENTS IN HIGHER-PLANTS .2. A METHOD FOR ESTIMATING ELASTIC PROPERTIES OF ISOLATED PLANT-CELLS AND PLANT-TISSUE CELLS

Based on the previously described method of soft flattening, a method was developed for measuring the rigidity index of the cell wall alpha = epsilon/P, which, in contrast to the volumetric elastic modulus epsi lon, does not depend on cell turgor P. The dependence of the change in relative volume (V) over bar = V/V-0 on the water potential Psi was i nvestigated experimentally over the whole range of water potential Psi :-infinity<Psi less than or equal to 0 bar. The key parameters, pi(0) and (V) over bar V-pl, were calculated from the experimental data by a graphical method. Then, the parameters pi(in), P, alpha, and epsilon. were calculated with the corresponding formulas. The main difficultie s resolved consisted in calculating (V) over bar for nonturgescent (pl asmolyzed) samples.