title: Dimethylsulfoxide as a potential tool for analysis of compartmentation in living plant cells.
abstract: Data are presented which indicate that dimethylsulfoxide (DMSO) acts selectively on the plasma membrane of cultured tobacco cells, rendering it more permeable to small molecules, while having a far smaller effect on the permeability of the vacuolar membrane. The results which support this conclusion are: (a) DMSO (5 to 10%, by volume) causes complete release of [(14)C]tryptophan newly synthesized from [(14)C]indole while causing efflux of only about 20% of the total intracellular tryptophan pool; (b) similar concentrations of DMSO do not cause substantial release from these cells of phenolic compounds or preloaded neutral red, nor of beta-cyanin from fresh beet discs; (c) kinetic studies of release of tryptophan and neutral sugars and of efflux of (86)Rb(+) show that DMSO selectively promotes rapid release of a portion of the total pool, followed by a substantially slower release of the remaining pool; (d) when tobacco cell protoplasts are incubated in the presence of 7.5% (by volume) DMSO, rapid lysis is observed concomitant with the release of intact vacuoles. These data indicate that a procedure involving a brief treatment of intact plant cells or tissues with DMSO may be used to assess the distribution of metabolites between cytoplasmic and vacuolar compartments.
authors: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824.
authors: D P
authors: DP
authors: Delmer