Induction of “Pore” Formation in Plant Cell Membranes by Toluene

Abstract

Treatment with aqueous toluene-ethanol was shown to induce pore formation in plant cell membranes. Toluene treatment induced preloaded vital dyes to leak from cells as observed under the microscope. It also brought about inward diffusion of 1-anilinonaphthalene-8-sulfonate. Compartmental analysis indicated that the space within the tissue accessible to the free diffusion of a molecule of the size of thiourea was increased about 3-fold by the toluene treatment. Gel filtration on Sephadex G-25 showed that a substantial fraction of the low MW cellular solutes leaked out as a result of toluene treatment, while no leakage of macromolecules (proteins) were detected. The results with gel filtration, as well as in situ measurements of enzymic reactions, indicated that the pores induced by toluene in the cytoplasmic membranes were smaller than the Stokes'' radius NAD. While the principal experimental material was roots of Atriplex nummularia Lindl., the fact that similar results were also observed with leaves of Pisum sativum L. and with the alga Chlorella pyrenoidosa Chik. suggests that the phenomenon is general. Although the phenomenon of pore induction is qualitatively similar to that in microorganisms, the pores induced appear to be smaller. Possibly induced leakage could be the basis for the development of simple and rapid methods for plant biochemical studies.