Changes of Cell Membrane Permeability Induced by DMSO and Ethanol in Suspension Cultures of Taxus Cuspidata

Abstract

The changes of cell membrane permeability caused by dimethyl sulphoxide (DMSO) and ethanol, two commonly used solvents in study of water-insoluble elicitors, were investigated in suspension cultures of Taxus cuspidata. The extracellular medium became alkalinized in the case of DMSO while the medium pH fluctuated upon the addition of ethanol. When the content of DMSO or ethanol was larger than 2% (v/v), the concentration of intracellular malonyl dialdehyde (MDA) increased remarkably at day 5 compared to that of the control, while that of the extracellular MDA less changed at a DMSO content of below 2% (v/v) and increased rapidly within 15 min at a DMSO content of 4% (v/v). The electrical conductivity (EC) decreased slightly when DMSO content was below 2% (v/v) but increased markedly at day 5 when DMSO content reached 4% (v/v). EC less varied when the content of ethanol was below 0.4% (v/v) but changed obviously when the ethanol content was larger than 1% (v/v). The cell membrane integrity hardly broke in the case of small concentration of DMSO (below 1%, v/v), but the presence of even small amount of ethanol (0.4%, v/v) caused cell membrane integrity lost partly, especially long time contact. It is thus concluded that DMSO is a more suitable solvent for water-insoluble elicitors compared to ethanol especially at low concentration levels.