Biological changes in suspension cultures of Taxus cuspidata induced by dimethyl sulphoxide and ethanol

The biological changes in suspension cultures of Taxus cuspidata caused by dimethyl sulphoxide (DMSO) and ethanol, two commonly used solvents for water-insoluble elicitors, were investigated. The activities of peroxidase (POD) and superoxide dismutase (SOD) changed remarkably after the addition of small amount (0.4% (v/v)) of DMSO compared to those of the control culture at 4 h, however, they were less affected by small amount (0.4% (v/v)) of ethanol within 20 h. The biomass, cell viability, contents of intra/extracellular proteins did not change obviously when the amounts of DMSO and ethanol were below 1% (v/v) and 0.4% (v/v), respectively, but they varied significantly when the contents of DMSO and ethanol were 4% (v/v) and 1% (v/v), respectively. Obvious DNA fragmentation occurred in the case of ethanol at 2% (v/v), while no DNA fragments were observed in the case of DMSO at the same concentration level. It is inferred that DMSO below 1% (v/v) is a better solvent for investigating the effects of water-insoluble elicitors at a long-term contact, while ethanol less than 0.4% (v/v) is more suitable for a short-term contact.