Age-related responses of suspension cultured Taxus cuspidata to hydrodynamic shear stress

Hydrodynamic shear sensitivity is considered one of the obstacles for large-scale plant cell culture. Understanding the mechanism of shear sensitivity might assist the industrial application of plant cell culture. Here we investigated the responses of suspension cultured Taxus cuspidata in different culture phases under shear stress using a Couette reactor. It was found that the pH in medium and peroxide hydrogen (H2O2) in cells increased more rapidly in the exponential phase than that in lag phase under shear stress. The pH and H2O2 concentration in the exponential phase were also higher than those in the lag phase. Inhibition studies showed that there existed a 30–45 min delay in the action time of G-protein, Ca2+ channel and phospholipase C of T. cuspidata cells in the lag phase than that in the exponential phase. Age-related different membrane fluidity and H+-ATPase activity may partially contribute to the observed responses. These early responses might be indicators for selecting shear-resistant cell lines and for cell damage caused by shear stress.