GIULIETTI Ana Maria
congresos y reuniones científicas
Signal transduction events mediating shear stress-induced AQs production in Rubia tinctorum cell suspension cultures.
BUSTO, V; CALABRÓ LOPEZ, A; RODRIGUEZ TALOU, J; GIULIETTI, A M; MERCHUK, J.C
Congreso; II Reunión de Biotecnología aplicada a Plantas Medicinales y Aromáticas; 2009
Shear stress has been used as a mechanical elicitor to induce secondary metabolites accumulation in many plant species. However, little attention was paid to considering the mechanism of the shear stress as a stimulating signal of defense responses and the pathway of the shear signal transduction. We previously found that shear stress elicits anthraquinones (AQs) production in Rubia tinctorum suspension cultures. Thus, the aim of this work was to study the intracellular mechanisms of shear stress-induced AQs production in R. tinctorum cell suspension cultures. To subject the cultures to shear stress 100 mL baffled shake flasks were agitated on an orbital shaker at 360 rpm during 48 hs. Controls were carried out in 100 mL baffled flasks agitated at 100 rpm. All the cultures were grown at 25 °C in absence of light. Specific modulators, 100 µM neomycin (a PLC inhibitor), and 1 mM LaCl3 (an intracellular calcium channels inhibitor), were used. Biomass concentration, cell death and AQs production were evaluated. When cells were stressed, a decrease in biomass concentration (from 28% to 39%) was observed in all treatments compared with control cultures. Cell death increased up to 87% after 48 hs of shear stress. The presence of neomycin and LaCl3 reduced the stimulatory effect of the shear stress on AQs production by 80% and 18% respectively. These results suggest that shear stress-induced AQs accumulation would involve PLC activation. Moreover, since AQs biosynthesis was partially blocked by LaCl3 the requirement of an increase in intracellular Ca2+ should be further investigated.