To examine the existence of the RNA degradation pathway in yeast under oxidative stress, we have performed treatments with low doses of oxidative agents generating different ROS. These included the inorganic H 2 O 2 (concentrations 0.4-3 mM), superoxide-generating menadione (concentrations 0.05-0.6 mM), paraquat (concentrations 0.1-10 mM), thiol oxidant diamide (concentrations 0.2-2 mM), organic CHP (concentrations 0.1-0.2 mM), t-BHP (concentrations 1-3 mM) and a LoaOOH (concentrations 0.05-0.2 mM). Such concentrations of oxidants result in 30-90% of cell death (2, 36, 37) .