The invertase mutant defective in the glucose signaling pathway of () is resistant to glucose repression. This mutant is able to consume sucrose alongside glucose and grows in glucose-containing media with a generation time close to that of the wild type. Intracellular oxidation, protein carbonyl, and reduced glutathione levels and catalase, superoxide dismutase, and glutathione peroxidase activity were investigated in , to determine the relationship between oxidative stress response and glucose signaling. The expression profiles of some genes involved in regulation of glucose repression ( fructose-1,6-bis-phosphatase; hexokinase) and stress response ( and transcription factors; catalase; Cu,Zn superoxide dismutase) were analyzed using the quantitative real-time PCR technique. Oxidative stress response in seems to be affected by glucose signaling in a manner different from that caused by glucose deprivation.