Impacts of X-ray irradiation on Saccharomyces cerevisiae cells growth and physiological-biochemical characteristic

In this paper, the growth curves of yeast cells exposed to X-rays were detected, and then fitted by Gompertz equation. The yeast cells treated with 50–125 Gy showed an increased exponential growth rate, and lower total biomass at plateau. At doses ≥ 150 Gy, cells showed a decreased exponential growth rate and higher total biomass at plateau. DNA lesions were detected by comet assay. Meanwhile, intracellular accumulation of reactive oxygen species(ROS), reduction of mitochondrial membrane potential(?Ψ m) and cell membrane integrity were evaluated. We conclude that X-ray irradiation results in DNA lesions, ROS accumulation and?Ψ m decline in a dose-dependent manner, and that these changes may be one of causes of X-rays-induced apoptosis in yeast. Furthermore, yeast cell membrane integrity appeared compromised following irradiation,suggesting that membrane damage may also have a role in the biological effects of radiation.