[en] Effects of 300Gy 60Co-γ ray irradiation on the activities of 3 antioxidant enzymes in tobacco were studied in this paper. The results showed that the activities of superoxide dismutase (SOD), peroxidas (POD) and catalse (CAT) in tobacco were gradually increased. All the activities of SOD POD and CAT reached the maximums at 12 h and then gradually decreased. Similar results were also observed in the expression of sod, pod and cat genes. These results indicated that the activities of antioxidant enzymes could play an important role in tobacco tolerance against irradiation

[en] Changes of activities of antioxidant enzymes in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings after different doses ⁶⁰Co γ-rays irradiation were studied. The results showed that the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings were gradually increased after different doses ⁶⁰Co γ-rays irradiation. The activity of SOD was to the maximum at 100 Gy treatment, but the activity of POD and CAT at 300 Gy treatment, and then these three antioxidant enzymes gradually decreased with the increase of irradiation dose. Quantitative real-time PCR analysis also revealed that the over-express of these antioxidant enzymes were induced after different doses ⁶⁰Co γ-rays irradiation and were consistent with the variance of their enzymic activities, which enhanced the tolerance of tobacco against irradiation. (authors)