二氧化硫胁迫对不同抗性玉米幼苗活性氧代谢的影响

采用60mg·m-3SO2气体处理玉米（Zea Mays.L）幼苗,通过组织化学染色和定量测定,分析了高抗自交系齐139和敏感自交系昌7-2在活性氧代谢上的差异。结果表明：SO2胁迫处理3h后,高抗系齐139幼苗叶片积累了较高的O2-和H2O2,12h后被迅速清除而趋于平衡;而高感系昌7-2叶片在胁迫早期产生的O2-和H2O2较少,后期有大量的O2-和H2O2积累,导致细胞损伤。抗氧化酶SOD和CAT在抗性系中显著升高,而敏感系中增幅不显著。这一研究表明不同抗性系中活性氧代谢的差异可能与其对SO2的抗性密切相关。

Effects of sulfur dioxide stress on reactive oxygen species metabolism of maize seedlings with contrasting tolerance

Differences in reactive oxygen species（ROS）metabolism were analyzed in maize（Zea Mays.L）seedlings from highly tolerant inbred Qi139 and highly sensitive inbred Chang7-2 by 60 mg·m-3 SO2 treatment.The results showed that in the tolerant line Qi139 a significant increase in the production of O2 – and H2O2 occurred within the first 3 h of treatment;subsequently,the increased ROS were rapidly scavenged and reached the balance states at 12 h of the stress.On the contrary,in the sensitive line chang7-2 a less increase in the production of O2 – and H2O2 was observed within the first 3 h of treatment,and the ROS production was increased rapidly after 12 h of the stress,which caused oxidative damage to cells.The activities of the main antioxidant enzymes Superoxide dismutase（SOD）and catalase（CAT）in the tolerant inbred were up-regulated significantly,but not in the sensitive inbred seedlings. This study suggests that the differences in active oxygen species metabolism among maize inbred lines with different sensitivities may be closely relevant to SO2 tolerance.