二氧化硫对玉米细胞过氧化氢酶活性的影响

对亲缘关系较远的鲁单981、莱农14、DH3、苏玉9号和掖单2号5个玉米杂交种采用简易自制密闭式熏气装置的短时处理，通过酶活性测定、同工酶电泳及RT-PCR检测，初步研究了二氧化硫(SO₂)对玉米过氧化氢酶(CAT)活性的影响。结果表明，相同浓度的SO₂对不同玉米品种CAT活性的影响不同。用60 mg m^-3 SO₂熏气处理敏感玉米品种鲁单981和不敏感玉米品种掖单2号，其CAT活性分别下降59%和38%。当逆境因子SO₂去除后，CAT活性逐渐恢复，处理后48 h基本恢复到正常水平。酶活性测定、同工酶电泳及RT-PCR分析取得了一致的结果。因此认为，CAT在SO₂对玉米的伤害和玉米对SO2的抗性中可能具有重要的作用。

Catalase Activity Response to Sulfur Dioxide in Zea mays L

Sulfur dioxide (SO₂) content in the air is tending higher with the industrial development. Sulfur dioxide pollution causes environment deterioration and acid rain, which bring about severe harmfulness to plant growth and development. Catalase (CAT) plays an important role in keeping the balance of active oxygen metabolism in plant cell. However, the effects of SO2 on CAT activity in crops including maize (Zea mays L.) are rarely reported. The present study was conducted to provide primary result in the area with 5 maize hybrids of Ludan 981, Lainong14, DH3, Suyu 9, and Yedan 2. In a simple self-made obturator (168 cm×65 cm×63 cm), maize seedling was treated with 60 mg m^-3 SO₂ for 2 h. The CAT activity of treated leaf was measured at 0, 6, 12, 24, 48, and 72 h after treatment, respectively. The CAT isoenzymes and CAT gene were analyzed by PAGE and RT-PCR, respectively. The results showed that the CAT activity of leaf response to SO₂ differed significantly (P<0.01) among maize cultivars. The CAT activity reduced by 59% and 38% in the sensitive hybrid Ludan 981 and non-sensitive hybrid Yedan 2 respectively as compared with control (no SO₂ treatment). The CAT activity rose gradually after SO₂ treatment and restored to the normal level at 48 h after treatment. The analyses of isoenzymes and RT-PCR also received the same results, indicating that CAT might play an important role in the interaction of SO₂ and maize.