Tepperman J M, Dunsmuir P
DNA Plant Technology Corporation, Oakland, CA 94608.
Plant Mol Biol. 1990 Apr;14(4):501-11. doi: 10.1007/BF00027496.
The petunia nuclear gene which encodes the chloroplast isozyme of superoxide dismutase, SOD-1, has been fused with an efficient rbcS promoter fragment and 3' flanking region and introduced into tobacco and tomato cells. Transformed plants carrying this chimeric gene have up to 50-fold the levels of SOD-1 which occur in wild-type plants. However, tobacco plants with 30- to 50-fold the normal SOD-1 activity do not exhibit resistance to the light-activated herbicide paraquat. Similarly, tomato plants with 2- to 4-fold increases in SOD-1 do not exhibit tolerance to photoinhibitory conditions known to increase superoxide levels (high light, low temperatures and low CO2 concentrations). Our data indicate that increasing the chloroplastic SOD level in a plant cell is not sufficient to reduce the toxicity of superoxide.
编码叶绿体超氧化物歧化酶同工酶SOD-1的矮牵牛核基因已与高效的rbcS启动子片段和3'侧翼区域融合，并导入烟草和番茄细胞中。携带这种嵌合基因的转基因植物中SOD-1的水平比野生型植物高出50倍。然而，SOD-1活性比正常水平高30至50倍的烟草植株对光激活除草剂百草枯并不具有抗性。同样，SOD-1增加了2至4倍的番茄植株对已知会增加超氧化物水平的光抑制条件（高光、低温和低二氧化碳浓度）也没有耐受性。我们的数据表明，提高植物细胞中叶绿体SOD的水平不足以降低超氧化物的毒性。
