转基因甘薯旱后复水的修复机制和叶片喷施H_2O_2的效果

Recovery effect of re-watering condition on transgenic sweet potato after drought stress and the effect of pre-spray leaves with H_2O_2

对转入铜/锌超氧化物歧化酶(Cu/Zn SOD)和抗坏血酸氧化酶(APX)基因的甘薯和非转基因甘薯进行PEG胁迫处理(PE组)和H2O2处理后再胁迫处理(PE+组),对比胁迫后两个处理组及其对照组的抗氧化酶活性、MDA与H2O2的变化情况。得出胁迫和复水前期,转基因植株抗氧化酶活性和光合速率高于非转基因植株,MDA和H2O2含量则低于非转基因植株,复水后期抗氧化酶活性下降较快,出现较高的光合速率以及较低的MDA和H2O2含量;PE+组比PE组表现出了较强的抗氧化酶活性,也出现较高的MDA和H2O2含量和较低光合速率。研究表明:转基因甘薯更具有抗旱优势;H2O2预处理后有加重其胁迫程度的趋势。

In the experiment,the recoverability of the sweet potato,which expressed both Cu/Zn superoxidedismutase（SOD） and ascorbate peroxidase（APX） in chloroplasts,was compared with its control plants,and foliar application of exogenous hydrogen peroxide（H2O2） before drought stress on enhancement of seedling recovery capability after drought stress was studied.The transgenic sweet potato and its non-transgenic control plants were treated with 10% PEG and pretreated with 1.0 mmol/L H2O2 before drought stress,anti-oxidative enzymes system,content of MDA and H2O2 and photosynthetic rate of each plant were tested in this experiment.Under water stress and a short time after re-watering,for transgenic sweet potatothe,activities of the three mentioned anti-oxidative enzymes and photosynthetic rate were higher and the content of MDA and H2O2 were lower compared with the non-treatments;At the terminal of re-watering,the recovery capabilities of the anti-oxidative enzymes were stronger,the content of MDA and H2O2 was lower,and photosynthetic rate was higher.It was also observed that in the recovery process of the plants treated with 1.0 mmol/L H2O2 before drought stress,compared with the non-treatments,anti-oxidative enzymes was stronger,and the content of MDA and H2O2 was higher,while the photosynthetic rate was lower.A stronger drought-resistant ability and a stronger recovery capability after stress was showed in transgenic sweet potato compared with non-transgenic sweet potato under the treatment of drought stress.However,the pretreatment with 1.0 mmol/L H2O2 enhanced stress level.