微囊藻毒素MC-LR通过NO引起青菜幼苗的氧化胁迫反应

Microcystins-LR-induced oxidative stress mediated by nitric oxide in Chinese cabbage seedlings

研究了微囊藻毒素(MC-LR)对青菜幼苗的胁迫效应。通过回归方程计算得出,浓度为4.23 mg/L的MC-LR处理5 d使青菜幼苗生长减少50%。通过特异性荧光探针DCFH-DA和DAF-2DA实时监测青菜幼苗体内活性氧(ROS)和一氧化氮(NO)含量,发现MC-LR处理能够诱导ROS和NO的产生。抑制剂研究结果表明,MC-LR胁迫下,NO主要通过硝酸还原酶(NR)途径产生。采用NR抑制剂结合MC-LR共同处理,能够显著缓解MC-LR单独处理引起的ROS含量上升和抗氧化酶基因(Cu/Zn-SOD、CAT、APX)的转录水平升高。这些结果表明,微囊藻毒素MC-LR通过NO引起青菜幼苗的氧化胁迫反应。

This experiment aimed to study the response of Chinese cabbage seedling to microcystins-LR（MC-LR） stress.By calculation from regression equation,after exposure to 4.23 mg/L MC-LR for 5 d,the growth of Chinese cabbage seedlings decreased by 50% compared to that of control.Exposing to MC-LR significantly enhanced the intercellular levels of total reactive oxygen species（ROS） and nitric oxide（NO）,which could be visually detected by using specific florescent probes DCFH-DA and DAD-2DA,respectively.Nitrate reductase（NR） mainly contributed to NO production under MC-LR stress.NaN3（NR inhibitor） significantly reduced MC-LR-induced increases in ROS production and the transcripts of Cu/Zn-SOD,CAT and APX genes in Chinese cabbages seedlings.It indicated that NO mediated MC-LR-induced oxidative stress in Chinese cabbage seedlings.