植物体超氧阴离子自由基不同检测方法的比较

Comparative study on different detection methods of superoxide radicals in plant tissues

应用顺磁共振波谱仪(EPR)自旋捕获法、羟胺氧化法、二氢乙锭(DHE)荧光探针和硝基四氮唑蓝(NBT)原位显色法,分别检测了暴露于梯度镉(Cd)溶液2 d后的水稻幼苗根叶组织超氧阴离子自由基(O.-2)的变化水平.结果表明,0—60 mg.L-1Cd诱导了O2.-随着Cd剂量的增加而升高,高于此剂量范围则呈现下降趋势.4种方法的检测结果基本一致,但前两种方法更适用于定量O2.-的生成水平,而后两种显色方法仅能反映O2.-的变化趋势,难以精确定量.因此,可以选择性地应用4种方法揭示暴露于污染物的植物组织O2.-的响应水平.

Changes of superoxide anion radicals（O·-2） in roots and leaves of rice seedlings exposed to Cd for two days were investigated using electron paramagnetic resonance（EPR） spin trapping technique,hydroxylamine oxidation method,dihydroethidium（DHE） fluorescent probing method as well as nitroblue tetrazolium（NBT） in situ localization,respectively.The results showed that O·-2 production increased with the increase of extraneous Cd from 0 to 60 mg· L-1,followed by a decline hereafter.The four methods showed consistent results in general while the former two methods are more suitable for quantification,and the latter two ones can only show the trend of O·-2 production.Thus,these methods can be used selectively to reveal the change of O·-2 production in plant tissues exposed to environmental pollutants.