To test the hypothesis that oxidative stress is involved in inducing freezing injury of plants,nitroblue tetrazolium (NBT) was infiltrated into cabbage leaf tissues before they were frozen.

• 为检验植物冻害的发生和氧化胁迫这一假说 ；在冰冻前把氮蓝四唑 (NBT)真空渗入到甘蓝叶圆片中 .