摘要
Abstract
[ Objective ] The research aimed to study the influence of stress on the diurnal variation of cell defense enzyme activity in plants.[ Method] Effects of osmotic stress on the diurnal variation of electrolyte leakage and change in activities of the main anfioxidant enzymes, inchuding superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), in leaves of maize seedlings were investigated with differentconcentrations of polyethylene glycol ( PEG-6000 ) treatment. [ Result ] The results showed that the activity of protective enzymes not only be impacted by the PEG concentration and stress time, but also by light in one round the clock. As the illumination time and stress time prolong,electrolyte leakage and MDA content increased, SOD activity decreased, the activity of POD and CAT increased first and then decreased; Asthe prolong of darkness after light, electrolyte leakage and protective enzymes activity closed to the control level first and after that varied rather highly. It indicated that light exacerbated the balance of oxygen free radical damage, while darkness conduced its recovery; however, as thestress time prolong, plant hurted sharply, even leading to irreversible damage in the balance of oxygen free radical eventually. [ Conclusion]The changes of cell defense enzyme activity in leaves of maize seedling were influenced by density of PEG, time of stress and illumination.关键词
玉米幼苗/保护酶活性/昼夜变化/PEG胁迫Key words
Maize seedling/Cell defense enzyme/ Change in daytime and at night/ Stress of polyethylene glycol-6000分类
农业科技
