摘要
通过分析MDA,GSH,Asc和Chl含量及质膜透性,探讨了低温诱导水稻幼苗的光氧化伤害。在5℃、白昼PFD为400μmol m^(-2)s^(-1)对,叶片光氧化伤害随低温处理时间的延长而加强,其程度并随温度下降而加剧;耐冷不同的品种表现也有差异。在昼夜10℃/0℃温度下,叶片光氧化程度随PFD的提高而增强。低温处理后恢复期间,470μmol m^(-2) s^(-1)光强会加剧光氧化伤害,而60μmol m^(-2) s^(-1)光强则有利于伤害的恢复。光是植物冷害研究中不可忽略的环境因子。
The changes of MDA, Asc, GSH and Chl contents, electrolyte leakage in rice seedling leaves under chilling stress were studied. The relationship between chilling-induced photooxidation with different degree of low temperature and its duration as well as the pboton flux density during or after low temperature stress were also examined. The result indicated that photooxidation in rice leaves increased with the prolorgation of treatment at 5℃ under a PFD of 400 μmol m^(-2) s^(-1). Chl degradation, increase of MDA and electrolyte leakage and decrease of GSH and Asc contents appeared in rice leaves. These changes were significantly different between different chilling-sensitive species. 'The photooxidation in rice leaves under a PFD of 400 μmol m^(-2)s^(-1) was enhanced with a decrease of temperature. Rice leaves show no symptom of photooxidation at 26℃ under 400 μmol m^(-2)s^(-1) and very a little at 5℃ in the dark, while the photooxidation damage occurred only under the interaction of 5℃ with 400 μmol m^(-2)s^(-2). It was enhanced with an increase in PFD when rice seedlings were treated under light/dark of 10℃/0℃. PFD also exerted an influence on photooxidative damage in rice leaves recovered under normal temperature after low temperature treatment. The photooxidative damage was enhanced in rice leaves exposed to a PFD of 470μmol m^(-2)s^(-1), while there was no harmful effect on seedlings recovered under a PFD of 60 μmol m^(-2)s^(-1). These results suggest that light intensity is an important environmental factor in plant chilling injury.
基金
国家自然科学基金
中澳合作项目
关键词
水稻
幼苗
低温
光氧化伤害
rice seedling, low temperature, photooxidation
