低温解除牡丹休眠过程中花芽细胞的膜脂过氧化研究

A Research on Changes of Membrane Lipid Peroxidation in Buds of Paeonia During Low Temperature Induced Dormancy Release

低温诱导解除牡丹休眠过程中,花芽细胞发生膜脂过氧化变化.低温诱导前期,花芽细胞内活性氧、O2.-产生速率上升,然后急剧下降,低温处理24d趋于稳定.MDA含量变化趋势与O2.-基本一致.SOD在低温诱导前期下降,后随低温的积累上升.POD活性在休眠解除过程中一直上升.CAT活性在低温处理16d上升至最大值,然后急剧下降,24d后稳定.一直处于温室较高温度下的对照植株,细胞的膜脂过氧化水平变化不大.试验表明,低温诱导牡丹花芽休眠解除过程中,细胞内活性氧、O2.-产生速率快速上升,很可能是花芽休眠解除的信号,花芽细胞的膜脂过氧化程度与休眠解除有密切关系.

The membrane lipid peroxidation in buds of paeonia changes during low temperature induced dormancy release. The O2^-. production rate increases at first, decreases after 16 days and keeps balance after breaking of dormancy. The changing trend of malondialdehyde （MDA） content is as the same as O^2. production rate. The activity of superoxide dismutase （SOD） of paeonia buds under cold treatment decreases at the beginning, but increases rapidly after 16 days. On the contrary, the activity of catalase （CAT） increases sharply at the beginning of cold treatment, decreases after breaking dormancy and keeps at a stable low level after 24 days. The activity of peroxidase （POD） even keeps increasing during cold treatment. The paeonia in the greenhouse are different from those under low temperature, and the membrane lipid peroxidation in buds keeps balance. The results indicate that the membrane lipid peroxidatlon has certain strong correlation with the dormancy release of paeonia buds under cold treatment.