6-BA对低温下水稻幼苗细胞膜系统保护作用的研究

在低温胁迫（3℃, 48 h)）前后用6-苄基腺嘌呤（6-BA）（44 μmol/L）处理水稻幼苗，可增强水稻幼苗的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性，降低电解质渗漏率和丙二醛（MDA）含量，同时也提高不饱和脂肪酸指数（IUFA）和叶绿素含量，但过氧化物酶（POD）活性无明显变化。在黑暗中处理效果优于在光照条件下的处理。亚细胞组分测定表明，SOD活性对低温敏感的顺序是叶绿体＞线粒体＞细胞溶质，6-BA对低温下叶绿体的保护作用最明显。外源抗氧化剂抗坏血酸（Vc）（1 mmol/L ）、苯甲酸钠（SB）（5 mmol/L）和二苯胺（DPA）（5 mmol/L）与6-BA配合，比单独施用对膜系统保护作用的效果更佳。

Protection of 6-Benzyladenine on Cell Membrane System of Rice Seedlings under Chilling Stress

Chilled (3℃, 48 h) rice (Oryza sativa L.) seedlings were sprayed with 44 μmol/L 6-benzyladenine (6-BA), the increases of superoxide dismutase (SOD) and catalase (CAT) activities and the decreases of malondialdehyde (MDA) and cell electrolyte leakage were observed. In the same time, 6-BA treatment also enhanced the index of unsaturated fatty acids (IUFA) and chlorophyll content. But no obvious change was found for peroxidase (POD) activity. The protective function of 6-BA to chilled rice seedlings in the dark was stronger than in the light. The sensitivity of SOD located in chloroplasts was higher than in mitochondria and in cytosol. And the result of raising SOD activity of 6-BA treatment to chloroplasts was more effective than to mitochondria and cytosol. When 6-BA was combined with antioxidants, such as 1 mmol/L ascorbic acid (Vc), 5 mmol/L sodium benzoate (SB) and 5 mmol/L diphenylamine (DPA), the coordination for cell membrane system protection was observed.