小麦和花生叶细胞内超氧物歧化酶(SOD)同工酶的特性和分布

用等电聚焦凝胶电泳方法对小麦、花生叶内超氧物歧化酶同工酶进行了研究,在栽培小麦叶中发现4条 SOD 同工酶谱带。证明位于图谱下方迁移率最大的强单带是叶绿体 SOD,其它3个可能是细胞质 SOD。对野生花生和栽培花生的比较研究结果表明,前者叶中包含3类不同的谱带(文中 A、B 和 C 带)。A 带及 B 带对氰化物敏感,是 Cu-Zn-SOD,C 带不敏感,可能是线粒体 Mn-SOD。栽培花生叶内 SOD 大部集中在叶绿体中,主要是 Cu-Zn-SOD。本文测定了各谱带的 PI 值,并就两类花生叶中 SOD 的不同特性和分布可能对其生物保护功能的影响作了讨论。

CHARACTERISTICS AND DISTRIBUTIONS OF ISOZYMES OF SUPEROXIDE DISMUTASE IN LEAF CELLS OF PEANUT AND WHEAT

The isozymes of superoxide dismutase(SOD)in leaves of wheat and peanut were investi- gated and identified by isoelectric focusing gel electrophoresis.The total four bands were found in wheat leaves,among them the band with the highest mobility was proved to be the chloroplastic SOD,the others with intermediate mobilities were probably cytoplasmic SODs.It was observed that there was apparent difference between patterns of SOD isozymes from leaves of wild and cultivated peanut.Leaves of wild peanut contain three different types of SOD isozyme(band A,band B and band C).Band A and B were cyanide-sensitive,hence they should be Cu-Zn-SOD.Band C was cyanide-insensitive and might be Mn-SOD located in mitochondria.The major part of SOD activity in cultivated peanut leaves was concentrated in chloroplasts,and it was cyanide-sensitive.The experiments of SOD activity inhibition by KCN showed that leaves of cultivated peanut contained more Cu-Zn-SOD.On the contrary,the percentage of non-Cu-Zn-SOD was highter in wild species than in cultivated.The PI values of distinct bands were determined and the significance of this study for the further evaluation of resistance of peanut plant is discussed.