软X射线同步辐射对小麦细胞膜脂质过氧化产物及相关酶活性的影响

Effects of synchrotron radiation soft X-rays on peroxidation product of membrane lipids and activity of relative enzymes in wheat seeds

采用不同剂量的软X射线辐照处理小麦种子,研究了种子的萌发率、幼苗组织细胞的脂质过氧化作用的产物及其相关酶活性变化等生物效应。同时,还对其作用机理进行了初步探讨。结果表明:在剂量为72216 J/cm2范围内,小麦种子萌发率随剂量的增加而增加,但随后急剧下降;在剂量为72216 J/cm2范围内, 脂质过氧化作用产物丙二醛(MDA)的含量随剂量增加而增加;其相关的过氧化保护酶:过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)等并不随MDA增加而稳定增加,并且三种酶之间的活性变化不表现出明显的同步性,存在相互协调的关系;叶绿体中叶绿素含量及抗坏血酸过氧化物酶(APX)的活性始终低于对照组。

After wheat seeds were irradiated with different doses of synchrotron radiation (SR) (soft X-rays), the biological effects on the germination rate, the membrane lipids peroxidation product of cells and the activities of some related enzymes were studied. Results showed that with the increase of the SR dose (within the range of 72—216 J·cm-2 ), the germination rate of the wheat seeds rised, but reduced rapidly when the dose beyond 216 J·cm-2; MDA, the peroxidation product of membrane lipids, rised with the SR dose (within 72—216 J·cm-2 ); and that the relative enzymes, such as SOD, CAT and POD, didn抰 increase stably with the rise of MDA. Moreover, the changes of their activities were` not simultaneous though the activity of APX and the content of chlorophyll in treated-group were lower than those in control group all along. Mechanism of the effects was discussed as well.