咖啡因和 EDTA 后处理对不同辐射敏感性作物核酸代谢的影响

INFLUENCE OF IRRADIATION AND Caf EDTA ON THE METABOLISM OF NUCLEUS ACID OF THE DIFFERENT RADIOSENSITIVE CROPS

研究了辐射损伤修复抑制剂咖啡因和ＥＤＴＡ（乙二胺四乙酸二钠盐）后处理对不同辐射敏感性作物大豆和油菜的核酸代谢的影响。结果表明，随着辐射剂量的增大，辐射敏感的大豆和耐辐射的油菜７ｄ龄幼苗下胚轴内ＤＮＡ和ＲＮＡ的含量有所增加，咖啡因和ＥＤＴＡ后处理又进一步提高了两种作物核酸的含量；大豆幼苗内ＤＮＡ、ＲＮＡ的含量均高于油菜。放射性３ＨＴｄＲ（３Ｈ胸腺嘧啶核苷）掺入试验证明，种子辐照后的浸种２４ｈ内有非按期的ＤＮＡ含成，且油菜的非按期ＤＮＡ合成能力强于大豆，咖啡因和ＥＤＴＡ及复合后处理不同程度的抑制了ＤＮＡ的非按期合成，其抑制程度为Ｃ＋Ｅ（咖啡因＋乙二胺四乙酸二钠盐）＞Ｃａｆ（咖啡因）＞ＥＤＴＡ，试验还证实了辐射与咖啡因和ＥＤＴＡ后处理抑制了正常的ＤＮＡ合成，延迟细胞分裂周期，且辐照剂量越大，抑制和延迟作用越强。

Irradiation and damage repair inhibitor (Caf and EDTA) posttreatment had a substantial effect on DNA and RNA content and DNA selfrepairing synthesis The experiment results showed the content of DNA and RNA increased with increase doses in the seedling hypocotyl of soybean and rape, Caf and EDTA posttreatment made them further higher than that of H2Otreatment Meanwhile, the content of DNA and RNA in hypocotyl of soybean seedling was more than that of rape Radioactive 3HTdR incorporation experiment showed γray irradiated seeds induced unschuled DNA synthesis in the primary cultivated seeds of two crops, which was inhibited by Caf, EDTA and C+E posttreatment in the order of C+E>Caf>EDTA Experiment also revealed irradiation and repair repressor posttreatment affected normal schuled DNA synthesis, postponed the cycle of cell division