Abstract: Different concentrations of 5-azacytidine combining with different treatment time were employed to treat the transgenic rice with a transcriptionally silenced cry1Ab transgene. The results indicated that 5-azacytidine could reactivate 8%-30% of the silenced transgenic rice plants and the expression of the reactivated cry1Ab transgene could reach as high as 0.147% of the total soluble protein. Treatment with low concentration of 5-azacytidine could lead to the highest reactivation ratio and the expression of the cry1Ab transgene. Meanwhile, treatment with azacytidine could result in dwarfism, reduction in tiller numbers, grain weight per plant, panicle length and the delaying in flowering. The study showed that 5-azacytidine could be used as a potential mutagen in overcoming of transgene silencing and creation of the transgenic plants with elite agronomic traits.

Key words: azacytidine, transgene, gene silencing, reactivation, biological effect, rice

摘要： 用不同浓度的5-氮胞苷溶液配合不同时间处理了发生在转录水平的转基因cry1Ab沉默水稻。结果表明，5-氮胞苷处理能使8%～30%转基因水稻植株的转基因cry1Ab恢复表达活性，复活转基因表达的Cry1Ab蛋白含量最高可达0.147%, 45 mg/L 5-氮胞苷处理1 d可使转基因cry1Ab的复活率及Cry1Ab蛋白含量达最高。同时，5-氮胞苷处理使转基因水稻植株出现矮化，分蘖数、单株粒重下降，穗长减小及开花期延迟等发育异常现象。5-氮胞苷作为一种弱诱变剂在克服转基因沉默及创造具优良农艺性状的转基因植物中具有一定的应用价值。

关键词: 5-氮胞苷, 转基因, 基因沉默, 复活, 生物效应, 水稻