低剂量重离子辐射对水稻种子和幼苗DNA甲基化的影响

DNA Methylation Alterations on Rice Seeds and Seedlings Induced by Low-dose Heavy Ion Irradiation

为了研究低剂量重离子辐射对植物产生的表观遗传学效应,采用高传能线密度(62.2 keV/μm)和低剂量(2 Gy)的放射性束流^(12)C对水稻(Oryza sativa,japonica)的干种子和幼苗进行辐射。采用甲基化敏感限制性酶切多态性分析(MSAP)的方法对材料基因组CCGG位点的甲基化状态进行检测。共选用12对选择性引物扩增了共800个条带,其中有65个条带(8.13%)在种子辐射后发现呈多态性,而只有10个条带(1.3%)在幼苗辐射后发现呈多态性。统计学分析显示高能量低剂量的重离子对水稻种子和幼苗的基因组甲基化状态都产生了影响,而且种子受到辐射后产生的甲基化改变明显高于幼苗(P=0.011)。另外,甲基化和去甲基化变化类型的分析也表明种子和幼苗辐射后发生甲基化变化的趋势也不相同。

To investigate the epigenetic effects of low-dose ion irradiation on plants, dry seeds and seedlings of rice （Oryza sativa, japonica） were irradiated with ^12C^6＋ ion beam at high LET （62.2 keV/μm） and low dose （2 Gy ）. Method of methylation-sensitive amplification polymorphism （MSAP） was used for DNA methylation analysis at CCGG sequences on rice genome. A total of 800 bands were amplified by 12 pairs of selective primers. Among them, 65 （8.13 % ） and 10 （ 1.3 % ） showed polymorphism in plants after irradiation at seed and seedling state respectively. Statistical analysis showed that both seed and seedling can be affected epigenetically by carbon ion irradiation at 2 Gy. Moreover, more polymorphic bands were found in plants after irradiation at seed state than at seedling state （ P = 0.011 ）. Additionally, the type of methyaltion changes in plants after seed and seedling irradiation were different.