Quantum Beam Science Directorate, Radiation-Applied Biology Division, Japan Atomic Energy Agency, Gunma 370-1292, Japan.
Int J Radiat Biol. 2010 Feb;86(2):125-31. doi: 10.3109/09553000903336826.
In an effort to assess the characteristics of mutation induced by different linear energy transfer (LET) radiation in higher plants, the mutational effects of carbon-ion beams and gamma-rays were investigated in Arabidopsis.
The rpsL (Escherichia coli ribosomal protein small subunit S12) transgenic Arabidopsis (Arabidopsis/rpsL) mutation detection system was adopted. Dry seeds of Arabidopsis/rpsL were irradiated with gamma-rays and 208-MeV carbon ions (208-MeV (12)C(5+)), and the mutation frequency and mutation spectrum were examined.
The frequency of mutant clones increased following irradiation with 208-MeV (12)C(5+) and gamma-rays. Mutation spectrum analysis showed that G:C to A:T transitions and >2 bp deletions/insertions were significantly induced by both 208-MeV (12)C(5+) and gamma-rays. -1 and -2 frameshift mutations were characteristic in the gamma-ray irradiated group.
208-MeV (12)C(5+) and gamma-rays induced different intragenic mutations in respect to the size of deletions, reflecting differences in the nature of the DNA damage induced. Our results also suggested that base substitutions derived from the generation of 8-oxoguanine were low in dry seeds. The mutation spectrum obtained in this study might have reflected the characteristic conditions of plant dry seeds such as low water content and cell proliferation activity.
为了评估不同线性能量传递（LET）辐射诱导突变的特性，本研究在拟南芥中研究了碳离子束和γ射线的诱变效应。
采用 rpsL（大肠杆菌核糖体蛋白小亚基 S12）转基因拟南芥（Arabidopsis/rpsL）突变检测系统。用γ射线和 208-MeV 碳离子（208-MeV（12）C（5+））辐照拟南芥/rpsL 干种子，检测突变频率和突变谱。
用 208-MeV（12）C（5+）和γ射线辐照后，突变克隆的频率增加。突变谱分析表明，G:C 到 A:T 的颠换和>2 bp 的缺失/插入均由 208-MeV（12）C（5+）和γ射线显著诱导。-1 和-2 移码突变是γ射线辐照组的特征。
208-MeV（12）C（5+）和γ射线诱导的缺失大小不同的基因内突变，反映了诱导的 DNA 损伤性质的差异。我们的结果还表明，在干种子中，源自 8-氧鸟嘌呤生成的碱基替换较少。本研究获得的突变谱可能反映了植物干种子的特征条件，如低含水量和细胞增殖活性。
