Hase Yoshihiro, Satoh Katsuya, Kitamura Satoshi
Takasaki Advanced Radiation Research Institute, National Institutes for Quantum Science and Technology (QST), Takasaki, Gunma, Japan.
Front Plant Sci. 2023 Apr 6;14:1149083. doi: 10.3389/fpls.2023.1149083. eCollection 2023.
The molecular nature of mutations induced by ionizing radiation and chemical mutagens in plants is becoming clearer owing to the availability of high-throughput DNA sequencing technology. However, few studies have compared the induced mutations between different radiation qualities and between different irradiated materials with the same analysis method. To compare mutation induction between dry-seeds and seedlings irradiated with carbon ions and gamma rays in Arabidopsis, in this study we detected the mutations induced by seedling irradiation with gamma rays and analyzed the data together with data previously obtained for the other irradiation treatments. Mutation frequency at the equivalent dose for survival reduction was higher with gamma rays than with carbon ions, and was higher with dry-seed irradiation than with seedling irradiation. Carbon ions induced a higher frequency of deletions (2-99 bp) than gamma rays in the case of dry-seed irradiation, but this difference was less evident in the case of seedling irradiation. This result supported the inference that dry-seed irradiation under a lower water content more clearly reflects the difference in radiation quality. However, the ratio of rearrangements (inversions, translocations, and deletions larger than 100 bp), which are considered to be derived from the rejoining of two distantly located DNA breaks, was significantly higher with carbon ions than gamma rays irrespective of the irradiated material. This finding suggested that high-linear energy transfer radiation induced closely located DNA damage, irrespective of the water content of the material, that could lead to the generation of rearrangements. Taken together, the results provide an overall picture of radiation-induced mutation in Arabidopsis and will be useful for selection of a suitable radiation treatment for mutagenesis.
由于高通量DNA测序技术的出现，植物中由电离辐射和化学诱变剂诱导产生的突变的分子本质正变得越来越清晰。然而，很少有研究使用相同的分析方法比较不同辐射性质以及不同辐照材料之间的诱导突变情况。为了比较拟南芥中经碳离子和γ射线辐照的干种子和幼苗之间的诱变情况，在本研究中，我们检测了γ射线辐照幼苗诱导产生的突变，并将这些数据与之前其他辐照处理获得的数据一起进行分析。在等效剂量下，γ射线导致的存活降低突变频率高于碳离子，且干种子辐照的突变频率高于幼苗辐照。在干种子辐照情况下，碳离子诱导的2至99碱基对缺失频率高于γ射线，但在幼苗辐照情况下这种差异不太明显。这一结果支持了以下推断：较低含水量下的干种子辐照更能清晰地反映辐射性质的差异。然而，无论辐照材料如何，被认为源自两个远距离DNA断裂重新连接的重排（倒位、易位和大于100碱基对的缺失）比例，碳离子诱导的显著高于γ射线。这一发现表明，无论材料的含水量如何，高传能线密度辐射都会诱导紧密定位的DNA损伤，从而导致重排的产生。综上所述，这些结果提供了拟南芥辐射诱导突变的整体情况，将有助于为诱变选择合适的辐射处理方法。
