Mutation spectrum of 184 keV/m Ar ion beams inducing large-scale mutations

Ishii, Kotaro*; Ohu, Sumie*; Shirakawa, Yuki*; Ikeda, Tokihiro*; Abe, Tomoko*; Matsuya, Yusuke  ; Kai, Takeshi   

High-LET ions induce mutations in biological materials, including seeds, with high probability. Our previous studies have analyzed the LET dependene on mutation induction in seeds at the gene and genome levels. Here, we investigated the characteristics of mutations induced by 160 MeV/n Ar ions in Arabidopsis thaliana (Col-0), comparing to those by 135 MeV/n C ions. As a result, Ar ions induced large-scale mutations at a frequency 5.3 times higher than C ions, showing more efficient gene disruption. This characteristic was further elucidated by ionization events and OH radicals using the radiation transport simulation code PHITS, which revealed that complex DNA damage is generated at high frequency through direct action.