title: Mutational effects of γ-rays and carbon ion beams on Arabidopsis seedlings.
abstract: To assess the mutational effects of radiation on vigorously proliferating plant tissue, the mutation spectrum was analyzed with Arabidopsis seedlings using the plasmid-rescue method. Transgenic plants containing the Escherichia coli rpsL gene were irradiated with γ-rays and carbon ion beams (320-MeV (12)C(6+)), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV (12)C(6+). Mutation spectra showed that both radiations increased the frequency of frameshifts and other mutations, including deletions and insertions, but only γ-rays increased the frequency of total base substitutions. These results suggest that the type of DNA lesions which cause base substitutions were less often induced by 320-MeV (12)C(6+) than by γ-rays in Arabidopsis seedlings. Furthermore, γ-rays never increased the frequencies of G:C to T:A or A:T to C:G transversions, which are caused by oxidized guanine; 320-MeV (12)C(6+), however, produced a slight increase in both transversions. Instead, γ-rays produced a significant increase in the frequency of G:C to A:T transitions. These results suggest that 8-oxoguanine has little effect on mutagenesis in Arabidopsis cells.
authors.affiliation: Research Center for Environmental Genomics, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
authors.forename: Ryouhei
authors.initials: R
authors.lastname: Yoshihara
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nozawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hase
authors.forename: Issay
authors.initials: I
authors.lastname: Narumi
authors.forename: Jun
authors.initials: J
authors.lastname: Hidema
authors.forename: Ayako N
authors.initials: AN
authors.lastname: Sakamoto
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects*; D002244:Carbon; D004249:DNA Damage / Q000235:genetics*; D004307:Dose-Response Relationship, Radiation; D029968:Escherichia coli Proteins; D020450:Heavy Ions; D009154:Mutation / Q000235:genetics* / Q000528:radiation effects*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000528:radiation effects; D011829:Radiation Dosage; D000091243:Ribosomal Protein S9; D036226:Seedlings / Q000235:genetics* / Q000528:radiation effects*; D014965:X-Rays
chemical_list: D029968:Escherichia coli Proteins; D000091243:Ribosomal Protein S9; C000717190:RpsI protein, E coli; D002244:Carbon
keywords: Arabidopsis; mutation spectrum; rpsL gene; γ-rays; carbon ion beams