Molecular nature of mutations induced by high-LET irradiation with argon and carbon ions in Arabidopsis thaliana
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- 作者：Tomonari Hirano ; Yusuke Kazama ; Sumie Ohbu ; Yuki Shirakawa ; Yang Liu ; Tadashi Kambara ; Nobuhisa Fukunishi ; Tomoko Abe
- 关键词：Arabidopsis thaliana ; Double-strand break ; Heavy-ion irradiation ; Large deletions ; Linear energy transfer ; Mutation
- 刊名：Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
- 出版年：2012
- 出版时间：1 July, 2012
- 年：2012
- 卷：735
- 期：1-2
- 页码：19-31
- 全文大小：1787 K
文摘
Linear energy transfer (LET) is an important parameter to be considered in heavy-ion mutagenesis. However, in plants, no quantitative data are available on the molecular nature of the mutations induced with high-LET radiation above 101-124 keV ¦Ìm?1. In this study, we irradiated dry seeds of Arabidopsis thaliana with Ar and C ions with an LET of 290 keV ¦Ìm?1. We analyzed the DNA alterations caused by the higher-LET radiation. Mutants were identified from the M2 pools. In total, 14 and 13 mutated genes, including bin2, egy1, gl1, gl2, hy1, hy3-5, ttg1, and var2, were identified in the plants derived from Ar- and C-ions irradiation, respectively. In the mutants from both irradiations, deletion was the most frequent type of mutation; 13 of the 14 mutated genes from the Ar ion-irradiated plants and 11 of the 13 mutated genes from the C ion-irradiated plants harbored deletions. Analysis of junction regions generated by the 2 types of irradiation suggested that alternative non-homologous end-joining was the predominant pathway of repair of break points. Among the deletions, the proportion of large deletions (>100 bp) was about 54 % for Ar-ion irradiation and about 64 % for C-ion irradiation. Both current results and previously reported data revealed that the proportions of the large deletions induced by 290-keV ¦Ìm?1 radiations were higher than those of the large deletions induced by lower-LET radiations (6 % for 22.5-30.0 keV ¦Ìm?1 and 27 % for 101-124 keV ¦Ìm?1). Therefore, the 290 keV ¦Ìm?1 heavy-ion beams can effectively induce large deletions and will prove useful as novel mutagens for plant breeding and analysis of gene functions, particularly tandemly arrayed genes.