Mutational effects of different LET radiations in rpsL transgenic Arabidopsis

Abstract

Purpose: 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 γ-rays were investigated in Arabidopsis.

Materials and methods: 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 γ-rays and 208-MeV carbon ions (208-MeV ¹²C⁵⁺), and the mutation frequency and mutation spectrum were examined.

Results: The frequency of mutant clones increased following irradiation with 208-MeV ¹²C⁵⁺ and γ-rays. Mutation spectrum analysis showed that G:C to A:T transitions and >2 bp deletions/insertions were significantly induced by both 208-MeV ¹²C⁵⁺ and γ-rays. −1 and −2 frameshift mutations were characteristic in the γ-ray irradiated group.

Conclusions: 208-MeV ¹²C⁵⁺ and γ-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.

Keywords:

• ionising radiation
• mutation spectrum
• Arabidopsis

Acknowledgements

We would like to thank K. Sato, S. Nozawa, C. Suzuki and all members of our research group for their support during the course of these experiments and for valuable discussions. We also thank Y. Nakatsu for providing E. coli strain DH10B/pFSE101. Grateful acknowledgement is made to T. Todo, A. Tachibana and J. Kobayashi for X-ray irradiation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.