@misc{oai:repo.qst.go.jp:00077523,
 author = {Yokota, Yuuichiro and Sakamoto, Ayako and Yokota, Yuuichiro and Sakamoto, Ayako},
 month = {Nov},
 note = {[Introduction] Although many plants show radioresistance, the mechanism has not been fully elucidated. Physcomitrella patens is a moss plant that has a genome size of 511 Mb and 17 chromosomes and spends most of its life cycle in haploidy. The purpose of this study is to elucidate the mechanism of radioresistance found in P. patens. [Methods] Knockout strains of RAD51B, LIG4 and POLQ genes, which are important in homologous recombination, non-homologous end joining and alternative end joining repair, were kindly gifted from Dr. Nogué of INRA. Single cells were obtained by treating plant tissues with cell wall degrading enzymes. Plant tissues and single cells were irradiated with 60Co gamma rays and 18.3 MeV/u carbon ions (LET = 108 keV/μm). To measure the radiosensitivity, the irradiated plant tissues were grown for 6 days and then the dry weight was measured. The irradiated single cells were cultured for 2 weeks, and then colony forming ability was measured. To measure the radiation-induced DNA damage and its repair rate, DNA double strand breaks (DSB) were detected by pulsed field gel electrophoresis. [Results] Compared to the wild strain, the lig4 strain was slightly more radiosensitive. The polq strain was slightly more resistant at low dose, but was more sensitive at high dose. The radiosensitivity was significantly enhanced in the rad51b strain. The repair rate of DSB in the wild strain was slower compared to angiosperm tobacco and mammalian cells. [Conclusion] P. patens repairs most DSBs via the homologous recombination pathway., 日本放射線影響学会第62回大会},
 title = {Contribution of the homologous recombination pathway in DNA double-strand break repair of the haploid model plant Physcomitrella patens},
 year = {2019}
}