Dajana Blagojevic1,2, YeonKyeong Lee1,2, Dag A Brede2,3, Ole Christian Lind2,3, Igor Yakovlev4, Knut Asbjørn Solhaug2,3, Carl Gunnar Fossdal4, Brit Salbu2,3, Jorunn E Olsen5,6. 1. Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway. 2. Centre of Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway. 3. Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway. 4. Norwegian Institute of Bioeconomy Research, 1431, Ås, Norway. 5. Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway. jorunn.olsen@nmbu.no. 6. Centre of Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway. jorunn.olsen@nmbu.no.
Abstract
MAIN CONCLUSION: Persistent DNA damage in gamma-exposed Norway spruce, Scots pine and Arabidopsis thaliana, but persistent adverse effects at the organismal and cellular level in the conifers only. Gamma radiation emitted from natural and anthropogenic sources may have strong negative impact on plants, especially at high dose rates. Although previous studies implied different sensitivity among species, information from comparative studies under standardized conditions is scarce. In this study, sensitivity to gamma radiation was compared in young seedlings of the conifers Scots pine and Norway spruce and the herbaceous Arabidopsis thaliana by exposure to 60Co gamma dose rates of 1-540 mGy h-1 for 144 h, as well as 360 h for A. thaliana. Consistent with slightly less prominent shoot apical meristem, in the conifers growth was significantly inhibited with increasing dose rate ≥ 40 mGy h-1. Post-irradiation, the conifers showed dose-rate-dependent inhibition of needle and root development consistent with increasingly disorganized apical meristems with increasing dose rate, visible damage and mortality after exposure to ≥ 40 mGy h-1. Regardless of gamma duration, A. thaliana showed no visible or histological damage or mortality, only delayed lateral root development after ≥ 100 mGy h-1 and slightly, but transiently delayed post-irradiation reproductive development after ≥ 400 mGy h-1. In all species dose-rate-dependent DNA damage occurred following ≥ 1-10 mGy h-1 and was still at a similar level at day 44 post-irradiation. In conclusion, the persistent DNA damage (possible genomic instability) following gamma exposure in all species may suggest that DNA repair is not necessarily mobilized more extensively in A. thaliana than in Norway spruce and Scots pine, and the far higher sensitivity at the organismal and cellular level in the conifers indicates lower tolerance to DNA damage than in A. thaliana.
MAIN CONCLUSION: Persistent DNA damage in gamma-exposed Norway spruce, Scots pine and Arabidopsis thaliana, but persistent adverse effects at the organismal and cellular level in the conifers only. Gamma radiation emitted from natural and anthropogenic sources may have strong negative impact on plants, especially at high dose rates. Although previous studies implied different sensitivity among species, information from comparative studies under standardized conditions is scarce. In this study, sensitivity to gamma radiation was compared in young seedlings of the conifers Scots pine and Norway spruce and the herbaceous Arabidopsis thaliana by exposure to 60Co gamma dose rates of 1-540 mGy h-1 for 144 h, as well as 360 h for A. thaliana. Consistent with slightly less prominent shoot apical meristem, in the conifers growth was significantly inhibited with increasing dose rate ≥ 40 mGy h-1. Post-irradiation, the conifers showed dose-rate-dependent inhibition of needle and root development consistent with increasingly disorganized apical meristems with increasing dose rate, visible damage and mortality after exposure to ≥ 40 mGy h-1. Regardless of gamma duration, A. thaliana showed no visible or histological damage or mortality, only delayed lateral root development after ≥ 100 mGy h-1 and slightly, but transiently delayed post-irradiation reproductive development after ≥ 400 mGy h-1. In all species dose-rate-dependent DNA damage occurred following ≥ 1-10 mGy h-1 and was still at a similar level at day 44 post-irradiation. In conclusion, the persistent DNA damage (possible genomic instability) following gamma exposure in all species may suggest that DNA repair is not necessarily mobilized more extensively in A. thaliana than in Norway spruce and Scots pine, and the far higher sensitivity at the organismal and cellular level in the conifers indicates lower tolerance to DNA damage than in A. thaliana.
Authors: Dietrich Averbeck; Sisko Salomaa; Simon Bouffler; Andrea Ottolenghi; Vere Smyth; Laure Sabatier Journal: Mutat Res Rev Mutat Res Date: 2018-04-17 Impact factor: 5.657
Authors: Craig H Bassing; Katrin F Chua; JoAnn Sekiguchi; Heikyung Suh; Scott R Whitlow; James C Fleming; Brianna C Monroe; David N Ciccone; Catherine Yan; Katerina Vlasakova; David M Livingston; David O Ferguson; Ralph Scully; Frederick W Alt Journal: Proc Natl Acad Sci U S A Date: 2002-05-28 Impact factor: 11.205