CIBIO/InBIO, Research Center in Biodiversity and Genetic Resources, Associated Laboratory of the University of Porto, Vairão, PT-4485-661 Vairão, Portugal.
Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.
Sci Rep. 2016 Dec 16;6:39282. doi: 10.1038/srep39282.
Radioactivity released from disasters like Chernobyl and Fukushima is a global hazard and a threat to exposed biota. To minimize the deleterious effects of stressors organisms adopt various strategies. Plants, for example, may delay germination or stay dormant during stressful periods. However, an intense stress may halt germination or heavily affect various developmental stages and select for life history changes. Here, we test for the consequence of exposure to ionizing radiation on plant development. We conducted a common garden experiment in an uncontaminated greenhouse using 660 seeds originating from 33 wild carrots (Daucus carota) collected near the Chernobyl nuclear power plant. These maternal plants had been exposed to radiation levels that varied by three orders of magnitude. We found strong negative effects of elevated radiation on the timing and rates of seed germination. In addition, later stages of development and the timing of emergence of consecutive leaves were delayed by exposure to radiation. We hypothesize that low quality of resources stored in seeds, damaged DNA, or both, delayed development and halted germination of seeds from plants exposed to elevated levels of ionizing radiation. We propose that high levels of spatial heterogeneity in background radiation may hamper adaptive life history responses.
切尔诺贝利和福岛等灾难释放的放射性物质是一种全球性危害，对暴露的生物群构成威胁。为了将压力源对生物体的有害影响降到最低，生物会采用各种策略。例如，植物在压力时期可能会延迟发芽或处于休眠状态。然而，强烈的压力可能会阻止发芽，或者严重影响各种发育阶段，并选择改变生活史。在这里，我们研究了暴露于电离辐射对植物发育的影响。我们在一个未受污染的温室中进行了一个普通花园实验，使用了 660 颗种子，这些种子来自于切尔诺贝利核电站附近采集的 33 株野生胡萝卜（Daucus carota）。这些母株曾暴露在辐射水平相差三个数量级的环境中。我们发现，辐射水平的升高对种子发芽的时间和速度有强烈的负面影响。此外，暴露于辐射还会延迟后续发育阶段和连续叶片出现的时间。我们假设，储存的种子质量低、DNA 受损或两者兼而有之，这会延迟发育并阻止暴露于高剂量电离辐射的植物的种子发芽。我们提出，背景辐射的空间异质性水平很高可能会阻碍适应性的生活史反应。
