Emergent Properties of Fungi Exposed to Long-Term Radiation: Fungal Ecophysiology

由于前切尔诺贝利原子能发电站所在地受到极端的辐射，已查明土壤真菌群落组成发生了变化。这些真菌中的一些已经被证明能够分解燃料棒和受污染的屋顶材料中的一些碳基放射性物质。在这些真菌中发现的特性之一是，从切尔诺贝利地区分离的菌株似乎显示出“正向放射性”。这些真菌似乎已经进化出了识别放射性的能力，放射源的方向，然后朝着放射源生长。这种能力似乎并没有在离切尔诺贝利很远的地方分离出的同一种真菌中进化出来，我们的建议是进一步研究这种“向辐射性”的机制。我们希望确定引起真菌反应的放射性线索的性质，并将使用一系列剂量的放射源（a，B，g，混合bg，中子和X射线）来确定这些真菌对哪种类型和剂量的放射性作出反应。我们还将开始调查可能引发这些“适应”真菌生长变化的潜在生化变化。这项工作具有生态和环境意义，如果我们能够证明真菌可以对放射性线索做出反应，朝着放射性来源生长，然后它们可以分解，这可能是一种潜在的生物修复工具，可用于污染物修复。

As a result of the extreme exposure to radiation at the site of the former Chernobyl Atomic Electric Station, changes in the community composition of soil fungi have been identified. Some of these fungi have been shown to be able to decompose some of the carbon based radioactive materials from the fuel rods and from contaminated roof material. One of the properties that has been found in these fungi is that isolates from the Chernobyl area appear to show 'positive radiotropism'. These fungi appear to have evolved an ability to recognize radioactivity, the direction of the source and then grow towards the source. This ability does not seem to have evolved in isolates of the same fungal species isolated at a distance from Chernobyl.Our proposal is to further investigate the mechanics of this 'radiotropism'. We wish to identify the nature of the radioactive cues that elicit a response in the fungi and will use a range of radioactive sources (a, b, g, mixed bg, neutron and X-ray) at a range of doses to determine which type and dose of radioactivity these fungi respond to. We will also initiate investigations of the underlying biochemical changes that may be triggered to cause the growth changes in these 'adapted' fungi.The work has ecological and environmental significance in that, if we can show that fungi can respond to radioactive cues, grow towards sources of radioactivity, which they can then decompose, this may be a potential bioremediation tool that could be used in contaminant remediation.