Department of Biology, University of York, York, UK.
New Phytol. 2011 Oct;192(2):405-13. doi: 10.1111/j.1469-8137.2011.03807.x. Epub 2011 Jul 6.
The explosive compounds hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT) are widespread environmental contaminants commonly found as co-pollutants on military training ranges. TNT is a toxic carcinogen which remains tightly bound to the soil, whereas RDX is highly mobile leaching into groundwater and threatening drinking water supplies. We have engineered Arabidopsis plants that are able to degrade RDX, whilst withstanding the phytotoxicity of TNT. Arabidopsis thaliana (Arabidopsis) was transformed with the bacterial RDX-degrading xplA, and associated reductase xplB, from Rhodococcus rhodochrous strain 11Y, in combination with the TNT-detoxifying nitroreductase (NR), nfsI, from Enterobacter cloacae. Plants expressing XplA, XplB and NR remove RDX from soil leachate and grow on soil contaminated with RDX and TNT at concentrations inhibitory to XplA-only expressing plants. This is the first study to demonstrate the use of transgenic plants to tackle two chemically diverse organic compounds at levels comparable with those found on contaminated training ranges, indicating that this technology is capable of remediating concentrations of RDX found in situ. In addition, plants expressing XplA and XplB have substantially less RDX available in aerial tissues for herbivory and potential bioaccumulation.
六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）和 2,4,6-三硝基甲苯（TNT）是两种广泛存在的环境污染物，通常作为军事训练场上的共污染物出现。TNT 是一种有毒的致癌物质，与土壤紧密结合，而 RDX 则具有很强的移动性，会渗滤到地下水中，威胁到饮用水供应。我们已经培育出能够降解 RDX 同时耐受 TNT 植物毒性的拟南芥。将来自红球菌 Rhodococcus rhodochrous 菌株 11Y 的细菌 RDX 降解酶 xplA 和相关还原酶 xplB，与来自阴沟肠杆菌的 TNT 解毒硝基还原酶（NR）nfsI，一起转化到拟南芥中。表达 XplA、XplB 和 NR 的植物能够从土壤浸出液中去除 RDX，并在抑制仅表达 XplA 的植物生长的 RDX 和 TNT 污染土壤中生长。这是首次证明利用转基因植物来处理两种化学性质差异很大的有机化合物的研究，其水平与污染训练场地上发现的水平相当，表明该技术能够修复现场发现的 RDX 浓度。此外，表达 XplA 和 XplB 的植物在空气中组织中可用于草食和潜在生物积累的 RDX 含量明显减少。
