Zhang Long, Rylott Elizabeth L, Bruce Neil C, Strand Stuart E
Department of Civil and Environmental Engineering, University of Washington, Box 355014, Seattle, WA, 98195-5014, USA.
CNAP, Department of Biology, University of York, York, YO10 5DD, UK.
Plant Mol Biol. 2017 Sep;95(1-2):99-109. doi: 10.1007/s11103-017-0639-z. Epub 2017 Jul 31.
Expression of the bacterial nitroreductase gene, nfsI, in tobacco plastids conferred the ability to detoxify TNT. The toxic pollutant 2,4,6-trinitrotoluene (TNT) is recalcitrant to degradation in the environment. Phytoremediation is a potentially low cost remediation technique that could be applied to soil contaminated with TNT; however, progress is hindered by the phytotoxicity of this compound. Previous studies have demonstrated that plants transformed with the bacterial nitroreductase gene, nfsI have increased ability to tolerate and detoxify TNT. It has been proposed that plants engineered to express nfsI could be used to remediate TNT on military ranges, but this could require steps to mitigate transgene flow to wild populations. To address this, we have developed nfsI transplastomic tobacco (Nicotiana tabacum L.) to reduce pollen-borne transgene flow. Here we have shown that when grown on solid or liquid media, the transplastomic tobacco expressing nfsI were significantly more tolerant to TNT, produced increased biomass and removed more TNT from the media than untransformed plants. Additionally, transplastomic plants expressing nfsI regenerated with high efficiency when grown on medium containing TNT, suggesting that nfsI and TNT could together be used to provide a selectable screen for plastid transformation.
细菌硝基还原酶基因nfsI在烟草质体中的表达赋予了烟草对三硝基甲苯（TNT）的解毒能力。有毒污染物2,4,6-三硝基甲苯（TNT）在环境中难以降解。植物修复是一种潜在的低成本修复技术，可应用于受TNT污染的土壤；然而，该化合物的植物毒性阻碍了其进展。先前的研究表明，用细菌硝基还原酶基因nfsI转化的植物具有更强的耐受和解毒TNT的能力。有人提出，经过基因工程改造以表达nfsI的植物可用于修复军事靶场的TNT，但这可能需要采取措施来减少转基因向野生种群的流动。为了解决这个问题，我们培育了nfsI转基因烟草（Nicotiana tabacum L.）以减少花粉传播的转基因流动。我们在此表明，当在固体或液体培养基上生长时，表达nfsI的转基因烟草比未转化的植物对TNT的耐受性显著更高，生物量增加，并且从培养基中去除的TNT更多。此外，在含有TNT的培养基上生长时，表达nfsI的转基因植物能够高效再生，这表明nfsI和TNT可共同用于为质体转化提供一个选择筛选。
