Expressing the Bacterial Nitroreductase and XplA Genes in Creeping Bentgrass for Phytoremediation of the Explosives, TNT and RDX.

Phytoremediation refers to the use of plants to remove pollutants from the environment or to render them harmless.  It provides a low cost and aesthetic way for pollutant remediation.  TNT and RDX are widespread toxic contaminants at military training ranges.  TNT and RDX are toxic, mutagenic and have a serious impact on the environment and human health.  Recent advances have shown that transgenic plants, such as tobacco, Arabdopsis and poplar [Populus tremula x P. alba], which integrated with the bacterial nfsI and XplA genes, are effective for phytodetoxification and restoration of explosives contaminated soil.  Perennial grass species, such as turfgrasses, due to their wide geographic distribution and their ability to grow and cover ground totally year round, are excellent candidates for phytoremediation.  In order to test the performance of these genes in perennial grasses, the nfsI and XplA genes were transformed into creeping bentgrass [Agrostis stolonifera (L.)] with co-transformation method.  From 8 dishes of transformed embryogenic calli that  induced from nodes of a single creeping bentgrass strain, 84 hygromycin resistant callus lines ontained.  The integration of the nfsI and XplA genes was confirmed by PCR assay.  Results of TNT and RDX stress tests with culture medium supplemented with TNT or RDX indicated that 12 transgenic lines showed obvious improvement on TNT toxicity tolerance at 0.15 mM TNT level and 7 transgenic lines showed better RDX toxicity tolerance.