explosive-degrading cytochrome P450 activity and its targeted application for the phytoremediation of RDX

• Published in: Nature biotechnology 2006-02, Vol.24 (2), p.216-219
• Main Authors: Rylott, E.L, Jackson, R.G, Edwards, J, Womack, G.L, Seth-Smith, H.M.B, Rathbone, D.A, Strand, S.E, Bruce, N.C
• Format: Article
• Language: English
• Subjects: Agriculture; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis thaliana; Base Sequence; biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biomedicine; bioremediation; Biotechnology; Chemical contaminants; Cytochrome; cytochrome P-450; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Drug Delivery Systems - methods; Environment and pollution; Environmental Pollution - prevention & control; Escherichia coli - enzymology; Escherichia coli - genetics; Explosions; Explosives; Flowers & plants; Fundamental and applied biological sciences. Psychology; gene expression; Genetic Enhancement - methods; Genetics; hexahydro-1,3,5-trinitro-1,3,5-triazine; Industrial applications and implications. Economical aspects; letter; Life Sciences; Molecular Sequence Data; Phytoremediation; Phytotoxicity; Plants, Genetically Modified - metabolism; polluted soils; Protein Engineering - methods; RDX; Recombinant Proteins - metabolism; Refuse Disposal - methods; Rhodococcus rhodochrous; Soil contamination; soil pollution; Toxicity; Toxins; transgenes; transgenic plants; triazines; Triazines - isolation & purification; Triazines - pharmacokinetics; unspecific monooxygenase; xplA gene
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/nbt1184

The widespread presence in the environment of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), one of the most widely used military explosives, has raised concern owing to its toxicity and recalcitrance to degradation. To investigate the potential of plants to remove RDX from contaminated soil and water, we engineered Arabidopsis thaliana to express a bacterial gene xplA encoding an RDX-degrading cytochrome P450 (ref. 1). We demonstrate that the P450 domain of XplA is fused to a flavodoxin redox partner and catalyzes the degradation of RDX in the absence of oxygen. Transgenic A. thaliana expressing xplA removed and detoxified RDX from liquid media. As a model system for RDX phytoremediation, A. thaliana expressing xplA was grown in RDX-contaminated soil and found to be resistant to RDX phytotoxicity, producing shoot and root biomasses greater than those of wild-type plants. Our work suggests that expression of xplA in landscape plants may provide a suitable remediation strategy for sites contaminated by this class of explosives.