Transformation of TNT by Aquatic Plants and Plant Tissue Cultures

Abstract

The ability of plants to uptake and transform 2,4,6-trinitrotoluene (TNT) was investigated using the aquatic plant Myriophyllum spicatum, axenic Myriophyllum aquaticum, and Catharanthus roseus hairy root cultures. Studies demonstrate that Myriophyllum, with or without its periphyton, and C. roseus transform TNT. Low concentrations of aminated nitrotoluenes (2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene) were observed in the extracellular medium and tissue extracts. Primary products of transformation were not identified, and mineralization was not observed. Mass balances demonstrate that a large percentage of the unknown TNT transformation products were associated with the plant. This fraction could be at least partially recovered from the plant tissue with methanol extraction. A soluble fraction was also present in the medium. The absence of periphyton had little impact on the results observed. Medium concentrations of 4-amino-2,6-dinitrotoluene were greater in systems in which the periphyton was not removed. For the first time, the intrinsic ability of plants to transform TNT has been confirmed. The formation of soluble, uncharacterized transformation products is a concern for potential phytoremediation applications.

Short-term physiological responses to copper stress in Salvinia auriculata Aubl.

“…Currently, the use of aquatic macrophytes is under investigation as a viable alternative for remediation of a wide range of contaminants including heavy metals (Hughes et al, 1996;Lee et al, 1998;Rodgers and Bunce, 2001;Miglioranza et al, 2004;Miretzky et al, 2004;Polomski et al, 2009;Augustynowicz et al, 2010;Rahman and Hasegawa, 2011). These researches emphasize that the plant-based approach to remediation of the environments highly contaminated has an interesting cost-effective, because it is cheaper than other methods and safe for human.…”

Enhanced metabolism of halogenated hydrocarbons in transgenic plants containing mammalian cytochrome P450 2E1

“…Plants have been shown to take up and, in some cases, to metabolize organic pollutants (6), excess nutrients (6, 7), 2,4,6-trinitrotoluene (TNT) (8,9), and metals (10,11). Work in our laboratory has demonstrated that poplar trees are able to take up and metabolize TCE both under laboratory conditions and in a field test (12)(13)(14).…”

Identification of Metabolic Routes and Catabolic Enzymes Involved in Phytoremediation of the Nitro- Substituted Explosives TNT, RDX, and HMX

“…GSTs are enzymes known to be involved in the transformation of a large variety of toxic chemicals (Pflugmacher et al, 2000;Schroder et al, 2001;Maars, 1996;Edwards and Dixon, 2004), and they also are suspected to be (at least partially) responsible for the detoxification of TNT (Hughes et al, 1997;Bhadra et al, 1999). Even thought no direct evidence of such a mechanism has been obtained, we showed here that a purified, commercially-available GST was able to catalyze in vitro the conjugation of TNT with GSH.…”

“…A few transformation products have been identified, predominantly amino-and diamino-nitrotoluenes, (Harvey et al, 1990;Hughes et al, 1997;Thompson et al, 1998b;Larson et al, 1999), but incomplete information is available about the metabolism of TNT inside plant tissues.…”