TRANSFORMATION OF TNT BY AQUATIC PLANTS AND PLANT-TISSUE CULTURES

The ability of plants to uptake and transform 2,4,6-trinitrotoluene (T NT) was investigated using the aquatic plant Myriophyllum spicatum, ax enic Myriophyllum aquaticum, and Catharanthus roseus hairy root cultur es. Studies demonstrate that Myriophyllum, with or without its periphy ton, and C. roseus transform TNT. Low concentrations of aminated nitro toluenes (2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene) w ere 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 th e unknown TNT transformation products were associated with the plant T his fraction could be at least partially recovered from the plant tiss ue with methanol extraction. A soluble fraction was also present in th e medium. The absence of periphyton had little impact on the results o bserved. Medium concentrations of 4-amino-2,6-dinitrotoluene were grea ter in systems in which the periphyton was not removed. For the first lime, the intrinsic ability of plants to transform TNT has been confir med. The formation of soluble, uncharacterized transformation products is a concern for potential phytoremediation applications.