Recent investigations indicate that 2,4,6-trinitrotoluene (TNT) is rapidly transformed in an aquatic environment by the action of photosynthetic organisms. Several plant species from a variety of culture conditions were examined that displayed the capacity to transform TNT. The kinetics of transformation and the fate of transformation products were monitored by MECE and HPLC analysis in both the aquatic media and within the plant tissues. (U)\sp14C-TNT was introduced into the plant systems in order to monitor the fate of the aromatic ring. In order to assess the action of plant biochemistry in isolation from ordinary periphyton, axenic plants were examined for their metabolic capacity. Experiments showed that the majority of TNT is rapidly transformed into an unidentified soluble product in the medium and plant tissues with small quantities of reduction products appeared transiently. Over time, an increasing amount of \sp14C was irreversibly associated with the plant tissue.