Studies on plant-mediated fate of the explosives RDX and HMX

The fate of the explosives RDX and HMX on exposure to plants was investigated in 'natural' aquatic systems of Myriophyllum aquaticum for 16 days, and in axenic hairy root cultures of Catharanthus roseus for > or = 9 weeks. Exposure levels were: HMX, 5 mg/l; and RDX, approximately 8 mg/l. Exposure outcomes observed include: HMX, no transformation by aquatic plants, and minimal biological activity by axenic roots; and RDX, removal by both plant systems. In the case of RDX exposure to axenic roots, since 14C-RDX was included, removal was confirmed by the accumulation of 14C-label in the biomass. The intracellular 14C-label in these RDX studies was detected in two forms: intact RDX and bound unknown(s).