2,4-Dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) are being evaluated as replacements for TNT and RDX in insensitive munitions compositions. These energetic compounds will likely be released into the environment on training ranges in the event of incomplete detonation. It is, therefore, essential that the DoD consider the fate and transport mechanisms, breakdown products and degradation processes and subsequent impact on the terrestrial environment. Understanding how new munitions formulations will affect the environment will allow the DoD to reduce future environmental cleanup costs. The major objective of this project is to rigorously and quantitatively establish the fate and effects of the components DNAN and NTO on plants. 

In order to achieve the project objective, five major tasks will be undertaken to: 1) understand the physicochemical parameters of DNAN and NTO in soil, 2) assess the toxicity of DNAN and NTO on plant species native to U.S. military training ranges, 3) elucidate mechanisms of NTO and DNAN toxicity in plants, 4) identify the plant detoxification intermediates of DNAN and NTO in a model plant system, and 5) resolve the biochemical pathways for the detoxification of DNAN and NTO in plants. Arabidopsis (Arabidopsis thaliana L.) will be used as a model plant species. Arabidopsis mutants with enhanced resistance to DNAN or NTO toxicity will be characterized and the mutated gene(s) identified. Data on the identified genes will yield information on the roles of these genes in the metabolism of DNAN and NTO in plants. 

Investigations into the impact of DNAN and NTO on plants will provide a clearer understanding of the fate of these compounds in field settings. The availability of bench mark data regarding the transport and fate of the energetic materials will support predictions and modeling. These models will enable the DoD to use best management practices in identifying training ranges with ecosystems that are particularly sensitive to DNAN and NTO, and allow the identification of others that present an acceptable risk. The results obtained will provide potential cost savings, since such knowledge will mitigate contamination and alleviate the need for future clean-up operations. (Anticipated Project Completion - 02/2020)