Phytotechnology Projects

A group of angiospermous herbaceous plants were assayed for symptomatic foliar changes in response to RDX contaminant levels found in soils of military ranges. Among five species selected for testing on the basis of RDX tolerance, only prickly sida (Sida spinosa) exhibited foliar symptoms upon exposure. At plant maturity red patches were produced in the leaf margins and interveinal chlorosis developed. Other members of the family Malvaceae are used to produce a red tea rich in anthocyanins. Because of these symptoms, there is potential for using prickly sida as a cost effective field and laboratory indicator of RDX contamination and for RDX phytoremediation.

Liz Rylott and Neil Bruce (York), Sharon Doty and Stuart Strand (Univ. of Washington), Antonio Palazzo (US Army, USA CRREL) The toxic explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is both resistant to degradation and highly mobile through soils and ground water and, as a result of this, RDX is now a significant threat to drinking sources such as those close to the US Massachusetts Military. We have demonstrated that Arabidopsis expressing bacterial RDX degrading enzymes remove and degrade saturating concentrations of RDX from soil leachate. We are currently transferring this technology into selected perennial wheatgrass species for the phytoremediation of RDX from soil leachate.