Superfund Research Program
Molecular Mechanisms of Heavy Metal Detoxification and Accumulation in Plants
Project Leader: Julian I. Schroeder
Grant Number: P42ES010337
Funding Period: 2000-2017
Soils and waters with high levels of toxic heavy metals such as cadmium, arsenic, lead and mercury are detrimental to human and environmental health. These 4 metal(loid)s are among the Superfund's top 7 priority hazardous substances. Research and applications show that uptake of heavy metals into plants via the root system and accumulation of heavy metals in plant shoots could provide a cost-effective approach for toxic metal removal and remediation of heavy metal-laden soils and waters. However, key genes mechanisms and pathways that function in heavy metal over-accumulation and transport in plants remain to be identified and characterized. In SRP-supported research the research team has made important advances in understanding mechanisms that mediate heavy metal detoxification and transport in plants, including the identification of the heavy metal(loid) detoxifying gene encoding phytochelatin synthases, the identification of a family of long-sought transporter genes that mediate phytochelatin-cadmium, -arsenic and -mercury complex sequestration and detoxification in vacuoles of plants and fungi. Important genes and pathways that function in heavy metal detoxification, sequestration and rapid metal-induced gene expression are being characterized and identified in this project. This project is providing key advances for developing bioremediation strategies and for technologies for reducing toxic metals from entering the human food chain due to accumulation in edible plant tissues.