Arsenic Phytosensors

DESCRIPTION (provided by applicant): This Small Business Technology Transfer project seeks to develop a plant bioreporter for arsenic, a carcinogen that is widely dispersed in the environment and is one of the two most common contaminants at Superfund sites. Currently, extensive sampling and laboratory analysis of soil and water is often required to detect and monitor arsenic over large areas affected by activities such as pesticide use, mining, smelting, and construction with pressure-treated wood. The expense and inconvenience of such sampling restricts characterization and remediation of environmental health hazards caused by arsenic, indicating an urgent need for more cost-effective approaches. An interdisciplinary solution to this problem is create an arsenic phytosensor that combines microbial genes responsive to the presence of arsenic, with a green fluorescent protein (GFP) reporter, in a plant known to hyper accumulate arsenic. When illuminated with ultraviolet light, the engineered plant would fluoresce green in the presence of arsenic, acting as an amplifying transducer of the environmental arsenic "signal" into visual wavelengths. In preliminary research on creating an arsenic phytosensor, well- characterized arsenic promoter (ars) and repressor (arsR) genes from E. coli have been fused to the GFP gene, and techniques of genetically engineering arsenic- hyper accumulating fern plants have been developed. Building on this work, in Phase I ars/arsR/GFP gene constructs will be inserted in an arsenic hyper accumulating fern to develop phytosensors that can be used for detection as well as cleanup of environmental arsenic. Testing of the plants, and a field demonstration, are planned to be completed in Phase II. The research project is expected to lead to the development of innovative, cost-effective, real-time, solar-powered phytosensors to monitor water and soil quality, which could offer high spatial resolution, stand-off reporting, ready scaling to large treatment areas, and continuous in situ monitoring of bioavailable arsenic in government, industrial, commercial, and residential properties. Benefits to customers of the new phytosensor technology include reducing environmental health hazards posed by arsenic, and assisting efforts to monitor and clean the environment. The research project is expected to lead to the development of a plant that provides a visual indication of soil arsenic contamination. The plant-based sensor will provide continuous real-time indication of arsenic present in soils in residential and industrial settings.