The invention provides a system for monitoring the bioavailability and/or
toxicity of contaminants in the environment. The system includes plant
biosensors that indicate the presence of contaminants, such as, for
example, volatile organics or heavy metals, using an in situ monitoring
approach. The plant biosensors are genetically engineered to exhibit a
change in color phenotype under the control of promoter elements that are
selectively responsive to the presence of a particular contaminant. The
plant biosensing system provides a cost-effective approach to monitoring
large and remote territories with high-spatial resolution. The transgenic
plants can also be placed at strategic locations, before, during and
after remedial activities at a site.
