IDENTIFICATION OF COPPER-INDUCIBLE GENES IN Pistia stratiotes

This technique makes use of biological endpoints in living organisms
(biomarker) of environmental insults. In a way, biomarkers offer promise as
sensitive indicators which can indicate the uptake of toxicants into organisms,
distribution of toxicants within tissues, and toxicological effect of toxicants at
critical targets. Due to these attributes, biomarkers measured in animals from
sites of suspected contamination can be an important and informative
component of an environmental monitoring program. In such a monitoring
program, the biomarker responses of animals or plants from a suspect site
would be compared to those of the same species collected from reference
sites (McCarthy and Shugart, 1990).
Measurement of biomarker responses to exposure offers the potential
of providing information that cannot be obtain from measurements of chemical
concentrations in environmental media or in body burdens. For example,
measurement of biomarker responses at the molecular and cellular level can
provide evidence that organisms have been exposed to toxicants at levels
that exceed normal detoxification and repair capacity (McCarthy and Shugart,
1990). Responses either at the lower level or higher level of biological
organization provide information to understand and interpret the relationship
between exposure and adverse effect. In particular, responses measured
from the lower levels of biological organization such as DNA damage or
enzyme activity, often manage to provide sensitive and specific response to
particular toxicant. Hence, this kind of biomarkers gives an opportunity to
measure and diagnose the type of contaminant or toxicant that particular
organism is exposed to (McCarthy and Shugart, 1990). Moreover, the
exposure of an organism to toxic chemicals may result in the induction of a
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