Molecular Markers in Plant Based Bioassays for the Detection of Levels of Endpoints to Probe of Aquatic Genotoxicity

Abstract

Environmental pollution today stands out to be one of the gravest concerns for the modern world, in connection to the mismanaged waste water discharge from agricultural, industrial vis-a-vis domestic sources, representing an arduous challenge for the environmentalists. Mention may be made that effluents are complex concoction of chemicals with variable proportion of heavy metals, metalloids and metaloxides both in quality and quantity. A large number and variety of chemicals present in these mixtures, together with potential synergistic effects imparts great challenges to detect and characterize the types of chemicals present and corroborate their individual/collective toxicity. Many contaminants entering the aquatic environment have been lipophilic by nature and can be readily taken up by aquatic organisms. Therefore, the impact of these aquatic contaminants on ecosystems largely depends upon factors including uptake and biotransformation by different species, and effects can be easily seen at the cellular level through the individual, population and ultimately the ecosystem as a whole. Research in this particular area has gained much attention and momentum in the recent past, with particular interests thirsted upon the presence of different genotoxic agents surrounding in the environment. It is therefore clear that the assessment of complex mixtures for their genotoxic potential fits in the list of an extremely important consideration for environmental pollution monitoring and management. Concomitantly, it is important to develop reliable and effective methods for detecting endpoints indicative of exposure to genotoxicants, in particular using test methods that would be simple, rapid and cost effective. In the present communication the role of antioxidant enzymes, i.e., ROS (Reactive Oxygen Species) scavengers, chromosomal abnormalities resultant of altered mitotic index and micronuclei formation is reviewed. It is suggested that alkaline COMET Assay, RAPD couple with PCR can be employed as effective biochemical, cytogenetic and molecular markers in plants (as model systems for aquatic toxicology) which serve as best tools to detect the mode of action and levels of genotoxic endpoints upon exposure to different genotoxins in aquatic environments.