Increase in environmental pollution as well as contamination of water by heavy metals, associated with plants and other food products due to increase in human anthropogenic activities, has resulted in damages to natural resources. Plants, be aquatic or submerged ones, are the best indicators of such unseen killers, and as such develop tolerance to such metabolically toxic pollutants, including heavy metals. Aquatic ecosystem is susceptible to such pollution, precisely because of different effluents draining off finally to some water bodies that subject the flora of that system to encountering toxic substances. Screening followed by the proper monitoring of the impacts of these heavy metals is very important. Therefore, approaches to develop plants with reduced heavy metal uptake are important. "Plant Heavy Metal Stress" aims at giving an overview of the most important basic aspects of physiological and biochemical basis for such contamination, toxicity and tolerance in widely grown aquatic model plants. The book is expected to serve as a reference to researchers and students of plant sciences and environmental stress.