The Effect of Heavy Metals on the Growth and Development of Different Plants: A Synoptic Review

Heavy metals are non-essential elements for plants. If plentiful amounts are accumulated in the plants, heavy metals will adversely affect the absorption and transport of essential elements, disturb the metabolism, and have an impact on growth and reproduction. Toxic Levels of Lead (Pb), Cadmium (Cd), Mercury (Hg), Arsenic (As) affects plant processes at physiological and biochemical levels. When the metals reacts with important functional groups, the activity of several enzymes is influenced, some of which are important in photosynthesis and nitrogen metabolism. Research has identified several important aspects of metal tolerance in some plant, but there is no model species in which the entire process/ steps of tolerance has been determined. A better understanding of the knowledge is required to handle the acute problem of increasing metal toxicity to the plants and human life. Efforts to coordinate research to address all aspects of tolerance are required. In addition to provide the necessary data for the production of models that will accurately predict the impact of certain metal related industrial activities on the plant life, the study of metal tolerance may also provide methods to detoxify metal contaminated solid through the use of metal accumulating species. As such the pathway of metal detoxification in plants needs to be studied in depth.