The effect of lead on plants in terms of growing and biochemical parameters: a review

Abstract

Contamination of soil and water by various heavy metals such as lead, silver and cadmium is increasing day by day as result of different activities, such as industrialization and urbanization. Lead (Pb) is an example of potential heavy metal that is neither essential element nor have any role in the process of cell metabolism but is easily absorbed and accumulated in different parts of a plant. The lead uptake is mainly regulated by PH, particle size, and cation exchange capacity of the soil, root exudation and by different other physical and chemical parameters. The high concentration of the heavy metals such as lead can cause a number of toxic symptoms in plants that may be retardation in growth (Stunted growth), negative effects on photosynthesis (chlorosis), blackening of roots and different other symptoms. Lead has the ability to inhibit photosynthesis, disturb mineral nutrition and water balance, changes hormonal status and affects membrane structure and permeability. The paper reviewed the effects of lead ion on the growth and some biochemical parameters in plants.