Lead toxicity in plants: A review

Abstract

Heavy metal pollution of soils is a common consequence of agricultural, industrial, and human activity. Lead is one of the heavy metals that can pollute soils and sediments easily. Lead is readily absorbed and accumulates in many plant parts even though it is not a necessary element for plants. Plant uptake of lead is influenced by a variety of physicochemical factors, including root exudation, soil pH, particle size, and cation exchange capacity. Various toxicity signs in plants, such as chlorosis, reduced development, and blackening of the root system, are caused by excess lead. Lead suppresses photosynthesis, modifies hormonal status, disrupts mineral nutrition and water balance, andalters membrane permeability and structure. This review reports various morphological, physiological and biochemical effects of lead toxicity in plants.