Cytotoxicity of metal/metalloids’ pollution in plants

Abstract

Cytotoxicity is an endogenous and/or exogenous effect of metals/metalloids that leads to cell death. Excessive amounts of elements, such as Co, Cu, Fe, Mn, Mo, Ni, V, Zn, Pb, Cd, Hg, and As are main threats to plants. They are exposed to many stress factors including chemical compounds and radiation affecting their seed germination, seedling growth, and floral and fruit development. These stress factors can adversely affect the quality and quantity of the product with leading to morphological, anatomical, physiological, biochemical, and molecular damage to plants. They adversely affect the plant both directly and indirectly. Some of the direct toxic effects caused by high metal concentration include inhibition of cytoplasmic enzymes and damage to cell structures due to oxidative stress, while indirect toxic effect is the replacement of essential nutrients at cation exchange sites of plants. However, there are different kinds of methods for examining cytotoxicity, because usually there is no standard national procedure. Therefore, the parameters of these methods vary depending on the test substances, the test plants, or the individual procedures. This review deals with the use of entire plants, seedlings, cell suspension cultures, and pollen tubes for the estimation of potential toxicity in the environment, and for risk assessment of chemicals and formulations of human relevance. Another reason for selecting plants for assessing adverse effects of these chemicals is the ease of experimentation with plants. This chapter covers the detection of environmental mutagens through plant bioassays, considering the increasing importance of biomonitoring using plants for assessing the mutagenicity of relevant chemicals and industrial waste. The aim of this study was to assess possible cytotoxic effects of metal/metalloid pollution, mechanisms of tolerance, and assessment procedures.