Impacts of Metal, Metalloid and Their Effects in Plant Physiology: A Review

Abstract

Due to anthropogenic activities effects of metal and metalloid toxicity are gradually increasing, furthermore contamination soil ranks among the most important factors, affecting crop yield production. The metals and / or metalloids can enter the food chain and, affecting on human health and alterations to the environment. Metalloids represent a wide range of elements with intermediate physiochemical properties between metals and non-metals. Metalloids, such as boron, selenium, and silicon are known to be essential or quasi-essential for plant growth. In contrast, metalloids like arsenic and germanium are toxic to plant growth. Metalloids toxicity is largely depending on their concentration within the living cells. Some of them are beneficial for plant growth and development particularly, at low concentration; however, high concentration has negative effects. Uptake mechanisms of metalloids by roots systems and their subsequent transport to different tissues and inter/intra-cellular redistribution have great importance. However, uptake of metalloids by plants has been well-studied .In addition various transporters, as well as membrane channels involved in these processes, have been identified. In order to overcome the biotic and abiotic stresses particularly, during mechanisms have been
developed by plants. Metals and metalloids such as Zn, Cu, Al, Pb, Cd, and as, exert several effects on plants, the main strategies involve hyperaccumulation, tolerance, exclusion, and chelation with organic molecules. Recently omics era has increased knowledge on the plant genome and transcriptome plasticity to defend against these stimuli. Summarizing the relevant findings on the uptake mechanisms by plants, accumulate, transport, tolerate, and respond to this metal/metalloid stress. Furthermore, potential applications of biotechnology for improving plant tolerance or increasing the accumulation was also discussed.