Phytochelatin and Oxidative Stress Under Heavy Metal Stress Tolerance in Plants

Abstract

With the rapid developing of industry and agriculture, heavy metal pollution in environment has been both serious and widespread worldwide. To cope with adverse environmental heavy metal toxicity, plants have evolved a variety of adaptive responses, which include immobilization, exclusion, chelation, and compartmentalization of metal ions and often involve metal-binding ligands. Particularly, phytochelatins (PCs), a family of peptides, have been regarded as the best-characterized heavy metal chelators especially in detoxication of heavy metals such as cadmium (Cd) in plants and some microorganisms. Generally, PCs have the general structure (γ-Glu-Cys) n -Gly (n = 2–11) and are produced by the enzyme phytochelatin synthases, which can bind to various metals including Cd, As Cu, or Zn. In this chapter, we focused on the biosynthesis and function of PCs and the role of PCs in metal detoxification and tolerance. Finally, the molecular biology of PCs has been briefly reviewed.