Phytochelatins: Peptides Involved in Heavy Metal Detoxification

Abstract

Phytochelatins (PCs) are enzymatically synthesized peptides known to involve in heavy metal detoxification and accumulation, which have been measured in plants grown at high heavy metal concentrations, but few studies have examined the response of plants even at lower environmentally relevant metal concentrations. Recently, genes encoding the enzyme PC synthase have been identified in plants and other species enabling molecular biological studies to untangle the mechanisms underlying PC synthesis and its regulation. The present paper embodies review on recent advances in structure of PCs, their biosynthetic regulation, roles in heavy metal detoxification and/or accumulation, and PC synthase gene expression for better understanding of mechanism involved and to improve phytoremediation efficiency of plants for wider application.

Assessment of Heavy Metal Pollution through Index Analysis for Yamuna Water in Agra Region, India

“…The increase in mean concentration of Fe, Zn, Cr and Mn in post-rainy season with respect to summer followed the order as Mn>Cr>Zn>Fe which was inversely proportional to their covalent index Fe>Zn>Cr>Mn. Higher the covalent index of a heavy metal stronger will be its adsorption (Pal and Rai, 2009) and hence lower will be its desorption due to dilution. Desorption of other heavy metals i.e., Pb, Cd, Cu and Ni also would had occurred but dilution was dominant factor, hence net result was decrease in concentration.…”

<htm>Phytohyperaccumulator-AMF (arbuscularmycorrhizal fungi) interaction in heavy metals detoxification of soil </htm>

“…Proteinsare involved in linkages with metals, thereby forming complex biochemical compounds called metal-proteins, metallothionein and peptideslike phytochelatins. Besides these, organic acids and amino acids take active part in detoxification of heavy metals in plants (PAL and RAI, 2009). …”

Strategies for Iron Biofortification of Crop Plants

“…In plants, oganic acids like citrate and malate, the amino acid histidine and the plant-specific methionine derivative nicotianamine are mainly involved in Fe transport and solubility (Briat et al, 2007;Callahan et al, 2006). Chelators for metals also include polypeptides such as phytochelatins (PCs) and metallothioneins (MTs) which are essentially involved in the tolerance to potentially toxic heavy metal ions (Hassinen et al, 2011;Pal & Rai, 2010). Fe can be stored in form of ferritin in the plastids which also serves to reduce oxidative stress (Briat et al, 2010b).…”