Phytochelatins plant

Grill, E., Winnacker, E.-L. Zenk, M.H. (1985). Phytochelatins The principal heavy-metal complexing peptides of higher plants. Science, 230, 674-6. 

Nickel is localized predominantly in the epidermal and subepidermal of the leaves. However, in leaves of some hyperaccumulator plants such as T. caerulescens and T. goesingense, Ni and Zn are found mainly in vacuoles (Salt and Kramer, 2000). Trace elements also are inactivated in the vacuoles as high-affinity low-molecular-weight metal chelators (such as Cd-phytochelatin complex), providing plants with trace element tolerance. Some Ni in leaves is found to be associated with cell wall pectates as well. 

Cobbett C. S., 2000, Phytochelatins and their role in heavy metal detoxification, Plant Physiol. 123 825-832. 

Goldsbrough P., 2000, Metal tolerance in plants The role of phytochelatins and metallothioneins, in Phytoremediation of contaminated soil and water, N. Terry, G. Banuelos, eds, Lewis Publishers, Boca Raton. 

The metabolism of sulphur plays an important role in metal response, since most chelators, including metallothioneins and phytochelatins, contain this element. APSl encodes an ATP sulfurylase and Brassica juncea has been engineered to constitutively express this gene (Pilon-Smits et al., 1999). The plants showed increased S assimilation, higher glutathione (GSH) levels and were more tolerant to Se, accumulating 2-fold higher Se levels in the shoots. 

Lee, S., Moon, J. S., Ko, T.-S., Petros, D., Goldsbrough, P. B., and Korhan, S. S., 2003b, Overexpression of Arabidopsis phytochelatin synthase paradoxically leads to hypersensitivity to cadmium stress, Plant Physiol. 131 656-663. 

Schmoger MEV, Oven M, Grill E. 2000. Detoxification of arsenic by phytochelatins in plants. Plant Physiology 122 793-801. 

Scheller, H.V., Haung, B., Hatch, E. Goldsbrough, P.B. (1987). Phytochelatin synthesis and glutathione levels in response to heavy metals in tomato cells. Plant Physiology 85, 1031-5. 

Some natural sources containing these functional groups are phytochelatins (siderophores), biopolymers (e.g., proteins), and humic substances (see chapters 8 and 9 for more details on these compounds). Compounds such as phytochelatins are used by algae (Donat and Bruland, 1995) and higher plants (Grill et al., 1985) to enhance metal uptake capability in the natural environment, particularly in systems where their concentrations are exceptionally low. 

Phytochelatins organic compounds, produced by plants that have chelating properties. 

Bleeker, P.M., HakvoorL H.W., Bliek, M., Souer, E., and Schat, H. 2006. Enhanced arsenate reduction by aCDC25-like tyrosine phosphatase explains increased phytochelatin accumulation in arsenate-tolerant Holcus lanatus. Plant Journal, 45 917-29. 

Cobbett, C. and Goldsbrough, P. 2002. Phytochelatins and metallothioneins Roles in heavy metal detoxification and homeostasis. Annual Reviews in Plant Biology, 53 159-82. 

Raab, A., Eeldmann, J., Meharg, A.A. The nature of arsenic-phytochelatin complexes in Holcus lanatus and Pteris cretica. Plant Physiol. 134, 1113-1122 (2004)... 

Li, Y., Dhankher, O.P., Carreira, L., Lee, D., Chen, A., Schroeder, J.I., Balish, R.S., Meagher, R.B. (2004). Overexpression of phytochelatin synthase in Arabidopsis leads to enhanced arsenic tolerance and cadmium hypersensitivity. Plant Cell Physiol. 45 1787-97. 

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