Using Plants Against Soils Contaminated With Metals: More work on phytoremediation/phytochelatins

see all at:
http://www.sciencedaily.com/releases/2010/11/101116093825.htm

(Nov. 16, 2010) — Two essential genes that control the accumulation and detoxification of arsenic in plant cells have been identified. This discovery was made by an international collaboration involving laboratories in Switzerland, South Korea and the United States, with the participation of members of the National Centre of Competence in Research (NCCR) Plant Survival. The results are a promising basis for reducing the accumulation of arsenic in crops from regions in Asia that are polluted by this toxic metalloid, as well as for the cleanup of soils contaminated by heavy metals.
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Plants offer a way for toxic metals to enter the food chain. We know, for example, that arsenic is stored within rice grains, which, in regions polluted with this toxic metalloid, constitutes a danger for the population whose diet depends to a great extent on this cereal.

Arsenic or cadmium in soils is transported to plant cells and stored in compartments called vacuoles. Within the cell, the translocation of arsenic and its storage in vacuoles is ensured by a category of peptides -- the phytochelatins -- that bind to the toxic metalloid, and are transported into the vacuole for detoxification, similar to hooking up a trailer to a truck. In terms of the process, it is the "truck and trailer" complex that is stored in the vacuole.

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At the same time, researchers have discovered a way to produce plants capable of accumulating a greater amount of toxic metals which consequently can be used to clean up contaminated soils. These plants would then be burned in blast furnaces in order to eliminate the toxic elements.