Enhanced Phytochelation And Uptake Of

The applicability of certain cultivars of plants in extraction of heavy metals from contaminated soil andor water has been well reported in the literature. One restriction to the commercial application ofphytoextraction is the inherent limitation of plants in supplying their own chelates to their rhizosphere.We are proposing to apply recent advances in the field of mammalian toxicology to the creation of amore suitable metal consuming plant. The role of reduced glutathione (GSH) in cell defense to toxiccompounds has long been recognized. GSH-mediated mobilization, uptake and transport of heavymetals in plants has also been observed following rhizospheric application of GSH. Efforts are nowunderway to engineer plants to release GSH from their roots by expressing a rat GSH transporter genein the roots of transgenic tobacco. Excretion of GSH from roots should enhance phytoremediationperformance by significantly increasing the bioavailability of heavy metals and enhancing the uptakeand transport of metals to the shoots. The objectives of the proposed work are to screen transgenictobacco plants for GSH release and to evaluate the performance of GSH-secreting plants in extractingheavy metals from soil in comparison with their non-transformed parent. Commercial application oftransgenic cultivars engineered for enhanced mobilization and uptake of toxic heavy metals will resultin a more efficient, cost-effective and environmentally sound in situ remediation technology.