title: Engineering plant-microbe symbiosis for rhizoremediation of heavy metals.
abstract: The use of plants for rehabilitation of heavy-metal-contaminated environments is an emerging area of interest because it provides an ecologically sound and safe method for restoration and remediation. Although a number of plant species are capable of hyperaccumulation of heavy metals, the technology is not applicable for remediating sites with multiple contaminants. A clever solution is to combine the advantages of microbe-plant symbiosis within the plant rhizosphere into an effective cleanup technology. We demonstrated that expression of a metal-binding peptide (EC20) in a rhizobacterium, Pseudomonas putida 06909, not only improved cadmium binding but also alleviated the cellular toxicity of cadmium. More importantly, inoculation of sunflower roots with the engineered rhizobacterium resulted in a marked decrease in cadmium phytotoxicity and a 40% increase in cadmium accumulation in the plant root. Owing to the significantly improved growth characteristics of both the rhizobacterium and plant, the use of EC20-expressing P. putida endowed with organic-degrading capabilities may be a promising strategy to remediate mixed organic-metal-contaminated sites.
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
authors.forename: Cindy H
authors.initials: CH
authors.lastname: Wu
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
authors.forename: Ashok
authors.initials: A
authors.lastname: Mulchandani
authors.forename: Wilfred
authors.initials: W
authors.lastname: Chen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002616:Chemical Engineering; D006368:Helianthus / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D019216:Metals, Heavy / Q000378:metabolism* / Q000633:toxicity; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D010944:Plants / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology*; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D019216:Metals, Heavy; D011994:Recombinant Proteins; D012989:Soil Pollutants; D002104:Cadmium