|
|
||||||||
|
Plant Physiology Preview Published on May 8, 2008; 10.1104/pp.108.119008
OPEN ACCESS ARTICLE
Received March 12, 2008 Engineering a Catabolic Pathway in Plants for the Degradation of 1,2-Dichloroethane
CNAP, Department of Biology, University of York, PO Box 373, York, YO10 5YW, UK; Institute of Structural & Molecular Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3JR, UK * Corresponding author; email: ncb5{at}york.ac.uk.
Plants are increasingly being employed to clean up environmental pollutants such as heavy metals; however, a major limitation of phytoremediation is the inability of plants to mineralize most organic pollutants. A key component of organic pollutants is halogenated aliphatic compounds which include 1,2-dichloroethane. Although plants lack the enzymatic activity required to metabolise this compound, two bacterial enzymes, haloalkane dehalogenase (DhlA) and haloacid dehalogenase (DhlB) from the bacterium Xanthobacter autotrophicus GJ10, have the ability to dehalogenate a range of halogenated aliphatics including 1,2-dichloroethane. We have engineered the dhlA and dhlB genes into Nicotiana tabacum cv Xanthi (tobacco) plants, and used 1,2-dichlorethane as a model substrate to demonstrate the ability of the transgenic tobacco to remediate a range of halogenated, aliphatic hydrocarbons. DhlA converts 1,2-dichloroethane to 2-chloroethanol, which is then metabolised to the phytotoxic 2-chloroacetaldehyde then chloroacetic acid by endogenous plant alcohol dehydrogenase and aldehyde dehydrogenase activities respectively. Chloroacetic acid is dehalogenated by DhlB to produce the glyoxylate cycle intermediate glycolate. Plants expressing dhlA only, produced phytotoxic levels of chlorinated intermediates and died, whilst plants expressing dhlA together with dhlB thrived at levels of 1,2-dichloroethane that were toxic to dhlA-expressing plants. This represents a significant advance in the development of a low cost, phytoremediation approach towards the clean-up of halogenated organic pollutants from contaminated soil and groundwater.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| ASPB Publications | PLANT PHYSIOLOGY® | THE PLANT CELL | |
|---|---|---|---|