Metabolism of organic xenobiotics in plants: Conjugating enzymes and metabolic end points

The increasing use of chemicals in all sectors of modern agriculture, production systems and private households has led to increased pollution of soil and water ecosystems. The fate of these compound in the biosphere creates the impression that consumers might be exposed to numerous xenobiotics with high potential of toxicity. Several removal techniques are available, but only the uptake and subsequent removal of chemicals from the environment by plants seems to be an environmentally sound methodology in the remediation of organic foreign compounds. Even recalcitrant substances of high stability with phytotoxic properties might be taken up in the rhizosphere of plants. Remediation of these compounds may be achieved if some precautions are taken and the final fate of the foreign compound is taken into consideration. Plants are able to metabolise and detoxify xenobiotics by sugar conjugation, glutathione conjugation and more complex reactions ending in different metabolic endpoints. This review emphasises the enzymatic detoxification systems and the role of bound xenobiotic residues in plants.