The NATO Advanced Research Workshop (ARW) on "Regulation of Enzymatic Systems Detoxifying Xenobiotics in Plants" intended to provide a forum to scientists from academia, industry, and govemment for discussing and critically assessing recent advances in the field of xenobiotic metabolism in plants and for identifying new directions for future research. Plants function in a chemical environment made up of nutrients and xenobiotics. Xenobiotics (foreign chemicals) are natural or synthetic compounds that can not be utilized by plants for energy-yielding metabolism. Plants may be exposed to xenobiotics either deliberately, due to their use as pesticides or accidentally, from industrial, agricultural, and other uses. Plants, like most other organisms, evolved a remarkable battery or metabolic reactions to defend themselves against the potentially toxic effects of xenobiotics. The main enzymatic reactions utilized by plants for xenobiotic detoxification include oxidation, reduction, hydrolysis and conjugation with glutathione, sugars (e.g., glucose), and amino acids. Eventually, xenobiotic conjugates are converted to insoluble bound residues or to secondary conjugates, which are deposited in the vacuole of plant cells.

Inhalt
Regulation of Enzymatic Systems Detoxifying Xenobiotics in Plants: A Brief Overview and Directions for Future Research.- Endogenous Reactions and Substrate Specificity of Herbicide Metabolizing Enzymes.- Induction of Plant Cytochrome P450.- Role of Cytochrome P450s in Herbicide Metabolism and Selectivity and Multiple Herbicide Metabolizing Cytochrome P450 Activities in Maize.- Inhibition of Plant Oxidative Deactivation: A Mechanism to Enhance Efficacy and Manage Resistance to Thiazopyr Herbicide.- Enzymatic De-Esterification of Xenobiotics in Plants.- The Ascorbate-Glutathione Cycle and Oxidative Stresses in Plants.- Molecular Biology of the Antioxidant Defense Genes Encoding Catalases and Superoxide Dismutases in Maize.- The Biosynthesis of Glutathione Explored in Transformed Plants.- Glutathione, A Regulator of Chloroplast Transcription.- Glutathione Transferases in Crops and Major Weeds.- Characterization and Induction of Maize Glutathione S-Transferases Involved in Herbicide Detoxification.- Role of the Different GST Isozymes of Maize in Herbicide Tolerance: Genetics and Biochemical Analysis.- Activation of Proherbicides by Glutathione S-Transferase.- Flavonoids and Phytohormones, two Toxic Secondary Metabolites, are GST Substrates.- The Role of Glucosyl and Malonyl Conjugation in Herbicide Selectivity.- Fate of Glutathione S-Conjugates in Plants: Degradation of the Glutathione Moiety.- Compartmentation of Detoxified Xenobiotics in Plant Cells.- Defining and Characterizing Synergism and Antagonism for Xenobiotic Mixtures.- Regulation of Xenobiotic Degrading Enzymes with Herbicide Safeners.- Regulation of Xenobiotic Degrading Enzymes with Insecticides and Other Synergists.- Herbicide-Resistant Tobacco and Potato Plants Expressing Mammalian P450 Monooxygenases.- Transgenic Plant Analysis as a Tool for the Study of Maize Glutathione S-Transferases.- Foreign Detoxification Genes Expressed in Plants for Developing Herbicide Tolerant Genotypes: Development of Glufosinate Resistant Vegetables.- Herbicide Tolerance in Transgenic Plants Expressing Bacterial Detoxification Genes. The Case of Bromoxynil.- Cross-Resistance and Herbicide Metabolism in Alopecurus myosuroides Huds..