Herbicide Classes in Development : Mode of Action, Targets, Genetic Engineering, Chemistry

Chemical pest control is in use in practically every country in the world since agrochemicals play a decisive role in ensuring food supply and protection against damage by pests, insects and pathogenic fungi. Particularly in the half­ century since World War II, food production has risen dramatically in most parts of the world. In the last 20 years, the yield of major crops has roughly doubled in Western agriculture and there is still the potential for further achievements, particularly in the developing countries. The world's cereal and rice production, now more than 2 billion tons/year, has to increase by 2. 4% annually to cope with the rising food demand caused mainly by the growing population and improvement of living standards in most of the developing countries. Such a demand for food has to be achieved by higher yields from the restricted arable land already in use. Global farm­ land resources are about 1. 4 billion ha, of which 1. 2 billion ha is cultivated with major crops. Experts agree that a future substantial addition of new produc­ tive areas is unlikely. Those with a high yield potential are already in use; new fields with a lower output may possibly be obtained by cultivation of arid or cold areas. More recently, new areas of large-scale farmland have been devel­ oped in tropical regions of Latin America, primarily in Argentina and Brazil, at the cost of the destruction of tropical rain forest.

1 Acetolactate Synthase Inhibitors.- 1.1 Introduction.- 1.2 Acetolactate Synthase-Inhibiting Herbicides Actively Developed in the Late 1990s.- 1.3 Discovery of Pyrimidinyl Carboxy Herbicides (Pyrimidinylsalicylate Class Herbicides).- 1.3.1 Discovery of the Lead Structures.- 1.3.2 Discovery and Optimizations of the Secondary Lead Structure.- 1.3.3 Further Optimizations of the Pyrimidinyl Carboxy Herbicides.- 1.4 Herbicidal Activity of Pyrimidinyl Carboxy Herbicides.- 1.4.1 Pyrithiobac-Sodium for Use in Cotton.- 1.4.2 Bispyribac-Sodium for Use in Rice.- 1.4.3 Bispyribac-Sodium for Vegetation Management.- 1.4.4 Pyriminobac-Methyl for Use in Rice.- 1.5 Physiological Plant Response to Pyrimidinyl Carboxy Herbicides.- 1.6 Mode of Action and Selectivity of Pyrimidinyl Carboxy Herbicides.- 1.6.1 Primary Target.- 1.6.2 Inhibition of Bacterial Acetolactate Synthase.- 1.6.3 Selectivity.- 1.7 Biological Characteristics of the Target Enzyme.- 1.7.1 Kinetic Studies of Plant Acetolactate Synthase.- 1.7.2 Subunit Compositions of Plant Acetolactate Synthase.- 1.7.3 Recombinant Systems.- 1.8 Inhibition Mechanism of the Target Enzyme by Pyrimidinyl Carboxy Herbicides.- 1.8.1 Inhibition Kinetics with Plant Acetolactate Synthase.- 1.8.2 Inhibition Kinetics with Bacterial Acetolactate Synthase.- 1.9 Molecular Genetics of Target Enzyme.- 1.9.1 Acetolactate Synthase Genes of Plants.- 1.9.2 Acetolactate Synthase-Inhibiting Herbicide-Resistant Crops (Including Arabidopsis thaliana) and Their Acetolactate Synthase Genes.- 1.9.3 Acetolactate Synthase-Inhibiting Herbicide-Resistant Weeds and Their Acetolactate Synthase Genes.- 1.9.4 Genetic Engineering.- References.- 2 Bleaching Herbicides: Action Mechanism in Carotenoid Biosynthesis, Structural Requirements and Engineering of Resistance.- 2.1 Herbicidal Effect and Mode of Action.- 2.2 Interaction of Inhibitors with Carotene Desaturation.- 2.3 Structural Requirements for an Inhibitor of Phytoene Desaturase.- 2.4 Strategies for Genetic Engineering of Herbicide Resistance by Modification of the Carotenogenic Pathway.- 2.4.1 Overexpression of a Susceptible Lycopene Cyclase in Synechococcus.- 2.4.2 Selection of Mutants with Resistant Phytoene Desaturase and Gene Transfer into Tobacco.- 2.4.3 Naturally Resistant Phytoene Desaturase from Bacteria and Genetic Engineering of a Resistant Tobacco.- 2.5 Conclusion and Perspectives.- References.- 3 Inhibitors of Aromatic Amino Acid Biosynthesis (Glyphosate).- 3.1 Introduction.- 3.2 Symptoms of Herbicidal Activity.- 3.3 Mode of Action of Glyphosate.- 3.3.1 Overview of the Mode of Action.- 3.3.2 Primary Mode of Action.- 3.3.2.1 Biochemical Characteristics of the Target Enzyme.- 3.3.2.2 Structural Characteristics of the Target Enzyme.- 3.3.2.3 Interaction Between 5-Enolpyruvylshikimate 3-Phosphate Synthase and Glyphosate.- 3.3.2.4 Molecular Requirements for Herbicidal Activity of Glyphosate.- 3.3.3 Secondary Physiological Consequences of Inhibition of 5-Enolpyruvylshikimate 3-Phosphate Synthase.- 3.3.3.1 Inhibition of Chorismate Synthesis.- 3.3.3.2 Depletion of Photosynthetic Carbon Reduction Cycle Intermediate Metabolites.- 3.3.3.3 Development of Secondary Damage Symptoms.- 3.3.3.4 Bases of Development of Lethal Symptoms Among Species.- 3.4 Mechanisms for Resistance and Tolerance to Glyphosate.- 3.4.1 Development of Commercially Valuable Glyphosate-Resistant Plants.- 3.4.2 Tolerance to Field Doses of Glyphosate in Field-Grown Plants.- 3.5 Summary.- References.- 4 Inhibitors of Glutamine Synthetase.- 4.1 Introduction.- 4.2 Plant Glutamine Synthetase Isoforms and Their Function.- 4.3 Glutamine Synthetase Inhibitors.- 4.4 Discovery of the Herbicidal Activity of Phosphinothricin and Bialaphos.- 4.5 Mode of Glutamine Synthetase Inhibition.- 4.6 Effects of Glutamine Synthetase Inhibitors in Plants.- 4.6.1 Visible Symptoms of Herbicidal Action.- 4.6.2 Physiological Effects of Glutamine Synthetase Inhibition in Plants by Phosphinothricin.- 4.7 Attempts to Generate Selectivity for Glufosinate.- 4.7.1 Attempts to Select Glufosinate Tolerant Mutants.- 4.7.2 Metabolic Inactivation of Glufosinate by Bar and Pat Enzymes.- References.- 5 Acetyl-CoA Carboxylase Inhibitors.- 5.1 Introduction.- 5.2 Symptoms of Herbicidal Activity.- 5.3 Biochemical Characteristics of the Target Enzyme.- 5.4 Mode of Action of Cyclohexanedione and Aryloxyphenoxypropanoate Herbicides.- 5.5 Assays for Acetyl-CoA Carboxylase Activity.- 5.6 Molecular Genetics of Resistance to Acetyl-CoA Carboxylase Inhibitors.- References.- 6 Inhibitors of Biosynthesis of Very-Long-Chain Fatty Acids.- 6.1 Introduction.- 6.2 The Model System.- 6.3 Very Long-Chain Fatty Acid Biosynthesis Inhibition in Intact Leaves.- 6.4 The Cell-Free Elongase System.- 6.5 Assumptions of the Reaction Mechanism.- 6.6 Considerations on Resistance.- References.- 7 Cellulose Biosynthesis Inhibitor Herbicides.- 7.1 Introduction.- 7.2 Mode of Action Studies.- 7.2.1 Cell Plates.- 7.2.2 Developing Cotton Fibers.- 7.2.3 Azido-Dichlobenil Derivatives.- 7.3 Resistant Biotypes.- 7.4 Habituation.- 7.5 The Unusual Case of Quinclorac.- 7.6 Conspectus.- References.- 8 Inhibitors of Protoporphyrinogen Oxidase: A Brief Update.- 8.1 Introduction.- 8.2 Protoporphyrinogen Oxidase Inhibitors and Their Mode of Action.- 8.3 Biochemical Characterization of Protoporphyrinogen Oxidase.- 8.4 Protoporphyrinogen Oxidase Genes and Transgenic Herbicide-Resistant Plants.- 8.5 Recent Advances in QSAR Studies.- 8.6 Antioxidative Stress Responses of Plants to Protoporphyrinogen Oxidase Inhibitors.- References.- 9 Genetic Engineering of Herbicide-Resistant Plants.- 9.1 Introduction.- 9.2 Strategy.- 9.2.1 The Gene Encoding the Herbicide-Inactivating Enzyme.- 9.2.2 Mutant or Foreign Gene Encoding the Target Enzyme with Low Affinity to the Herbicide.- 9.3 Cloning of the Genes.- 9.3.1 Genetic Resource.- 9.3.1.1 Microorganism.- 9.3.1.2 Plant Tissue Culture.- 9.3.1.3 Mutant Plants.- 9.3.2 Cloning Methods.- 9.3.2.1 The Information of Protein.- 9.3.2.2 The Information of Nucleic Acid.- 9.3.2.3 Bacterial Genetics.- 9.4 Gene Transfer.- 9.4.1 PEG-Mediated Gene Transfer and Electroporation.- 9.4.2 Particle Bombardment.- 9.4.3 Agrobacterium-Mediated Gene Transfer.- 9.5 Vector Constructs.- 9.5.1 Expression Cassettes.- 9.5.1.1 Promoter and Terminator.- 9.5.1.2 Selection Marker Gene.- 9.5.1.3 Enhancer Sequence.- 9.5.1.4 Transit Peptide Sequence.- 9.5.2 Type of Vectors.- 9.5.2.1 Vector for Direct Gene Transfer.- 9.5.2.2 Vectors for Agrobacterium-Mediated Gene Transfer 173.- 9.5.2.3 Other Vectors.- 9.6 Conclusions.- References.- 10 Major Synthetic Routes for Modern Herbicide Classes and Agrochemical Characteristics.- 10.1 Introduction.- 10.2 Acetolactate Synthase Inhibitors.- 10.2.1 Sulfonylurea Acetolactate Synthase Inhibitors.- 10.2.1.1 Practical Sulfonylurea Acetolactate Synthase Inhibitors.- 10.2.1.2 Structural Evolution of Sulfonylurea Acetolactate Synthase Inhibitors.- 10.2.1.3 Major Synthetic Routes for Sulfonylureas.- 10.2.2 Triazolinone Acetolactate Synthase Inhibitors.- 10.2.2.1 Practical Triazolinone Acetolactate Synthase Inhibitors.- 10.2.2.2 Structural Evolution of Triazolinone Acetolactate Synthase Inhibitors.- 10.2.2.3 Major Synthetic Routes for Triazolinone Acetolactate Synthase Inhibitors.- 10.2.3 Triazolopyrimidine Acetolactate Synthase Inhibitors.- 10.2.3.1 Practical Triazolopyrimidine Acetolactate Synthase Inhibitors.- 10.2.3.2 Structural Evolution of Triazolopyrimidine Acetolactate Synthase Inhibitors.- 10.2.3.3 Major Synthetic Routes for Triazolopyrimidine Acetolactate Synthase Inhibitors.- 10.2.4 Acetolactate Synthase Inhibitor-Like Miscellaneous Pyrimidines and Related Compounds.- 10.2.5 Pyrimidyl(thio)oxybenzoate Acetolactate Synthase Inhibitors.- 10.2.5.1 Practical Pyrimidyl(thio)oxybenzoate Acetolactate Synthase Inhibitors.- 10.2.5.2 Structural Evolution of Pyrimidyl(thio)oxybenzoate Acetolactate Synthase Inhibitors.- 10.2.5.3 Major Synthetic Routes for Pyrimidyl(thio)oxybenzoate Acetolactate Synthase Inhibitors.- 10.2.6 Imidazolinone Acetolactate Synthase Inhibitors.- 10.2.6.1 Practical Imidazolinone Acetolactate Synthase Inhibitors.- 10.2.6.2 Structural Evolution of Imidazolinone ALS Inhibitors.- 10.2.6.3 Major Synthetic Routes for Imidazolinone Acetolactate Synthase Inhibitors.- 10.3 Carotenogenesis Inhibitors.- 10.3.1 Phytoene Desaturase Inhibitors.- 10.3.1.1 Practical Phytoene Desaturase Inhibitors.- 10.3.1.2 Structural Evolution of Phytoene Desaturase Inhibitors.- 10.3.1.3 Major Synthetic Routes for Phytoene Desaturase Inhibitors.- 10.3.2 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors.- 10.3.2.1 Practical 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors.- 10.3.2.2 Structural Evolution of 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors.- 10.3.2.3 Major Synthetic Routes for 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors.- 10.3.3 Other Carotenogenesis Inhibitors.- 10.4 Aromatic Amino Acid Biosynthesis Inhibitors.- 10.5 Glutamine Synthetase Inhibitors.- 10.6 Acetyl CoA Carboxylase (ACCase) Inhibitors.- 10.6.1 Practical Acetyl CoA Carboxylase Inhibitors.- 10.6.2 Structural Evolution of Acetyl CoA Carboxylase Inhibitors.- 10.6.3 Major Synthetic Routes for Acetyl CoA Carboxylase Inhibitors.- 10.7 Very Long-Chain Fatty Acids Biosynthesis Inhibitors.- 10.7.1 Practical Chloroacetamide Very Long-Chain Fatty Acids Biosynthesis Inhibitors.- 10.7.2 Other Very Long-Chain Fatty Acids Biosynthesis Inhibitors.- 10.8 Cellulose Biosynthesis Inhibitors.- 10.8.1 Practical Cellulose Biosynthesis Inhibitors.- 10.8.2 Structural Evolution of Cellulose Biosynthesis Inhibitors.- 10.8.3 Major Synthetic Routes for Cellulose Biosynthesis Inhibitors.- 10.9 Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.1 Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.1.1 First-Generation Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.1.2 Second-Generation Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.2 Structural Evolution of Protoporphyrinogen-IX Oxidase Inhibitors Since 1995.- 10.9.2.1 Structural Evolution of First-Generation Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.2.2 Structural Evolution of Second-Generation Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.2.3 Next-Generation Heterocycle Protoporphyrinogen-IX Oxidase Inhibitors.- 10.9.3 Major Synthetic Routes for Protoporphyrinogen-IX Oxidase Inhibitors.- 10.10 Notes.- Patent Literature.- 11 Diverse Response of Plants Towards Chiral Phytotoxic Chemicals.- 11.1 Introduction.- 11.2 Diverse Response of Optically Active Herbicides.- 11.2.1 Qualitatively Similar Enantioselective Action.- 11.2.2 Enantiomeric Metabolism.- 11.2.3 Chiral Inversion.- 11.3 Diverse Response of Plants Through Chirality.- 11.3.1 Chiral s-Triazines.- 11.3.1.1 Light-Dependent and Light-Independent Growth Inhibition.- 11.3.1.2 Cytokinin-Like Activity.- 11.3.2 Chiral Ureas.- 11.3.2.1 Enantioselective Phytotoxicity.- 11.3.2.2 Stress-Relieving Activity.- 11.3.2.3 Cross Intergenus Selective Phytotoxicit Among Gramineae.- 11.4 Chirality and Activity Relationship.- 11.4.1 Binding Direction of s-Triazines at the Photosystem II Reaction Center.- 11.4.2 Eudismic Analysis.- 11.4.2.1 Photosystem II Inhibition.- 11.4.2.2 Light-Independent Inhibition.- 11.4.2.3 Stress Relief.- References.- 12 Transcuticular Penetration of Foliar-Applied Pesticides - Its Analysis by a Logistic-Kinetic Penetration Model.- 12.1 Introduction.- 12.2 Overview.- 12.3 Logistic-Kinetic Transcuticular Penetration Model of Foliar-Applied Pesticides.- 12.3.1 Scenario.- 12.3.2 Transcuticular Penetration-Measuring Cell.- 12.4 Parameters and Factors Governing Transcuticular Penetration Kinetics of Foliar-Applied Pesticides.- 12.4.1 Adaptability of the Logistic-Kinetic Penetration Model.- 12.4.2 Factors Influencing Transcuticular Penetration Kinetics.- 12.4.3 Effect of Molecular Parameters of Pesticides on Transcuticular Penetration Kinetics.- 12.5 Effects of Adjuvants on Transcuticular Penetration Kinetics of Foliar-Applied Pesticides.- 12.5.1 Analysis of Adjuvant Action (Adjuvancy).- 12.5.2 Effect of Triton Surfactants.- 12.5.3 Effect of Emulsifiable Oils.- 12.5.4 Effect of Humectants.- 12.5.5 Effect of Amine Surfactants on Glyphosate Penetration.- 12.6 Discussion and Conclusions.- References.- 13 Structure-Activity Correlation of Very Long-Chain Fatty Acid Biosynthesis Inhibitors.- 13.1 Introduction.- 13.2 Very Long-Chain Fatty Acid Biosynthesis Inhibition by Herbicides.- 13.3 Very Long-Chain Fatty Acid Biosynthesis Inhibition by Thenylchlor and Its Analogs.- 13.4 Action of Cafenstrole and its Analogs.- 13.5 Action of Indanofan and its Analogs.- 13.6 Outlook.- References.