Chapters authored
Molecular Mechanism of Action of Herbicides
Part of the book: Herbicides
Herbicide Metabolism in Weeds — Selectivity and Herbicide Resistance
The metabolic detoxication/bioactivation pathways, the levels and activity of enzymes, and endogenous cofactors mediating these reactions in crops have been well documented; however, much less evidence has been accumulated in weed species. The herbicide metabolism as a selectivity factor is summarized with special attention to acetyl-CoA carboxylases (ACCase)-inhibiting aryloxyphenoxypropionate, protoporphyrinogen IX oxidase (PPO) inhibitor, carotenoid biosynthesis inhibitor clomazone, and acetolactate synthase (ALS) inhibitor imidazolinone and sulfonylurea herbicides in various weed species. The metabolism-based herbicide resistance related to these herbicide classes is also discussed along with the role and level of metabolizing enzymes and cofactors in weed species.
Part of the book: Herbicides
Molecular Defense Mechanisms in Plants to Tolerate Toxic Action of Heavy Metal Environmental Pollution
Toxic action of heavy metals on plants growing in contaminated soils intensified the research on detoxification and sequestering mechanisms existing in plants to understand and manipulate defense mechanisms that confer tolerance against metal ions. Increased biosynthesis of plant biomolecules to confer tolerance during toxic action of heavy metals is an intrinsic ability of plants. Induced formation of low-molecular weight amino acids, peptides or proteines as chelators such as proline (Pro), glutathione (GSH), phytochelatins (PCs) or metallothioneins (MTs) under heavy metal stress enhances metal binding and detoxification capability of plants. In addition, proline and GSH related enzymes such as GSH reductase, GSH peroxidases and glutathione S-transferases are also key components of the antioxidant defense system in the cells to scavenge reactive oxygen species (ROS). Protective action of oxidized fatty acids oxylipins at toxic levels of heavy metals is considered to activate detoxification processes as signaling molecules.
Part of the book: Plant Defense Mechanisms