Casida John E
Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3112, USA.
Chem Res Toxicol. 2009 Apr;22(4):609-19. doi: 10.1021/tx8004949.
Pesticides are used to control pests before they harm us or our crops. They are selective toxicants in the form and manner used. Pesticides must be effective without human or crop injury. They must also be safe relative to human and environmental toxicology. The study of how the pesticide works on the pest is referred to here as pest toxicology. About 700 pesticides, including insecticides, herbicides, and fungicides, act on perhaps 95 biochemical targets in pest insects, weeds, and destructive fungi. Current insecticides act primarily on four nerve targets, i.e., acetylcholinesterase, the voltage-gated chloride channel, the acetylcholine receptor, and the gamma-aminobutyric acid receptor, systems which are present in animals but not plants. Herbicides act mostly on plant specific pathways by blocking photosynthesis, carotenoid synthesis, or aromatic and branched chain amino acid synthesis essential in plants but not mammals. Many fungicides block ergosterol (the fungal sterol) or tubulin biosynthesis or cytochrome c reductase, while others disrupt basic cellular functions. A major limiting factor in the continuing use of almost all pesticides is the selection of strains not only resistant to the selecting or pressuring compounds but also cross-resistant to other pesticides acting at the same target. One approach to reinstating control is to shift from compounds with the resistant target site or mode of action to another set which have a sensitive target. This type of pesticide management led to the formation of Resistance Action Committees for insecticides, herbicides, and fungicides with very knowledgable experts to define resistance groups, which are in fact listings of primary target sites in pest toxicology. Continued success in pest and pesticide management requires an understanding of comparative biochemistry and molecular toxicology considering pests, people, and crops. Defining and applying the principles of pest toxicology are critical to food production and human health.
农药用于在害虫危害我们或我们的作物之前对其进行控制。就其使用的形式和方式而言，它们是选择性毒剂。农药必须有效且不会对人类或作物造成伤害。在人类和环境毒理学方面，它们也必须是安全的。在此，将农药作用于害虫的方式的研究称为害虫毒理学。大约700种农药，包括杀虫剂、除草剂和杀菌剂，作用于害虫、杂草和有害真菌中可能约95个生化靶点。目前的杀虫剂主要作用于四个神经靶点，即乙酰胆碱酯酶、电压门控氯离子通道、乙酰胆碱受体和γ-氨基丁酸受体，这些系统存在于动物而非植物中。除草剂大多通过阻断植物特有的途径来发挥作用，这些途径包括光合作用、类胡萝卜素合成或植物而非哺乳动物所必需的芳香族和支链氨基酸合成。许多杀菌剂会阻断麦角固醇（真菌固醇）或微管蛋白生物合成或细胞色素c还原酶，而其他一些杀菌剂则会破坏基本的细胞功能。几乎所有农药持续使用的一个主要限制因素是害虫品系的选择，这些品系不仅对选择或施压化合物具有抗性，而且对作用于同一靶点的其他农药也具有交叉抗性。恢复控制的一种方法是从具有抗性靶点或作用方式的化合物转向另一组具有敏感靶点的化合物。这种类型的农药管理导致成立了杀虫剂、除草剂和杀菌剂抗性行动委员会，委员会中有非常专业的专家来定义抗性组，而抗性组实际上就是害虫毒理学中主要靶点位点的清单。要在害虫和农药管理方面持续取得成功，需要了解考虑害虫、人类和作物的比较生物化学和分子毒理学。定义和应用害虫毒理学原理对粮食生产和人类健康至关重要。
