Plant defense mechanisms are the mechanisms that plants use to defend themselves against pests, pathogens, and herbivores. These mechanisms can be grouped into two main categories: constitutive defenses and induced defenses. Constitutive defenses are physical or chemical traits that are always present in the plant, such as thorns, tough outer coverings, and toxic compounds. Induced defenses, on the other hand, are activated in response to an attack and include things like the production of toxins, odor compounds to attract predators of herbivores, and the activation of defensive proteins. Plants can also employ a variety of other defense strategies, such as mimicry, the release of volatile compounds to warn neighboring plants, and the use of mutualistic relationships with other organisms for protection. Understanding plant defense mechanisms is essential for developing sustainable agricultural practices and enhancing crop resistance to pests and diseases.