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The induction of P-450 after initial nicotine ingestion allowed the larval tobacco hornworms to increase feeding on the toxic plant tissues. [12] An important enzyme produced by herbivorous insects is protease. The protease enzyme is a protein in the gut that helps the insect digest its main source of food: plant tissue.
For example, plants growing in nitrogen-poor soils will use carbon-based defenses (mostly digestibility reducers), while those growing in low-carbon environments (such as shady conditions) are more likely to produce nitrogen-based toxins. The hypothesis further predicts that plants can change their defenses in response to changes in nutrients.
Some of these species produce harmful toxins such as botulinum toxin and tetanus toxin among others. Most Clostridium species that do have toxins typically have binary toxins with the first unit involved in getting the toxin into the cell and the second unit cause cellular stress or deformation. [6]
When the required dietary components are absent, such as in captivity, the frog is no longer able to produce the toxins, making them nonpoisonous. The profile of toxins may even change with the season, as is the case for the Climbing Mantella, whose diet and feeding behavior differ between wet and dry seasons [64]
One of the most toxic plants found in the Western Hemisphere, all parts of the plant contain tropane alkaloids [61] – as do those of its equally deadly sister species A. baetica, A. pallidiflora and A. acuminata. The active agents are atropine, hyoscine (scopolamine), and hyoscyamine, which have anticholinergic properties.
Hence, a plant which produces variable levels of defensive chemicals is better defended than one that always produces the mean level of toxin. [5] Second, synthesizing a continually high level of defensive chemicals renders a cost to the plant. This is particularly the case where the presence of herbivorous insects is not always predictable. [7]
The structure of a plant cell wall is incredibly important for wound responses, as both protect the plant from pathogenic infections by preventing various molecules from entering the cell. [ 1 ] Plants are capable of activating innate immunity, by responding to wounding events with damage-associated Molecular Patterns (DAMPs). [ 1 ]
The term is also used to describe toxic chemicals produced by plants themselves, which function as defensive agents against their predators. Most examples pertaining to this definition of phytotoxin are members of various classes of specialised or secondary metabolites , including alkaloids , terpenes , and especially phenolics , though not all ...