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Tanins ou alcaloïdes: deux tactiques phytochimiques de dissuasion des herbivores

Auteur :
LEBRETON, P.

Description :
A negative correlation is shown to exist between the frequencies of occurrence of tannins and alkaloids among the major orders and families of Dicotyledons (and other Spermatophytes as well). Tannins and alkaloids are both used by plants to discourage consumption by animal consumers. Two phytochemical tactics can be identified: (1) the T-tactic, based on the mass use of molecules (tannins and terpenoids) which influence the palatability and digestibility of plant material, and (2) the a-tactic, based on the use of various toxic micromolecules, often nitrogenous, present at low concentrations in plant tissues, such as alkaloids, nonproteic amino-acids, cyanogenic glycosides, glycosinolates, etc. T-tacticians are generally found among K-strategists, i.e. plant species growing in stable and predictable environments, mostly forests. On the other hand, a-tacticians are mostly found among r-strategists, i.e. plants living in unstable and marginal environments, more particularly those characterizing the first stages of a succession.


Type de document :
Article de périodique

Source :
Revue d'écologie. La terre et la vie Paris, 1982, vol. 36, n°. 4, p. 539-572, Références bibliographiques : 56 réf.

Date :
1982

Langue :
Français
Droits :
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