ABSTRACT
Traditionally, the secondary chemistry of the Poaceae has been viewed by ecologists as poorly developed and relatively ineffective in deterring herbivory. It has been thought that, unlike most plants, grasses depend on silicification, lignification, trichomes, and a basal meristem instead of relying on secondary metabolites as defenses against herbivory. Most of the known grass alkaloids are derived from the amino acids tyrosine and tryptophan. That alkaloids are present in grasses at concentrations that can affect herbivory is well documented. Upon tissue damage, through herbivore feeding, dhurrin is enzymatically converted to glucose and cyanohydrin. Like almost all plants, grasses contain a wide variety of monomelic phenolic compounds. In addition to the relatively simple phenolics described above, members of the Poaceae also possess condensed tannins or procyanidins. Terpenes and terpenoids occur within the Poaceae. Most of the research concerning grass terpenoids has been confined to identifying and quantifying these compounds.
