Allelochemic function for a primary metabolite: the case of L-tyrosine hyper-production in Inga umbellifera (Fabaceae)

Young leaves of tropical forest trees experience far higher herbivory pressure than mature leaves of the same species. Selection on young leaves has led to diverse forms of defense chemical expression. Though most allelochemicals are secondary metabolites, allelochemic function for a primary metabolite remains a possibility. We recently observed this phenomenon in the young leaves of Inga umbellifera, which accumulate the protein amino acid L-tyrosine to very high levels. We isolated L-tyrosine from young leaves of trees in Panama and characterized it using spectroscopic and chemical means.