Methionine as a Dominant Precursor of Phytosiderophores in <italic>Graminaceae</italic> Plants

Abstract

Nine 14C-labeled amino acids and 14C-acetic acid from root tips of Fe-deficient Graminaceae plants (Hordeum vulgare, Oryzae sativa and Avena saliva) were surveyed to determine the precursor amino acid of phytosiderophores. The dominant precursor was methionine, which was incorporated into avenic acid → deoxymugineic acid → mugineic acid → epihydroxymugineic acid and/or hydroxymugineic acid in this order. Methionine sulfoxide or methionine sulfone may be important intermediates in going from methionine to avenic acid.