We characterized the biosynthesis of indole-3-acetic acid by the mycoherbic
ide Colletotrichum gloeosporioides f. sp, aeschynomene. Aurin production wa
s tryptophan dependent. Compounds from the indole-3-acetamide and indole-3-
pyruvic acid pathways mere detected in culture filtrates. Feeding experimen
ts and in vitro assay confirmed the presence of both pathways. Indole-3-ace
tamide was the major pathway utilized by the fungus to produce indole-3-ace
tic acid in culture.