auxin conjugation indoleacetic acid conjugation UPa:UPA00376 PMID:8085154 PMID:11830675 indole-3-acetic acid conjugation indole-3-acetate conjugation PMID:17509086 pathway IAA conjugation Conjugation of auxin (indole-3-acetic acid, IAA) to many kinds of molecules is part of a regulatory mechanism for controlling IAA levels through sequestration and reuse, or as an entry into catabolism. IAA in plants occurs in both conjugated and free forms, and there is increasing evidence that the ratio of free to conjugated IAA is controlled by tissue-specific and developmentally regulated processes. The use of conjugation by plants to regulate IAA levels appears to have become increasingly more important as plants evolved from liverworts to mosses and tracheophytes. plant hormone metabolism auxin metabolism