Although the molecular mechanisms by which plants respond to gibberellins are largely unknown, several components of the signal transduction pathway have been identified and a broad outline of how these components act in signal transduction is emerging. One component of the pathway, SPINDLY, is believed to be an O-GlcNAc transferase that post-translationally modifies cytosolic and nuclear proteins by the addition of O-linked N-acetylglucosamine. Although analysis of the properties of O-GlcNAc-modified proteins from animals has led to the hypothesis that this modification is regulatory, it has not been linked to specific signal transduction pathways.