Abstract
The formation and degradation of IAA-amino acid conjugates (IAA-aa) play an important role in IAA homeostasis. Hence the inhibition of IAA-aa synthesis is a key to understanding the mechanism of IAA homeostasis. Recently, GH3s, early auxin-inducible genes were reported to have IAA-aa synthetic activities. However, due to the presence of multiple pathways of IAA-aa synthesis catalyzed by several GH3s, a chemical approach using specific inhibitors of GH3s is expected to be more promising than a genetic one such as gene knockout. We therefore synthesized specific inhibitors of GH3 on the basis of its proposed catalytic mechanism. This chemical approach is expected to inhibit all the GH3s involved in IAA-aa synthesis, and the inhibitors are expected to serve as a highly effective tool to study IAA homeostasis. Here, we report the characterization of GH3-5 and GH3-6, and the inhibitory activities of synthesized inhibitors.
