HTL/KAI2 protein was identified as a receptor of karrikins, which are lactonic compounds contained in smoke derived from burning plant material. The genes encoding HTL/KAI2 are widely conserved in land plants.
However, the internal ligand of HTL/KAI2 has not been identified yet and the biological functions of HTL/KAI2 remain unclear.
Some wild plants, called "fire followers", receive karrikins or its metabolite by HTL/KAI2 and break their seed dormancy. Arabidopsis thaliana, one of the most studied model plants, also responds to karrikins and germinates.
We develop a series of chemical agonists of HTL/KAI2 to stimulate seed germination and to investigate the unknown biological functions of HTL/KAI2.
In this work, we demonstrate the potential of our chemical agonists as seed germination stimulants and present evidence of our chemicals interacting with HTL/KAI2 and activating the following signal transductions.