Similar but Different: A Functionally Conserved of COI1 Receptor Recognizes Jasmonate Precursors in the Liverwort Marchantia polymorpha ($)

Land plants evolved from freshwater charophyte algae over 450 million years ago and have since diverged into the multitude of plant lineages observed today. The extent to which prominent plant hormones and cognate receptor proteins, which play essential roles in evolutionarily young angiosperms, are conserved across the green plant lineage is currently unknown. In a keystone paper published in Nature Chemical Biology (2018), Monte et al. demonstrate that the COI1 receptor protein is functionally conserved in the early land plant model system Marchantia polymorpha (liverwort), which specifically recognizes the jasmonate precursor molecule dn-OPDA rather than JA-isoleucine. Strikingly, the authors demonstrate that a single amino acid change in the COI1 receptor determines ligand specificity, such that targeted mutations resembling angiosperm COI1 homologs affords sensitivity to JA-ile in liverworts. This study highlights the usefulness of early land plant model systems in revealing essential plant traits and begins to unravel receptor-ligand co-evolution in the jasmonate signalling pathway across land plants. (Summary by Philip Carella) Nat. Chem. Bio. 10.1038/s41589-018-0033-4