The central mediator of auxin-triggered phosphorylation in plants is a RAF-like kinase.

The plant signaling molecule auxin triggers both fast and slow cellular responses across the plant lineage, including both land plants and algae. We discovered an ultra-fast proteome-wide phosphorylation response to auxin across 5 land plant and algal species, converging on a core group of shared target proteins. We find conserved rapid physiological responses to auxin in the same species and identified a RAF-like protein kinase as a central mediator of auxin-triggered phosphorylation across species.