The dawn of stomatal control by the hormone of darkness.

This article comments on: Liu X-D, Ren Y-L, Li Y-L, Zeng Y-Y, Zhang X-Y, Li Y-R, Du Y-X, Fang X-W. 2026. Lineage-specific response to melatonin in stomatal regulation across vascular plants. Journal of Experimental Botany 77, 4668–4678. https://doi.org/10.1093/jxb/erag146