Phytomelatonin prevents bacterial invasion during nighttime

Phytomelatonin is an emerging new plant hormone. The identification of phytomelatonin receptor 1 (PMTR1) has been a turning point for understanding phytomelatonin functions, but many uncertainties remain. Here we highlight how PMTR1-mediated phytomelatonin signaling closes stomata, not just to avoid water loss but also to prevent bacterial invasion at night.