Extracellular ATP: an emerging multifaceted regulator of plant fitness

Adenosine 5 '-triphosphate (ATP) is the energy currency of living organisms and the primary form of organic phosphate (Po) involved in cellular metabolism. In plants, some ATP is released into the extracellular matrix (ECM) in response to various stimuli, where it functions as extracellular ATP (eATP), a key signalling molecule. Recent advances have shed light on the mechanisms of eATP signalling in plants. This review consolidates these findings, beginning with the role of eATP in regulating plant growth, development and responses to biotic and abiotic stresses. It further summarizes the pathways of eATP accumulation and degradation in the ECM and introduces the cellular signalling pathways mediating eATP responses, as reported in key studies. Finally, perspectives on future research directions in this field are presented.