extracellular ATP: an emerging primer for plant stress memory

Plants can retain information from prior stress exposure as strong and durable memory, but the proximal signals that establish the primed state remain elusive. Extracellular ATP (eATP), a ubiquitous damage-associated molecular pattern released upon cellular perturbation, is emerging as an early orchestrator of plant stress adaptation. Herein, we advance a framework positioning eATP as a regulatory hub that integrates stress perception via the purinoceptor 2K1/2 (P2K1/2), amplifies Ca²⁺ and reactive oxygen species signaling, and interfaces with phytohormone networks, energy sensors, chromatin regulation, and noncoding RNAs. We propose eATP as an integrative priming hub, explicitly separating established signaling from hypothesized epigenetic memory, and discuss how this framework can guide plant resilience strategies.