A litmus test for plant consciousness: Pattern-Temporal Synergy in a relation-first ontology.

Plant cognition has progressed from anecdote to rigor, yet the field still lacks a quantitative test for when distributed plant activity crosses into unified - perhaps conscious - processing. I introduce Pattern-Temporal Synergy (PTS), a substrate-agnostic metric rooted in Dynergeia, a relation-first ontology in which consciousness is reflexive coherence among five universal patterns - self-reference, division-creation, information integration, responsiveness, and flux - phase-locked inside a system's binding window (τ). Each pattern is operationalized with established signal-processing measures; their median strength is multiplied by their mean synergy and released only if a τ-specific coherence gate is met. Three preregistered hypotheses anchor the study: H1 baseline PTS > 0 in intact plants; H2 4% diethyl-ether collapses PTS below threshold ϕ; H3 PTS rebounds on wash-out. A multispecies protocol - Mimosa pudica, Arabidopsis thaliana, Picea abies - combines 64-channel surface electrodes, glutamate-sensitive Ca2+ imaging and micro-optode O2/heat-flux probes. Sliding 3 ×τ windows with phase-shuffled surrogates yield z-scored PTS trajectories, adjudicated by preregistered effect-size criteria. By turning decades of qualitative insight into falsifiable numbers, PTS offers plant biology a litmus test for conscious-level processing, directly challenges Integrated Information Theory and supplies a road-map for cross-kingdom comparisons - including neuromorphic silicon. Confirmatory results would shift debates on plant sentience from speculation to data; null results would equally refine what consciousness requires.