Cellular identity dynamics during plant regeneration: lineage, state, and developmental competence

Plant regeneration requires cells to alter developmental trajectories by reorganization of the existing cellular state, rather than uniform erasure of cellular identity. Increasing evidence from lineage tracing, single-cell transcriptomics, chromatin profiling and spatial approaches has revealed substantial heterogeneity and temporal separation in cellular properties. This review examines regeneration from four distinct properties of a cell: lineage history, molecular state, developmental competence, and fate, with positional information considered as a contextual constraint. Transcriptomic and chromatin studies show that pre-existing regulatory programs can be selectively repressed, retained or remodeled. Regenerative competence emerges from the interaction between this molecular state and contextual signals. We discuss how wound-associated signals, optimum stress, hormones, transcriptional networks, chromatin remodeling and cell-cycle dynamics reshape these properties over time in overlapping and context-dependent ways. We propose that regeneration can therefore involve temporary dissociation of lineage history, molecular state, competence, and fate, followed by their coordination during developmental stabilization. This provides a framework for understanding how cells retain aspects of their developmental history while acquiring the competence for new developmental fates and highlights the need for approaches that resolve these properties in the same cells over time. Distinguishing what a cell was, what state it occupies, what it can become, and what it ultimately becomes provides a framework for interpreting cellular identity dynamics during plant regeneration.