Proline transporters coordinate immune activation and regenerative capacity after injury in plants

Effective survival after injury requires the precise coordination of immune activation and tissue regeneration, yet the molecular mechanisms balancing these opposing processes remain poorly understood. Here, we identify proline transporters as key regulators of this trade-off in plants. Genetic disruption of two wound-induced proline transporters, ProT2 and ProT3, enhances regenerative capacity and abolishes salicylic acid (SA)-mediated suppression of regeneration while preserving SA-responsive gene expression and SA-mediated antibacterial resistance. Mechanistically, a ProT3-CPK1 complex modulates wound-induced reactive oxygen species (ROS), sustaining a ROS level that restricts de novo root regeneration (DNRR) after wounding. Notably, pharmacological inhibition of proline transport functionally separates immune activation from regenerative suppression and promotes regeneration across multiple plant species. These findings support the role of proline transporters as a regulatory hub integrating stress-induced proline metabolism, SA signaling, and ROS homeostasis to coordinate immunity and regeneration, and highlight chemical inhibition of proline transport as a strategy to improve regeneration without compromising immune defense.