Hormonomics-driven bloom regulation and delay: Enhancing climate resilience in peach

• Phytohormonal networks orchestrate perennial phenological transitions • A pre-bloom jasmonate surge governs flowering time in peaches • JA-inhibitor antipyrine delays bloom without phytotoxicity or impacting fruit quality • Antipyrine-induced bloom delay mitigates catastrophic spring frost damage in peach buds • Targeted bloom delay is a viable climate adaptation strategy for mitigating frost risk Maintaining phenological synchrony with climate—particularly the timely transition to flowering—is critical for reproductive success in deciduous fruit trees. However, this synchrony is increasingly disrupted by abiotic stressors such as climate-induced spring frosts. Although phytohormonal networks are recognized as central regulators of developmental transitions, an integrative mechanistic understanding of their crosstalk during the dormancy–regrowth cycle remains lacking. Compounding this challenge, proposed bloom-delay agents (e.g., ethephon) often exhibit undesirable phytotoxic effects, underscoring the urgent need for a more robust mechanistic framework to guide the development of targeted and sustainable interventions. To address this, we investigated the phytohormonal landscape in Prunus persica cv. 'Redhaven' floral buds under ethephon treatment throughout dormancy progression, aiming to identify translational opportunities for phytohormone-mediated bloom delay. Our hormonomics analysis revealed dynamic spatiotemporal hormone profiles, notably a sharp increase in jasmonates (JAs) prior to budbreak—suggesting a flower-inducing role for JA. Building on this finding, we evaluated the bloom-delaying potential of two JA biosynthesis inhibitors—antipyrine and propyl gallate—over three consecutive seasons (2023-2025). Antipyrine consistently outperformed propyl gallate, delaying bloom by up to five days without negatively impacting fruit quality or tree health. These findings highlight the JA signaling pathway as a key determinant of floral transition timing in peach and position antipyrine as a promising candidate for bloom regulation. This study provides a mechanistically informed foundation for developing climate-resilient strategies to mitigate frost-induced yield losses in perennial fruit crops.