From challenges to solutions: The impact of melatonin on abiotic stress synergies in horticultural plants via redox regulation and epigenetic signaling.

• Melatonin harmoniously coordinates plant responses to abiotic stressors. • Melatonin-induced ROS-RNS interplay activates plant antioxidant system. • Melatonin crosstalk with phytohormones and nitric oxide is pivotal for plant growth and stress tolerance. • The effect of melatonin on epigenetic pathways reveals crucial insights into cellular systems. In the face of escalating environmental challenges, plants encounter complex combinations of abiotic stresses that pose severe threats to their growth and survival. Recent advancements have shed light on the multifaceted role of melatonin, revealing its intricate interplay with redox regulation and epigenetic signaling in plant stress responses. As a versatile ally, melatonin orchestrates a cascade of redox regulatory events that counteract the oxidative damage caused by abiotic stress synergies. Melatonin strengthens plant defenses by fine-tuning antioxidant systems and directly scavenging reactive oxygen species (ROS), mitigating oxidative stress, and preserving cellular homeostasis. Moreover, melatonin interacts with epigenetic mechanisms, exerting control over gene expression through DNA methylation, histone modifications, and miRNA regulation. These epigenetic modifications have far-reaching implications in shaping stress-responsive gene networks and enabling plants to adapt to complex stress scenarios. However, understanding the intricate crosstalk by which melatonin coordinates redox regulation and epigenetic signaling to develop novel strategies to enhance plant resilience against a wide range of abiotic stresses remains unclear. This review delves into the current advancements, knowledge gaps, and charting future directions of melatonin-induced redox regulation and epigenetic signaling as the key mechanisms underlying abiotic stress resilience in plants. This study will pave the way for the future development of sustainable agricultural production of major horticulture crops, offering a beacon of hope amid mounting environmental challenges. [Display omitted] [ABSTRACT FROM AUTHOR]