Molecular Insights into Melatonin-Mediated Stress Tolerance in Dendrobium: Integrating Antioxidant Defense, Hormonal Networks, and Omics Approaches

Dendrobium, a diverse genus of orchids with considerable horticultural and medicinal value, is highly susceptible to abiotic stresses such as drought, salinity, temperature extremes, and oxidative stress. Melatonin (MT) is emerging as a pivotal signaling molecule that enhances stress tolerance across plant species; however, its roles in Dendrobium remain insufficiently explored. This review critically synthesizes current knowledge on MT biosynthesis, its regulatory functions under abiotic stress, physiological and molecular mechanisms in Dendrobium , and potential molecular innovations to harness MT signaling for improved stress tolerance. Particular emphasis is placed on antioxidant defense modulation, hormonal crosstalk, transcriptional reprogramming, and emerging omics-based insights associated with MT-mediated stress responses. In addition, future research priorities and biotechnological applications for developing stress-resilient Dendrobium cultivation systems are discussed.