Melatonin was found in plants in the late 1990s, but its function, signaling, and interaction with other phytohormones still unclear. Melatonin research in plants has increased substantially in recent years, including reports on the impact of this putative plant hormone under biotic and abiotic stress situations. Temperature extremes, salt, drought, hypoxia or anoxia, nutrient deficiency, herbicides, UV radiation stress, and heavy metal toxicity are all important obstacles to horticulture crop production worldwide. To deal with these environmental challenges, plants have evolved complex signaling networks. Phytohormones are essential for controlling plant growth, development, and stress responses. Melatonin, a pleiotropic chemical present in a variety of species, has recently emerged as a powerful regulator of plant abiotic stress tolerance. The purpose of this review is to investigate the interplay between melatonin and phytohormones in the control of abiotic stress responses in horticultural crops. We explore the interactions of melatonin with several phytohormones under various abiotic stresses.

Controlled Environment Agriculture (CEA) has become a key driver of vertical farming (VF), offering innovative solutions for the sustainable production of ornamental plants in urban environments with limited arable land. This review examines recent advances in VF technologies and their applications in foliage and flowering ornamental plant production. The literature indicates that precise environmental control, including optimized LED lighting spectra, hydroponic and aeroponic nutrient delivery, and automated climate regulation, can significantly enhance plant growth, morphological characteristics, color intensity, and overall market quality of ornamental species. In addition, VF systems demonstrate substantial reductions in water consumption, pesticide use, and land requirements compared with conventional cultivation methods. However, several challenges remain, including high-energy demand, economic feasibility, and the need for crop-specific environmental optimization for different ornamental species. This review synthesizes current research on VF systems, highlights the integration of emerging technologies such as the Internet of Things (IoT), artificial intelligence (AI), and data-driven management tools, and evaluates their potential to improve production efficiency and sustainability in ornamental horticulture. Overall, vertical farming represents a promising approach for high-quality ornamental plant production, although further research is required to optimize energy efficiency and cultivation protocols for diverse ornamental crops.