Climate Change and Horticultural Crop Resilience: Developments in Stress Physiology and Adaptation Mechanisms

Climate change poses significant challenges to global agriculture, particularly to horticulture, which is highly sensitive to climatic variations. Rising temperatures, changed precipitation patterns, and an increase in the frequency of extreme weather events highlight how urgent it is to implement climate-smart techniques since they all represent serious risks to conventional horticulture systems. Horticultural crops—fruits, vegetables, spices, ornamentals, and plantation crops—are uniquely vulnerable to climate change because quality traits and reproductive success are exquisitely sensitive to heat waves, droughts, salinity, flooding, and compound extremes. This review synthesizes recent advances (primarily 2021–2025) in the physiology and molecular biology of stress perception, signalling, and acclimation in horticultural species, with emphasis on traits that safeguard yield and quality. We summarise progress in understanding combinatorial stress responses, integrative hormone crosstalk, ROS–Ca²⁺ signalling, osmotic regulation, and source–sink balance under heat and water deficits. We then examine emerging levers for adaptation: epigenetic and priming-based memory, microbiome mediation, and organ-specific mechanisms in flowers, fruits, and storage tissues. A second focus covers practical strategies—from climate-smart rootstocks and grafting, CRISPR-enabled breeding, seed/foliar priming (e.g., melatonin, seaweed biostimulants), silicon nutrition, to protected cultivation and digital phenotyping—highlighting trade-offs and translational pathways. We close by outlining evidence gaps, research priorities, and policy-relevant directions to accelerate climate resilience in high-value horticulture.