Heat Stress Tolerance in Fruit Crops: Integrating Physiology, Hormonal Regulation, and Omics for Climate-Resilient Production

Global warming and temperature rise are now recognized as one of the biggest problems faced by humanity. Even a 1ºC rise in temperature affects all living beings, including crops. Heat stress affects crop physiology from seed germination to fruit abscission and senescence. Some crops and plants have the potential to withstand heat stress and exhibit this ability to varying degrees through a series of biochemical and molecular changes. This review critically examines the impact of high-temperature stress on key physiological processes in fruit crops, including photosynthesis, reproductive development, assimilate partitioning, and yield formation. It also emphasizes how phytohormonal interaction, metabolic modifications, and stress-responsive signalling pathways contribute to thermotolerance. With a focus on their use in identifying heat-tolerant characteristics, genes, and rootstock-scion pairings in fruit crops, recent developments in omics approaches, genomics, transcriptomics, proteomics, metabolomics, and phenomics are described. Furthermore, based on current research, management-based mitigation techniques such as grafting, cultivar selection, antitranspirants, and water and canopy management techniques are assessed. This review outlines knowledge gaps and future research goals for creating heat-resilient fruit production systems under changing climatic conditions by integrating traditional physiological knowledge with new omics-driven insights. The synthesis presented here will be valuable for plant physiologists, horticulturists, breeders, and researchers working on climate adaptation in perennial fruit crops.