Archives of Current Research International

Global temperatures are rising at an unprecedented rate, posing a severe threat to horticultural crop production worldwide. Heat stress, defined as a rise in temperature beyond a threshold level sufficient to cause irreversible damage to plant growth and development, adversely affects virtually every stage of the plant life cycle, from germination and vegetative growth to reproduction and yield formation. Horticultural crops, including vegetables, fruits, and ornamental plants, are particularly susceptible to thermal stress owing to their narrow temperature optima for growth and reproduction. This review synthesises current knowledge on the physiological, biochemical, and molecular mechanisms underlying heat stress responses in horticultural crops. It further evaluates the agronomic and biotechnological strategies available to mitigate heat-stress impacts and discusses conventional and molecular breeding approaches aimed at improving thermotolerance. Key mechanisms explored include membrane thermostability, impairment of photosynthetic efficiency, induction of reactive oxygen species, activation of heat shock proteins and heat shock transcription factors, and disruption of reproductive processes. The reviewed management strategies encompass agronomic and cultural practices, exogenous chemical applications, and irrigation-based microclimate modification. Breeding approaches discussed include phenotypic selection, marker-assisted selection, genomic selection, and CRISPR-mediated genome editing. The review identifies significant research gaps, particularly in the multi-omics characterisation of thermotolerance in underexplored horticultural species, and outlines future priorities for developing heat-resilient cultivars capable of sustaining food security under climate change.