Harnessing genomics approaches for heat stress resilience in wheat: from discovery to deployment

Global warming poses a critical threat to wheat (Triticum aestivum L.) production, particularly during sensitive reproductive stages. This review synthesizes current understanding of how heat stress affects wheat and the adaptive mechanisms that confer tolerance, with emphasis on recent advances in genomics and biotechnology. Heat stress impairs morphological, physiological, biochemical, and molecular processes, reducing photosynthetic efficiency, accelerating senescence, disrupting assimilate partitioning, and damaging cellular structures. Adaptive responses include optimized water relations, antioxidant defences, osmolyte accumulation, heat shock protein induction, and hormonal regulation, all coordinated by complex gene networks. Advances in genetic dissection through quantitative trait locus (QTL) mapping, genome-wide association studies, and candidate gene discovery have identified loci and alleles linked to thermotolerance. Multi-omics integration has uncovered regulatory pathways, transcription factors, and epigenetic mechanisms, including stress memory, that underpin resilience. Emerging tools such as genome sequencing, pangenomics, genomic prediction, haplotype-informed breeding, and CRISPR-based editing are accelerating the translation of these discoveries into improved cultivars. In addition to summarizing these advances, this review highlights key challenges, from harmonizing heat stress phenotyping and validating causal variants to integrating multi-omics into breeding pipelines, and proposes targeted strategies to bridge the gap between discovery and deployment to enable the development of climate-ready wheat cultivars.