Engineering climate-resilient horticultural crops: advances in transcriptional regulation, genome editing, and synthetic networks.

Abiotic stresses-particularly cold, drought, and salinity-pose significant threats to the productivity and sustainability of horticultural crops. Recent studies have revealed conserved and species-specific regulatory mechanisms that allow plants to adapt dynamically to these environmental constraints. This review synthesizes advances in understanding key transcription factor families-such as CBF/DREB, NAC, MYB, WRKY, and bHLH-that orchestrate stress-responsive gene networks and modulate physiological processes, including osmotic regulation, antioxidant defense, and ionic homeostasis. We also discuss the emerging roles of chromatin remodeling, DNA methylation, histone modifications, and noncoding RNAs in conferring transcriptional plasticity and stress memory. Beyond endogenous pathways, we evaluate transgenic strategies, CRISPR/Cas-based genome editing, and synthetic gene circuits for engineering abiotic stress tolerance. Particular attention is given to trade-offs between growth and defense, challenges in horticultural crop transformation, and gaps in field translation. We further examine the regulatory role of secondary metabolites-such as flavonoids and salicylic acid-as biochemical interfaces between signal transduction and adaptive responses. Finally, we propose a forward-looking roadmap integrating multi-omics, ideotype design, and precision breeding toward climate-resilient horticultural systems.