Seed priming as a tool to improve crop resilience to abiotic stress: methodology, mechanisms of action and usefulness in crops of agronomic interest

• Seed priming is capable of improving seed germination and seedling establishment. • There are numerous priming agents from diverse nature that can be used in agriculture. • Seed priming activates pre-germinative metabolism through key molecular mechanisms. • Seed priming can improve abiotic stress tolerance of crops of agronomic interest. • It is necessary to standardize priming protocols adapted to each horticultural crop. Agricultural production is increasingly constrained by adverse edaphoclimatic conditions, the decline of cultivable land, and intensifying anthropogenic pressures, all resulting from climate change and the continuous expansion of the global population. Germination represents one of the most critical and limiting stages in the life cycle of a crop, as it marks the completion of the plant’s reproductive phase and determines the successful embryonic development of the next generation. The success of the germination process, and consequently the final crop yield, is often compromised under marginal environmental conditions such as arid, saline, or contaminated soils containing potentially hazardous elements. Under these circumstances, seed priming has emerged as an effective pre-sowing treatment that enhances seed tolerance to adverse conditions, accelerates germination, improves seedling vigour, and ultimately contributes to higher crop productivity. This review critically examines the methodological basis of seed priming technology, the major categories of priming treatments, and the molecular and physiological mechanisms underlying priming-induced germination enhancement. Current evidence indicates that priming enhances germination performance through coordinated effects on reserve mobilization, hormonal rebalancing, antioxidant defence, repair pathways, membrane and desiccation protection, and water and ion homeostasis. The review also highlights and exemplifies the potential of seed priming to enhance resilience in crops of major agronomic relevance. Finally, the principal limitations of the technique are also addressed, together with prospective solutions and future research directions aimed at overcoming these constraints.