Seed Biopriming for Climate Stress Resilience: Molecular, Physiological, and Epigenetic Mechanisms.

The mutualistic association between plants and their seed-associated microbiota has emerged as a key determinant of crop productivity, influencing plant nutrition, immunity, and tolerance to abiotic stress. Seed biopriming, the controlled application of beneficial microorganisms to seeds before sowing, exploits this interaction to enhance germination, seedling establishment, and stress resilience. Unlike conventional chemical priming, seed biopriming induces coordinated molecular reprogramming through changes in the seed metabolome, proteome, and epigenome. This review synthesizes current evidence demonstrating that seed biopriming promotes the accumulation of osmoprotectants, strengthens antioxidant defenses, enhances secondary metabolism, and generates priming-specific proteomic responses. We further examine how these changes interact with phytohormonal signaling networks and epigenetic mechanisms, including DNA methylation, histone modification, and small RNA-mediated regulation, to establish stress memory and improve plant adaptation. The review also discusses recent advances in synthetic microbial communities and nanobiotechnology for improving inoculant stability and efficacy. Despite promising progress, large-scale application remains constrained by inconsistent field performance, formulation stability, and regulatory challenges. Finally, we highlight the integration of multi-omics and artificial intelligence as promising approaches to improve mechanistic understanding, optimize microbial selection, and accelerate the development of reliable seed biopriming strategies for sustainable agriculture under climate change.