A practical guide to the discovery of biomolecules with biostimulant activity.

This article focuses on the discovery, development, and commercialization of biomolecule-based plant biostimulants as sustainable agricultural tools that enhance crop growth, nutrient use efficiency, abiotic stress tolerance, and soil health restoration. It outlines a practical, stepwise roadmap starting from biomolecule mining in natural extracts, through extraction, bioactivity identification, formulation, and effectiveness assessment, to regulatory approval and market introduction. The review highlights key biomolecule classes such as flavonoids, terpenoids, carbohydrates, proteins, and nucleic acids, detailing their modes of action and the challenges in isolating active compounds from complex mixtures. It also discusses advances in eco-friendly extraction methods, bioassays, biosensors for in vivo plant signaling monitoring, and the importance of standardized formulations and regulatory compliance across global regions. The article emphasizes that tailored biostimulants with well-characterized bioactive components and validated efficacy are essential for integrating these products into sustainable farming practices.