Seed priming with bare and PVP-coated boron-based nanoparticles modulated the germination and early growth of tomato

Enhancing seed germination and early development is vital for sustainable agriculture and nutrient-efficient crop production. In this context, we investigated the application of boron-based nanoparticles (B NPs), with or without polyvinylpyrrolidone (PVP) coating (B-PVP NPs), as seed priming agents to enhance germination and early growth performance in tomato ( Solanum lycopersicum ), given the essential role of B as a micronutrient. Physicochemical characterization of B-based NPs by XRD, Raman, FTIR, and DLS confirmed the presence of B₂O₃ phases I and II, with partial β-boron composition. PVP-coating increased crystallinity and exhibited smaller crystallite sizes, therefore enhancing nanoparticle dispersion and stability. Nanopriming improved germination in a coating- and dose-dependent manner; B-PVP NPs (0.1 ppm) and B NPs (10 ppm) were the optimal treatments. In addition, redox and defense metabolisms were strongly modulated, as evidenced by total antioxidant capacity (TAC) (101.08–234.04%), GSH (-46.78%), and proline levels (-86.63%), which varied depending on dose and coating. Positive correlations of B NPs with Ca and Zn, and B-PVP NPs with Fe revealed the interactions between B-based NPs and nutrient homeostasis, and B from NPs up-regulated total soluble sugars (130.86%). In contrast, negative correlations of B-PVP NPs with total soluble sugars and chlorophyll b were identified, revealing that PVP-mediated interactions can disrupt essential metabolisms. Taking all these findings into consideration, we suggest that B NPs can serve as effective B-nanofertilizers, modulating germination and early growth of tomato, while minimizing stress-related damage. Nonetheless, proper dose management is crucial to strike a balance between efficacy and unintended nutrient homeostasis and interactions with essential metabolisms. • PVP-coating altered NPs physicochemical properties and interactions with tomato. • Boron-based NPs improved seed germination performance in tomato. • Germination gains were coating- and dose-dependent: B NPs (10 ppm), B-PVP (0.1 ppm). • NPs modulated nutrient homeostasis and metabolism in tomato seeds and seedlings. • PVP-coating disrupted total soluble sugars and B NPs up-regulated them.